Vendor dependencies for 0.3.0 release

vendor/rodio/CHANGELOG.md

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+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+# Version 0.20.1 (2024-11-08)
+
+### Fixed
+- Builds without the `symphonia` feature did not compile
+
+# Version 0.20.0 (2024-11-08)
+
+### Added
+- Support for *ALAC/AIFF*
+- Add `automatic_gain_control` source for dynamic audio level adjustment.
+- New test signal generator sources:
+    - `SignalGenerator` source generates a sine, triangle, square wave or sawtooth
+      of a given frequency and sample rate.
+    - `Chirp` source generates a sine wave with a linearly-increasing
+      frequency over a given frequency range and duration.
+    - `white` and `pink` generate white or pink noise, respectively. These
+      sources depend on the `rand` crate and are guarded with the "noise"
+      feature.
+    - Documentation for the "noise" feature has been added to `lib.rs`.
+- New Fade and Crossfade sources:
+    - `fade_out` fades an input out using a linear gain fade.
+    - `linear_gain_ramp` applies a linear gain change to a sound over a
+      given duration. `fade_out` is implemented as a `linear_gain_ramp` and
+      `fade_in` has been refactored to use the `linear_gain_ramp`
+      implementation.
+
+### Fixed
+- `Sink.try_seek` now updates `controls.position` before returning. Calls to `Sink.get_pos`
+  done immediately after a seek will now return the correct value.
+
+### Changed
+- `SamplesBuffer` is now `Clone`
+
+# Version 0.19.0 (2024-06-29)
+
+### Added
+- Adds a new source `track_position`. It keeps track of duration since the
+  beginning of the underlying source.
+
+### Fixed
+- Mp4a with decodable tracks after undecodable tracks now play. This matches
+  VLC's behaviour.
+
+# Version 0.18.1 (2024-05-23)
+
+### Fixed
+- Seek no longer hangs if the sink is empty.
+
+# Version 0.18.0 (2024-05-05)
+
+### Changed
+- `Source` trait is now also implemented for `Box<dyn Source>` and `&mut Source`
+- `fn new_vorbis` is now also available when the `symphonia-vorbis` feature is enabled
+
+### Added
+- Adds a new method `try_seek` to all sources. It returns either an error or
+  seeks to the given position. A few sources are "unsupported" they return the
+  error `Unsupported`.
+- Adds `SpatialSink::clear()` bringing it in line with `Sink`
+
+### Fixed
+- channel upscaling now follows the 'WAVEFORMATEXTENSIBLE' format and no longer
+  repeats the last source channel on all extra output channels.
+  Stereo content playing on a 5.1 speaker set will now only use the front left
+  and front right speaker instead of repeating the right sample on all speakers
+  except the front left one.
+- `mp3::is_mp3()` no longer changes the position in the stream when the stream
+  is mp3
+
+# Version 0.17.3 (2023-10-23)
+
+- Build fix for `minimp3` backend.
+
+# Version 0.17.2 (2023-10-17)
+
+- Add `EmptyCallback` source.
+- Fix index out of bounds bug.
+- Use non-vulnerable `minimp3` fork.
+- Add filter functions with additional q parameter.
+
+# Version 0.17.1 (2023-02-25)
+
+- Disable `symphonia`'s default features.
+
+# Version 0.17.0 (2023-02-17)
+
+- Update `cpal` to [0.15](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0150-2022-01-29).
+- Default to `symphonia` for mp3 decoding.
+
+# Version 0.16.0 (2022-09-14)
+
+- Update `cpal` to [0.14](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0140-2022-08-22).
+- Update `symphonia` to [0.5](https://github.com/pdeljanov/Symphonia/releases/tag/v0.5.1).
+
+# Version 0.15.0 (2022-01-23)
+
+- Remove requirement that the argument `Decoder::new` and `LoopedDecoder::new` implement `Send`.
+- Add optional symphonia backend.
+- `WavDecoder`'s `total_duration` now returns the total duration of the sound rather than the remaining duration.
+- Add 32-bit signed in WAV decoding.
+- `SineWave::new()` now takes a `f32` instead of a `u32`.
+- Add `len()` method to `SpatialSink`.
+
+# Version 0.14.0 (2021-05-21)
+
+- Re-export `cpal` in full.
+- Replace panics when calling `OutputStream::try_default`, `OutputStream::try_from_device` with new
+  `StreamError` variants.
+- `OutputStream::try_default` will now fallback to non-default output devices if an `OutputStream`
+  cannot be created from the default device.
+
+# Version 0.13.1 (2021-03-28)
+
+- Fix panic when no `pulseaudio-alsa` was installed.
+
+# Version 0.13.0 (2020-11-03)
+
+- Update `cpal` to [0.13](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0130-2020-10-28).
+- Add Android support.
+
+# Version 0.12.0 (2020-10-05)
+
+- Breaking: Update `cpal` to [0.12](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0120-2020-07-09).
+- Breaking: Rework API removing global "rodio audio processing" thread & adapting to the upstream cpal API changes.
+- Add new_X format specific methods to Decoder.
+- Fix resampler dependency on internal `Vec::capacity` behaviour.
+
+# Version 0.11.0 (2020-03-16)
+
+- Update `lewton` to [0.10](https://github.com/RustAudio/lewton/blob/master/CHANGELOG.md#release-0100---january-30-2020).
+- Breaking: Update `cpal` to [0.11](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0110-2019-12-11)
+
+# Version 0.10.0 (2019-11-16)
+
+- Removal of nalgebra in favour of own code.
+- Fix a bug that switched channels when resuming after having paused.
+- Attempt all supported output formats if the default format fails in `Sink::new`.
+- Breaking: Update `cpal` to [0.10](https://github.com/RustAudio/cpal/blob/master/CHANGELOG.md#version-0100-2019-07-05).
+
+# Version 0.9.0 (2019-06-08)
+
+- Remove exclusive `&mut` borrow requirements in `Sink` & `SpatialSink` setters.
+- Use `nalgebra` instead of `cgmath` for `Spatial` source.
+
+# Version 0.8.1 (2018-09-18)
+
+- Update `lewton` dependency to [0.9](https://github.com/RustAudio/lewton/blob/master/CHANGELOG.md#release-090---august-16-2018)
+- Change license from `Apache-2.0` only to `Apache-2.0 OR MIT`
+
+# Version 0.8.0 (2018-06-22)
+
+- Add mp3 decoding capabilities via `minimp3`
+
+# Version 0.7.0 (2018-04-19)
+
+- Update `cpal` dependency to 0.8, and adopt the new naming convention
+- BREAKING CHANGES:
+    - renamed `Endpoint` to `Device`
+    - split `default_endpoint()` into `default_output_device()` and `default_input_device()`
+    - renamed `endpoints()` to `devices()`
+    - introduced `output_devices()` and `input_devices()`

vendor/rodio/CONTRIBUTING.md

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+# Rodio Development Guide
+
+## Quick Start
+
+1. Clone the repository: `git clone https://github.com/RustAudio/rodio.git`
+2. Navigate to the project: `cd rodio`
+3. Build the project: `cargo build`
+
+## Project Structure
+
+src/:
+- `source/`: Audio source implementations
+- `decoder/`: Audio format decoders
+- `sink/`: Audio playback and mixing
+- `dynamic_mixer/`: Real-time audio mixing
+- `spatial/`: Spatial audio capabilities
+
+## Coding Guidelines
+
+- Follow [Rust API Guidelines](https://rust-lang.github.io/api-guidelines/)
+- Use `rustfmt` for formatting
+- Implement `Source` trait for new audio sources
+- Use `Sink` for playback management
+
+## Common Tasks
+
+### Adding a New Audio Source or Effect
+
+1. Create a new file in `src/source/`
+2. Implement the `Source` trait to define how audio samples are generated or modified
+3. Consider implementing sources like oscillators, noise generators, or effects like amplification, filtering, or distortion
+4. If your contribution creates sound you should give it a public (factory) function that constructs it. If its an effect then add a method with default implementation for it in the `Source` trait.
+5. Begin with a test for your new feature (see the [Testing](#testing)). This approach ensures your PR is ready and simplifies development. Don't worry about optimizing initially; focus on functionality.
+6. Once your feature works, celebrate your progress! 🎉 Open a draft PR at this stage - we're here to assist with refactoring and optimization.
+7. Refactor your code, add benchmarks, and work on improving performance, especially for real-time processing in effects. Refer to the [Rust Performance Book](https://nnethercote.github.io/perf-book/introduction.html) for optimization techniques.
+8. Finally add some documentation and an example. For details see [Documentation]($documentation)
+9. If you're unsure about creating tests, implement your feature first, then open a PR with what you have asking for guidance. We're happy to help!
+
+### Implementing a New Decoder
+
+1. Add new module in `src/decoder/`
+2. Implement necessary traits (e.g., `Decoder`) to handle specific audio formats
+3. Focus on efficiently parsing audio file headers and decoding compressed audio data
+4. Update `src/decoder/mod.rs` to integrate the new decoder
+
+### Unit Tests
+
+- Feel free to write temporary unit tests during development if they help you verify functionality
+- These tests can be rough and don't need to be comprehensive - they're just development aids
+- It's okay to include these temporary unit tests in your pull request
+- We'll remove these tests before merging into the main codebase, primarily because:
+  - They can make refactoring more difficult as tests may break with code changes
+  - Rust's robust type system reduces the need for extensive unit testing compared to dynamically typed languages
+
+### Integration Tests
+
+When possible, add integration tests for your new features. Keep in mind:
+
+- Integration tests do not create sound through your speakers. Instead, you write code that examines the produced *samples*.
+- For new audio sources:
+  - Verify that samples have changed from their initial state.
+  - Check if samples are non-zero where appropriate.
+  - Look for expected patterns or characteristics in the audio data.
+- Examples of integration tests:
+  - The `tests/wav_test.rs` test simply checks if the decoder produces nonzero samples.
+  - The test `seek_does_not_break_channel_order` in `tests/seek.rs` uses a beeping sound that alternates between two channels. It seeks to a point where we know only the second channel should make sound. Then we check if the first channel is silent while the second is not.
+- Be aware that many aspects of audio processing are challenging to verify automatically.
+- It's impossible to write a test that checks if something sounds "good". For features requiring audible verification:
+  - Create an example in the `examples/` directory that demonstrates the functionality.
+  - These examples can produce sound for manual testing.
+  - Document the expected behavior in the example's comments.
+- We love integration tests but they can be hard to write. If you have trouble adding one its fine to leave it out. If you do add one create a new file for it in `tests/`.
+- Run tests: `cargo test`
+- Run examples: `cargo run --example <example_name>`
+
+## Documentation
+
+- Add inline documentation to all public items.
+- Look at the [documenting components](https://doc.rust-lang.org/rustdoc/how-to-write-documentation.html#documenting-components) section of the rustdoc book.
+- Generate docs: `cargo doc --open`
+- Add an example. That could be as part of the inline documentation or a more complex scenario in `examples/`
+
+## Contribution Workflow
+
+1. Fork the repository on GitHub
+2. Clone your fork locally: `git clone https://github.com/YOUR_USERNAME/rodio.git`
+3. Create a feature branch: `git checkout -b feature/your-feature-name`
+4. Make changes and add tests where applicable (Dont be afraid to ask for help)
+5. Commit your changes following these guidelines: (`git commit`)
+  - Write clear, concise commit messages
+  - Limit the first line to 50 characters
+  - Provide a detailed description after a blank line, if necessary
+  - Reference relevant issue numbers (e.g., "Fixes #123")
+  - Separate logical changes into multiple commits
+  - Avoid commits with unrelated changes
+  Example:
+  ```
+  Add spatial audio support for stereo sources
+
+  - Implement SpatialSource struct
+  - Add panning and distance attenuation
+  - Update documentation for spatial audio usage
+
+  Fixes #456
+  ```
+6. Push your changes to your fork: `git push origin feature/your-feature-name`
+7. Create a pull request on GitHub
+
+## Getting Help / Got a question?
+
+- Open an issue on GitHub
+- Ask questions in your pull request
+- Open an issue for guidance/questions
+- Join the Rust Audio Discord
+
+## Useful Commands
+
+- Format: `cargo fmt` - Automatically formats the code according to Rust style guidelines
+- Lint: `cargo clippy` - Runs the Clippy linter to catch common mistakes and improve code quality
+- Benchmark: `cargo bench` - Executes performance benchmarks for the project
+
+For more detailed information, refer to the full documentation and source code.
+
+## Useful External Resources
+
+- [Rust API Guidelines](https://rust-lang.github.io/api-guidelines/)
+- [Rustdoc book](https://doc.rust-lang.org/rustdoc/how-to-write-documentation.html)
+- [Rust Performance Book](https://nnethercote.github.io/perf-book/introduction.html)
+- [Rust Audio Discord](https://discord.com/invite/8qW6q2k)
+
+
+## Disclaimer
+
+Please note that the guidelines and practices outlined in this document
+are not strict rules. They are general recommendations to promote
+consistency and quality in contributions.
+
+We understand that every situation is unique and encourage contributors
+to use their best judgment. If you have any doubts or questions about
+how to approach a particular task or contribution, don't hesitate to
+reach out to the maintainers for guidance.

vendor/rodio/Cargo.toml

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+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+name = "rodio"
+version = "0.20.1"
+build = false
+exclude = [
+    "assets/**",
+    "tests/**",
+]
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "Audio playback library"
+documentation = "https://docs.rs/rodio"
+readme = "README.md"
+keywords = [
+    "audio",
+    "playback",
+    "gamedev",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/RustAudio/rodio"
+
+[lib]
+name = "rodio"
+path = "src/lib.rs"
+
+[[example]]
+name = "automatic_gain_control"
+path = "examples/automatic_gain_control.rs"
+
+[[example]]
+name = "basic"
+path = "examples/basic.rs"
+
+[[example]]
+name = "mix_multiple_sources"
+path = "examples/mix_multiple_sources.rs"
+
+[[example]]
+name = "music_flac"
+path = "examples/music_flac.rs"
+
+[[example]]
+name = "music_m4a"
+path = "examples/music_m4a.rs"
+required-features = [
+    "symphonia-isomp4",
+    "symphonia-aac",
+]
+
+[[example]]
+name = "music_mp3"
+path = "examples/music_mp3.rs"
+
+[[example]]
+name = "music_ogg"
+path = "examples/music_ogg.rs"
+
+[[example]]
+name = "music_wav"
+path = "examples/music_wav.rs"
+
+[[example]]
+name = "noise_generator"
+path = "examples/noise_generator.rs"
+required-features = ["noise"]
+
+[[example]]
+name = "reverb"
+path = "examples/reverb.rs"
+
+[[example]]
+name = "seek_mp3"
+path = "examples/seek_mp3.rs"
+
+[[example]]
+name = "signal_generator"
+path = "examples/signal_generator.rs"
+
+[[example]]
+name = "spatial"
+path = "examples/spatial.rs"
+
+[[example]]
+name = "stereo"
+path = "examples/stereo.rs"
+
+[[bench]]
+name = "conversions"
+path = "benches/conversions.rs"
+harness = false
+
+[[bench]]
+name = "effects"
+path = "benches/effects.rs"
+harness = false
+
+[[bench]]
+name = "shared"
+path = "benches/shared.rs"
+
+[dependencies.atomic_float]
+version = "1.1.0"
+optional = true
+
+[dependencies.claxon]
+version = "0.4.2"
+optional = true
+
+[dependencies.cpal]
+version = "0.15.3"
+
+[dependencies.crossbeam-channel]
+version = "0.5.8"
+optional = true
+
+[dependencies.hound]
+version = "3.3.1"
+optional = true
+
+[dependencies.lewton]
+version = "0.10"
+optional = true
+
+[dependencies.minimp3_fixed]
+version = "0.5.4"
+optional = true
+
+[dependencies.rand]
+version = "0.8.5"
+features = ["small_rng"]
+optional = true
+
+[dependencies.symphonia]
+version = "0.5.4"
+optional = true
+default-features = false
+
+[dependencies.tracing]
+version = "0.1.40"
+optional = true
+
+[dev-dependencies.approx]
+version = "0.5.1"
+
+[dev-dependencies.dasp_sample]
+version = "0.11.0"
+
+[dev-dependencies.divan]
+version = "0.1.14"
+
+[dev-dependencies.quickcheck]
+version = "0.9.2"
+
+[dev-dependencies.rstest]
+version = "0.18.2"
+
+[dev-dependencies.rstest_reuse]
+version = "0.6.0"
+
+[features]
+cpal-shared-stdcxx = ["cpal/oboe-shared-stdcxx"]
+default = [
+    "flac",
+    "vorbis",
+    "wav",
+    "mp3",
+]
+experimental = ["dep:atomic_float"]
+flac = ["claxon"]
+minimp3 = ["dep:minimp3_fixed"]
+mp3 = ["symphonia-mp3"]
+noise = ["rand"]
+symphonia-aac = ["symphonia/aac"]
+symphonia-aiff = [
+    "symphonia/aiff",
+    "symphonia/pcm",
+]
+symphonia-alac = [
+    "symphonia/isomp4",
+    "symphonia/alac",
+]
+symphonia-all = [
+    "symphonia-aac",
+    "symphonia-flac",
+    "symphonia-isomp4",
+    "symphonia-mp3",
+    "symphonia-vorbis",
+    "symphonia-wav",
+]
+symphonia-flac = ["symphonia/flac"]
+symphonia-isomp4 = ["symphonia/isomp4"]
+symphonia-mp3 = ["symphonia/mp3"]
+symphonia-vorbis = ["symphonia/vorbis"]
+symphonia-wav = [
+    "symphonia/wav",
+    "symphonia/pcm",
+    "symphonia/adpcm",
+]
+tracing = ["dep:tracing"]
+vorbis = ["lewton"]
+wasm-bindgen = ["cpal/wasm-bindgen"]
+wav = ["hound"]

vendor/rodio/LICENSE-APACHE

@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
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+
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+
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+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+
+   Copyright 2015 Pierre Krieger
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/rodio/LICENSE-MIT

@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

vendor/rodio/README.md

@@ -0,0 +1,43 @@
+# Audio playback library
+
+[![Crates.io Version](https://img.shields.io/crates/v/rodio.svg)](https://crates.io/crates/rodio)
+[![Crates.io Downloads](https://img.shields.io/crates/d/rodio.svg)](https://crates.io/crates/rodio)
+[![Build Status](https://github.com/RustAudio/rodio/workflows/CI/badge.svg)](https://github.com/RustAudio/rodio/actions)
+
+Rust playback library.
+
+Playback is handled by [cpal](https://github.com/RustAudio/cpal). Format decoding can be handled either by [Symphonia](https://github.com/pdeljanov/Symphonia), or by format-specific decoders:
+
+ - MP3 by [minimp3](https://github.com/lieff/minimp3) (but defaults to [Symphonia](https://github.com/pdeljanov/Symphonia)).
+ - WAV by [hound](https://github.com/ruud-v-a/hound).
+ - Vorbis by [lewton](https://github.com/est31/lewton).
+ - FLAC by [claxon](https://github.com/ruuda/claxon).
+ - MP4 and AAC (both disabled by default) are handled only by [Symphonia](https://github.com/pdeljanov/Symphonia).
+
+See [the docs](https://docs.rs/rodio/latest/rodio/#alternative-decoder-backends) for more details on backends.
+
+# [Documentation](http://docs.rs/rodio)
+
+[The documentation](http://docs.rs/rodio) contains an introduction to the library.
+
+## Dependencies(Linux only)
+
+Rodio uses `cpal` to send audio to the OS for playback. On Linux `cpal` needs the ALSA development files. These are provided as part of the libasound2-dev package on Debian and Ubuntu distributions and alsa-lib-devel on Fedora.
+
+# Contributing
+
+For information on how to contribute to this project, please see our [Contributing Guide](https://github.com/RustAudio/rodio/CONTRIBUTING.md).
+
+## License
+[License]: #license
+
+Licensed under either of
+
+* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0), or
+* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### License of your contributions
+
+Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

vendor/rodio/benches/conversions.rs

@@ -0,0 +1,21 @@
+use cpal::FromSample;
+use divan::Bencher;
+use rodio::Source;
+
+mod shared;
+use shared::TestSource;
+
+fn main() {
+    divan::main();
+}
+
+#[divan::bench(types = [i16, u16, f32])]
+fn from_i16_to<T: rodio::Sample + FromSample<i16>>(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav())
+        .bench_values(|source| {
+            source
+                .convert_samples::<T>()
+                .for_each(divan::black_box_drop)
+        })
+}

vendor/rodio/benches/effects.rs

@@ -0,0 +1,87 @@
+use std::time::Duration;
+
+use divan::Bencher;
+use rodio::Source;
+
+mod shared;
+use shared::TestSource;
+
+fn main() {
+    divan::main();
+}
+
+#[divan::bench]
+fn reverb(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav())
+        .bench_values(|source| {
+            source
+                .buffered()
+                .reverb(Duration::from_secs_f32(0.05), 0.3)
+                .for_each(divan::black_box_drop)
+        })
+}
+
+#[divan::bench]
+fn high_pass(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav().to_f32s())
+        .bench_values(|source| source.high_pass(200).for_each(divan::black_box_drop))
+}
+
+#[divan::bench]
+fn fade_out(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav())
+        .bench_values(|source| {
+            source
+                .fade_out(Duration::from_secs(5))
+                .for_each(divan::black_box_drop)
+        })
+}
+
+#[divan::bench]
+fn amplify(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav().to_f32s())
+        .bench_values(|source| source.amplify(0.8).for_each(divan::black_box_drop))
+}
+
+#[divan::bench]
+fn agc_enabled(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav().to_f32s())
+        .bench_values(|source| {
+            source
+                .automatic_gain_control(
+                    1.0,   // target_level
+                    4.0,   // attack_time (in seconds)
+                    0.005, // release_time (in seconds)
+                    5.0,   // absolute_max_gain
+                )
+                .for_each(divan::black_box_drop)
+        })
+}
+
+#[cfg(feature = "experimental")]
+#[divan::bench]
+fn agc_disabled(bencher: Bencher) {
+    bencher
+        .with_inputs(|| TestSource::music_wav().to_f32s())
+        .bench_values(|source| {
+            // Create the AGC source
+            let amplified_source = source.automatic_gain_control(
+                1.0,   // target_level
+                4.0,   // attack_time (in seconds)
+                0.005, // release_time (in seconds)
+                5.0,   // absolute_max_gain
+            );
+
+            // Get the control handle and disable AGC
+            let agc_control = amplified_source.get_agc_control();
+            agc_control.store(false, std::sync::atomic::Ordering::Relaxed);
+
+            // Process the audio stream with AGC disabled
+            amplified_source.for_each(divan::black_box_drop)
+        })
+}

vendor/rodio/benches/shared.rs

@@ -0,0 +1,83 @@
+use std::io::Cursor;
+use std::time::Duration;
+use std::vec;
+
+use rodio::Source;
+
+pub struct TestSource<T> {
+    samples: vec::IntoIter<T>,
+    channels: u16,
+    sample_rate: u32,
+    total_duration: Duration,
+}
+
+impl<T> Iterator for TestSource<T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.samples.next()
+    }
+}
+
+impl<T> ExactSizeIterator for TestSource<T> {
+    fn len(&self) -> usize {
+        self.samples.len()
+    }
+}
+
+impl<T: rodio::Sample> Source for TestSource<T> {
+    fn current_frame_len(&self) -> Option<usize> {
+        None // forever
+    }
+
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    fn total_duration(&self) -> Option<Duration> {
+        Some(self.total_duration)
+    }
+}
+
+impl TestSource<i16> {
+    pub fn music_wav() -> Self {
+        let data = include_bytes!("../assets/music.wav");
+        let cursor = Cursor::new(data);
+
+        let duration = Duration::from_secs(10);
+        let sound = rodio::Decoder::new(cursor)
+            .expect("music.wav is correctly encoded & wav is supported")
+            .take_duration(duration);
+
+        TestSource {
+            channels: sound.channels(),
+            sample_rate: sound.sample_rate(),
+            total_duration: duration,
+            samples: sound.into_iter().collect::<Vec<_>>().into_iter(),
+        }
+    }
+
+    #[allow(unused, reason = "not everything from shared is used in all libs")]
+    pub fn to_f32s(self) -> TestSource<f32> {
+        let TestSource {
+            samples,
+            channels,
+            sample_rate,
+            total_duration,
+        } = self;
+        let samples = samples
+            .map(|s| cpal::Sample::from_sample(s))
+            .collect::<Vec<_>>()
+            .into_iter();
+        TestSource {
+            samples,
+            channels,
+            sample_rate,
+            total_duration,
+        }
+    }
+}

vendor/rodio/examples/automatic_gain_control.rs

@@ -0,0 +1,46 @@
+use rodio::source::Source;
+use rodio::Decoder;
+use std::fs::File;
+use std::io::BufReader;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+use std::thread;
+use std::time::Duration;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    // Decode the sound file into a source
+    let file = BufReader::new(File::open("assets/music.flac").unwrap());
+    let source = Decoder::new(file).unwrap();
+
+    // Apply automatic gain control to the source
+    let agc_source = source.automatic_gain_control(1.0, 4.0, 0.005, 5.0);
+
+    // Make it so that the source checks if automatic gain control should be
+    // enabled or disabled every 5 milliseconds. We must clone `agc_enabled`
+    // or we would lose it when we move it into the periodic access.
+    let agc_enabled = Arc::new(AtomicBool::new(true));
+    let agc_enabled_clone = agc_enabled.clone();
+    let controlled = agc_source.periodic_access(Duration::from_millis(5), move |agc_source| {
+        agc_source.set_enabled(agc_enabled_clone.load(Ordering::Relaxed));
+    });
+
+    // Add the source now equipped with automatic gain control and controlled via
+    // periodic_access to the sink for playback
+    sink.append(controlled);
+
+    // after 5 seconds of playback disable automatic gain control using the
+    // shared AtomicBool `agc_enabled`. You could do this from another part
+    // of the program since `agc_enabled` is of type Arc<AtomicBool> which
+    // is freely clone-able and move-able.
+    //
+    // Note that disabling the AGC takes up to 5 millis because periodic_access
+    // controls the source every 5 millis.
+    thread::sleep(Duration::from_secs(5));
+    agc_enabled.store(false, Ordering::Relaxed);
+
+    // Keep the program running until playback is complete
+    sink.sleep_until_end();
+}

vendor/rodio/examples/basic.rs

@@ -0,0 +1,36 @@
+use std::io::BufReader;
+use std::thread;
+use std::time::Duration;
+
+fn main() {
+    let (_stream, stream_handle) = rodio::OutputStream::try_default().unwrap();
+
+    let file = std::fs::File::open("assets/beep.wav").unwrap();
+    let beep1 = stream_handle.play_once(BufReader::new(file)).unwrap();
+    beep1.set_volume(0.2);
+    println!("Started beep1");
+
+    thread::sleep(Duration::from_millis(1500));
+
+    let file = std::fs::File::open("assets/beep2.wav").unwrap();
+    let beep2 = stream_handle.play_once(BufReader::new(file)).unwrap();
+    beep2.set_volume(0.3);
+    beep2.detach();
+    println!("Started beep2");
+
+    thread::sleep(Duration::from_millis(1500));
+    let file = std::fs::File::open("assets/beep3.ogg").unwrap();
+    let beep3 = stream_handle.play_once(file).unwrap();
+    beep3.set_volume(0.2);
+    println!("Started beep3");
+
+    thread::sleep(Duration::from_millis(1500));
+    drop(beep1);
+    println!("Stopped beep1");
+
+    thread::sleep(Duration::from_millis(1500));
+    drop(beep3);
+    println!("Stopped beep3");
+
+    thread::sleep(Duration::from_millis(1500));
+}

vendor/rodio/examples/mix_multiple_sources.rs

@@ -0,0 +1,38 @@
+use rodio::source::{SineWave, Source};
+use rodio::{dynamic_mixer, OutputStream, Sink};
+use std::time::Duration;
+
+fn main() {
+    // Construct a dynamic controller and mixer, stream_handle, and sink.
+    let (controller, mixer) = dynamic_mixer::mixer::<f32>(2, 44_100);
+    let (_stream, stream_handle) = OutputStream::try_default().unwrap();
+    let sink = Sink::try_new(&stream_handle).unwrap();
+
+    // Create four unique sources. The frequencies used here correspond
+    // notes in the key of C and in octave 4: C4, or middle C on a piano,
+    // E4, G4, and A4 respectively.
+    let source_c = SineWave::new(261.63)
+        .take_duration(Duration::from_secs_f32(1.))
+        .amplify(0.20);
+    let source_e = SineWave::new(329.63)
+        .take_duration(Duration::from_secs_f32(1.))
+        .amplify(0.20);
+    let source_g = SineWave::new(392.0)
+        .take_duration(Duration::from_secs_f32(1.))
+        .amplify(0.20);
+    let source_a = SineWave::new(440.0)
+        .take_duration(Duration::from_secs_f32(1.))
+        .amplify(0.20);
+
+    // Add sources C, E, G, and A to the mixer controller.
+    controller.add(source_c);
+    controller.add(source_e);
+    controller.add(source_g);
+    controller.add(source_a);
+
+    // Append the dynamic mixer to the sink to play a C major 6th chord.
+    sink.append(mixer);
+
+    // Sleep the thread until sink is empty.
+    sink.sleep_until_end();
+}

vendor/rodio/examples/music_flac.rs

@@ -0,0 +1,11 @@
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.flac").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/music_m4a.rs

@@ -0,0 +1,11 @@
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.m4a").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/music_mp3.rs

@@ -0,0 +1,11 @@
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.mp3").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/music_ogg.rs

@@ -0,0 +1,11 @@
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.ogg").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/music_wav.rs

@@ -0,0 +1,11 @@
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.wav").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/noise_generator.rs

@@ -0,0 +1,41 @@
+//! Noise generator example. Use the "noise" feature to enable the noise generator sources.
+
+#[cfg(feature = "noise")]
+fn main() {
+    use rodio::source::{pink, white, Source};
+    use std::thread;
+    use std::time::Duration;
+
+    let (_stream, stream_handle) = rodio::OutputStream::try_default().unwrap();
+
+    let noise_duration = Duration::from_millis(1000);
+    let interval_duration = Duration::from_millis(1500);
+
+    stream_handle
+        .play_raw(
+            white(cpal::SampleRate(48000))
+                .amplify(0.1)
+                .take_duration(noise_duration),
+        )
+        .unwrap();
+    println!("Playing white noise");
+
+    thread::sleep(interval_duration);
+
+    stream_handle
+        .play_raw(
+            pink(cpal::SampleRate(48000))
+                .amplify(0.1)
+                .take_duration(noise_duration),
+        )
+        .unwrap();
+    println!("Playing pink noise");
+
+    thread::sleep(interval_duration);
+}
+
+#[cfg(not(feature = "noise"))]
+fn main() {
+    println!("rodio has not been compiled with noise sources, use `--features noise` to enable this feature.");
+    println!("Exiting...");
+}

vendor/rodio/examples/reverb.rs

@@ -0,0 +1,15 @@
+use rodio::Source;
+use std::io::BufReader;
+use std::time::Duration;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.ogg").unwrap();
+    let source = rodio::Decoder::new(BufReader::new(file)).unwrap();
+    let with_reverb = source.buffered().reverb(Duration::from_millis(40), 0.7);
+    sink.append(with_reverb);
+
+    sink.sleep_until_end();
+}

vendor/rodio/examples/seek_mp3.rs

@@ -0,0 +1,22 @@
+use std::io::BufReader;
+use std::time::Duration;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/music.mp3").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    std::thread::sleep(std::time::Duration::from_secs(2));
+    sink.try_seek(Duration::from_secs(0)).unwrap();
+
+    std::thread::sleep(std::time::Duration::from_secs(2));
+    sink.try_seek(Duration::from_secs(4)).unwrap();
+
+    sink.sleep_until_end();
+
+    // wont do anything since the sound has ended already
+    sink.try_seek(Duration::from_secs(5)).unwrap();
+    println!("seek example ended");
+}

vendor/rodio/examples/signal_generator.rs

@@ -0,0 +1,83 @@
+//! Test signal generator example.
+
+fn main() {
+    use rodio::source::{chirp, Function, SignalGenerator, Source};
+    use std::thread;
+    use std::time::Duration;
+
+    let (_stream, stream_handle) = rodio::OutputStream::try_default().unwrap();
+
+    let test_signal_duration = Duration::from_millis(1000);
+    let interval_duration = Duration::from_millis(1500);
+
+    println!("Playing 1000 Hz tone");
+    stream_handle
+        .play_raw(
+            SignalGenerator::new(cpal::SampleRate(48000), 1000.0, Function::Sine)
+                .amplify(0.1)
+                .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+
+    println!("Playing 10,000 Hz tone");
+    stream_handle
+        .play_raw(
+            SignalGenerator::new(cpal::SampleRate(48000), 10000.0, Function::Sine)
+                .amplify(0.1)
+                .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+
+    println!("Playing 440 Hz Triangle Wave");
+    stream_handle
+        .play_raw(
+            SignalGenerator::new(cpal::SampleRate(48000), 440.0, Function::Triangle)
+                .amplify(0.1)
+                .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+
+    println!("Playing 440 Hz Sawtooth Wave");
+    stream_handle
+        .play_raw(
+            SignalGenerator::new(cpal::SampleRate(48000), 440.0, Function::Sawtooth)
+                .amplify(0.1)
+                .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+
+    println!("Playing 440 Hz Square Wave");
+    stream_handle
+        .play_raw(
+            SignalGenerator::new(cpal::SampleRate(48000), 440.0, Function::Square)
+                .amplify(0.1)
+                .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+
+    println!("Playing 20-10000 Hz Sweep");
+    stream_handle
+        .play_raw(
+            chirp(
+                cpal::SampleRate(48000),
+                20.0,
+                10000.0,
+                Duration::from_secs(1),
+            )
+            .amplify(0.1)
+            .take_duration(test_signal_duration),
+        )
+        .unwrap();
+
+    thread::sleep(interval_duration);
+}

vendor/rodio/examples/spatial.rs

@@ -0,0 +1,53 @@
+use std::io::BufReader;
+use std::thread;
+use std::time::Duration;
+
+use rodio::Source;
+
+fn main() {
+    let iter_duration = Duration::from_secs(5);
+    let iter_distance = 5.;
+
+    let refresh_duration = Duration::from_millis(10);
+
+    let num_steps = iter_duration.as_secs_f32() / refresh_duration.as_secs_f32();
+    let step_distance = iter_distance / num_steps;
+    let num_steps = num_steps as u32;
+
+    let repeats = 5;
+
+    let total_duration = iter_duration * 2 * repeats;
+
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let mut positions = ([0., 0., 0.], [-1., 0., 0.], [1., 0., 0.]);
+    let sink = rodio::SpatialSink::try_new(&handle, positions.0, positions.1, positions.2).unwrap();
+
+    let file = std::fs::File::open("assets/music.ogg").unwrap();
+    let source = rodio::Decoder::new(BufReader::new(file))
+        .unwrap()
+        .repeat_infinite()
+        .take_duration(total_duration);
+    sink.append(source);
+    // A sound emitter playing the music starting at the centre gradually moves to the right
+    // until it stops and begins traveling to the left, it will eventually pass through the
+    // listener again and go to the far left.
+    // This is repeated 5 times.
+    for _ in 0..repeats {
+        for _ in 0..num_steps {
+            thread::sleep(refresh_duration);
+            positions.0[0] += step_distance;
+            sink.set_emitter_position(positions.0);
+        }
+        for _ in 0..(num_steps * 2) {
+            thread::sleep(refresh_duration);
+            positions.0[0] -= step_distance;
+            sink.set_emitter_position(positions.0);
+        }
+        for _ in 0..num_steps {
+            thread::sleep(refresh_duration);
+            positions.0[0] += step_distance;
+            sink.set_emitter_position(positions.0);
+        }
+    }
+    sink.sleep_until_end();
+}

vendor/rodio/examples/stereo.rs

@@ -0,0 +1,12 @@
+//! Plays a tone alternating between right and left ears, with right being first.
+use std::io::BufReader;
+
+fn main() {
+    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
+    let sink = rodio::Sink::try_new(&handle).unwrap();
+
+    let file = std::fs::File::open("assets/RL.ogg").unwrap();
+    sink.append(rodio::Decoder::new(BufReader::new(file)).unwrap());
+
+    sink.sleep_until_end();
+}

vendor/rodio/outreach/v0.20_announcement_and_call_for_userstories.md

@@ -0,0 +1,48 @@
+<!---
+ When 0.20.0 is released this announcement will be posted to r/rust and the
+ rust user forum. Also post in rust audio discord: https://discord.gg/8qW6q2k
+-->
+
+# Announcing rodio 0.20 and call for help
+
+
+Rodio is an audio playback library. It can decode audio files, synthesize new
+sounds, apply effects to sounds & mix them. Rodio has been part of the Rust
+ecosystem for 9 years now! 🎉.
+
+## New release
+The rodio contributors have made many improvements in the last 5 months. Rodio can now:
+
+- Seek back and forth through sound efficiently
+- Track the playback position at sample accuracy!
+- Generate more signals such as chirps, white & pink noise and different
+  wavesforms
+- Automatically adjust the gain to limit the peak volume and change in loudness
+
+This is ignoring the many fixes and smaller additions made by the many
+contributors who helped out expand rodio.
+
+## Call for help
+
+In its 9 years of existence Rust has changed a lot. Further more Rodio is being
+used for applications beyond its original scope. To improve rodio we believe its
+time for larger (breaking) changes. 
+
+### User feedback
+To ensure we make the right changes we want
+to know what rodio is being used for and what you all would like to use it for. 
+
+We can use any input you have but are especially looking for users who are:
+- using rodio and feel some part of the API is hard to use.
+- have experienced footguns/pain point
+- wanted to use rodio but could not make it fit their use-case (excluding complex
+  game audio (best served by [kira](https://crates.io/crates/kira)) and advanced
+  dsp). If you disagree and think rodio can server those excluded use-case too
+  let us know!
+
+The best way to leave your feedback is a short user story on our issue
+[tracker](https://github.com/RustAudio/rodio/issues). If that is not your thing
+any other form posted there works too!
+
+### Architecture & API
+We can use input on our planned [changes](https://github.com/RustAudio/rodio/issues/614) and how to best implement them.

vendor/rodio/src/buffer.rs

@@ -0,0 +1,201 @@
+//! A simple source of samples coming from a buffer.
+//!
+//! The `SamplesBuffer` struct can be used to treat a list of values as a `Source`.
+//!
+//! # Example
+//!
+//! ```
+//! use rodio::buffer::SamplesBuffer;
+//! let _ = SamplesBuffer::new(1, 44100, vec![1i16, 2, 3, 4, 5, 6]);
+//! ```
+//!
+
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::{Sample, Source};
+
+/// A buffer of samples treated as a source.
+#[derive(Debug, Clone)]
+pub struct SamplesBuffer<S> {
+    data: Vec<S>,
+    pos: usize,
+    channels: u16,
+    sample_rate: u32,
+    duration: Duration,
+}
+
+impl<S> SamplesBuffer<S>
+where
+    S: Sample,
+{
+    /// Builds a new `SamplesBuffer`.
+    ///
+    /// # Panic
+    ///
+    /// - Panics if the number of channels is zero.
+    /// - Panics if the samples rate is zero.
+    /// - Panics if the length of the buffer is larger than approximately 16 billion elements.
+    ///   This is because the calculation of the duration would overflow.
+    ///
+    pub fn new<D>(channels: u16, sample_rate: u32, data: D) -> SamplesBuffer<S>
+    where
+        D: Into<Vec<S>>,
+    {
+        assert!(channels != 0);
+        assert!(sample_rate != 0);
+
+        let data = data.into();
+        let duration_ns = 1_000_000_000u64.checked_mul(data.len() as u64).unwrap()
+            / sample_rate as u64
+            / channels as u64;
+        let duration = Duration::new(
+            duration_ns / 1_000_000_000,
+            (duration_ns % 1_000_000_000) as u32,
+        );
+
+        SamplesBuffer {
+            data,
+            pos: 0,
+            channels,
+            sample_rate,
+            duration,
+        }
+    }
+}
+
+impl<S> Source for SamplesBuffer<S>
+where
+    S: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        Some(self.duration)
+    }
+
+    // this is fast because all the samples are in memory already
+    // and due to the constant sample_rate we can jump to the right
+    // sample directly
+    //
+    /// This jumps in memory till the sample for `pos`.
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        let curr_channel = self.pos % self.channels() as usize;
+        let new_pos = pos.as_secs_f32() * self.sample_rate() as f32 * self.channels() as f32;
+        // saturate pos at the end of the source
+        let new_pos = new_pos as usize;
+        let new_pos = new_pos.min(self.data.len());
+
+        // make sure the next sample is for the right channel
+        let new_pos = new_pos.next_multiple_of(self.channels() as usize);
+        let new_pos = new_pos - curr_channel;
+
+        self.pos = new_pos;
+        Ok(())
+    }
+}
+
+impl<S> Iterator for SamplesBuffer<S>
+where
+    S: Sample,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        let sample = self.data.get(self.pos)?;
+        self.pos += 1;
+        Some(*sample)
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.data.len(), Some(self.data.len()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::buffer::SamplesBuffer;
+    use crate::source::Source;
+
+    #[test]
+    fn basic() {
+        let _ = SamplesBuffer::new(1, 44100, vec![0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    #[should_panic]
+    fn panic_if_zero_channels() {
+        SamplesBuffer::new(0, 44100, vec![0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    #[should_panic]
+    fn panic_if_zero_sample_rate() {
+        SamplesBuffer::new(1, 0, vec![0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    fn duration_basic() {
+        let buf = SamplesBuffer::new(2, 2, vec![0i16, 0, 0, 0, 0, 0]);
+        let dur = buf.total_duration().unwrap();
+        assert_eq!(dur.as_secs(), 1);
+        assert_eq!(dur.subsec_nanos(), 500_000_000);
+    }
+
+    #[test]
+    fn iteration() {
+        let mut buf = SamplesBuffer::new(1, 44100, vec![1i16, 2, 3, 4, 5, 6]);
+        assert_eq!(buf.next(), Some(1));
+        assert_eq!(buf.next(), Some(2));
+        assert_eq!(buf.next(), Some(3));
+        assert_eq!(buf.next(), Some(4));
+        assert_eq!(buf.next(), Some(5));
+        assert_eq!(buf.next(), Some(6));
+        assert_eq!(buf.next(), None);
+    }
+
+    #[cfg(test)]
+    mod try_seek {
+        use super::*;
+        use std::time::Duration;
+
+        #[test]
+        fn channel_order_stays_correct() {
+            const SAMPLE_RATE: u32 = 100;
+            const CHANNELS: u16 = 2;
+            let mut buf = SamplesBuffer::new(
+                CHANNELS,
+                SAMPLE_RATE,
+                (0..2000i16).into_iter().collect::<Vec<_>>(),
+            );
+            buf.try_seek(Duration::from_secs(5)).unwrap();
+            assert_eq!(
+                buf.next(),
+                Some(5i16 * SAMPLE_RATE as i16 * CHANNELS as i16)
+            );
+
+            assert!(buf.next().is_some_and(|s| s % 2 == 1));
+            assert!(buf.next().is_some_and(|s| s % 2 == 0));
+
+            buf.try_seek(Duration::from_secs(6)).unwrap();
+            assert!(buf.next().is_some_and(|s| s % 2 == 1),);
+        }
+    }
+}

vendor/rodio/src/conversions/channels.rs

@@ -0,0 +1,181 @@
+use cpal::Sample;
+
+/// Iterator that converts from a certain channel count to another.
+#[derive(Clone, Debug)]
+pub struct ChannelCountConverter<I>
+where
+    I: Iterator,
+{
+    input: I,
+    from: cpal::ChannelCount,
+    to: cpal::ChannelCount,
+    sample_repeat: Option<I::Item>,
+    next_output_sample_pos: cpal::ChannelCount,
+}
+
+impl<I> ChannelCountConverter<I>
+where
+    I: Iterator,
+{
+    /// Initializes the iterator.
+    ///
+    /// # Panic
+    ///
+    /// Panics if `from` or `to` are equal to 0.
+    ///
+    #[inline]
+    pub fn new(
+        input: I,
+        from: cpal::ChannelCount,
+        to: cpal::ChannelCount,
+    ) -> ChannelCountConverter<I> {
+        assert!(from >= 1);
+        assert!(to >= 1);
+
+        ChannelCountConverter {
+            input,
+            from,
+            to,
+            sample_repeat: None,
+            next_output_sample_pos: 0,
+        }
+    }
+
+    /// Destroys this iterator and returns the underlying iterator.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+
+    /// Get mutable access to the iterator
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+}
+
+impl<I> Iterator for ChannelCountConverter<I>
+where
+    I: Iterator,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    fn next(&mut self) -> Option<I::Item> {
+        let result = match self.next_output_sample_pos {
+            0 => {
+                // save first sample for mono -> stereo conversion
+                let value = self.input.next();
+                self.sample_repeat = value;
+                value
+            }
+            x if x < self.from => self.input.next(),
+            1 => self.sample_repeat,
+            _ => Some(I::Item::EQUILIBRIUM),
+        };
+
+        if result.is_some() {
+            self.next_output_sample_pos += 1;
+        }
+
+        if self.next_output_sample_pos == self.to {
+            self.next_output_sample_pos = 0;
+
+            if self.from > self.to {
+                for _ in self.to..self.from {
+                    self.input.next(); // discarding extra input
+                }
+            }
+        }
+
+        result
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let (min, max) = self.input.size_hint();
+
+        let consumed = std::cmp::min(self.from, self.next_output_sample_pos) as usize;
+        let calculate = |size| {
+            (size + consumed) / self.from as usize * self.to as usize
+                - self.next_output_sample_pos as usize
+        };
+
+        let min = calculate(min);
+        let max = max.map(calculate);
+
+        (min, max)
+    }
+}
+
+impl<I> ExactSizeIterator for ChannelCountConverter<I>
+where
+    I: ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+#[cfg(test)]
+mod test {
+    use super::ChannelCountConverter;
+
+    #[test]
+    fn remove_channels() {
+        let input = vec![1u16, 2, 3, 4, 5, 6];
+        let output = ChannelCountConverter::new(input.into_iter(), 3, 2).collect::<Vec<_>>();
+        assert_eq!(output, [1, 2, 4, 5]);
+
+        let input = vec![1u16, 2, 3, 4, 5, 6, 7, 8];
+        let output = ChannelCountConverter::new(input.into_iter(), 4, 1).collect::<Vec<_>>();
+        assert_eq!(output, [1, 5]);
+    }
+
+    #[test]
+    fn add_channels() {
+        let input = vec![1i16, 2, 3, 4];
+        let output = ChannelCountConverter::new(input.into_iter(), 1, 2).collect::<Vec<_>>();
+        assert_eq!(output, [1, 1, 2, 2, 3, 3, 4, 4]);
+
+        let input = vec![1i16, 2];
+        let output = ChannelCountConverter::new(input.into_iter(), 1, 4).collect::<Vec<_>>();
+        assert_eq!(output, [1, 1, 0, 0, 2, 2, 0, 0]);
+
+        let input = vec![1i16, 2, 3, 4];
+        let output = ChannelCountConverter::new(input.into_iter(), 2, 4).collect::<Vec<_>>();
+        assert_eq!(output, [1, 2, 0, 0, 3, 4, 0, 0]);
+    }
+
+    #[test]
+    fn size_hint() {
+        fn test(input: &[i16], from: cpal::ChannelCount, to: cpal::ChannelCount) {
+            let mut converter = ChannelCountConverter::new(input.iter().copied(), from, to);
+            let count = converter.clone().count();
+            for left_in_iter in (0..=count).rev() {
+                println!("left_in_iter = {left_in_iter}");
+                assert_eq!(converter.size_hint(), (left_in_iter, Some(left_in_iter)));
+                converter.next();
+            }
+            assert_eq!(converter.size_hint(), (0, Some(0)));
+        }
+
+        test(&[1i16, 2, 3], 1, 2);
+        test(&[1i16, 2, 3, 4], 2, 4);
+        test(&[1i16, 2, 3, 4], 4, 2);
+        test(&[1i16, 2, 3, 4, 5, 6], 3, 8);
+        test(&[1i16, 2, 3, 4, 5, 6, 7, 8], 4, 1);
+    }
+
+    #[test]
+    fn len_more() {
+        let input = vec![1i16, 2, 3, 4];
+        let output = ChannelCountConverter::new(input.into_iter(), 2, 3);
+        assert_eq!(output.len(), 6);
+    }
+
+    #[test]
+    fn len_less() {
+        let input = vec![1i16, 2, 3, 4];
+        let output = ChannelCountConverter::new(input.into_iter(), 2, 1);
+        assert_eq!(output.len(), 2);
+    }
+}

vendor/rodio/src/conversions/mod.rs

@@ -0,0 +1,17 @@
+/*!
+This module contains function that will convert from one PCM format to another.
+
+This includes conversion between sample formats, channels or sample rates.
+
+*/
+
+pub use self::channels::ChannelCountConverter;
+pub use self::sample::DataConverter;
+pub use self::sample::Sample;
+pub use self::sample_rate::SampleRateConverter;
+
+mod channels;
+// TODO: < shouldn't be public ; there's a bug in Rust 1.4 and below that makes This
+// `pub` mandatory
+pub mod sample;
+mod sample_rate;

vendor/rodio/src/conversions/sample.rs

@@ -0,0 +1,180 @@
+use cpal::{FromSample, Sample as CpalSample};
+use std::marker::PhantomData;
+
+/// Converts the samples data type to `O`.
+#[derive(Clone, Debug)]
+pub struct DataConverter<I, O> {
+    input: I,
+    marker: PhantomData<O>,
+}
+
+impl<I, O> DataConverter<I, O> {
+    /// Builds a new converter.
+    #[inline]
+    pub fn new(input: I) -> DataConverter<I, O> {
+        DataConverter {
+            input,
+            marker: PhantomData,
+        }
+    }
+
+    /// Destroys this iterator and returns the underlying iterator.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+
+    /// get mutable access to the iterator
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+}
+
+impl<I, O> Iterator for DataConverter<I, O>
+where
+    I: Iterator,
+    I::Item: Sample,
+    O: FromSample<I::Item> + Sample,
+{
+    type Item = O;
+
+    #[inline]
+    fn next(&mut self) -> Option<O> {
+        self.input.next().map(|s| CpalSample::from_sample(s))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I, O> ExactSizeIterator for DataConverter<I, O>
+where
+    I: ExactSizeIterator,
+    I::Item: Sample,
+    O: FromSample<I::Item> + Sample,
+{
+}
+
+/// Represents a value of a single sample.
+///
+/// This trait is implemented by default on three types: `i16`, `u16` and `f32`.
+///
+/// - For `i16`, silence corresponds to the value `0`. The minimum and maximum amplitudes are
+///   represented by `i16::min_value()` and `i16::max_value()` respectively.
+/// - For `u16`, silence corresponds to the value `u16::max_value() / 2`. The minimum and maximum
+///   amplitudes are represented by `0` and `u16::max_value()` respectively.
+/// - For `f32`, silence corresponds to the value `0.0`. The minimum and maximum amplitudes are
+///   represented by `-1.0` and `1.0` respectively.
+///
+/// You can implement this trait on your own type as well if you wish so.
+///
+pub trait Sample: CpalSample {
+    /// Linear interpolation between two samples.
+    ///
+    /// The result should be equal to
+    /// `first * numerator / denominator + second * (1 - numerator / denominator)`.
+    fn lerp(first: Self, second: Self, numerator: u32, denominator: u32) -> Self;
+    /// Multiplies the value of this sample by the given amount.
+    fn amplify(self, value: f32) -> Self;
+
+    /// Converts the sample to an f32 value.
+    fn to_f32(self) -> f32;
+
+    /// Calls `saturating_add` on the sample.
+    fn saturating_add(self, other: Self) -> Self;
+
+    /// Returns the value corresponding to the absence of sound.
+    fn zero_value() -> Self;
+}
+
+impl Sample for u16 {
+    #[inline]
+    fn lerp(first: u16, second: u16, numerator: u32, denominator: u32) -> u16 {
+        let a = first as i32;
+        let b = second as i32;
+        let n = numerator as i32;
+        let d = denominator as i32;
+        (a + (b - a) * n / d) as u16
+    }
+
+    #[inline]
+    fn amplify(self, value: f32) -> u16 {
+        ((self as f32) * value) as u16
+    }
+
+    #[inline]
+    fn to_f32(self) -> f32 {
+        // Convert u16 to f32 in the range [-1.0, 1.0]
+        (self as f32 - 32768.0) / 32768.0
+    }
+
+    #[inline]
+    fn saturating_add(self, other: u16) -> u16 {
+        self.saturating_add(other)
+    }
+
+    #[inline]
+    fn zero_value() -> u16 {
+        32768
+    }
+}
+
+impl Sample for i16 {
+    #[inline]
+    fn lerp(first: i16, second: i16, numerator: u32, denominator: u32) -> i16 {
+        (first as i32 + (second as i32 - first as i32) * numerator as i32 / denominator as i32)
+            as i16
+    }
+
+    #[inline]
+    fn amplify(self, value: f32) -> i16 {
+        ((self as f32) * value) as i16
+    }
+
+    #[inline]
+    fn to_f32(self) -> f32 {
+        // Convert i16 to f32 in the range [-1.0, 1.0]
+        self as f32 / 32768.0
+    }
+
+    #[inline]
+    fn saturating_add(self, other: i16) -> i16 {
+        self.saturating_add(other)
+    }
+
+    #[inline]
+    fn zero_value() -> i16 {
+        0
+    }
+}
+
+impl Sample for f32 {
+    #[inline]
+    fn lerp(first: f32, second: f32, numerator: u32, denominator: u32) -> f32 {
+        first + (second - first) * numerator as f32 / denominator as f32
+    }
+
+    #[inline]
+    fn amplify(self, value: f32) -> f32 {
+        self * value
+    }
+
+    #[inline]
+    fn to_f32(self) -> f32 {
+        // f32 is already in the correct format
+        self
+    }
+
+    #[inline]
+    fn saturating_add(self, other: f32) -> f32 {
+        self + other
+    }
+
+    #[inline]
+    fn zero_value() -> f32 {
+        0.0
+    }
+}

vendor/rodio/src/conversions/sample_rate.rs

@@ -0,0 +1,377 @@
+use crate::conversions::Sample;
+
+use std::mem;
+
+/// Iterator that converts from a certain sample rate to another.
+#[derive(Clone, Debug)]
+pub struct SampleRateConverter<I>
+where
+    I: Iterator,
+{
+    /// The iterator that gives us samples.
+    input: I,
+    /// We convert chunks of `from` samples into chunks of `to` samples.
+    from: u32,
+    /// We convert chunks of `from` samples into chunks of `to` samples.
+    to: u32,
+    /// Number of channels in the stream
+    channels: cpal::ChannelCount,
+    /// One sample per channel, extracted from `input`.
+    current_frame: Vec<I::Item>,
+    /// Position of `current_sample` modulo `from`.
+    current_frame_pos_in_chunk: u32,
+    /// The samples right after `current_sample` (one per channel), extracted from `input`.
+    next_frame: Vec<I::Item>,
+    /// The position of the next sample that the iterator should return, modulo `to`.
+    /// This counter is incremented (modulo `to`) every time the iterator is called.
+    next_output_frame_pos_in_chunk: u32,
+    /// The buffer containing the samples waiting to be output.
+    output_buffer: Vec<I::Item>,
+}
+
+impl<I> SampleRateConverter<I>
+where
+    I: Iterator,
+    I::Item: Sample,
+{
+    ///
+    ///
+    /// # Panic
+    ///
+    /// Panics if `from` or `to` are equal to 0.
+    ///
+    #[inline]
+    pub fn new(
+        mut input: I,
+        from: cpal::SampleRate,
+        to: cpal::SampleRate,
+        num_channels: cpal::ChannelCount,
+    ) -> SampleRateConverter<I> {
+        let from = from.0;
+        let to = to.0;
+
+        assert!(from >= 1);
+        assert!(to >= 1);
+
+        // finding greatest common divisor
+        let gcd = {
+            #[inline]
+            fn gcd(a: u32, b: u32) -> u32 {
+                if b == 0 {
+                    a
+                } else {
+                    gcd(b, a % b)
+                }
+            }
+
+            gcd(from, to)
+        };
+
+        let (first_samples, next_samples) = if from == to {
+            // if `from` == `to` == 1, then we just pass through
+            debug_assert_eq!(from, gcd);
+            (Vec::new(), Vec::new())
+        } else {
+            let first = input
+                .by_ref()
+                .take(num_channels as usize)
+                .collect::<Vec<_>>();
+            let next = input
+                .by_ref()
+                .take(num_channels as usize)
+                .collect::<Vec<_>>();
+            (first, next)
+        };
+
+        SampleRateConverter {
+            input,
+            from: from / gcd,
+            to: to / gcd,
+            channels: num_channels,
+            current_frame_pos_in_chunk: 0,
+            next_output_frame_pos_in_chunk: 0,
+            current_frame: first_samples,
+            next_frame: next_samples,
+            output_buffer: Vec::with_capacity(num_channels as usize - 1),
+        }
+    }
+
+    /// Destroys this iterator and returns the underlying iterator.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+
+    /// get mutable access to the iterator
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    fn next_input_frame(&mut self) {
+        self.current_frame_pos_in_chunk += 1;
+
+        mem::swap(&mut self.current_frame, &mut self.next_frame);
+        self.next_frame.clear();
+        for _ in 0..self.channels {
+            if let Some(i) = self.input.next() {
+                self.next_frame.push(i);
+            } else {
+                break;
+            }
+        }
+    }
+}
+
+impl<I> Iterator for SampleRateConverter<I>
+where
+    I: Iterator,
+    I::Item: Sample + Clone,
+{
+    type Item = I::Item;
+
+    fn next(&mut self) -> Option<I::Item> {
+        // the algorithm below doesn't work if `self.from == self.to`
+        if self.from == self.to {
+            debug_assert_eq!(self.from, 1);
+            return self.input.next();
+        }
+
+        // Short circuit if there are some samples waiting.
+        if !self.output_buffer.is_empty() {
+            return Some(self.output_buffer.remove(0));
+        }
+
+        // The frame we are going to return from this function will be a linear interpolation
+        // between `self.current_frame` and `self.next_frame`.
+
+        if self.next_output_frame_pos_in_chunk == self.to {
+            // If we jump to the next frame, we reset the whole state.
+            self.next_output_frame_pos_in_chunk = 0;
+
+            self.next_input_frame();
+            while self.current_frame_pos_in_chunk != self.from {
+                self.next_input_frame();
+            }
+            self.current_frame_pos_in_chunk = 0;
+        } else {
+            // Finding the position of the first sample of the linear interpolation.
+            let req_left_sample =
+                (self.from * self.next_output_frame_pos_in_chunk / self.to) % self.from;
+
+            // Advancing `self.current_frame`, `self.next_frame` and
+            // `self.current_frame_pos_in_chunk` until the latter variable
+            // matches `req_left_sample`.
+            while self.current_frame_pos_in_chunk != req_left_sample {
+                self.next_input_frame();
+                debug_assert!(self.current_frame_pos_in_chunk < self.from);
+            }
+        }
+
+        // Merging `self.current_frame` and `self.next_frame` into `self.output_buffer`.
+        // Note that `self.output_buffer` can be truncated if there is not enough data in
+        // `self.next_frame`.
+        let mut result = None;
+        let numerator = (self.from * self.next_output_frame_pos_in_chunk) % self.to;
+        for (off, (cur, next)) in self
+            .current_frame
+            .iter()
+            .zip(self.next_frame.iter())
+            .enumerate()
+        {
+            let sample = Sample::lerp(*cur, *next, numerator, self.to);
+
+            if off == 0 {
+                result = Some(sample);
+            } else {
+                self.output_buffer.push(sample);
+            }
+        }
+
+        // Incrementing the counter for the next iteration.
+        self.next_output_frame_pos_in_chunk += 1;
+
+        if result.is_some() {
+            result
+        } else {
+            // draining `self.current_frame`
+            if !self.current_frame.is_empty() {
+                let r = Some(self.current_frame.remove(0));
+                mem::swap(&mut self.output_buffer, &mut self.current_frame);
+                self.current_frame.clear();
+                r
+            } else {
+                None
+            }
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let apply = |samples: usize| {
+            // `samples_after_chunk` will contain the number of samples remaining after the chunk
+            // currently being processed
+            let samples_after_chunk = samples;
+            // adding the samples of the next chunk that may have already been read
+            let samples_after_chunk = if self.current_frame_pos_in_chunk == self.from - 1 {
+                samples_after_chunk + self.next_frame.len()
+            } else {
+                samples_after_chunk
+            };
+            // removing the samples of the current chunk that have not yet been read
+            let samples_after_chunk = samples_after_chunk.saturating_sub(
+                self.from
+                    .saturating_sub(self.current_frame_pos_in_chunk + 2) as usize
+                    * usize::from(self.channels),
+            );
+            // calculating the number of samples after the transformation
+            // TODO: this is wrong here \|/
+            let samples_after_chunk = samples_after_chunk * self.to as usize / self.from as usize;
+
+            // `samples_current_chunk` will contain the number of samples remaining to be output
+            // for the chunk currently being processed
+            let samples_current_chunk = (self.to - self.next_output_frame_pos_in_chunk) as usize
+                * usize::from(self.channels);
+
+            samples_current_chunk + samples_after_chunk + self.output_buffer.len()
+        };
+
+        if self.from == self.to {
+            self.input.size_hint()
+        } else {
+            let (min, max) = self.input.size_hint();
+            (apply(min), max.map(apply))
+        }
+    }
+}
+
+impl<I> ExactSizeIterator for SampleRateConverter<I>
+where
+    I: ExactSizeIterator,
+    I::Item: Sample + Clone,
+{
+}
+
+#[cfg(test)]
+mod test {
+    use super::SampleRateConverter;
+    use core::time::Duration;
+    use cpal::SampleRate;
+    use quickcheck::quickcheck;
+
+    // TODO: Remove once cpal 0.12.2 is released and the dependency is updated
+    //  (cpal#483 implemented ops::Mul on SampleRate)
+    const fn multiply_rate(r: SampleRate, k: u32) -> SampleRate {
+        SampleRate(k * r.0)
+    }
+
+    quickcheck! {
+        /// Check that resampling an empty input produces no output.
+        fn empty(from: u32, to: u32, n: u16) -> () {
+            let from = if from == 0 { return; } else { SampleRate(from) };
+            let to   = if   to == 0 { return; } else { SampleRate(to)   };
+            if n == 0 { return; }
+
+            let input: Vec<u16> = Vec::new();
+            let output =
+                SampleRateConverter::new(input.into_iter(), from, to, n)
+                  .collect::<Vec<_>>();
+
+            assert_eq!(output, []);
+        }
+
+        /// Check that resampling to the same rate does not change the signal.
+        fn identity(from: u32, n: u16, input: Vec<u16>) -> () {
+            let from = if from == 0 { return; } else { SampleRate(from) };
+            if n == 0 { return; }
+
+            let output =
+                SampleRateConverter::new(input.clone().into_iter(), from, from, n)
+                  .collect::<Vec<_>>();
+
+            assert_eq!(input, output);
+        }
+
+        /// Check that dividing the sample rate by k (integer) is the same as
+        ///   dropping a sample from each channel.
+        fn divide_sample_rate(to: u32, k: u32, input: Vec<u16>, n: u16) -> () {
+            let to = if to == 0 { return; } else { SampleRate(to) };
+            let from = multiply_rate(to, k);
+            if k == 0 || n == 0 { return; }
+
+            // Truncate the input, so it contains an integer number of frames.
+            let input = {
+                let ns = n as usize;
+                let mut i = input;
+                i.truncate(ns * (i.len() / ns));
+                i
+            };
+
+            let output =
+                SampleRateConverter::new(input.clone().into_iter(), from, to, n)
+                  .collect::<Vec<_>>();
+
+            assert_eq!(input.chunks_exact(n.into())
+                         .step_by(k as usize).collect::<Vec<_>>().concat(),
+                       output)
+        }
+
+        /// Check that, after multiplying the sample rate by k, every k-th
+        ///  sample in the output matches exactly with the input.
+        fn multiply_sample_rate(from: u32, k: u32, input: Vec<u16>, n: u16) -> () {
+            let from = if from == 0 { return; } else { SampleRate(from) };
+            let to = multiply_rate(from, k);
+            if k == 0 || n == 0 { return; }
+
+            // Truncate the input, so it contains an integer number of frames.
+            let input = {
+                let ns = n as usize;
+                let mut i = input;
+                i.truncate(ns * (i.len() / ns));
+                i
+            };
+
+            let output =
+                SampleRateConverter::new(input.clone().into_iter(), from, to, n)
+                  .collect::<Vec<_>>();
+
+            assert_eq!(input,
+                       output.chunks_exact(n.into())
+                         .step_by(k as usize).collect::<Vec<_>>().concat()
+            )
+        }
+
+        #[ignore]
+        /// Check that resampling does not change the audio duration,
+        ///  except by a negligible amount (± 1ms).  Reproduces #316.
+        /// Ignored, pending a bug fix.
+        fn preserve_durations(d: Duration, freq: f32, to: u32) -> () {
+            use crate::source::{SineWave, Source};
+
+            let to = if to == 0 { return; } else { SampleRate(to) };
+            let source = SineWave::new(freq).take_duration(d);
+            let from = SampleRate(source.sample_rate());
+
+            let resampled =
+                SampleRateConverter::new(source, from, to, 1);
+            let duration =
+                Duration::from_secs_f32(resampled.count() as f32 / to.0 as f32);
+
+            let delta = if d < duration { duration - d } else { d - duration };
+            assert!(delta < Duration::from_millis(1),
+                    "Resampled duration ({:?}) is not close to original ({:?}); Δ = {:?}",
+                    duration, d, delta);
+        }
+    }
+
+    #[test]
+    fn upsample() {
+        let input = vec![2u16, 16, 4, 18, 6, 20, 8, 22];
+        let output =
+            SampleRateConverter::new(input.into_iter(), SampleRate(2000), SampleRate(3000), 2);
+        assert_eq!(output.len(), 12);
+
+        let output = output.collect::<Vec<_>>();
+        assert_eq!(output, [2, 16, 3, 17, 4, 18, 6, 20, 7, 21, 8, 22]);
+    }
+}

vendor/rodio/src/decoder/flac.rs

@@ -0,0 +1,144 @@
+use std::cmp::Ordering;
+use std::io::{Read, Seek, SeekFrom};
+use std::mem;
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::Source;
+
+use claxon::FlacReader;
+
+/// Decoder for the Flac format.
+pub struct FlacDecoder<R>
+where
+    R: Read + Seek,
+{
+    reader: FlacReader<R>,
+    current_block: Vec<i32>,
+    current_block_channel_len: usize,
+    current_block_off: usize,
+    bits_per_sample: u32,
+    sample_rate: u32,
+    channels: u16,
+    samples: Option<u64>,
+}
+
+impl<R> FlacDecoder<R>
+where
+    R: Read + Seek,
+{
+    /// Attempts to decode the data as Flac.
+    pub fn new(mut data: R) -> Result<FlacDecoder<R>, R> {
+        if !is_flac(data.by_ref()) {
+            return Err(data);
+        }
+
+        let reader = FlacReader::new(data).unwrap();
+        let spec = reader.streaminfo();
+
+        Ok(FlacDecoder {
+            reader,
+            current_block: Vec::with_capacity(
+                spec.max_block_size as usize * spec.channels as usize,
+            ),
+            current_block_channel_len: 1,
+            current_block_off: 0,
+            bits_per_sample: spec.bits_per_sample,
+            sample_rate: spec.sample_rate,
+            channels: spec.channels as u16,
+            samples: spec.samples,
+        })
+    }
+    pub fn into_inner(self) -> R {
+        self.reader.into_inner()
+    }
+}
+
+impl<R> Source for FlacDecoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        // `samples` in FLAC means "inter-channel samples" aka frames
+        // so we do not divide by `self.channels` here.
+        self.samples
+            .map(|s| Duration::from_micros(s * 1_000_000 / self.sample_rate as u64))
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+impl<R> Iterator for FlacDecoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        loop {
+            if self.current_block_off < self.current_block.len() {
+                // Read from current block.
+                let real_offset = (self.current_block_off % self.channels as usize)
+                    * self.current_block_channel_len
+                    + self.current_block_off / self.channels as usize;
+                let raw_val = self.current_block[real_offset];
+                self.current_block_off += 1;
+                let real_val = match self.bits_per_sample.cmp(&16) {
+                    Ordering::Less => (raw_val << (16 - self.bits_per_sample)) as i16,
+                    Ordering::Equal => raw_val as i16,
+                    Ordering::Greater => (raw_val >> (self.bits_per_sample - 16)) as i16,
+                };
+                return Some(real_val);
+            }
+
+            // Load the next block.
+            self.current_block_off = 0;
+            let buffer = mem::take(&mut self.current_block);
+            match self.reader.blocks().read_next_or_eof(buffer) {
+                Ok(Some(block)) => {
+                    self.current_block_channel_len = (block.len() / block.channels()) as usize;
+                    self.current_block = block.into_buffer();
+                }
+                _ => return None,
+            }
+        }
+    }
+}
+
+/// Returns true if the stream contains Flac data, then resets it to where it was.
+fn is_flac<R>(mut data: R) -> bool
+where
+    R: Read + Seek,
+{
+    let stream_pos = data.stream_position().unwrap();
+
+    if FlacReader::new(data.by_ref()).is_err() {
+        data.seek(SeekFrom::Start(stream_pos)).unwrap();
+        return false;
+    }
+
+    data.seek(SeekFrom::Start(stream_pos)).unwrap();
+    true
+}

vendor/rodio/src/decoder/mod.rs

@@ -0,0 +1,585 @@
+//! Decodes samples from an audio file.
+
+use std::error::Error;
+use std::fmt;
+#[allow(unused_imports)]
+use std::io::{Read, Seek, SeekFrom};
+use std::mem;
+use std::str::FromStr;
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::Source;
+
+#[cfg(feature = "symphonia")]
+use self::read_seek_source::ReadSeekSource;
+#[cfg(feature = "symphonia")]
+use ::symphonia::core::io::{MediaSource, MediaSourceStream};
+
+#[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+mod flac;
+#[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+mod mp3;
+#[cfg(feature = "symphonia")]
+mod read_seek_source;
+#[cfg(feature = "symphonia")]
+/// Symphonia decoders types
+pub mod symphonia;
+#[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+mod vorbis;
+#[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+mod wav;
+
+/// Source of audio samples from decoding a file.
+///
+/// Supports MP3, WAV, Vorbis and Flac.
+pub struct Decoder<R>(DecoderImpl<R>)
+where
+    R: Read + Seek;
+
+/// Source of audio samples from decoding a file that never ends. When the
+/// end of the file is reached the decoder starts again from the beginning.
+///
+/// Supports MP3, WAV, Vorbis and Flac.
+pub struct LoopedDecoder<R>(DecoderImpl<R>)
+where
+    R: Read + Seek;
+
+// Cannot really reduce the size of the VorbisDecoder. There are not any
+// arrays just a lot of struct fields.
+#[allow(clippy::large_enum_variant)]
+enum DecoderImpl<R>
+where
+    R: Read + Seek,
+{
+    #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+    Wav(wav::WavDecoder<R>),
+    #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+    Vorbis(vorbis::VorbisDecoder<R>),
+    #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+    Flac(flac::FlacDecoder<R>),
+    #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+    Mp3(mp3::Mp3Decoder<R>),
+    #[cfg(feature = "symphonia")]
+    Symphonia(symphonia::SymphoniaDecoder),
+    None(::std::marker::PhantomData<R>),
+}
+
+impl<R: Read + Seek> DecoderImpl<R> {
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.next(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.next(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.next(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.next(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.next(),
+            DecoderImpl::None(_) => None,
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.size_hint(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.size_hint(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.size_hint(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.size_hint(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.size_hint(),
+            DecoderImpl::None(_) => (0, None),
+        }
+    }
+
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.current_frame_len(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.current_frame_len(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.current_frame_len(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.current_frame_len(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.current_frame_len(),
+            DecoderImpl::None(_) => Some(0),
+        }
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.channels(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.channels(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.channels(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.channels(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.channels(),
+            DecoderImpl::None(_) => 0,
+        }
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.sample_rate(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.sample_rate(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.sample_rate(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.sample_rate(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.sample_rate(),
+            DecoderImpl::None(_) => 1,
+        }
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.total_duration(),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.total_duration(),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.total_duration(),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.total_duration(),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.total_duration(),
+            DecoderImpl::None(_) => Some(Duration::default()),
+        }
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        match self {
+            #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+            DecoderImpl::Wav(source) => source.try_seek(pos),
+            #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+            DecoderImpl::Vorbis(source) => source.try_seek(pos),
+            #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+            DecoderImpl::Flac(source) => source.try_seek(pos),
+            #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+            DecoderImpl::Mp3(source) => source.try_seek(pos),
+            #[cfg(feature = "symphonia")]
+            DecoderImpl::Symphonia(source) => source.try_seek(pos),
+            DecoderImpl::None(_) => Err(SeekError::NotSupported {
+                underlying_source: "DecoderImpl::None",
+            }),
+        }
+    }
+}
+
+impl<R> Decoder<R>
+where
+    R: Read + Seek + Send + Sync + 'static,
+{
+    /// Builds a new decoder.
+    ///
+    /// Attempts to automatically detect the format of the source of data.
+    #[allow(unused_variables)]
+    pub fn new(data: R) -> Result<Decoder<R>, DecoderError> {
+        #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+        let data = match wav::WavDecoder::new(data) {
+            Err(data) => data,
+            Ok(decoder) => {
+                return Ok(Decoder(DecoderImpl::Wav(decoder)));
+            }
+        };
+
+        #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+        let data = match flac::FlacDecoder::new(data) {
+            Err(data) => data,
+            Ok(decoder) => {
+                return Ok(Decoder(DecoderImpl::Flac(decoder)));
+            }
+        };
+
+        #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+        let data = match vorbis::VorbisDecoder::new(data) {
+            Err(data) => data,
+            Ok(decoder) => {
+                return Ok(Decoder(DecoderImpl::Vorbis(decoder)));
+            }
+        };
+
+        #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+        let data = match mp3::Mp3Decoder::new(data) {
+            Err(data) => data,
+            Ok(decoder) => {
+                return Ok(Decoder(DecoderImpl::Mp3(decoder)));
+            }
+        };
+
+        #[cfg(feature = "symphonia")]
+        {
+            let mss = MediaSourceStream::new(
+                Box::new(ReadSeekSource::new(data)) as Box<dyn MediaSource>,
+                Default::default(),
+            );
+
+            match symphonia::SymphoniaDecoder::new(mss, None) {
+                Err(e) => Err(e),
+                Ok(decoder) => Ok(Decoder(DecoderImpl::Symphonia(decoder))),
+            }
+        }
+        #[cfg(not(feature = "symphonia"))]
+        Err(DecoderError::UnrecognizedFormat)
+    }
+
+    /// Builds a new looped decoder.
+    ///
+    /// Attempts to automatically detect the format of the source of data.
+    pub fn new_looped(data: R) -> Result<LoopedDecoder<R>, DecoderError> {
+        Self::new(data).map(LoopedDecoder::new)
+    }
+
+    /// Builds a new decoder from wav data.
+    #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+    pub fn new_wav(data: R) -> Result<Decoder<R>, DecoderError> {
+        match wav::WavDecoder::new(data) {
+            Err(_) => Err(DecoderError::UnrecognizedFormat),
+            Ok(decoder) => Ok(Decoder(DecoderImpl::Wav(decoder))),
+        }
+    }
+
+    /// Builds a new decoder from wav data.
+    #[cfg(feature = "symphonia-wav")]
+    pub fn new_wav(data: R) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, "wav")
+    }
+
+    /// Builds a new decoder from flac data.
+    #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+    pub fn new_flac(data: R) -> Result<Decoder<R>, DecoderError> {
+        match flac::FlacDecoder::new(data) {
+            Err(_) => Err(DecoderError::UnrecognizedFormat),
+            Ok(decoder) => Ok(Decoder(DecoderImpl::Flac(decoder))),
+        }
+    }
+
+    /// Builds a new decoder from flac data.
+    #[cfg(feature = "symphonia-flac")]
+    pub fn new_flac(data: R) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, "flac")
+    }
+
+    /// Builds a new decoder from vorbis data.
+    #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+    pub fn new_vorbis(data: R) -> Result<Decoder<R>, DecoderError> {
+        match vorbis::VorbisDecoder::new(data) {
+            Err(_) => Err(DecoderError::UnrecognizedFormat),
+            Ok(decoder) => Ok(Decoder(DecoderImpl::Vorbis(decoder))),
+        }
+    }
+
+    /// Builds a new decoder from vorbis data.
+    #[cfg(feature = "symphonia-vorbis")]
+    pub fn new_vorbis(data: R) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, "ogg")
+    }
+
+    /// Builds a new decoder from mp3 data.
+    #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+    pub fn new_mp3(data: R) -> Result<Decoder<R>, DecoderError> {
+        match mp3::Mp3Decoder::new(data) {
+            Err(_) => Err(DecoderError::UnrecognizedFormat),
+            Ok(decoder) => Ok(Decoder(DecoderImpl::Mp3(decoder))),
+        }
+    }
+
+    /// Builds a new decoder from mp3 data.
+    #[cfg(feature = "symphonia-mp3")]
+    pub fn new_mp3(data: R) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, "mp3")
+    }
+
+    /// Builds a new decoder from aac data.
+    #[cfg(feature = "symphonia-aac")]
+    pub fn new_aac(data: R) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, "aac")
+    }
+
+    /// Builds a new decoder from mp4 data.
+    #[cfg(feature = "symphonia-isomp4")]
+    pub fn new_mp4(data: R, hint: Mp4Type) -> Result<Decoder<R>, DecoderError> {
+        Decoder::new_symphonia(data, &hint.to_string())
+    }
+
+    #[cfg(feature = "symphonia")]
+    fn new_symphonia(data: R, hint: &str) -> Result<Decoder<R>, DecoderError> {
+        let mss = MediaSourceStream::new(
+            Box::new(ReadSeekSource::new(data)) as Box<dyn MediaSource>,
+            Default::default(),
+        );
+
+        match symphonia::SymphoniaDecoder::new(mss, Some(hint)) {
+            Err(e) => Err(e),
+            Ok(decoder) => Ok(Decoder(DecoderImpl::Symphonia(decoder))),
+        }
+    }
+}
+
+#[allow(missing_docs)] // Reason: will be removed, see: #612
+#[derive(Debug)]
+pub enum Mp4Type {
+    Mp4,
+    M4a,
+    M4p,
+    M4b,
+    M4r,
+    M4v,
+    Mov,
+}
+
+impl FromStr for Mp4Type {
+    type Err = String;
+
+    fn from_str(input: &str) -> Result<Mp4Type, Self::Err> {
+        match &input.to_lowercase()[..] {
+            "mp4" => Ok(Mp4Type::Mp4),
+            "m4a" => Ok(Mp4Type::M4a),
+            "m4p" => Ok(Mp4Type::M4p),
+            "m4b" => Ok(Mp4Type::M4b),
+            "m4r" => Ok(Mp4Type::M4r),
+            "m4v" => Ok(Mp4Type::M4v),
+            "mov" => Ok(Mp4Type::Mov),
+            _ => Err(format!("{input} is not a valid mp4 extension")),
+        }
+    }
+}
+
+impl fmt::Display for Mp4Type {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let text = match self {
+            Mp4Type::Mp4 => "mp4",
+            Mp4Type::M4a => "m4a",
+            Mp4Type::M4p => "m4p",
+            Mp4Type::M4b => "m4b",
+            Mp4Type::M4r => "m4r",
+            Mp4Type::M4v => "m4v",
+            Mp4Type::Mov => "mov",
+        };
+        write!(f, "{text}")
+    }
+}
+
+impl<R> LoopedDecoder<R>
+where
+    R: Read + Seek,
+{
+    fn new(decoder: Decoder<R>) -> LoopedDecoder<R> {
+        Self(decoder.0)
+    }
+}
+
+impl<R> Iterator for Decoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        self.0.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
+}
+
+impl<R> Source for Decoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.0.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.0.channels()
+    }
+
+    fn sample_rate(&self) -> u32 {
+        self.0.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.0.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.0.try_seek(pos)
+    }
+}
+
+impl<R> Iterator for LoopedDecoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        if let Some(sample) = self.0.next() {
+            Some(sample)
+        } else {
+            let decoder = mem::replace(&mut self.0, DecoderImpl::None(Default::default()));
+            let (decoder, sample) = match decoder {
+                #[cfg(all(feature = "wav", not(feature = "symphonia-wav")))]
+                DecoderImpl::Wav(source) => {
+                    let mut reader = source.into_inner();
+                    reader.seek(SeekFrom::Start(0)).ok()?;
+                    let mut source = wav::WavDecoder::new(reader).ok()?;
+                    let sample = source.next();
+                    (DecoderImpl::Wav(source), sample)
+                }
+                #[cfg(all(feature = "vorbis", not(feature = "symphonia-vorbis")))]
+                DecoderImpl::Vorbis(source) => {
+                    use lewton::inside_ogg::OggStreamReader;
+                    let mut reader = source.into_inner().into_inner();
+                    reader.seek_bytes(SeekFrom::Start(0)).ok()?;
+                    let mut source = vorbis::VorbisDecoder::from_stream_reader(
+                        OggStreamReader::from_ogg_reader(reader).ok()?,
+                    );
+                    let sample = source.next();
+                    (DecoderImpl::Vorbis(source), sample)
+                }
+                #[cfg(all(feature = "flac", not(feature = "symphonia-flac")))]
+                DecoderImpl::Flac(source) => {
+                    let mut reader = source.into_inner();
+                    reader.seek(SeekFrom::Start(0)).ok()?;
+                    let mut source = flac::FlacDecoder::new(reader).ok()?;
+                    let sample = source.next();
+                    (DecoderImpl::Flac(source), sample)
+                }
+                #[cfg(all(feature = "minimp3", not(feature = "symphonia-mp3")))]
+                DecoderImpl::Mp3(source) => {
+                    let mut reader = source.into_inner();
+                    reader.seek(SeekFrom::Start(0)).ok()?;
+                    let mut source = mp3::Mp3Decoder::new(reader).ok()?;
+                    let sample = source.next();
+                    (DecoderImpl::Mp3(source), sample)
+                }
+                #[cfg(feature = "symphonia")]
+                DecoderImpl::Symphonia(source) => {
+                    let mut reader = source.into_inner();
+                    reader.seek(SeekFrom::Start(0)).ok()?;
+                    let mut source = symphonia::SymphoniaDecoder::new(reader, None).ok()?;
+                    let sample = source.next();
+                    (DecoderImpl::Symphonia(source), sample)
+                }
+                none @ DecoderImpl::None(_) => (none, None),
+            };
+            self.0 = decoder;
+            sample
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
+}
+
+impl<R> Source for LoopedDecoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.0.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.0.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.0.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.0.try_seek(pos)
+    }
+}
+
+/// Error that can happen when creating a decoder.
+#[derive(Debug, Clone)]
+pub enum DecoderError {
+    /// The format of the data has not been recognized.
+    UnrecognizedFormat,
+
+    /// An IO error occurred while reading, writing, or seeking the stream.
+    #[cfg(feature = "symphonia")]
+    IoError(String),
+
+    /// The stream contained malformed data and could not be decoded or demuxed.
+    #[cfg(feature = "symphonia")]
+    DecodeError(&'static str),
+
+    /// A default or user-defined limit was reached while decoding or demuxing the stream. Limits
+    /// are used to prevent denial-of-service attacks from malicious streams.
+    #[cfg(feature = "symphonia")]
+    LimitError(&'static str),
+
+    /// The demuxer or decoder needs to be reset before continuing.
+    #[cfg(feature = "symphonia")]
+    ResetRequired,
+
+    /// No streams were found by the decoder
+    #[cfg(feature = "symphonia")]
+    NoStreams,
+}
+
+impl fmt::Display for DecoderError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let text = match self {
+            DecoderError::UnrecognizedFormat => "Unrecognized format",
+            #[cfg(feature = "symphonia")]
+            DecoderError::IoError(msg) => &msg[..],
+            #[cfg(feature = "symphonia")]
+            DecoderError::DecodeError(msg) => msg,
+            #[cfg(feature = "symphonia")]
+            DecoderError::LimitError(msg) => msg,
+            #[cfg(feature = "symphonia")]
+            DecoderError::ResetRequired => "Reset required",
+            #[cfg(feature = "symphonia")]
+            DecoderError::NoStreams => "No streams",
+        };
+        write!(f, "{text}")
+    }
+}
+
+impl Error for DecoderError {}

vendor/rodio/src/decoder/mp3.rs

@@ -0,0 +1,125 @@
+use std::io::{Read, Seek, SeekFrom};
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::Source;
+
+use minimp3::Decoder;
+use minimp3::Frame;
+use minimp3_fixed as minimp3;
+
+pub struct Mp3Decoder<R>
+where
+    R: Read + Seek,
+{
+    // decoder: SeekDecoder<R>,
+    decoder: Decoder<R>,
+    current_frame: Frame,
+    current_frame_offset: usize,
+}
+
+impl<R> Mp3Decoder<R>
+where
+    R: Read + Seek,
+{
+    pub fn new(mut data: R) -> Result<Self, R> {
+        if !is_mp3(data.by_ref()) {
+            return Err(data);
+        }
+        // let mut decoder = SeekDecoder::new(data)
+        let mut decoder = Decoder::new(data);
+        // parameters are correct and minimp3 is used correctly
+        // thus if we crash here one of these invariants is broken:
+        // .expect("should be able to allocate memory, perform IO");
+        // let current_frame = decoder.decode_frame()
+        let current_frame = decoder.next_frame()
+            // the reader makes enough data available therefore 
+            // if we crash here the invariant broken is:
+            .expect("data should not corrupt");
+
+        Ok(Mp3Decoder {
+            decoder,
+            current_frame,
+            current_frame_offset: 0,
+        })
+    }
+    pub fn into_inner(self) -> R {
+        self.decoder.into_inner()
+    }
+}
+
+impl<R> Source for Mp3Decoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        Some(self.current_frame.data.len())
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.current_frame.channels as _
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.current_frame.sample_rate as _
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        // TODO waiting for PR in minimp3_fixed or minimp3
+
+        // let pos = (pos.as_secs_f32() * self.sample_rate() as f32) as u64;
+        // // do not trigger a sample_rate, channels and frame len update
+        // // as the seek only takes effect after the current frame is done
+        // self.decoder.seek_samples(pos)?;
+        // Ok(())
+
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+impl<R> Iterator for Mp3Decoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    fn next(&mut self) -> Option<i16> {
+        if self.current_frame_offset == self.current_frame_len().unwrap() {
+            if let Ok(frame) = self.decoder.next_frame() {
+                // if let Ok(frame) = self.decoder.decode_frame() {
+                self.current_frame = frame;
+                self.current_frame_offset = 0;
+            } else {
+                return None;
+            }
+        }
+
+        let v = self.current_frame.data[self.current_frame_offset];
+        self.current_frame_offset += 1;
+
+        Some(v)
+    }
+}
+
+/// Returns true if the stream contains mp3 data, then resets it to where it was.
+fn is_mp3<R>(mut data: R) -> bool
+where
+    R: Read + Seek,
+{
+    let stream_pos = data.seek(SeekFrom::Current(0)).unwrap();
+    let mut decoder = Decoder::new(data.by_ref());
+    let ok = decoder.next_frame().is_ok();
+    data.seek(SeekFrom::Start(stream_pos)).unwrap();
+
+    ok
+}

vendor/rodio/src/decoder/read_seek_source.rs

@@ -0,0 +1,37 @@
+use std::io::{Read, Result, Seek, SeekFrom};
+
+use symphonia::core::io::MediaSource;
+
+pub struct ReadSeekSource<T: Read + Seek + Send + Sync> {
+    inner: T,
+}
+
+impl<T: Read + Seek + Send + Sync> ReadSeekSource<T> {
+    /// Instantiates a new `ReadSeekSource<T>` by taking ownership and wrapping the provided
+    /// `Read + Seek`er.
+    pub fn new(inner: T) -> Self {
+        ReadSeekSource { inner }
+    }
+}
+
+impl<T: Read + Seek + Send + Sync> MediaSource for ReadSeekSource<T> {
+    fn is_seekable(&self) -> bool {
+        true
+    }
+
+    fn byte_len(&self) -> Option<u64> {
+        None
+    }
+}
+
+impl<T: Read + Seek + Send + Sync> Read for ReadSeekSource<T> {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
+        self.inner.read(buf)
+    }
+}
+
+impl<T: Read + Seek + Send + Sync> Seek for ReadSeekSource<T> {
+    fn seek(&mut self, pos: SeekFrom) -> Result<u64> {
+        self.inner.seek(pos)
+    }
+}

vendor/rodio/src/decoder/symphonia.rs

@@ -0,0 +1,333 @@
+use core::fmt;
+use core::time::Duration;
+use symphonia::{
+    core::{
+        audio::{AudioBufferRef, SampleBuffer, SignalSpec},
+        codecs::{Decoder, DecoderOptions, CODEC_TYPE_NULL},
+        errors::Error,
+        formats::{FormatOptions, FormatReader, SeekedTo},
+        io::MediaSourceStream,
+        meta::MetadataOptions,
+        probe::Hint,
+        units::{self, Time},
+    },
+    default::get_probe,
+};
+
+use crate::{source, Source};
+
+use super::DecoderError;
+
+// Decoder errors are not considered fatal.
+// The correct action is to just get a new packet and try again.
+// But a decode error in more than 3 consecutive packets is fatal.
+const MAX_DECODE_RETRIES: usize = 3;
+
+pub(crate) struct SymphoniaDecoder {
+    decoder: Box<dyn Decoder>,
+    current_frame_offset: usize,
+    format: Box<dyn FormatReader>,
+    total_duration: Option<Time>,
+    buffer: SampleBuffer<i16>,
+    spec: SignalSpec,
+}
+
+impl SymphoniaDecoder {
+    pub(crate) fn new(
+        mss: MediaSourceStream,
+        extension: Option<&str>,
+    ) -> Result<Self, DecoderError> {
+        match SymphoniaDecoder::init(mss, extension) {
+            Err(e) => match e {
+                Error::IoError(e) => Err(DecoderError::IoError(e.to_string())),
+                Error::DecodeError(e) => Err(DecoderError::DecodeError(e)),
+                Error::SeekError(_) => {
+                    unreachable!("Seek errors should not occur during initialization")
+                }
+                Error::Unsupported(_) => Err(DecoderError::UnrecognizedFormat),
+                Error::LimitError(e) => Err(DecoderError::LimitError(e)),
+                Error::ResetRequired => Err(DecoderError::ResetRequired),
+            },
+            Ok(Some(decoder)) => Ok(decoder),
+            Ok(None) => Err(DecoderError::NoStreams),
+        }
+    }
+
+    pub(crate) fn into_inner(self) -> MediaSourceStream {
+        self.format.into_inner()
+    }
+
+    fn init(
+        mss: MediaSourceStream,
+        extension: Option<&str>,
+    ) -> symphonia::core::errors::Result<Option<SymphoniaDecoder>> {
+        let mut hint = Hint::new();
+        if let Some(ext) = extension {
+            hint.with_extension(ext);
+        }
+        let format_opts: FormatOptions = FormatOptions {
+            enable_gapless: true,
+            ..Default::default()
+        };
+        let metadata_opts: MetadataOptions = Default::default();
+        let mut probed = get_probe().format(&hint, mss, &format_opts, &metadata_opts)?;
+
+        let stream = match probed.format.default_track() {
+            Some(stream) => stream,
+            None => return Ok(None),
+        };
+
+        // Select the first supported track
+        let track_id = probed
+            .format
+            .tracks()
+            .iter()
+            .find(|t| t.codec_params.codec != CODEC_TYPE_NULL)
+            .ok_or(symphonia::core::errors::Error::Unsupported(
+                "No track with supported codec",
+            ))?
+            .id;
+
+        let track = probed
+            .format
+            .tracks()
+            .iter()
+            .find(|track| track.id == track_id)
+            .unwrap();
+
+        let mut decoder = symphonia::default::get_codecs()
+            .make(&track.codec_params, &DecoderOptions::default())?;
+        let total_duration = stream
+            .codec_params
+            .time_base
+            .zip(stream.codec_params.n_frames)
+            .map(|(base, frames)| base.calc_time(frames));
+
+        let mut decode_errors: usize = 0;
+        let decoded = loop {
+            let current_frame = match probed.format.next_packet() {
+                Ok(packet) => packet,
+                Err(Error::IoError(_)) => break decoder.last_decoded(),
+                Err(e) => return Err(e),
+            };
+
+            // If the packet does not belong to the selected track, skip over it
+            if current_frame.track_id() != track_id {
+                continue;
+            }
+
+            match decoder.decode(&current_frame) {
+                Ok(decoded) => break decoded,
+                Err(e) => match e {
+                    Error::DecodeError(_) => {
+                        decode_errors += 1;
+                        if decode_errors > MAX_DECODE_RETRIES {
+                            return Err(e);
+                        } else {
+                            continue;
+                        }
+                    }
+                    _ => return Err(e),
+                },
+            }
+        };
+        let spec = decoded.spec().to_owned();
+        let buffer = SymphoniaDecoder::get_buffer(decoded, &spec);
+        Ok(Some(SymphoniaDecoder {
+            decoder,
+            current_frame_offset: 0,
+            format: probed.format,
+            total_duration,
+            buffer,
+            spec,
+        }))
+    }
+
+    #[inline]
+    fn get_buffer(decoded: AudioBufferRef, spec: &SignalSpec) -> SampleBuffer<i16> {
+        let duration = units::Duration::from(decoded.capacity() as u64);
+        let mut buffer = SampleBuffer::<i16>::new(duration, *spec);
+        buffer.copy_interleaved_ref(decoded);
+        buffer
+    }
+}
+
+impl Source for SymphoniaDecoder {
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        Some(self.buffer.samples().len())
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.spec.channels.count() as u16
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.spec.rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.total_duration
+            .map(|Time { seconds, frac }| Duration::new(seconds, (1f64 / frac) as u32))
+    }
+
+    fn try_seek(&mut self, pos: Duration) -> Result<(), source::SeekError> {
+        use symphonia::core::formats::{SeekMode, SeekTo};
+
+        let seek_beyond_end = self
+            .total_duration()
+            .is_some_and(|dur| dur.saturating_sub(pos).as_millis() < 1);
+
+        let time = if seek_beyond_end {
+            let time = self.total_duration.expect("if guarantees this is Some");
+            skip_back_a_tiny_bit(time) // some decoders can only seek to just before the end
+        } else {
+            pos.as_secs_f64().into()
+        };
+
+        // make sure the next sample is for the right channel
+        let to_skip = self.current_frame_offset % self.channels() as usize;
+
+        let seek_res = self
+            .format
+            .seek(
+                SeekMode::Accurate,
+                SeekTo::Time {
+                    time,
+                    track_id: None,
+                },
+            )
+            .map_err(SeekError::BaseSeek)?;
+
+        self.refine_position(seek_res)?;
+        self.current_frame_offset += to_skip;
+
+        Ok(())
+    }
+}
+
+/// Error returned when the try_seek implementation of the symphonia decoder fails.
+#[derive(Debug)]
+pub enum SeekError {
+    /// Could not get next packet while refining seek position
+    Refining(symphonia::core::errors::Error),
+    /// Format reader failed to seek
+    BaseSeek(symphonia::core::errors::Error),
+    /// Decoding failed retrying on the next packet failed
+    Retrying(symphonia::core::errors::Error),
+    /// Decoding failed on multiple consecutive packets
+    Decoding(symphonia::core::errors::Error),
+}
+impl fmt::Display for SeekError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            SeekError::Refining(err) => {
+                write!(
+                    f,
+                    "Could not get next packet while refining seek position: {:?}",
+                    err
+                )
+            }
+            SeekError::BaseSeek(err) => {
+                write!(f, "Format reader failed to seek: {:?}", err)
+            }
+            SeekError::Retrying(err) => {
+                write!(
+                    f,
+                    "Decoding failed retrying on the next packet failed: {:?}",
+                    err
+                )
+            }
+            SeekError::Decoding(err) => {
+                write!(
+                    f,
+                    "Decoding failed on multiple consecutive packets: {:?}",
+                    err
+                )
+            }
+        }
+    }
+}
+impl std::error::Error for SeekError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            SeekError::Refining(err) => Some(err),
+            SeekError::BaseSeek(err) => Some(err),
+            SeekError::Retrying(err) => Some(err),
+            SeekError::Decoding(err) => Some(err),
+        }
+    }
+}
+
+impl SymphoniaDecoder {
+    /// Note frame offset must be set after
+    fn refine_position(&mut self, seek_res: SeekedTo) -> Result<(), source::SeekError> {
+        let mut samples_to_pass = seek_res.required_ts - seek_res.actual_ts;
+        let packet = loop {
+            let candidate = self.format.next_packet().map_err(SeekError::Refining)?;
+            if candidate.dur() > samples_to_pass {
+                break candidate;
+            } else {
+                samples_to_pass -= candidate.dur();
+            }
+        };
+
+        let mut decoded = self.decoder.decode(&packet);
+        for _ in 0..MAX_DECODE_RETRIES {
+            if decoded.is_err() {
+                let packet = self.format.next_packet().map_err(SeekError::Retrying)?;
+                decoded = self.decoder.decode(&packet);
+            }
+        }
+
+        let decoded = decoded.map_err(SeekError::Decoding)?;
+        decoded.spec().clone_into(&mut self.spec);
+        self.buffer = SymphoniaDecoder::get_buffer(decoded, &self.spec);
+        self.current_frame_offset = samples_to_pass as usize * self.channels() as usize;
+        Ok(())
+    }
+}
+
+fn skip_back_a_tiny_bit(
+    Time {
+        mut seconds,
+        mut frac,
+    }: Time,
+) -> Time {
+    frac -= 0.0001;
+    if frac < 0.0 {
+        seconds = seconds.saturating_sub(1);
+        frac = 1.0 - frac;
+    }
+    Time { seconds, frac }
+}
+
+impl Iterator for SymphoniaDecoder {
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        if self.current_frame_offset >= self.buffer.len() {
+            let packet = self.format.next_packet().ok()?;
+            let mut decoded = self.decoder.decode(&packet);
+            for _ in 0..MAX_DECODE_RETRIES {
+                if decoded.is_err() {
+                    let packet = self.format.next_packet().ok()?;
+                    decoded = self.decoder.decode(&packet);
+                }
+            }
+            let decoded = decoded.ok()?;
+            decoded.spec().clone_into(&mut self.spec);
+            self.buffer = SymphoniaDecoder::get_buffer(decoded, &self.spec);
+            self.current_frame_offset = 0;
+        }
+
+        let sample = *self.buffer.samples().get(self.current_frame_offset)?;
+        self.current_frame_offset += 1;
+
+        Some(sample)
+    }
+}

vendor/rodio/src/decoder/vorbis.rs

@@ -0,0 +1,144 @@
+use std::io::{Read, Seek, SeekFrom};
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::Source;
+
+use lewton::inside_ogg::OggStreamReader;
+
+/// Decoder for an OGG file that contains Vorbis sound format.
+pub struct VorbisDecoder<R>
+where
+    R: Read + Seek,
+{
+    stream_reader: OggStreamReader<R>,
+    current_data: Vec<i16>,
+    next: usize,
+}
+
+impl<R> VorbisDecoder<R>
+where
+    R: Read + Seek,
+{
+    /// Attempts to decode the data as ogg/vorbis.
+    pub fn new(mut data: R) -> Result<VorbisDecoder<R>, R> {
+        if !is_vorbis(data.by_ref()) {
+            return Err(data);
+        }
+
+        let stream_reader = OggStreamReader::new(data).unwrap();
+        Ok(Self::from_stream_reader(stream_reader))
+    }
+    pub fn from_stream_reader(mut stream_reader: OggStreamReader<R>) -> Self {
+        let mut data = match stream_reader.read_dec_packet_itl() {
+            Ok(Some(d)) => d,
+            _ => Vec::new(),
+        };
+
+        // The first packet is always empty, therefore
+        // we need to read the second frame to get some data
+        if let Ok(Some(mut d)) = stream_reader.read_dec_packet_itl() {
+            data.append(&mut d);
+        }
+
+        VorbisDecoder {
+            stream_reader,
+            current_data: data,
+            next: 0,
+        }
+    }
+    pub fn into_inner(self) -> OggStreamReader<R> {
+        self.stream_reader
+    }
+}
+
+impl<R> Source for VorbisDecoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        Some(self.current_data.len())
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.stream_reader.ident_hdr.audio_channels as u16
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.stream_reader.ident_hdr.audio_sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    /// seek is broken, https://github.com/RustAudio/lewton/issues/73.
+    // We could work around it by:
+    //  - using unsafe to create an instance of Self
+    //  - use mem::swap to turn the &mut self into a mut self
+    //  - take out the underlying Read+Seek
+    //  - make a new self and seek
+    //
+    // If this issue is fixed use the implementation in
+    // commit: 3bafe32388b4eb7a48c6701e6c65044dc8c555e6
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+impl<R> Iterator for VorbisDecoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        if let Some(sample) = self.current_data.get(self.next).copied() {
+            self.next += 1;
+            if self.current_data.is_empty() {
+                if let Ok(Some(data)) = self.stream_reader.read_dec_packet_itl() {
+                    self.current_data = data;
+                    self.next = 0;
+                }
+            }
+            Some(sample)
+        } else {
+            if let Ok(Some(data)) = self.stream_reader.read_dec_packet_itl() {
+                self.current_data = data;
+                self.next = 0;
+            }
+            let sample = self.current_data.get(self.next).copied();
+            self.next += 1;
+            sample
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.current_data.len(), None)
+    }
+}
+
+/// Returns true if the stream contains Vorbis data, then resets it to where it was.
+fn is_vorbis<R>(mut data: R) -> bool
+where
+    R: Read + Seek,
+{
+    let stream_pos = data.stream_position().unwrap();
+
+    if OggStreamReader::new(data.by_ref()).is_err() {
+        data.seek(SeekFrom::Start(stream_pos)).unwrap();
+        return false;
+    }
+
+    data.seek(SeekFrom::Start(stream_pos)).unwrap();
+    true
+}

vendor/rodio/src/decoder/wav.rs

@@ -0,0 +1,221 @@
+use std::io::{Read, Seek, SeekFrom};
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::Source;
+
+use hound::{SampleFormat, WavReader};
+
+/// Decoder for the WAV format.
+pub struct WavDecoder<R>
+where
+    R: Read + Seek,
+{
+    reader: SamplesIterator<R>,
+    total_duration: Duration,
+    sample_rate: u32,
+    channels: u16,
+}
+
+impl<R> WavDecoder<R>
+where
+    R: Read + Seek,
+{
+    /// Attempts to decode the data as WAV.
+    pub fn new(mut data: R) -> Result<WavDecoder<R>, R> {
+        if !is_wave(data.by_ref()) {
+            return Err(data);
+        }
+
+        let reader = WavReader::new(data).unwrap();
+        let spec = reader.spec();
+        let len = reader.len() as u64;
+        let reader = SamplesIterator {
+            reader,
+            samples_read: 0,
+        };
+
+        let sample_rate = spec.sample_rate;
+        let channels = spec.channels;
+        let total_duration =
+            Duration::from_micros((1_000_000 * len) / (sample_rate as u64 * channels as u64));
+
+        Ok(WavDecoder {
+            reader,
+            total_duration,
+            sample_rate,
+            channels,
+        })
+    }
+    pub fn into_inner(self) -> R {
+        self.reader.reader.into_inner()
+    }
+}
+
+struct SamplesIterator<R>
+where
+    R: Read + Seek,
+{
+    reader: WavReader<R>,
+    samples_read: u32, // wav header is u32 so this suffices
+}
+
+impl<R> Iterator for SamplesIterator<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        let spec = self.reader.spec();
+        match (spec.sample_format, spec.bits_per_sample) {
+            (SampleFormat::Float, 32) => self.reader.samples().next().map(|value| {
+                self.samples_read += 1;
+                f32_to_i16(value.unwrap_or(0.0))
+            }),
+            (SampleFormat::Int, 8) => self.reader.samples().next().map(|value| {
+                self.samples_read += 1;
+                i8_to_i16(value.unwrap_or(0))
+            }),
+            (SampleFormat::Int, 16) => self.reader.samples().next().map(|value| {
+                self.samples_read += 1;
+                value.unwrap_or(0)
+            }),
+            (SampleFormat::Int, 24) => self.reader.samples().next().map(|value| {
+                self.samples_read += 1;
+                i24_to_i16(value.unwrap_or(0))
+            }),
+            (SampleFormat::Int, 32) => self.reader.samples().next().map(|value| {
+                self.samples_read += 1;
+                i32_to_i16(value.unwrap_or(0))
+            }),
+            (sample_format, bits_per_sample) => {
+                panic!("Unimplemented wav spec: {sample_format:?}, {bits_per_sample}")
+            }
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = (self.reader.len() - self.samples_read) as usize;
+        (len, Some(len))
+    }
+}
+
+impl<R> ExactSizeIterator for SamplesIterator<R> where R: Read + Seek {}
+
+impl<R> Source for WavDecoder<R>
+where
+    R: Read + Seek,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        Some(self.total_duration)
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        let file_len = self.reader.reader.duration();
+
+        let new_pos = pos.as_secs_f32() * self.sample_rate() as f32;
+        let new_pos = new_pos as u32;
+        let new_pos = new_pos.min(file_len); // saturate pos at the end of the source
+
+        // make sure the next sample is for the right channel
+        let to_skip = self.reader.samples_read % self.channels() as u32;
+
+        self.reader
+            .reader
+            .seek(new_pos)
+            .map_err(SeekError::HoundDecoder)?;
+        self.reader.samples_read = new_pos * self.channels() as u32;
+
+        for _ in 0..to_skip {
+            self.next();
+        }
+
+        Ok(())
+    }
+}
+
+impl<R> Iterator for WavDecoder<R>
+where
+    R: Read + Seek,
+{
+    type Item = i16;
+
+    #[inline]
+    fn next(&mut self) -> Option<i16> {
+        self.reader.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.reader.size_hint()
+    }
+}
+
+impl<R> ExactSizeIterator for WavDecoder<R> where R: Read + Seek {}
+
+/// Returns true if the stream contains WAV data, then resets it to where it was.
+fn is_wave<R>(mut data: R) -> bool
+where
+    R: Read + Seek,
+{
+    let stream_pos = data.stream_position().unwrap();
+
+    if WavReader::new(data.by_ref()).is_err() {
+        data.seek(SeekFrom::Start(stream_pos)).unwrap();
+        return false;
+    }
+
+    data.seek(SeekFrom::Start(stream_pos)).unwrap();
+    true
+}
+
+/// Returns a 32 bit WAV float as an i16. WAV floats are typically in the range of
+/// [-1.0, 1.0] while i16s are in the range [-32768, 32767]. Note that this
+/// function definitely causes precision loss but hopefully this isn't too
+/// audiable when actually playing?
+fn f32_to_i16(f: f32) -> i16 {
+    // prefer to clip the input rather than be excessively loud.
+    (f.clamp(-1.0, 1.0) * i16::MAX as f32) as i16
+}
+
+/// Returns an 8-bit WAV int as an i16. This scales the sample value by a factor
+/// of 256.
+fn i8_to_i16(i: i8) -> i16 {
+    i as i16 * 256
+}
+
+/// Returns a 24 bit WAV int as an i16. Note that this is a 24 bit integer, not a
+/// 32 bit one. 24 bit ints are in the range [−8,388,608, 8,388,607] while i16s
+/// are in the range [-32768, 32767]. Note that this function definitely causes
+/// precision loss but hopefully this isn't too audiable when actually playing?
+fn i24_to_i16(i: i32) -> i16 {
+    (i >> 8) as i16
+}
+
+/// Returns a 32 bit WAV int as an i16. 32 bit ints are in the range
+/// [-2,147,483,648, 2,147,483,647] while i16s are in the range [-32768, 32767].
+/// Note that this function definitely causes precision loss but hopefully this
+/// isn't too audiable when actually playing?
+fn i32_to_i16(i: i32) -> i16 {
+    (i >> 16) as i16
+}

vendor/rodio/src/dynamic_mixer.rs

@@ -0,0 +1,303 @@
+//! Mixer that plays multiple sounds at the same time.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use crate::source::{SeekError, Source, UniformSourceIterator};
+use crate::Sample;
+
+/// Builds a new mixer.
+///
+/// You can choose the characteristics of the output thanks to this constructor. All the sounds
+/// added to the mixer will be converted to these values.
+///
+/// After creating a mixer, you can add new sounds with the controller.
+pub fn mixer<S>(
+    channels: u16,
+    sample_rate: u32,
+) -> (Arc<DynamicMixerController<S>>, DynamicMixer<S>)
+where
+    S: Sample + Send + 'static,
+{
+    let input = Arc::new(DynamicMixerController {
+        has_pending: AtomicBool::new(false),
+        pending_sources: Mutex::new(Vec::new()),
+        channels,
+        sample_rate,
+    });
+
+    let output = DynamicMixer {
+        current_sources: Vec::with_capacity(16),
+        input: input.clone(),
+        sample_count: 0,
+        still_pending: vec![],
+        still_current: vec![],
+    };
+
+    (input, output)
+}
+
+/// The input of the mixer.
+pub struct DynamicMixerController<S> {
+    has_pending: AtomicBool,
+    pending_sources: Mutex<Vec<Box<dyn Source<Item = S> + Send>>>,
+    channels: u16,
+    sample_rate: u32,
+}
+
+impl<S> DynamicMixerController<S>
+where
+    S: Sample + Send + 'static,
+{
+    /// Adds a new source to mix to the existing ones.
+    #[inline]
+    pub fn add<T>(&self, source: T)
+    where
+        T: Source<Item = S> + Send + 'static,
+    {
+        let uniform_source = UniformSourceIterator::new(source, self.channels, self.sample_rate);
+        self.pending_sources
+            .lock()
+            .unwrap()
+            .push(Box::new(uniform_source) as Box<_>);
+        self.has_pending.store(true, Ordering::SeqCst); // TODO: can we relax this ordering?
+    }
+}
+
+/// The output of the mixer. Implements `Source`.
+pub struct DynamicMixer<S> {
+    // The current iterator that produces samples.
+    current_sources: Vec<Box<dyn Source<Item = S> + Send>>,
+
+    // The pending sounds.
+    input: Arc<DynamicMixerController<S>>,
+
+    // The number of samples produced so far.
+    sample_count: usize,
+
+    // A temporary vec used in start_pending_sources.
+    still_pending: Vec<Box<dyn Source<Item = S> + Send>>,
+
+    // A temporary vec used in sum_current_sources.
+    still_current: Vec<Box<dyn Source<Item = S> + Send>>,
+}
+
+impl<S> Source for DynamicMixer<S>
+where
+    S: Sample + Send + 'static,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+
+        // uncomment when #510 is implemented (query position of playback)
+
+        // let mut org_positions = Vec::with_capacity(self.current_sources.len());
+        // let mut encounterd_err = None;
+        //
+        // for source in &mut self.current_sources {
+        //     let pos = /* source.playback_pos() */ todo!();
+        //     if let Err(e) = source.try_seek(pos) {
+        //         encounterd_err = Some(e);
+        //         break;
+        //     } else {
+        //         // store pos in case we need to roll back
+        //         org_positions.push(pos);
+        //     }
+        // }
+        //
+        // if let Some(e) = encounterd_err {
+        //     // rollback seeks that happend before err
+        //     for (pos, source) in org_positions
+        //         .into_iter()
+        //         .zip(self.current_sources.iter_mut())
+        //     {
+        //         source.try_seek(pos)?;
+        //     }
+        //     Err(e)
+        // } else {
+        //     Ok(())
+        // }
+    }
+}
+
+impl<S> Iterator for DynamicMixer<S>
+where
+    S: Sample + Send + 'static,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        if self.input.has_pending.load(Ordering::SeqCst) {
+            self.start_pending_sources();
+        }
+
+        self.sample_count += 1;
+
+        let sum = self.sum_current_sources();
+
+        if self.current_sources.is_empty() {
+            None
+        } else {
+            Some(sum)
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
+
+impl<S> DynamicMixer<S>
+where
+    S: Sample + Send + 'static,
+{
+    // Samples from the #next() function are interlaced for each of the channels.
+    // We need to ensure we start playing sources so that their samples are
+    // in-step with the modulo of the samples produced so far. Otherwise, the
+    // sound will play on the wrong channels, e.g. left / right will be reversed.
+    fn start_pending_sources(&mut self) {
+        let mut pending = self.input.pending_sources.lock().unwrap(); // TODO: relax ordering?
+
+        for source in pending.drain(..) {
+            let in_step = self.sample_count % source.channels() as usize == 0;
+
+            if in_step {
+                self.current_sources.push(source);
+            } else {
+                self.still_pending.push(source);
+            }
+        }
+        std::mem::swap(&mut self.still_pending, &mut pending);
+
+        let has_pending = !pending.is_empty();
+        self.input.has_pending.store(has_pending, Ordering::SeqCst); // TODO: relax ordering?
+    }
+
+    fn sum_current_sources(&mut self) -> S {
+        let mut sum = S::zero_value();
+
+        for mut source in self.current_sources.drain(..) {
+            if let Some(value) = source.next() {
+                sum = sum.saturating_add(value);
+                self.still_current.push(source);
+            }
+        }
+        std::mem::swap(&mut self.still_current, &mut self.current_sources);
+
+        sum
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::buffer::SamplesBuffer;
+    use crate::dynamic_mixer;
+    use crate::source::Source;
+
+    #[test]
+    fn basic() {
+        let (tx, mut rx) = dynamic_mixer::mixer(1, 48000);
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+        tx.add(SamplesBuffer::new(1, 48000, vec![5i16, 5, 5, 5]));
+
+        assert_eq!(rx.channels(), 1);
+        assert_eq!(rx.sample_rate(), 48000);
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), None);
+    }
+
+    #[test]
+    fn channels_conv() {
+        let (tx, mut rx) = dynamic_mixer::mixer(2, 48000);
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+        tx.add(SamplesBuffer::new(1, 48000, vec![5i16, 5, 5, 5]));
+
+        assert_eq!(rx.channels(), 2);
+        assert_eq!(rx.sample_rate(), 48000);
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), None);
+    }
+
+    #[test]
+    fn rate_conv() {
+        let (tx, mut rx) = dynamic_mixer::mixer(1, 96000);
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+        tx.add(SamplesBuffer::new(1, 48000, vec![5i16, 5, 5, 5]));
+
+        assert_eq!(rx.channels(), 1);
+        assert_eq!(rx.sample_rate(), 96000);
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(-5));
+        assert_eq!(rx.next(), None);
+    }
+
+    #[test]
+    fn start_afterwards() {
+        let (tx, mut rx) = dynamic_mixer::mixer(1, 48000);
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![5i16, 5, 6, 6, 7, 7, 7]));
+
+        assert_eq!(rx.next(), Some(15));
+        assert_eq!(rx.next(), Some(-5));
+
+        assert_eq!(rx.next(), Some(6));
+        assert_eq!(rx.next(), Some(6));
+
+        tx.add(SamplesBuffer::new(1, 48000, vec![2i16]));
+
+        assert_eq!(rx.next(), Some(9));
+        assert_eq!(rx.next(), Some(7));
+        assert_eq!(rx.next(), Some(7));
+
+        assert_eq!(rx.next(), None);
+    }
+}

vendor/rodio/src/lib.rs

@@ -0,0 +1,152 @@
+//! Audio playback library.
+//!
+//! The main concept of this library is the [`Source`] trait, which
+//! represents a sound (streaming or not). In order to play a sound, there are three steps:
+//!
+//! - Create an object that represents the streaming sound. It can be a sine wave, a buffer, a
+//!   [`decoder`], etc. or even your own type that implements the [`Source`] trait.
+//! - Get an output stream handle to a physical device. For example, get a stream to the system's
+//!   default sound device with [`OutputStream::try_default()`]
+//! - Call [`.play_raw(source)`](OutputStreamHandle::play_raw) on the output stream handle.
+//!
+//! The [`play_raw`](OutputStreamHandle::play_raw) function expects the source to produce [`f32`]s,
+//! which may not be the case. If you get a compilation error, try calling
+//! [`.convert_samples()`](Source::convert_samples) on the source to fix it.
+//!
+//! For example, here is how you would play an audio file:
+//!
+//! ```no_run
+//! use std::fs::File;
+//! use std::io::BufReader;
+//! use rodio::{Decoder, OutputStream, source::Source};
+//!
+//! // Get an output stream handle to the default physical sound device.
+//! // Note that no sound will be played if _stream is dropped
+//! let (_stream, stream_handle) = OutputStream::try_default().unwrap();
+//! // Load a sound from a file, using a path relative to Cargo.toml
+//! let file = BufReader::new(File::open("examples/music.ogg").unwrap());
+//! // Decode that sound file into a source
+//! let source = Decoder::new(file).unwrap();
+//! // Play the sound directly on the device
+//! stream_handle.play_raw(source.convert_samples());
+//!
+//! // The sound plays in a separate audio thread,
+//! // so we need to keep the main thread alive while it's playing.
+//! std::thread::sleep(std::time::Duration::from_secs(5));
+//! ```
+//!
+//! ## Sink
+//!
+//! In order to make it easier to control the playback, the rodio library also provides a type
+//! named [`Sink`] which represents an audio track.
+//!
+//! Instead of playing the sound with [`play_raw`](OutputStreamHandle::play_raw), you can add it to
+//! a [`Sink`] instead.
+//!
+//! - Get a [`Sink`] to the output stream, and [`.append()`](Sink::append) your sound to it.
+//!
+//! ```no_run
+//! use std::fs::File;
+//! use std::io::BufReader;
+//! use std::time::Duration;
+//! use rodio::{Decoder, OutputStream, Sink};
+//! use rodio::source::{SineWave, Source};
+//!
+//! // _stream must live as long as the sink
+//! let (_stream, stream_handle) = OutputStream::try_default().unwrap();
+//! let sink = Sink::try_new(&stream_handle).unwrap();
+//!
+//! // Add a dummy source of the sake of the example.
+//! let source = SineWave::new(440.0).take_duration(Duration::from_secs_f32(0.25)).amplify(0.20);
+//! sink.append(source);
+//!
+//! // The sound plays in a separate thread. This call will block the current thread until the sink
+//! // has finished playing all its queued sounds.
+//! sink.sleep_until_end();
+//! ```
+//!
+//! The [`append`](Sink::append) method will add the sound at the end of the
+//! sink. It will be played when all the previous sounds have been played. If you want multiple
+//! sounds to play simultaneously, you should create multiple [`Sink`]s.
+//!
+//! The [`Sink`] type also provides utilities such as playing/pausing or controlling the volume.
+//!
+//! **Please note that the [`Sink`] requires the [`OutputStream`], make sure that the OutputStream is not dropped before the sink.**
+//!
+//! ## Filters
+//!
+//! The [`Source`] trait provides various filters, similar to the standard [`Iterator`] trait.
+//!
+//! Example:
+//!
+//! ```
+//! use rodio::Source;
+//! use std::time::Duration;
+//!
+//! // Repeats the first five seconds of the sound forever.
+//! # let source = rodio::source::SineWave::new(440.0);
+//! let source = source.take_duration(Duration::from_secs(5)).repeat_infinite();
+//! ```
+//!
+//! ## Alternative Decoder Backends
+//!
+//! [Symphonia](https://github.com/pdeljanov/Symphonia) is an alternative decoder library that can be used in place
+//! of many of the default backends.
+//! Currently, the main benefit is that Symphonia is the only backend that supports M4A and AAC,
+//! but it may be used to implement additional optional functionality in the future.
+//!
+//! To use, enable either the `symphonia-all` feature to enable all Symphonia codecs
+//! or enable specific codecs using one of the `symphonia-{codec name}` features.
+//! If you enable one or more of the Symphonia codecs, you may want to set `default-features = false` in order
+//! to avoid adding extra crates to your binary.
+//! See the [available feature flags](https://docs.rs/crate/rodio/latest/features) for all options.
+//!
+//! ## Optional Features
+//!
+//! Rodio provides several optional features that are guarded with feature gates.
+//!
+//! ### Feature "tracing"
+//!
+//! The "tracing" feature replaces the print to stderr when a stream error happens with a
+//! recording an error event with tracing.
+//!
+//! ### Feature "Noise"
+//!
+//! The "noise" feature adds support for white and pink noise sources. This feature requires the
+//! "rand" crate.
+//!
+//! ## How it works under the hood
+//!
+//! Rodio spawns a background thread that is dedicated to reading from the sources and sending
+//! the output to the device. Whenever you give up ownership of a [`Source`] in order to play it,
+//! it is sent to this background thread where it will be read by rodio.
+//!
+//! All the sounds are mixed together by rodio before being sent to the operating system or the
+//! hardware. Therefore there is no restriction on the number of sounds that play simultaneously or
+//! the number of sinks that can be created (except for the fact that creating too many will slow
+//! down your program).
+
+#![cfg_attr(test, deny(missing_docs))]
+pub use cpal::{
+    self, traits::DeviceTrait, Device, Devices, DevicesError, InputDevices, OutputDevices,
+    SupportedStreamConfig,
+};
+
+mod conversions;
+mod sink;
+mod spatial_sink;
+mod stream;
+
+pub mod buffer;
+pub mod decoder;
+pub mod dynamic_mixer;
+pub mod queue;
+pub mod source;
+pub mod static_buffer;
+
+pub use crate::conversions::Sample;
+pub use crate::decoder::Decoder;
+pub use crate::sink::Sink;
+pub use crate::source::Source;
+pub use crate::spatial_sink::SpatialSink;
+pub use crate::stream::{OutputStream, OutputStreamHandle, PlayError, StreamError};

vendor/rodio/src/queue.rs

@@ -0,0 +1,319 @@
+//! Queue that plays sounds one after the other.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use crate::source::{Empty, SeekError, Source, Zero};
+use crate::Sample;
+
+#[cfg(feature = "crossbeam-channel")]
+use crossbeam_channel::{unbounded as channel, Receiver, Sender};
+#[cfg(not(feature = "crossbeam-channel"))]
+use std::sync::mpsc::{channel, Receiver, Sender};
+
+/// Builds a new queue. It consists of an input and an output.
+///
+/// The input can be used to add sounds to the end of the queue, while the output implements
+/// `Source` and plays the sounds.
+///
+/// The parameter indicates how the queue should behave if the queue becomes empty:
+///
+/// - If you pass `true`, then the queue is infinite and will play a silence instead until you add
+///   a new sound.
+/// - If you pass `false`, then the queue will report that it has finished playing.
+///
+pub fn queue<S>(keep_alive_if_empty: bool) -> (Arc<SourcesQueueInput<S>>, SourcesQueueOutput<S>)
+where
+    S: Sample + Send + 'static,
+{
+    let input = Arc::new(SourcesQueueInput {
+        next_sounds: Mutex::new(Vec::new()),
+        keep_alive_if_empty: AtomicBool::new(keep_alive_if_empty),
+    });
+
+    let output = SourcesQueueOutput {
+        current: Box::new(Empty::<S>::new()) as Box<_>,
+        signal_after_end: None,
+        input: input.clone(),
+    };
+
+    (input, output)
+}
+
+// TODO: consider reimplementing this with `from_factory`
+
+type Sound<S> = Box<dyn Source<Item = S> + Send>;
+type SignalDone = Option<Sender<()>>;
+
+/// The input of the queue.
+pub struct SourcesQueueInput<S> {
+    next_sounds: Mutex<Vec<(Sound<S>, SignalDone)>>,
+
+    // See constructor.
+    keep_alive_if_empty: AtomicBool,
+}
+
+impl<S> SourcesQueueInput<S>
+where
+    S: Sample + Send + 'static,
+{
+    /// Adds a new source to the end of the queue.
+    #[inline]
+    pub fn append<T>(&self, source: T)
+    where
+        T: Source<Item = S> + Send + 'static,
+    {
+        self.next_sounds
+            .lock()
+            .unwrap()
+            .push((Box::new(source) as Box<_>, None));
+    }
+
+    /// Adds a new source to the end of the queue.
+    ///
+    /// The `Receiver` will be signalled when the sound has finished playing.
+    ///
+    /// Enable the feature flag `crossbeam-channel` in rodio to use a `crossbeam_channel::Receiver` instead.
+    #[inline]
+    pub fn append_with_signal<T>(&self, source: T) -> Receiver<()>
+    where
+        T: Source<Item = S> + Send + 'static,
+    {
+        let (tx, rx) = channel();
+        self.next_sounds
+            .lock()
+            .unwrap()
+            .push((Box::new(source) as Box<_>, Some(tx)));
+        rx
+    }
+
+    /// Sets whether the queue stays alive if there's no more sound to play.
+    ///
+    /// See also the constructor.
+    pub fn set_keep_alive_if_empty(&self, keep_alive_if_empty: bool) {
+        self.keep_alive_if_empty
+            .store(keep_alive_if_empty, Ordering::Release);
+    }
+
+    /// Removes all the sounds from the queue. Returns the number of sounds cleared.
+    pub fn clear(&self) -> usize {
+        let mut sounds = self.next_sounds.lock().unwrap();
+        let len = sounds.len();
+        sounds.clear();
+        len
+    }
+}
+/// The output of the queue. Implements `Source`.
+pub struct SourcesQueueOutput<S> {
+    // The current iterator that produces samples.
+    current: Box<dyn Source<Item = S> + Send>,
+
+    // Signal this sender before picking from `next`.
+    signal_after_end: Option<Sender<()>>,
+
+    // The next sounds.
+    input: Arc<SourcesQueueInput<S>>,
+}
+
+const THRESHOLD: usize = 512;
+impl<S> Source for SourcesQueueOutput<S>
+where
+    S: Sample + Send + 'static,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        // This function is non-trivial because the boundary between two sounds in the queue should
+        // be a frame boundary as well.
+        //
+        // The current sound is free to return `None` for `current_frame_len()`, in which case
+        // we *should* return the number of samples remaining the current sound.
+        // This can be estimated with `size_hint()`.
+        //
+        // If the `size_hint` is `None` as well, we are in the worst case scenario. To handle this
+        // situation we force a frame to have a maximum number of samples indicate by this
+        // constant.
+
+        // Try the current `current_frame_len`.
+        if let Some(val) = self.current.current_frame_len() {
+            if val != 0 {
+                return Some(val);
+            } else if self.input.keep_alive_if_empty.load(Ordering::Acquire)
+                && self.input.next_sounds.lock().unwrap().is_empty()
+            {
+                // The next source will be a filler silence which will have the length of `THRESHOLD`
+                return Some(THRESHOLD);
+            }
+        }
+
+        // Try the size hint.
+        let (lower_bound, _) = self.current.size_hint();
+        // The iterator default implementation just returns 0.
+        // That's a problematic value, so skip it.
+        if lower_bound > 0 {
+            return Some(lower_bound);
+        }
+
+        // Otherwise we use the constant value.
+        Some(THRESHOLD)
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.current.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.current.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    /// Only seeks within the current source.
+    // We can not go back to previous sources. We could implement seek such
+    // that it advances the queue if the position is beyond the current song.
+    //
+    // We would then however need to enable seeking backwards across sources too.
+    // That no longer seems in line with the queue behaviour.
+    //
+    // A final pain point is that we would need the total duration for the
+    // next few songs.
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.current.try_seek(pos)
+    }
+}
+
+impl<S> Iterator for SourcesQueueOutput<S>
+where
+    S: Sample + Send + 'static,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        loop {
+            // Basic situation that will happen most of the time.
+            if let Some(sample) = self.current.next() {
+                return Some(sample);
+            }
+
+            // Since `self.current` has finished, we need to pick the next sound.
+            // In order to avoid inlining this expensive operation, the code is in another function.
+            if self.go_next().is_err() {
+                return None;
+            }
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.current.size_hint().0, None)
+    }
+}
+
+impl<S> SourcesQueueOutput<S>
+where
+    S: Sample + Send + 'static,
+{
+    // Called when `current` is empty and we must jump to the next element.
+    // Returns `Ok` if the sound should continue playing, or an error if it should stop.
+    //
+    // This method is separate so that it is not inlined.
+    fn go_next(&mut self) -> Result<(), ()> {
+        if let Some(signal_after_end) = self.signal_after_end.take() {
+            let _ = signal_after_end.send(());
+        }
+
+        let (next, signal_after_end) = {
+            let mut next = self.input.next_sounds.lock().unwrap();
+
+            if next.len() == 0 {
+                let silence = Box::new(Zero::<S>::new_samples(1, 44100, THRESHOLD)) as Box<_>;
+                if self.input.keep_alive_if_empty.load(Ordering::Acquire) {
+                    // Play a short silence in order to avoid spinlocking.
+                    (silence, None)
+                } else {
+                    return Err(());
+                }
+            } else {
+                next.remove(0)
+            }
+        };
+
+        self.current = next;
+        self.signal_after_end = signal_after_end;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::buffer::SamplesBuffer;
+    use crate::queue;
+    use crate::source::Source;
+
+    #[test]
+    #[ignore] // FIXME: samples rate and channel not updated immediately after transition
+    fn basic() {
+        let (tx, mut rx) = queue::queue(false);
+
+        tx.append(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+        tx.append(SamplesBuffer::new(2, 96000, vec![5i16, 5, 5, 5]));
+
+        assert_eq!(rx.channels(), 1);
+        assert_eq!(rx.sample_rate(), 48000);
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        assert_eq!(rx.channels(), 2);
+        assert_eq!(rx.sample_rate(), 96000);
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), None);
+    }
+
+    #[test]
+    fn immediate_end() {
+        let (_, mut rx) = queue::queue::<i16>(false);
+        assert_eq!(rx.next(), None);
+    }
+
+    #[test]
+    fn keep_alive() {
+        let (tx, mut rx) = queue::queue(true);
+        tx.append(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+
+        for _ in 0..100000 {
+            assert_eq!(rx.next(), Some(0));
+        }
+    }
+
+    #[test]
+    #[ignore] // TODO: not yet implemented
+    fn no_delay_when_added() {
+        let (tx, mut rx) = queue::queue(true);
+
+        for _ in 0..500 {
+            assert_eq!(rx.next(), Some(0));
+        }
+
+        tx.append(SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10]));
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+    }
+}

vendor/rodio/src/sink.rs

@@ -0,0 +1,449 @@
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+#[cfg(feature = "crossbeam-channel")]
+use crossbeam_channel::{Receiver, Sender};
+#[cfg(not(feature = "crossbeam-channel"))]
+use std::sync::mpsc::{Receiver, Sender};
+
+use crate::source::SeekError;
+use crate::stream::{OutputStreamHandle, PlayError};
+use crate::{queue, source::Done, Sample, Source};
+use cpal::FromSample;
+
+/// Handle to a device that outputs sounds.
+///
+/// Dropping the `Sink` stops all sounds. You can use `detach` if you want the sounds to continue
+/// playing.
+pub struct Sink {
+    queue_tx: Arc<queue::SourcesQueueInput<f32>>,
+    sleep_until_end: Mutex<Option<Receiver<()>>>,
+
+    controls: Arc<Controls>,
+    sound_count: Arc<AtomicUsize>,
+
+    detached: bool,
+}
+
+struct SeekOrder {
+    pos: Duration,
+    feedback: Sender<Result<(), SeekError>>,
+}
+
+impl SeekOrder {
+    fn new(pos: Duration) -> (Self, Receiver<Result<(), SeekError>>) {
+        #[cfg(not(feature = "crossbeam-channel"))]
+        let (tx, rx) = {
+            use std::sync::mpsc;
+            mpsc::channel()
+        };
+
+        #[cfg(feature = "crossbeam-channel")]
+        let (tx, rx) = {
+            use crossbeam_channel::bounded;
+            bounded(1)
+        };
+        (Self { pos, feedback: tx }, rx)
+    }
+
+    fn attempt<S>(self, maybe_seekable: &mut S)
+    where
+        S: Source,
+        S::Item: Sample + Send,
+    {
+        let res = maybe_seekable.try_seek(self.pos);
+        let _ignore_receiver_dropped = self.feedback.send(res);
+    }
+}
+
+struct Controls {
+    pause: AtomicBool,
+    volume: Mutex<f32>,
+    stopped: AtomicBool,
+    speed: Mutex<f32>,
+    to_clear: Mutex<u32>,
+    seek: Mutex<Option<SeekOrder>>,
+    position: Mutex<Duration>,
+}
+
+impl Sink {
+    /// Builds a new `Sink`, beginning playback on a stream.
+    #[inline]
+    pub fn try_new(stream: &OutputStreamHandle) -> Result<Sink, PlayError> {
+        let (sink, queue_rx) = Sink::new_idle();
+        stream.play_raw(queue_rx)?;
+        Ok(sink)
+    }
+
+    /// Builds a new `Sink`.
+    #[inline]
+    pub fn new_idle() -> (Sink, queue::SourcesQueueOutput<f32>) {
+        let (queue_tx, queue_rx) = queue::queue(true);
+
+        let sink = Sink {
+            queue_tx,
+            sleep_until_end: Mutex::new(None),
+            controls: Arc::new(Controls {
+                pause: AtomicBool::new(false),
+                volume: Mutex::new(1.0),
+                stopped: AtomicBool::new(false),
+                speed: Mutex::new(1.0),
+                to_clear: Mutex::new(0),
+                seek: Mutex::new(None),
+                position: Mutex::new(Duration::ZERO),
+            }),
+            sound_count: Arc::new(AtomicUsize::new(0)),
+            detached: false,
+        };
+        (sink, queue_rx)
+    }
+
+    /// Appends a sound to the queue of sounds to play.
+    #[inline]
+    pub fn append<S>(&self, source: S)
+    where
+        S: Source + Send + 'static,
+        f32: FromSample<S::Item>,
+        S::Item: Sample + Send,
+    {
+        // Wait for queue to flush then resume stopped playback
+        if self.controls.stopped.load(Ordering::SeqCst) {
+            if self.sound_count.load(Ordering::SeqCst) > 0 {
+                self.sleep_until_end();
+            }
+            self.controls.stopped.store(false, Ordering::SeqCst);
+        }
+
+        let controls = self.controls.clone();
+
+        let start_played = AtomicBool::new(false);
+
+        let source = source
+            .speed(1.0)
+            // must be placed before pausable but after speed & delay
+            .track_position()
+            .pausable(false)
+            .amplify(1.0)
+            .skippable()
+            .stoppable()
+            // if you change the duration update the docs for try_seek!
+            .periodic_access(Duration::from_millis(5), move |src| {
+                if controls.stopped.load(Ordering::SeqCst) {
+                    src.stop();
+                    *controls.position.lock().unwrap() = Duration::ZERO;
+                }
+                {
+                    let mut to_clear = controls.to_clear.lock().unwrap();
+                    if *to_clear > 0 {
+                        src.inner_mut().skip();
+                        *to_clear -= 1;
+                        *controls.position.lock().unwrap() = Duration::ZERO;
+                    } else {
+                        *controls.position.lock().unwrap() = src.inner().inner().inner().inner().get_pos();
+                    }
+                }
+                let amp = src.inner_mut().inner_mut();
+                amp.set_factor(*controls.volume.lock().unwrap());
+                amp.inner_mut()
+                    .set_paused(controls.pause.load(Ordering::SeqCst));
+                amp.inner_mut()
+                    .inner_mut()
+                    .inner_mut()
+                    .set_factor(*controls.speed.lock().unwrap());
+                if let Some(seek) = controls.seek.lock().unwrap().take() {
+                    seek.attempt(amp)
+                }
+                start_played.store(true, Ordering::SeqCst);
+            })
+            .convert_samples();
+        self.sound_count.fetch_add(1, Ordering::Relaxed);
+        let source = Done::new(source, self.sound_count.clone());
+        *self.sleep_until_end.lock().unwrap() = Some(self.queue_tx.append_with_signal(source));
+    }
+
+    /// Gets the volume of the sound.
+    ///
+    /// The value `1.0` is the "normal" volume (unfiltered input). Any value other than 1.0 will
+    /// multiply each sample by this value.
+    #[inline]
+    pub fn volume(&self) -> f32 {
+        *self.controls.volume.lock().unwrap()
+    }
+
+    /// Changes the volume of the sound.
+    ///
+    /// The value `1.0` is the "normal" volume (unfiltered input). Any value other than `1.0` will
+    /// multiply each sample by this value.
+    #[inline]
+    pub fn set_volume(&self, value: f32) {
+        *self.controls.volume.lock().unwrap() = value;
+    }
+
+    /// Changes the play speed of the sound. Does not adjust the samples, only the playback speed.
+    ///
+    /// # Note:
+    /// 1. **Increasing the speed will increase the pitch by the same factor**
+    /// - If you set the speed to 0.5 this will halve the frequency of the sound
+    ///   lowering its pitch.
+    /// - If you set the speed to 2 the frequency will double raising the
+    ///   pitch of the sound.
+    /// 2. **Change in the speed affect the total duration inversely**
+    /// - If you set the speed to 0.5, the total duration will be twice as long.
+    /// - If you set the speed to 2 the total duration will be halve of what it
+    ///   was.
+    ///
+    /// See [`Speed`] for details
+    #[inline]
+    pub fn speed(&self) -> f32 {
+        *self.controls.speed.lock().unwrap()
+    }
+
+    /// Changes the speed of the sound.
+    ///
+    /// The value `1.0` is the "normal" speed (unfiltered input). Any value other than `1.0` will
+    /// change the play speed of the sound.
+    ///
+    /// #### Note:
+    /// 1. **Increasing the speed would also increase the pitch by the same factor**
+    /// - If you increased set the speed to 0.5, the frequency would be slower (0.5x the original frequency) .
+    /// - Also if you set the speed to 1.5 the frequency would be faster ( 1.5x the original frequency).
+    /// 2. **Change in the speed would affect your total duration inversely**
+    /// - if you set the speed by 0.5, your total duration would be (2x the original total duration) longer.
+    /// - Also if you set the speed to 2 the total duration would be (0.5 the original total_duration) shorter
+    #[inline]
+    pub fn set_speed(&self, value: f32) {
+        *self.controls.speed.lock().unwrap() = value;
+    }
+
+    /// Resumes playback of a paused sink.
+    ///
+    /// No effect if not paused.
+    #[inline]
+    pub fn play(&self) {
+        self.controls.pause.store(false, Ordering::SeqCst);
+    }
+
+    // There is no `can_seek()` method as it is impossible to use correctly. Between
+    // checking if a source supports seeking and actually seeking the sink can
+    // switch to a new source.
+
+    /// Attempts to seek to a given position in the current source.
+    ///
+    /// This blocks between 0 and ~5 milliseconds.
+    ///
+    /// As long as the duration of the source is known, seek is guaranteed to saturate
+    /// at the end of the source. For example given a source that reports a total duration
+    /// of 42 seconds calling `try_seek()` with 60 seconds as argument will seek to
+    /// 42 seconds.
+    ///
+    /// # Errors
+    /// This function will return [`SeekError::NotSupported`] if one of the underlying
+    /// sources does not support seeking.
+    ///
+    /// It will return an error if an implementation ran
+    /// into one during the seek.
+    ///
+    /// When seeking beyond the end of a source this
+    /// function might return an error if the duration of the source is not known.
+    pub fn try_seek(&self, pos: Duration) -> Result<(), SeekError> {
+        let (order, feedback) = SeekOrder::new(pos);
+        *self.controls.seek.lock().unwrap() = Some(order);
+
+        if self.sound_count.load(Ordering::Acquire) == 0 {
+            // No sound is playing, seek will not be performed
+            return Ok(());
+        }
+
+        match feedback.recv() {
+            Ok(seek_res) => {
+                *self.controls.position.lock().unwrap() = pos;
+                seek_res
+            }
+            // The feedback channel closed. Probably another SeekOrder was set
+            // invalidating this one and closing the feedback channel
+            // ... or the audio thread panicked.
+            Err(_) => Ok(()),
+        }
+    }
+
+    /// Pauses playback of this sink.
+    ///
+    /// No effect if already paused.
+    ///
+    /// A paused sink can be resumed with `play()`.
+    pub fn pause(&self) {
+        self.controls.pause.store(true, Ordering::SeqCst);
+    }
+
+    /// Gets if a sink is paused
+    ///
+    /// Sinks can be paused and resumed using `pause()` and `play()`. This returns `true` if the
+    /// sink is paused.
+    pub fn is_paused(&self) -> bool {
+        self.controls.pause.load(Ordering::SeqCst)
+    }
+
+    /// Removes all currently loaded `Source`s from the `Sink`, and pauses it.
+    ///
+    /// See `pause()` for information about pausing a `Sink`.
+    pub fn clear(&self) {
+        let len = self.sound_count.load(Ordering::SeqCst) as u32;
+        *self.controls.to_clear.lock().unwrap() = len;
+        self.sleep_until_end();
+        self.pause();
+    }
+
+    /// Skips to the next `Source` in the `Sink`
+    ///
+    /// If there are more `Source`s appended to the `Sink` at the time,
+    /// it will play the next one. Otherwise, the `Sink` will finish as if
+    /// it had finished playing a `Source` all the way through.
+    pub fn skip_one(&self) {
+        let len = self.sound_count.load(Ordering::SeqCst) as u32;
+        let mut to_clear = self.controls.to_clear.lock().unwrap();
+        if len > *to_clear {
+            *to_clear += 1;
+        }
+    }
+
+    /// Stops the sink by emptying the queue.
+    #[inline]
+    pub fn stop(&self) {
+        self.controls.stopped.store(true, Ordering::SeqCst);
+    }
+
+    /// Destroys the sink without stopping the sounds that are still playing.
+    #[inline]
+    pub fn detach(mut self) {
+        self.detached = true;
+    }
+
+    /// Sleeps the current thread until the sound ends.
+    #[inline]
+    pub fn sleep_until_end(&self) {
+        if let Some(sleep_until_end) = self.sleep_until_end.lock().unwrap().take() {
+            let _ = sleep_until_end.recv();
+        }
+    }
+
+    /// Returns true if this sink has no more sounds to play.
+    #[inline]
+    pub fn empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    /// Returns the number of sounds currently in the queue.
+    #[allow(clippy::len_without_is_empty)]
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.sound_count.load(Ordering::Relaxed)
+    }
+
+    /// Returns the position of the sound that's being played.
+    ///
+    /// This takes into account any speedup or delay applied.
+    ///
+    /// Example: if you apply a speedup of *2* to an mp3 decoder source and
+    /// [`get_pos()`](Sink::get_pos) returns *5s* then the position in the mp3
+    /// recording is *10s* from its start.
+    #[inline]
+    pub fn get_pos(&self) -> Duration {
+        *self.controls.position.lock().unwrap()
+    }
+}
+
+impl Drop for Sink {
+    #[inline]
+    fn drop(&mut self) {
+        self.queue_tx.set_keep_alive_if_empty(false);
+
+        if !self.detached {
+            self.controls.stopped.store(true, Ordering::Relaxed);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::buffer::SamplesBuffer;
+    use crate::{Sink, Source};
+    use std::sync::atomic::Ordering;
+
+    #[test]
+    fn test_pause_and_stop() {
+        let (sink, mut queue_rx) = Sink::new_idle();
+
+        // assert_eq!(queue_rx.next(), Some(0.0));
+
+        let v = vec![10i16, -10, 20, -20, 30, -30];
+
+        // Low rate to ensure immediate control.
+        sink.append(SamplesBuffer::new(1, 1, v.clone()));
+        let mut src = SamplesBuffer::new(1, 1, v).convert_samples();
+
+        assert_eq!(queue_rx.next(), src.next());
+        assert_eq!(queue_rx.next(), src.next());
+
+        sink.pause();
+
+        assert_eq!(queue_rx.next(), Some(0.0));
+
+        sink.play();
+
+        assert_eq!(queue_rx.next(), src.next());
+        assert_eq!(queue_rx.next(), src.next());
+
+        sink.stop();
+
+        assert_eq!(queue_rx.next(), Some(0.0));
+
+        assert_eq!(sink.empty(), true);
+    }
+
+    #[test]
+    fn test_stop_and_start() {
+        let (sink, mut queue_rx) = Sink::new_idle();
+
+        let v = vec![10i16, -10, 20, -20, 30, -30];
+
+        sink.append(SamplesBuffer::new(1, 1, v.clone()));
+        let mut src = SamplesBuffer::new(1, 1, v.clone()).convert_samples();
+
+        assert_eq!(queue_rx.next(), src.next());
+        assert_eq!(queue_rx.next(), src.next());
+
+        sink.stop();
+
+        assert!(sink.controls.stopped.load(Ordering::SeqCst));
+        assert_eq!(queue_rx.next(), Some(0.0));
+
+        src = SamplesBuffer::new(1, 1, v.clone()).convert_samples();
+        sink.append(SamplesBuffer::new(1, 1, v));
+
+        assert!(!sink.controls.stopped.load(Ordering::SeqCst));
+        // Flush silence
+        let mut queue_rx = queue_rx.skip_while(|v| *v == 0.0);
+
+        assert_eq!(queue_rx.next(), src.next());
+        assert_eq!(queue_rx.next(), src.next());
+    }
+
+    #[test]
+    fn test_volume() {
+        let (sink, mut queue_rx) = Sink::new_idle();
+
+        let v = vec![10i16, -10, 20, -20, 30, -30];
+
+        // High rate to avoid immediate control.
+        sink.append(SamplesBuffer::new(2, 44100, v.clone()));
+        let src = SamplesBuffer::new(2, 44100, v.clone()).convert_samples();
+
+        let mut src = src.amplify(0.5);
+        sink.set_volume(0.5);
+
+        for _ in 0..v.len() {
+            assert_eq!(queue_rx.next(), src.next());
+        }
+    }
+}

vendor/rodio/src/source/agc.rs

@@ -0,0 +1,490 @@
+//
+//      Automatic Gain Control (AGC) Algorithm
+//      Designed by @UnknownSuperficialNight
+//
+//   Features:
+//   • Adaptive peak detection
+//   • RMS-based level estimation
+//   • Asymmetric attack/release
+//   • RMS-based general adjustments with peak limiting
+//
+//   Optimized for smooth and responsive gain control
+//
+//   Crafted with love. Enjoy! :)
+//
+
+use super::SeekError;
+use crate::{Sample, Source};
+#[cfg(feature = "experimental")]
+use atomic_float::AtomicF32;
+#[cfg(feature = "experimental")]
+use std::sync::atomic::{AtomicBool, Ordering};
+#[cfg(feature = "experimental")]
+use std::sync::Arc;
+use std::time::Duration;
+
+#[cfg(feature = "tracing")]
+use tracing;
+
+/// Ensures `RMS_WINDOW_SIZE` is a power of two
+const fn power_of_two(n: usize) -> usize {
+    assert!(
+        n.is_power_of_two(),
+        "RMS_WINDOW_SIZE must be a power of two"
+    );
+    n
+}
+
+/// Size of the circular buffer used for RMS calculation.
+/// A larger size provides more stable RMS values but increases latency.
+const RMS_WINDOW_SIZE: usize = power_of_two(8192);
+
+#[cfg(feature = "experimental")]
+/// Automatic Gain Control filter for maintaining consistent output levels.
+///
+/// This struct implements an AGC algorithm that dynamically adjusts audio levels
+/// based on both **peak** and **RMS** (Root Mean Square) measurements.
+#[derive(Clone, Debug)]
+pub struct AutomaticGainControl<I> {
+    input: I,
+    target_level: Arc<AtomicF32>,
+    absolute_max_gain: Arc<AtomicF32>,
+    current_gain: f32,
+    attack_coeff: Arc<AtomicF32>,
+    release_coeff: Arc<AtomicF32>,
+    min_attack_coeff: f32,
+    peak_level: f32,
+    rms_window: CircularBuffer,
+    is_enabled: Arc<AtomicBool>,
+}
+
+#[cfg(not(feature = "experimental"))]
+/// Automatic Gain Control filter for maintaining consistent output levels.
+///
+/// This struct implements an AGC algorithm that dynamically adjusts audio levels
+/// based on both **peak** and **RMS** (Root Mean Square) measurements.
+#[derive(Clone, Debug)]
+pub struct AutomaticGainControl<I> {
+    input: I,
+    target_level: f32,
+    absolute_max_gain: f32,
+    current_gain: f32,
+    attack_coeff: f32,
+    release_coeff: f32,
+    min_attack_coeff: f32,
+    peak_level: f32,
+    rms_window: CircularBuffer,
+    is_enabled: bool,
+}
+
+/// A circular buffer for efficient RMS calculation over a sliding window.
+///
+/// This structure allows for constant-time updates and mean calculations,
+/// which is crucial for real-time audio processing.
+#[derive(Clone, Debug)]
+struct CircularBuffer {
+    buffer: Box<[f32; RMS_WINDOW_SIZE]>,
+    sum: f32,
+    index: usize,
+}
+
+impl CircularBuffer {
+    /// Creates a new `CircularBuffer` with a fixed size determined at compile time.
+    #[inline]
+    fn new() -> Self {
+        CircularBuffer {
+            buffer: Box::new([0.0; RMS_WINDOW_SIZE]),
+            sum: 0.0,
+            index: 0,
+        }
+    }
+
+    /// Pushes a new value into the buffer and returns the old value.
+    ///
+    /// This method maintains a running sum for efficient mean calculation.
+    #[inline]
+    fn push(&mut self, value: f32) -> f32 {
+        let old_value = self.buffer[self.index];
+        // Update the sum by first subtracting the old value and then adding the new value; this is more accurate.
+        self.sum = self.sum - old_value + value;
+        self.buffer[self.index] = value;
+        // Use bitwise AND for efficient index wrapping since RMS_WINDOW_SIZE is a power of two.
+        self.index = (self.index + 1) & (RMS_WINDOW_SIZE - 1);
+        old_value
+    }
+
+    /// Calculates the mean of all values in the buffer.
+    ///
+    /// This operation is `O(1)` due to the maintained running sum.
+    #[inline]
+    fn mean(&self) -> f32 {
+        self.sum / RMS_WINDOW_SIZE as f32
+    }
+}
+
+/// Constructs an `AutomaticGainControl` object with specified parameters.
+///
+/// # Arguments
+///
+/// * `input` - The input audio source
+/// * `target_level` - The desired output level
+/// * `attack_time` - Time constant for gain increase
+/// * `release_time` - Time constant for gain decrease
+/// * `absolute_max_gain` - Maximum allowable gain
+#[inline]
+pub(crate) fn automatic_gain_control<I>(
+    input: I,
+    target_level: f32,
+    attack_time: f32,
+    release_time: f32,
+    absolute_max_gain: f32,
+) -> AutomaticGainControl<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let sample_rate = input.sample_rate();
+    let attack_coeff = (-1.0 / (attack_time * sample_rate as f32)).exp();
+    let release_coeff = (-1.0 / (release_time * sample_rate as f32)).exp();
+
+    #[cfg(feature = "experimental")]
+    {
+        AutomaticGainControl {
+            input,
+            target_level: Arc::new(AtomicF32::new(target_level)),
+            absolute_max_gain: Arc::new(AtomicF32::new(absolute_max_gain)),
+            current_gain: 1.0,
+            attack_coeff: Arc::new(AtomicF32::new(attack_coeff)),
+            release_coeff: Arc::new(AtomicF32::new(release_coeff)),
+            min_attack_coeff: release_time,
+            peak_level: 0.0,
+            rms_window: CircularBuffer::new(),
+            is_enabled: Arc::new(AtomicBool::new(true)),
+        }
+    }
+
+    #[cfg(not(feature = "experimental"))]
+    {
+        AutomaticGainControl {
+            input,
+            target_level,
+            absolute_max_gain,
+            current_gain: 1.0,
+            attack_coeff,
+            release_coeff,
+            min_attack_coeff: release_time,
+            peak_level: 0.0,
+            rms_window: CircularBuffer::new(),
+            is_enabled: true,
+        }
+    }
+}
+
+impl<I> AutomaticGainControl<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn target_level(&self) -> f32 {
+        #[cfg(feature = "experimental")]
+        {
+            self.target_level.load(Ordering::Relaxed)
+        }
+        #[cfg(not(feature = "experimental"))]
+        {
+            self.target_level
+        }
+    }
+
+    #[inline]
+    fn absolute_max_gain(&self) -> f32 {
+        #[cfg(feature = "experimental")]
+        {
+            self.absolute_max_gain.load(Ordering::Relaxed)
+        }
+        #[cfg(not(feature = "experimental"))]
+        {
+            self.absolute_max_gain
+        }
+    }
+
+    #[inline]
+    fn attack_coeff(&self) -> f32 {
+        #[cfg(feature = "experimental")]
+        {
+            self.attack_coeff.load(Ordering::Relaxed)
+        }
+        #[cfg(not(feature = "experimental"))]
+        {
+            self.attack_coeff
+        }
+    }
+
+    #[inline]
+    fn release_coeff(&self) -> f32 {
+        #[cfg(feature = "experimental")]
+        {
+            self.release_coeff.load(Ordering::Relaxed)
+        }
+        #[cfg(not(feature = "experimental"))]
+        {
+            self.release_coeff
+        }
+    }
+
+    #[inline]
+    fn is_enabled(&self) -> bool {
+        #[cfg(feature = "experimental")]
+        {
+            self.is_enabled.load(Ordering::Relaxed)
+        }
+        #[cfg(not(feature = "experimental"))]
+        {
+            self.is_enabled
+        }
+    }
+
+    #[cfg(feature = "experimental")]
+    /// Access the target output level for real-time adjustment.
+    ///
+    /// Use this to dynamically modify the AGC's target level while audio is processing.
+    /// Adjust this value to control the overall output amplitude of the processed signal.
+    #[inline]
+    pub fn get_target_level(&self) -> Arc<AtomicF32> {
+        Arc::clone(&self.target_level)
+    }
+
+    #[cfg(feature = "experimental")]
+    /// Access the maximum gain limit for real-time adjustment.
+    ///
+    /// Use this to dynamically modify the AGC's maximum allowable gain during runtime.
+    /// Adjusting this value helps prevent excessive amplification in low-level signals.
+    #[inline]
+    pub fn get_absolute_max_gain(&self) -> Arc<AtomicF32> {
+        Arc::clone(&self.absolute_max_gain)
+    }
+
+    #[cfg(feature = "experimental")]
+    /// Access the attack coefficient for real-time adjustment.
+    ///
+    /// Use this to dynamically modify how quickly the AGC responds to level increases.
+    /// Smaller values result in faster response, larger values in slower response.
+    /// Adjust during runtime to fine-tune AGC behavior for different audio content.
+    #[inline]
+    pub fn get_attack_coeff(&self) -> Arc<AtomicF32> {
+        Arc::clone(&self.attack_coeff)
+    }
+
+    #[cfg(feature = "experimental")]
+    /// Access the release coefficient for real-time adjustment.
+    ///
+    /// Use this to dynamically modify how quickly the AGC responds to level decreases.
+    /// Smaller values result in faster response, larger values in slower response.
+    /// Adjust during runtime to optimize AGC behavior for varying audio dynamics.
+    #[inline]
+    pub fn get_release_coeff(&self) -> Arc<AtomicF32> {
+        Arc::clone(&self.release_coeff)
+    }
+
+    #[cfg(feature = "experimental")]
+    /// Access the AGC on/off control for real-time adjustment.
+    ///
+    /// Use this to dynamically enable or disable AGC processing during runtime.
+    /// Useful for comparing processed and unprocessed audio or for disabling/enabling AGC at runtime.
+    #[inline]
+    pub fn get_agc_control(&self) -> Arc<AtomicBool> {
+        Arc::clone(&self.is_enabled)
+    }
+
+    #[cfg(not(feature = "experimental"))]
+    /// Enable or disable AGC processing.
+    ///
+    /// Use this to enable or disable AGC processing.
+    /// Useful for comparing processed and unprocessed audio or for disabling/enabling AGC.
+    #[inline]
+    pub fn set_enabled(&mut self, enabled: bool) {
+        self.is_enabled = enabled;
+    }
+
+    /// Updates the peak level with an adaptive attack coefficient
+    ///
+    /// This method adjusts the peak level using a variable attack coefficient.
+    /// It responds faster to sudden increases in signal level by using a
+    /// minimum attack coefficient of `min_attack_coeff` when the sample value exceeds the
+    /// current peak level. This adaptive behavior helps capture transients
+    /// more accurately while maintaining smoother behavior for gradual changes.
+    #[inline]
+    fn update_peak_level(&mut self, sample_value: f32) {
+        let attack_coeff = if sample_value > self.peak_level {
+            self.attack_coeff().min(self.min_attack_coeff) // User-defined attack time limited via release_time
+        } else {
+            self.release_coeff()
+        };
+
+        self.peak_level = attack_coeff * self.peak_level + (1.0 - attack_coeff) * sample_value;
+    }
+
+    /// Updates the RMS (Root Mean Square) level using a circular buffer approach.
+    /// This method calculates a moving average of the squared input samples,
+    /// providing a measure of the signal's average power over time.
+    #[inline]
+    fn update_rms(&mut self, sample_value: f32) -> f32 {
+        let squared_sample = sample_value * sample_value;
+        self.rms_window.push(squared_sample);
+        self.rms_window.mean().sqrt()
+    }
+
+    /// Calculate gain adjustments based on peak levels
+    /// This method determines the appropriate gain level to apply to the audio
+    /// signal, considering the peak level.
+    /// The peak level helps prevent sudden spikes in the output signal.
+    #[inline]
+    fn calculate_peak_gain(&self) -> f32 {
+        if self.peak_level > 0.0 {
+            (self.target_level() / self.peak_level).min(self.absolute_max_gain())
+        } else {
+            self.absolute_max_gain()
+        }
+    }
+
+    #[inline]
+    fn process_sample(&mut self, sample: I::Item) -> I::Item {
+        // Convert the sample to its absolute float value for level calculations
+        let sample_value = sample.to_f32().abs();
+
+        // Dynamically adjust peak level using an adaptive attack coefficient
+        self.update_peak_level(sample_value);
+
+        // Calculate the current RMS (Root Mean Square) level using a sliding window approach
+        let rms = self.update_rms(sample_value);
+
+        // Compute the gain adjustment required to reach the target level based on RMS
+        let rms_gain = if rms > 0.0 {
+            self.target_level() / rms
+        } else {
+            self.absolute_max_gain() // Default to max gain if RMS is zero
+        };
+
+        // Calculate the peak limiting gain
+        let peak_gain = self.calculate_peak_gain();
+
+        // Use RMS for general adjustments, but limit by peak gain to prevent clipping
+        let desired_gain = rms_gain.min(peak_gain);
+
+        // Adaptive attack/release speed for AGC (Automatic Gain Control)
+        //
+        // This mechanism implements an asymmetric approach to gain adjustment:
+        // 1. **Slow increase**: Prevents abrupt amplification of noise during quiet periods.
+        // 2. **Fast decrease**: Rapidly attenuates sudden loud signals to avoid distortion.
+        //
+        // The asymmetry is crucial because:
+        // - Gradual gain increases sound more natural and less noticeable to listeners.
+        // - Quick gain reductions are necessary to prevent clipping and maintain audio quality.
+        //
+        // This approach addresses several challenges associated with high attack times:
+        // 1. **Slow response**: With a high attack time, the AGC responds very slowly to changes in input level.
+        //    This means it takes longer for the gain to adjust to new signal levels.
+        // 2. **Initial gain calculation**: When the audio starts or after a period of silence, the initial gain
+        //    calculation might result in a very high gain value, especially if the input signal starts quietly.
+        // 3. **Overshooting**: As the gain slowly increases (due to the high attack time), it might overshoot
+        //    the desired level, causing the signal to become too loud.
+        // 4. **Overcorrection**: The AGC then tries to correct this by reducing the gain, but due to the slow response,
+        //    it might reduce the gain too much, causing the sound to drop to near-zero levels.
+        // 5. **Slow recovery**: Again, due to the high attack time, it takes a while for the gain to increase
+        //    back to the appropriate level.
+        //
+        // By using a faster release time for decreasing gain, we can mitigate these issues and provide
+        // more responsive control over sudden level increases while maintaining smooth gain increases.
+        let attack_speed = if desired_gain > self.current_gain {
+            self.attack_coeff()
+        } else {
+            self.release_coeff()
+        };
+
+        // Gradually adjust the current gain towards the desired gain for smooth transitions
+        self.current_gain = self.current_gain * attack_speed + desired_gain * (1.0 - attack_speed);
+
+        // Ensure the calculated gain stays within the defined operational range
+        self.current_gain = self.current_gain.clamp(0.1, self.absolute_max_gain());
+
+        // Output current gain value for developers to fine tune their inputs to automatic_gain_control
+        #[cfg(feature = "tracing")]
+        tracing::debug!("AGC gain: {}", self.current_gain,);
+
+        // Apply the computed gain to the input sample and return the result
+        sample.amplify(self.current_gain)
+    }
+
+    /// Returns a mutable reference to the inner source.
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns the inner source.
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+}
+
+impl<I> Iterator for AutomaticGainControl<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next().map(|sample| {
+            if self.is_enabled() {
+                self.process_sample(sample)
+            } else {
+                sample
+            }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for AutomaticGainControl<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for AutomaticGainControl<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/amplify.rs

@@ -0,0 +1,103 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `Amplify` object.
+pub fn amplify<I>(input: I, factor: f32) -> Amplify<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    Amplify { input, factor }
+}
+
+/// Filter that modifies each sample by a given value.
+#[derive(Clone, Debug)]
+pub struct Amplify<I> {
+    input: I,
+    factor: f32,
+}
+
+impl<I> Amplify<I> {
+    /// Modifies the amplification factor.
+    #[inline]
+    pub fn set_factor(&mut self, factor: f32) {
+        self.factor = factor;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Amplify<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next().map(|value| value.amplify(self.factor))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for Amplify<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for Amplify<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/blt.rs

@@ -0,0 +1,252 @@
+use std::f32::consts::PI;
+use std::time::Duration;
+
+use crate::Source;
+
+use super::SeekError;
+
+// Implemented following http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
+
+/// Internal function that builds a `BltFilter` object.
+pub fn low_pass<I>(input: I, freq: u32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    low_pass_with_q(input, freq, 0.5)
+}
+
+pub fn high_pass<I>(input: I, freq: u32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    high_pass_with_q(input, freq, 0.5)
+}
+
+/// Same as low_pass but allows the q value (bandwidth) to be changed
+pub fn low_pass_with_q<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    BltFilter {
+        input,
+        formula: BltFormula::LowPass { freq, q },
+        applier: None,
+        x_n1: 0.0,
+        x_n2: 0.0,
+        y_n1: 0.0,
+        y_n2: 0.0,
+    }
+}
+
+/// Same as high_pass but allows the q value (bandwidth) to be changed
+pub fn high_pass_with_q<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    BltFilter {
+        input,
+        formula: BltFormula::HighPass { freq, q },
+        applier: None,
+        x_n1: 0.0,
+        x_n2: 0.0,
+        y_n1: 0.0,
+        y_n2: 0.0,
+    }
+}
+
+/// This applies an audio filter, it can be a high or low pass filter.
+#[derive(Clone, Debug)]
+pub struct BltFilter<I> {
+    input: I,
+    formula: BltFormula,
+    applier: Option<BltApplier>,
+    x_n1: f32,
+    x_n2: f32,
+    y_n1: f32,
+    y_n2: f32,
+}
+
+impl<I> BltFilter<I> {
+    /// Modifies this filter so that it becomes a low-pass filter.
+    pub fn to_low_pass(&mut self, freq: u32) {
+        self.to_low_pass_with_q(freq, 0.5);
+    }
+
+    /// Modifies this filter so that it becomes a high-pass filter
+    pub fn to_high_pass(&mut self, freq: u32) {
+        self.to_high_pass_with_q(freq, 0.5);
+    }
+
+    /// Same as to_low_pass but allows the q value (bandwidth) to be changed
+    pub fn to_low_pass_with_q(&mut self, freq: u32, q: f32) {
+        self.formula = BltFormula::LowPass { freq, q };
+        self.applier = None;
+    }
+
+    /// Same as to_high_pass but allows the q value (bandwidth) to be changed
+    pub fn to_high_pass_with_q(&mut self, freq: u32, q: f32) {
+        self.formula = BltFormula::HighPass { freq, q };
+        self.applier = None;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    type Item = f32;
+
+    #[inline]
+    fn next(&mut self) -> Option<f32> {
+        let last_in_frame = self.input.current_frame_len() == Some(1);
+
+        if self.applier.is_none() {
+            self.applier = Some(self.formula.to_applier(self.input.sample_rate()));
+        }
+
+        let sample = match self.input.next() {
+            None => return None,
+            Some(s) => s,
+        };
+
+        let result = self
+            .applier
+            .as_ref()
+            .unwrap()
+            .apply(sample, self.x_n1, self.x_n2, self.y_n1, self.y_n2);
+
+        self.y_n2 = self.y_n1;
+        self.x_n2 = self.x_n1;
+        self.y_n1 = result;
+        self.x_n1 = sample;
+
+        if last_in_frame {
+            self.applier = None;
+        }
+
+        Some(result)
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for BltFilter<I> where I: Source<Item = f32> + ExactSizeIterator {}
+
+impl<I> Source for BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}
+
+#[derive(Clone, Debug)]
+enum BltFormula {
+    LowPass { freq: u32, q: f32 },
+    HighPass { freq: u32, q: f32 },
+}
+
+impl BltFormula {
+    fn to_applier(&self, sampling_frequency: u32) -> BltApplier {
+        match *self {
+            BltFormula::LowPass { freq, q } => {
+                let w0 = 2.0 * PI * freq as f32 / sampling_frequency as f32;
+
+                let alpha = w0.sin() / (2.0 * q);
+                let b1 = 1.0 - w0.cos();
+                let b0 = b1 / 2.0;
+                let b2 = b0;
+                let a0 = 1.0 + alpha;
+                let a1 = -2.0 * w0.cos();
+                let a2 = 1.0 - alpha;
+
+                BltApplier {
+                    b0: b0 / a0,
+                    b1: b1 / a0,
+                    b2: b2 / a0,
+                    a1: a1 / a0,
+                    a2: a2 / a0,
+                }
+            }
+            BltFormula::HighPass { freq, q } => {
+                let w0 = 2.0 * PI * freq as f32 / sampling_frequency as f32;
+                let cos_w0 = w0.cos();
+                let alpha = w0.sin() / (2.0 * q);
+
+                let b0 = (1.0 + cos_w0) / 2.0;
+                let b1 = -1.0 - cos_w0;
+                let b2 = b0;
+                let a0 = 1.0 + alpha;
+                let a1 = -2.0 * cos_w0;
+                let a2 = 1.0 - alpha;
+
+                BltApplier {
+                    b0: b0 / a0,
+                    b1: b1 / a0,
+                    b2: b2 / a0,
+                    a1: a1 / a0,
+                    a2: a2 / a0,
+                }
+            }
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct BltApplier {
+    b0: f32,
+    b1: f32,
+    b2: f32,
+    a1: f32,
+    a2: f32,
+}
+
+impl BltApplier {
+    #[inline]
+    fn apply(&self, x_n: f32, x_n1: f32, x_n2: f32, y_n1: f32, y_n2: f32) -> f32 {
+        self.b0 * x_n + self.b1 * x_n1 + self.b2 * x_n2 - self.a1 * y_n1 - self.a2 * y_n2
+    }
+}

vendor/rodio/src/source/buffered.rs

@@ -0,0 +1,268 @@
+use std::cmp;
+use std::mem;
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `Buffered` object.
+#[inline]
+pub fn buffered<I>(input: I) -> Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let total_duration = input.total_duration();
+    let first_frame = extract(input);
+
+    Buffered {
+        current_frame: first_frame,
+        position_in_frame: 0,
+        total_duration,
+    }
+}
+
+/// Iterator that at the same time extracts data from the iterator and stores it in a buffer.
+pub struct Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Immutable reference to the next frame of data. Cannot be `Frame::Input`.
+    current_frame: Arc<Frame<I>>,
+
+    /// The position in number of samples of this iterator inside `current_frame`.
+    position_in_frame: usize,
+
+    /// Obtained once at creation and never modified again.
+    total_duration: Option<Duration>,
+}
+
+enum Frame<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Data that has already been extracted from the iterator. Also contains a pointer to the
+    /// next frame.
+    Data(FrameData<I>),
+
+    /// No more data.
+    End,
+
+    /// Unextracted data. The `Option` should never be `None` and is only here for easier data
+    /// processing.
+    Input(Mutex<Option<I>>),
+}
+
+struct FrameData<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    data: Vec<I::Item>,
+    channels: u16,
+    rate: u32,
+    next: Mutex<Arc<Frame<I>>>,
+}
+
+impl<I> Drop for FrameData<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    fn drop(&mut self) {
+        // This is necessary to prevent stack overflows deallocating long chains of the mutually
+        // recursive `Frame` and `FrameData` types. This iteratively traverses as much of the
+        // chain as needs to be deallocated, and repeatedly "pops" the head off the list. This
+        // solves the problem, as when the time comes to actually deallocate the `FrameData`,
+        // the `next` field will contain a `Frame::End`, or an `Arc` with additional references,
+        // so the depth of recursive drops will be bounded.
+        while let Ok(arc_next) = self.next.get_mut() {
+            if let Some(next_ref) = Arc::get_mut(arc_next) {
+                // This allows us to own the next Frame.
+                let next = mem::replace(next_ref, Frame::End);
+                if let Frame::Data(next_data) = next {
+                    // Swap the current FrameData with the next one, allowing the current one
+                    // to go out of scope.
+                    *self = next_data;
+                } else {
+                    break;
+                }
+            } else {
+                break;
+            }
+        }
+    }
+}
+
+/// Builds a frame from the input iterator.
+fn extract<I>(mut input: I) -> Arc<Frame<I>>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let frame_len = input.current_frame_len();
+
+    if frame_len == Some(0) {
+        return Arc::new(Frame::End);
+    }
+
+    let channels = input.channels();
+    let rate = input.sample_rate();
+    let data: Vec<I::Item> = input
+        .by_ref()
+        .take(cmp::min(frame_len.unwrap_or(32768), 32768))
+        .collect();
+
+    if data.is_empty() {
+        return Arc::new(Frame::End);
+    }
+
+    Arc::new(Frame::Data(FrameData {
+        data,
+        channels,
+        rate,
+        next: Mutex::new(Arc::new(Frame::Input(Mutex::new(Some(input))))),
+    }))
+}
+
+impl<I> Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Advances to the next frame.
+    fn next_frame(&mut self) {
+        let next_frame = {
+            let mut next_frame_ptr = match &*self.current_frame {
+                Frame::Data(FrameData { next, .. }) => next.lock().unwrap(),
+                _ => unreachable!(),
+            };
+
+            let next_frame = match &**next_frame_ptr {
+                Frame::Data(_) => next_frame_ptr.clone(),
+                Frame::End => next_frame_ptr.clone(),
+                Frame::Input(input) => {
+                    let input = input.lock().unwrap().take().unwrap();
+                    extract(input)
+                }
+            };
+
+            *next_frame_ptr = next_frame.clone();
+            next_frame
+        };
+
+        self.current_frame = next_frame;
+        self.position_in_frame = 0;
+    }
+}
+
+impl<I> Iterator for Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        let current_sample;
+        let advance_frame;
+
+        match &*self.current_frame {
+            Frame::Data(FrameData { data, .. }) => {
+                current_sample = Some(data[self.position_in_frame]);
+                self.position_in_frame += 1;
+                advance_frame = self.position_in_frame >= data.len();
+            }
+
+            Frame::End => {
+                current_sample = None;
+                advance_frame = false;
+            }
+
+            Frame::Input(_) => unreachable!(),
+        };
+
+        if advance_frame {
+            self.next_frame();
+        }
+
+        current_sample
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        // TODO:
+        (0, None)
+    }
+}
+
+// TODO: uncomment when `size_hint` is fixed
+/*impl<I> ExactSizeIterator for Amplify<I> where I: Source + ExactSizeIterator, I::Item: Sample {
+}*/
+
+impl<I> Source for Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        match &*self.current_frame {
+            Frame::Data(FrameData { data, .. }) => Some(data.len() - self.position_in_frame),
+            Frame::End => Some(0),
+            Frame::Input(_) => unreachable!(),
+        }
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        match *self.current_frame {
+            Frame::Data(FrameData { channels, .. }) => channels,
+            Frame::End => 1,
+            Frame::Input(_) => unreachable!(),
+        }
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        match *self.current_frame {
+            Frame::Data(FrameData { rate, .. }) => rate,
+            Frame::End => 44100,
+            Frame::Input(_) => unreachable!(),
+        }
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.total_duration
+    }
+
+    /// Can not support seek, in the end state we lose the underlying source
+    /// which makes seeking back impossible.
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+impl<I> Clone for Buffered<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn clone(&self) -> Buffered<I> {
+        Buffered {
+            current_frame: self.current_frame.clone(),
+            position_in_frame: self.position_in_frame,
+            total_duration: self.total_duration,
+        }
+    }
+}

vendor/rodio/src/source/channel_volume.rs

@@ -0,0 +1,150 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Combines channels in input into a single mono source, then plays that mono sound
+/// to each channel at the volume given for that channel.
+#[derive(Clone, Debug)]
+pub struct ChannelVolume<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    input: I,
+    // Channel number is used as index for amplification value.
+    channel_volumes: Vec<f32>,
+    // Current listener being processed.
+    current_channel: usize,
+    current_sample: Option<I::Item>,
+}
+
+impl<I> ChannelVolume<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Wrap the input source and make it mono. Play that mono sound to each
+    /// channel at the volume set by the user. The volume can be changed using
+    /// [`ChannelVolume::set_volume`].
+    pub fn new(mut input: I, channel_volumes: Vec<f32>) -> ChannelVolume<I>
+    where
+        I: Source,
+        I::Item: Sample,
+    {
+        let mut sample = None;
+        for _ in 0..input.channels() {
+            if let Some(s) = input.next() {
+                sample = Some(
+                    sample
+                        .get_or_insert_with(I::Item::zero_value)
+                        .saturating_add(s),
+                );
+            }
+        }
+        ChannelVolume {
+            input,
+            channel_volumes,
+            current_channel: 0,
+            current_sample: sample,
+        }
+    }
+
+    /// Sets the volume for a given channel number. Will panic if channel number
+    /// is invalid.
+    pub fn set_volume(&mut self, channel: usize, volume: f32) {
+        self.channel_volumes[channel] = volume;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for ChannelVolume<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        let ret = self
+            .current_sample
+            .map(|sample| sample.amplify(self.channel_volumes[self.current_channel]));
+        self.current_channel += 1;
+        if self.current_channel >= self.channel_volumes.len() {
+            self.current_channel = 0;
+            self.current_sample = None;
+            for _ in 0..self.input.channels() {
+                if let Some(s) = self.input.next() {
+                    self.current_sample = Some(
+                        self.current_sample
+                            .get_or_insert_with(I::Item::zero_value)
+                            .saturating_add(s),
+                    );
+                }
+            }
+        }
+        ret
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for ChannelVolume<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for ChannelVolume<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channel_volumes.len() as u16
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/chirp.rs

@@ -0,0 +1,76 @@
+//! Chirp/sweep source.
+
+use std::{f32::consts::TAU, time::Duration};
+
+use crate::Source;
+
+/// Convenience function to create a new `Chirp` source.
+#[inline]
+pub fn chirp(
+    sample_rate: cpal::SampleRate,
+    start_frequency: f32,
+    end_frequency: f32,
+    duration: Duration,
+) -> Chirp {
+    Chirp::new(sample_rate, start_frequency, end_frequency, duration)
+}
+
+/// Generate a sine wave with an instantaneous frequency that changes/sweeps linearly over time.
+/// At the end of the chirp, once the `end_frequency` is reached, the source is exhausted.
+#[derive(Clone, Debug)]
+pub struct Chirp {
+    start_frequency: f32,
+    end_frequency: f32,
+    sample_rate: cpal::SampleRate,
+    total_samples: u64,
+    elapsed_samples: u64,
+}
+
+impl Chirp {
+    fn new(
+        sample_rate: cpal::SampleRate,
+        start_frequency: f32,
+        end_frequency: f32,
+        duration: Duration,
+    ) -> Self {
+        Self {
+            sample_rate,
+            start_frequency,
+            end_frequency,
+            total_samples: (duration.as_secs_f64() * (sample_rate.0 as f64)) as u64,
+            elapsed_samples: 0,
+        }
+    }
+}
+
+impl Iterator for Chirp {
+    type Item = f32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let i = self.elapsed_samples;
+        let ratio = self.elapsed_samples as f32 / self.total_samples as f32;
+        self.elapsed_samples += 1;
+        let freq = self.start_frequency * (1.0 - ratio) + self.end_frequency * ratio;
+        let t = (i as f32 / self.sample_rate() as f32) * TAU * freq;
+        Some(t.sin())
+    }
+}
+
+impl Source for Chirp {
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate.0
+    }
+
+    fn total_duration(&self) -> Option<Duration> {
+        let secs: f64 = self.total_samples as f64 / self.sample_rate.0 as f64;
+        Some(Duration::new(1, 0).mul_f64(secs))
+    }
+}

vendor/rodio/src/source/crossfade.rs

@@ -0,0 +1,79 @@
+use std::time::Duration;
+
+use cpal::FromSample;
+
+use crate::source::{FadeIn, Mix, TakeDuration};
+use crate::{Sample, Source};
+
+/// Mixes one sound fading out with another sound fading in for the given
+/// duration.
+///
+/// Only the crossfaded portion (beginning of fadeout, beginning of fadein) is
+/// returned.
+pub fn crossfade<I1, I2>(
+    input_fadeout: I1,
+    input_fadein: I2,
+    duration: Duration,
+) -> Crossfade<I1, I2>
+where
+    I1: Source,
+    I2: Source,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2::Item: Sample,
+{
+    let mut input_fadeout = input_fadeout.take_duration(duration);
+    input_fadeout.set_filter_fadeout();
+    let input_fadein = input_fadein.take_duration(duration).fade_in(duration);
+    input_fadeout.mix(input_fadein)
+}
+
+/// Mixes one sound fading out with another sound fading in for the given
+/// duration.
+///
+/// Only the crossfaded portion (beginning of fadeout, beginning of fadein) is
+/// covered.
+pub type Crossfade<I1, I2> = Mix<TakeDuration<I1>, FadeIn<TakeDuration<I2>>>;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::buffer::SamplesBuffer;
+    fn dummysource(length: u8) -> SamplesBuffer<f32> {
+        let data: Vec<f32> = (1..=length).map(f32::from).collect();
+        SamplesBuffer::new(1, 1, data)
+    }
+
+    #[test]
+    fn test_crossfade_with_self() {
+        let source1 = dummysource(10);
+        let source2 = dummysource(10);
+        let mut mixed = crossfade(
+            source1,
+            source2,
+            Duration::from_secs(5) + Duration::from_nanos(1),
+        );
+        assert_eq!(mixed.next(), Some(1.0));
+        assert_eq!(mixed.next(), Some(2.0));
+        assert_eq!(mixed.next(), Some(3.0));
+        assert_eq!(mixed.next(), Some(4.0));
+        assert_eq!(mixed.next(), Some(5.0));
+        assert_eq!(mixed.next(), None);
+    }
+
+    #[test]
+    fn test_crossfade() {
+        let source1 = dummysource(10);
+        let source2 = dummysource(10).amplify(0.0);
+        let mut mixed = crossfade(
+            source1,
+            source2,
+            Duration::from_secs(5) + Duration::from_nanos(1),
+        );
+        assert_eq!(mixed.next(), Some(1.0 * 1.0));
+        assert_eq!(mixed.next(), Some(2.0 * 0.8));
+        assert_eq!(mixed.next(), Some(3.0 * 0.6));
+        assert_eq!(mixed.next(), Some(4.0 * 0.4));
+        assert_eq!(mixed.next(), Some(5.0 * 0.2));
+        assert_eq!(mixed.next(), None);
+    }
+}

vendor/rodio/src/source/delay.rs

@@ -0,0 +1,138 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+fn remaining_samples(until_playback: Duration, sample_rate: u32, channels: u16) -> usize {
+    let ns = until_playback.as_secs() * 1_000_000_000 + until_playback.subsec_nanos() as u64;
+    let samples = ns * channels as u64 * sample_rate as u64 / 1_000_000_000;
+    samples as usize
+}
+
+/// Internal function that builds a `Delay` object.
+pub fn delay<I>(input: I, duration: Duration) -> Delay<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    Delay {
+        remaining_samples: remaining_samples(duration, input.sample_rate(), input.channels()),
+        requested_duration: duration,
+        input,
+    }
+}
+
+/// A source that delays the given source by a certain amount.
+#[derive(Clone, Debug)]
+pub struct Delay<I> {
+    input: I,
+    remaining_samples: usize,
+    requested_duration: Duration,
+}
+
+impl<I> Delay<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Delay<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = <I as Iterator>::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<<I as Iterator>::Item> {
+        if self.remaining_samples >= 1 {
+            self.remaining_samples -= 1;
+            Some(Sample::zero_value())
+        } else {
+            self.input.next()
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let (min, max) = self.input.size_hint();
+        (
+            min + self.remaining_samples,
+            max.map(|v| v + self.remaining_samples),
+        )
+    }
+}
+
+impl<I> Source for Delay<I>
+where
+    I: Iterator + Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input
+            .current_frame_len()
+            .map(|val| val + self.remaining_samples)
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input
+            .total_duration()
+            .map(|val| val + self.requested_duration)
+    }
+
+    /// Pos is seen from the perspective of the api user.
+    ///
+    /// # Example
+    ///
+    /// ```ignore
+    /// use std::time::Duration;
+    ///
+    /// let mut source = inner_source.delay(Duration::from_secs(10));
+    /// source.try_seek(Duration::from_secs(15));
+    ///
+    /// // inner_source is now at pos: Duration::from_secs(5);
+    /// ```
+    ///
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        if pos < self.requested_duration {
+            self.input.try_seek(Duration::ZERO)?;
+            let until_playback = self.requested_duration - pos;
+            self.remaining_samples =
+                remaining_samples(until_playback, self.sample_rate(), self.channels());
+        }
+        let compensated_for_delay = pos.saturating_sub(self.requested_duration);
+        self.input.try_seek(compensated_for_delay)
+    }
+}

vendor/rodio/src/source/done.rs

@@ -0,0 +1,99 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// When the inner source is empty this decrements a `AtomicUsize`.
+#[derive(Debug, Clone)]
+pub struct Done<I> {
+    input: I,
+    signal: Arc<AtomicUsize>,
+    signal_sent: bool,
+}
+
+impl<I> Done<I> {
+    /// When the inner source is empty the AtomicUsize passed in is decremented.
+    /// If it was zero it will overflow negatively.
+    #[inline]
+    pub fn new(input: I, signal: Arc<AtomicUsize>) -> Done<I> {
+        Done {
+            input,
+            signal,
+            signal_sent: false,
+        }
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I: Source> Iterator for Done<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        let next = self.input.next();
+        if !self.signal_sent && next.is_none() {
+            self.signal.fetch_sub(1, Ordering::Relaxed);
+            self.signal_sent = true;
+        }
+        next
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for Done<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/empty.rs

@@ -0,0 +1,67 @@
+use std::marker::PhantomData;
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// An empty source.
+#[derive(Debug, Copy, Clone)]
+pub struct Empty<S>(PhantomData<S>);
+
+impl<S> Default for Empty<S> {
+    #[inline]
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<S> Empty<S> {
+    /// An empty source that immediately ends without ever returning a sample to
+    /// play
+    #[inline]
+    pub fn new() -> Empty<S> {
+        Empty(PhantomData)
+    }
+}
+
+impl<S> Iterator for Empty<S> {
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        None
+    }
+}
+
+impl<S> Source for Empty<S>
+where
+    S: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        48000
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        Some(Duration::new(0, 0))
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}

vendor/rodio/src/source/empty_callback.rs

@@ -0,0 +1,70 @@
+use std::marker::PhantomData;
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// An empty source which executes a callback function
+pub struct EmptyCallback<S> {
+    #[allow(missing_docs)] // See: https://github.com/RustAudio/rodio/issues/615
+    pub phantom_data: PhantomData<S>,
+    #[allow(missing_docs)] // See: https://github.com/RustAudio/rodio/issues/615
+    pub callback: Box<dyn Send + Fn()>,
+}
+
+impl<S> EmptyCallback<S> {
+    #[inline]
+    /// Create an empty source which executes a callback function.
+    /// Example use-case:
+    ///
+    /// Detect and do something when the source before this one has ended.
+    pub fn new(callback: Box<dyn Send + Fn()>) -> EmptyCallback<S> {
+        EmptyCallback {
+            phantom_data: PhantomData,
+            callback,
+        }
+    }
+}
+
+impl<S> Iterator for EmptyCallback<S> {
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        (self.callback)();
+        None
+    }
+}
+
+impl<S> Source for EmptyCallback<S>
+where
+    S: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        48000
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        Some(Duration::new(0, 0))
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}

vendor/rodio/src/source/fadein.rs

@@ -0,0 +1,102 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::{linear_ramp::linear_gain_ramp, LinearGainRamp, SeekError};
+
+/// Internal function that builds a `FadeIn` object.
+pub fn fadein<I>(input: I, duration: Duration) -> FadeIn<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    FadeIn {
+        input: linear_gain_ramp(input, duration, 0.0f32, 1.0f32, false),
+    }
+}
+
+/// Filter that modifies raises the volume from silence over a time period.
+#[derive(Clone, Debug)]
+pub struct FadeIn<I> {
+    input: LinearGainRamp<I>,
+}
+
+impl<I> FadeIn<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        self.input.inner()
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        self.input.inner_mut()
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input.into_inner()
+    }
+}
+
+impl<I> Iterator for FadeIn<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for FadeIn<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for FadeIn<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.inner().current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.inner().channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.inner().sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.inner().total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.inner_mut().try_seek(pos)
+    }
+}

vendor/rodio/src/source/fadeout.rs

@@ -0,0 +1,102 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::{linear_ramp::linear_gain_ramp, LinearGainRamp, SeekError};
+
+/// Internal function that builds a `FadeOut` object.
+pub fn fadeout<I>(input: I, duration: Duration) -> FadeOut<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    FadeOut {
+        input: linear_gain_ramp(input, duration, 1.0f32, 0.0f32, true),
+    }
+}
+
+/// Filter that modifies lowers the volume to silence over a time period.
+#[derive(Clone, Debug)]
+pub struct FadeOut<I> {
+    input: LinearGainRamp<I>,
+}
+
+impl<I> FadeOut<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        self.input.inner()
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        self.input.inner_mut()
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input.into_inner()
+    }
+}
+
+impl<I> Iterator for FadeOut<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for FadeOut<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for FadeOut<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.inner().current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.inner().channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.inner().sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.inner().total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.inner_mut().try_seek(pos)
+    }
+}

vendor/rodio/src/source/from_factory.rs

@@ -0,0 +1,37 @@
+use crate::source::{from_iter, FromIter};
+
+/// Builds a source that chains sources built from a factory.
+///
+/// The `factory` parameter is a function that produces a source. The source is then played.
+/// Whenever the source ends, `factory` is called again in order to produce the source that is
+/// played next.
+///
+/// If the `factory` closure returns `None`, then the sound ends.
+pub fn from_factory<F, S>(factory: F) -> FromIter<FromFactoryIter<F>>
+where
+    F: FnMut() -> Option<S>,
+{
+    from_iter(FromFactoryIter { factory })
+}
+
+/// Internal type used by `from_factory`.
+pub struct FromFactoryIter<F> {
+    factory: F,
+}
+
+impl<F, S> Iterator for FromFactoryIter<F>
+where
+    F: FnMut() -> Option<S>,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        (self.factory)()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}

vendor/rodio/src/source/from_iter.rs

@@ -0,0 +1,183 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Builds a source that chains sources provided by an iterator.
+///
+/// The `iterator` parameter is an iterator that produces a source. The source is then played.
+/// Whenever the source ends, the `iterator` is used again in order to produce the source that is
+/// played next.
+///
+/// If the `iterator` produces `None`, then the sound ends.
+pub fn from_iter<I>(iterator: I) -> FromIter<I::IntoIter>
+where
+    I: IntoIterator,
+{
+    let mut iterator = iterator.into_iter();
+    let first_source = iterator.next();
+
+    FromIter {
+        iterator,
+        current_source: first_source,
+    }
+}
+
+/// A source that chains sources provided by an iterator.
+#[derive(Clone)]
+pub struct FromIter<I>
+where
+    I: Iterator,
+{
+    // The iterator that provides sources.
+    iterator: I,
+    // Is only ever `None` if the first element of the iterator is `None`.
+    current_source: Option<I::Item>,
+}
+
+impl<I> Iterator for FromIter<I>
+where
+    I: Iterator,
+    I::Item: Iterator + Source,
+    <I::Item as Iterator>::Item: Sample,
+{
+    type Item = <I::Item as Iterator>::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<<I::Item as Iterator>::Item> {
+        loop {
+            if let Some(src) = &mut self.current_source {
+                if let Some(value) = src.next() {
+                    return Some(value);
+                }
+            }
+
+            if let Some(src) = self.iterator.next() {
+                self.current_source = Some(src);
+            } else {
+                return None;
+            }
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if let Some(cur) = &self.current_source {
+            (cur.size_hint().0, None)
+        } else {
+            (0, None)
+        }
+    }
+}
+
+impl<I> Source for FromIter<I>
+where
+    I: Iterator,
+    I::Item: Iterator + Source,
+    <I::Item as Iterator>::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        // This function is non-trivial because the boundary between the current source and the
+        // next must be a frame boundary as well.
+        //
+        // The current sound is free to return `None` for `current_frame_len()`, in which case
+        // we *should* return the number of samples remaining the current sound.
+        // This can be estimated with `size_hint()`.
+        //
+        // If the `size_hint` is `None` as well, we are in the worst case scenario. To handle this
+        // situation we force a frame to have a maximum number of samples indicate by this
+        // constant.
+        const THRESHOLD: usize = 10240;
+
+        // Try the current `current_frame_len`.
+        if let Some(src) = &self.current_source {
+            if let Some(val) = src.current_frame_len() {
+                if val != 0 {
+                    return Some(val);
+                }
+            }
+        }
+
+        // Try the size hint.
+        if let Some(src) = &self.current_source {
+            if let Some(val) = src.size_hint().1 {
+                if val < THRESHOLD && val != 0 {
+                    return Some(val);
+                }
+            }
+        }
+
+        // Otherwise we use the constant value.
+        Some(THRESHOLD)
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        if let Some(src) = &self.current_source {
+            src.channels()
+        } else {
+            // Dummy value that only happens if the iterator was empty.
+            2
+        }
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        if let Some(src) = &self.current_source {
+            src.sample_rate()
+        } else {
+            // Dummy value that only happens if the iterator was empty.
+            44100
+        }
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        if let Some(source) = self.current_source.as_mut() {
+            source.try_seek(pos)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::buffer::SamplesBuffer;
+    use crate::source::{from_iter, Source};
+
+    #[test]
+    fn basic() {
+        let mut rx = from_iter((0..2).map(|n| {
+            if n == 0 {
+                SamplesBuffer::new(1, 48000, vec![10i16, -10, 10, -10])
+            } else if n == 1 {
+                SamplesBuffer::new(2, 96000, vec![5i16, 5, 5, 5])
+            } else {
+                unreachable!()
+            }
+        }));
+
+        assert_eq!(rx.channels(), 1);
+        assert_eq!(rx.sample_rate(), 48000);
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        assert_eq!(rx.next(), Some(10));
+        assert_eq!(rx.next(), Some(-10));
+        /*assert_eq!(rx.channels(), 2);
+        assert_eq!(rx.sample_rate(), 96000);*/
+        // FIXME: not working
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), Some(5));
+        assert_eq!(rx.next(), None);
+    }
+}

vendor/rodio/src/source/linear_ramp.rs

@@ -0,0 +1,238 @@
+use std::time::Duration;
+
+use super::SeekError;
+use crate::{Sample, Source};
+
+/// Internal function that builds a `LinearRamp` object.
+pub fn linear_gain_ramp<I>(
+    input: I,
+    duration: Duration,
+    start_gain: f32,
+    end_gain: f32,
+    clamp_end: bool,
+) -> LinearGainRamp<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let duration_nanos = duration.as_nanos() as f32;
+    assert!(duration_nanos > 0.0f32);
+
+    LinearGainRamp {
+        input,
+        elapsed_ns: 0.0f32,
+        total_ns: duration_nanos,
+        start_gain,
+        end_gain,
+        clamp_end,
+        sample_idx: 0u64,
+    }
+}
+
+/// Filter that adds a linear gain ramp to the source over a given time range.
+#[derive(Clone, Debug)]
+pub struct LinearGainRamp<I> {
+    input: I,
+    elapsed_ns: f32,
+    total_ns: f32,
+    start_gain: f32,
+    end_gain: f32,
+    clamp_end: bool,
+    sample_idx: u64,
+}
+
+impl<I> LinearGainRamp<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns a reference to the innner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for LinearGainRamp<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        let factor: f32;
+        let remaining_ns = self.total_ns - self.elapsed_ns;
+
+        if remaining_ns < 0.0 {
+            if self.clamp_end {
+                factor = self.end_gain;
+            } else {
+                factor = 1.0f32;
+            }
+        } else {
+            self.sample_idx += 1;
+
+            let p = self.elapsed_ns / self.total_ns;
+            factor = self.start_gain * (1.0f32 - p) + self.end_gain * p;
+        }
+
+        if self.sample_idx % (self.channels() as u64) == 0 {
+            self.elapsed_ns += 1000000000.0 / (self.input.sample_rate() as f32);
+        }
+
+        self.input.next().map(|value| value.amplify(factor))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for LinearGainRamp<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for LinearGainRamp<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.elapsed_ns = pos.as_nanos() as f32;
+        self.input.try_seek(pos)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use approx::assert_abs_diff_eq;
+
+    use super::*;
+    use crate::buffer::SamplesBuffer;
+
+    /// Create a SamplesBuffer of identical samples with value `value`.
+    /// Returned buffer is one channel and has a sample rate of 1 hz.
+    fn const_source(length: u8, value: f32) -> SamplesBuffer<f32> {
+        let data: Vec<f32> = (1..=length).map(|_| value).collect();
+        SamplesBuffer::new(1, 1, data)
+    }
+
+    /// Create a SamplesBuffer of repeating sample values from `values`.
+    fn cycle_source(length: u8, values: Vec<f32>) -> SamplesBuffer<f32> {
+        let data: Vec<f32> = (1..=length)
+            .enumerate()
+            .map(|(i, _)| values[i % values.len()])
+            .collect();
+
+        SamplesBuffer::new(1, 1, data)
+    }
+
+    #[test]
+    fn test_linear_ramp() {
+        let source1 = const_source(10, 1.0f32);
+        let mut faded = linear_gain_ramp(source1, Duration::from_secs(4), 0.0, 1.0, true);
+
+        assert_eq!(faded.next(), Some(0.0));
+        assert_eq!(faded.next(), Some(0.25));
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), Some(0.75));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), Some(1.0));
+        assert_eq!(faded.next(), None);
+    }
+
+    #[test]
+    fn test_linear_ramp_clamped() {
+        let source1 = const_source(10, 1.0f32);
+        let mut faded = linear_gain_ramp(source1, Duration::from_secs(4), 0.0, 0.5, true);
+
+        assert_eq!(faded.next(), Some(0.0)); // fading in...
+        assert_eq!(faded.next(), Some(0.125));
+        assert_eq!(faded.next(), Some(0.25));
+        assert_eq!(faded.next(), Some(0.375));
+        assert_eq!(faded.next(), Some(0.5)); // fade is done
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), Some(0.5));
+        assert_eq!(faded.next(), None);
+    }
+
+    #[test]
+    fn test_linear_ramp_seek() {
+        let source1 = cycle_source(20, vec![0.0f32, 0.4f32, 0.8f32]);
+        let mut faded = linear_gain_ramp(source1, Duration::from_secs(10), 0.0, 1.0, true);
+
+        assert_abs_diff_eq!(faded.next().unwrap(), 0.0); // source value 0
+        assert_abs_diff_eq!(faded.next().unwrap(), 0.04); // source value 0.4, ramp gain 0.1
+        assert_abs_diff_eq!(faded.next().unwrap(), 0.16); // source value 0.8, ramp gain 0.2
+
+        if let Ok(_result) = faded.try_seek(Duration::from_secs(5)) {
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.40); // source value 0.8, ramp gain 0.5
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.0); // source value 0, ramp gain 0.6
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.28); // source value 0.4. ramp gain 0.7
+        } else {
+            panic!("try_seek() failed!");
+        }
+
+        if let Ok(_result) = faded.try_seek(Duration::from_secs(0)) {
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.0); // source value 0, ramp gain 0.0
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.04); // source value 0.4, ramp gain 0.1
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.16); // source value 0.8. ramp gain 0.2
+        } else {
+            panic!("try_seek() failed!");
+        }
+
+        if let Ok(_result) = faded.try_seek(Duration::from_secs(10)) {
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.4); // source value 0.4, ramp gain 1.0
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.8); // source value 0.8, ramp gain 1.0
+            assert_abs_diff_eq!(faded.next().unwrap(), 0.0); // source value 0. ramp gain 1.0
+        } else {
+            panic!("try_seek() failed!");
+        }
+    }
+}

vendor/rodio/src/source/mix.rs

@@ -0,0 +1,144 @@
+use std::cmp;
+use std::time::Duration;
+
+use crate::source::uniform::UniformSourceIterator;
+use crate::source::SeekError;
+use crate::{Sample, Source};
+use cpal::{FromSample, Sample as CpalSample};
+
+/// Internal function that builds a `Mix` object.
+pub fn mix<I1, I2>(input1: I1, input2: I2) -> Mix<I1, I2>
+where
+    I1: Source,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2: Source,
+    I2::Item: Sample,
+{
+    let channels = input1.channels();
+    let rate = input1.sample_rate();
+
+    Mix {
+        input1: UniformSourceIterator::new(input1, channels, rate),
+        input2: UniformSourceIterator::new(input2, channels, rate),
+    }
+}
+
+/// Filter that modifies each sample by a given value.
+#[derive(Clone)]
+pub struct Mix<I1, I2>
+where
+    I1: Source,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2: Source,
+    I2::Item: Sample,
+{
+    input1: UniformSourceIterator<I1, I1::Item>,
+    input2: UniformSourceIterator<I2, I2::Item>,
+}
+
+impl<I1, I2> Iterator for Mix<I1, I2>
+where
+    I1: Source,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2: Source,
+    I2::Item: Sample,
+{
+    type Item = I1::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I1::Item> {
+        let s1 = self.input1.next();
+        let s2 = self.input2.next();
+
+        match (s1, s2) {
+            (Some(s1), Some(s2)) => Some(s1.saturating_add(CpalSample::from_sample(s2))),
+            (Some(s1), None) => Some(s1),
+            (None, Some(s2)) => Some(CpalSample::from_sample(s2)),
+            (None, None) => None,
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let s1 = self.input1.size_hint();
+        let s2 = self.input2.size_hint();
+
+        let min = cmp::max(s1.0, s2.0);
+        let max = match (s1.1, s2.1) {
+            (Some(s1), Some(s2)) => Some(cmp::max(s1, s2)),
+            _ => None,
+        };
+
+        (min, max)
+    }
+}
+
+impl<I1, I2> ExactSizeIterator for Mix<I1, I2>
+where
+    I1: Source + ExactSizeIterator,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2: Source + ExactSizeIterator,
+    I2::Item: Sample,
+{
+}
+
+impl<I1, I2> Source for Mix<I1, I2>
+where
+    I1: Source,
+    I1::Item: FromSample<I2::Item> + Sample,
+    I2: Source,
+    I2::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        let f1 = self.input1.current_frame_len();
+        let f2 = self.input2.current_frame_len();
+
+        match (f1, f2) {
+            (Some(f1), Some(f2)) => Some(cmp::min(f1, f2)),
+            _ => None,
+        }
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input1.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input1.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        let f1 = self.input1.total_duration();
+        let f2 = self.input2.total_duration();
+
+        match (f1, f2) {
+            (Some(f1), Some(f2)) => Some(cmp::max(f1, f2)),
+            _ => None,
+        }
+    }
+
+    /// Will only attempt a seek if both underlying sources support seek.
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+
+        // uncomment when #510 is implemented (query position of playback)
+        // TODO use source_intact to check if rollback makes sense
+
+        // let org_pos = self.input1.playback_pos();
+        // self.input1.try_seek(pos)?;
+        //
+        // let res = self.input2.try_seek(pos);
+        // if res.is_err() { // rollback seek in input1
+        //     self.input1.try_seek(org_pos)?;
+        // }
+        //
+        // res
+    }
+}

vendor/rodio/src/source/mod.rs

@@ -0,0 +1,697 @@
+//! Sources of sound and various filters.
+
+use core::fmt;
+use core::time::Duration;
+
+use cpal::FromSample;
+
+use crate::Sample;
+
+pub use self::agc::AutomaticGainControl;
+pub use self::amplify::Amplify;
+pub use self::blt::BltFilter;
+pub use self::buffered::Buffered;
+pub use self::channel_volume::ChannelVolume;
+pub use self::chirp::{chirp, Chirp};
+pub use self::crossfade::Crossfade;
+pub use self::delay::Delay;
+pub use self::done::Done;
+pub use self::empty::Empty;
+pub use self::empty_callback::EmptyCallback;
+pub use self::fadein::FadeIn;
+pub use self::fadeout::FadeOut;
+pub use self::from_factory::{from_factory, FromFactoryIter};
+pub use self::from_iter::{from_iter, FromIter};
+pub use self::linear_ramp::LinearGainRamp;
+pub use self::mix::Mix;
+pub use self::pausable::Pausable;
+pub use self::periodic::PeriodicAccess;
+pub use self::position::TrackPosition;
+pub use self::repeat::Repeat;
+pub use self::samples_converter::SamplesConverter;
+pub use self::signal_generator::{Function, SignalGenerator};
+pub use self::sine::SineWave;
+pub use self::skip::SkipDuration;
+pub use self::skippable::Skippable;
+pub use self::spatial::Spatial;
+pub use self::speed::Speed;
+pub use self::stoppable::Stoppable;
+pub use self::take::TakeDuration;
+pub use self::uniform::UniformSourceIterator;
+pub use self::zero::Zero;
+
+mod agc;
+mod amplify;
+mod blt;
+mod buffered;
+mod channel_volume;
+mod chirp;
+mod crossfade;
+mod delay;
+mod done;
+mod empty;
+mod empty_callback;
+mod fadein;
+mod fadeout;
+mod from_factory;
+mod from_iter;
+mod linear_ramp;
+mod mix;
+mod pausable;
+mod periodic;
+mod position;
+mod repeat;
+mod samples_converter;
+mod signal_generator;
+mod sine;
+mod skip;
+mod skippable;
+mod spatial;
+mod speed;
+mod stoppable;
+mod take;
+mod uniform;
+mod zero;
+
+#[cfg(feature = "noise")]
+mod noise;
+#[cfg(feature = "noise")]
+pub use self::noise::{pink, white, PinkNoise, WhiteNoise};
+
+/// A source of samples.
+///
+/// # A quick lesson about sounds
+///
+/// ## Sampling
+///
+/// A sound is a vibration that propagates through air and reaches your ears. This vibration can
+/// be represented as an analog signal.
+///
+/// In order to store this signal in the computer's memory or on the disk, we perform what is
+/// called *sampling*. The consists in choosing an interval of time (for example 20µs) and reading
+/// the amplitude of the signal at each interval (for example, if the interval is 20µs we read the
+/// amplitude every 20µs). By doing so we obtain a list of numerical values, each value being
+/// called a *sample*.
+///
+/// Therefore a sound can be represented in memory by a frequency and a list of samples. The
+/// frequency is expressed in hertz and corresponds to the number of samples that have been
+/// read per second. For example if we read one sample every 20µs, the frequency would be
+/// 50000 Hz. In reality, common values for the frequency are 44100, 48000 and 96000.
+///
+/// ## Channels
+///
+/// But a frequency and a list of values only represent one signal. When you listen to a sound,
+/// your left and right ears don't receive exactly the same signal. In order to handle this,
+/// we usually record not one but two different signals: one for the left ear and one for the right
+/// ear. We say that such a sound has two *channels*.
+///
+/// Sometimes sounds even have five or six channels, each corresponding to a location around the
+/// head of the listener.
+///
+/// The standard in audio manipulation is to *interleave* the multiple channels. In other words,
+/// in a sound with two channels the list of samples contains the first sample of the first
+/// channel, then the first sample of the second channel, then the second sample of the first
+/// channel, then the second sample of the second channel, and so on. The same applies if you have
+/// more than two channels. The rodio library only supports this schema.
+///
+/// Therefore in order to represent a sound in memory in fact we need three characteristics: the
+/// frequency, the number of channels, and the list of samples.
+///
+/// ## The `Source` trait
+///
+/// A Rust object that represents a sound should implement the `Source` trait.
+///
+/// The three characteristics that describe a sound are provided through this trait:
+///
+/// - The number of channels can be retrieved with `channels`.
+/// - The frequency can be retrieved with `sample_rate`.
+/// - The list of values can be retrieved by iterating on the source. The `Source` trait requires
+///   that the `Iterator` trait be implemented as well. When a `Source` returns None the
+///   sound has ended.
+///
+/// # Frames
+///
+/// The samples rate and number of channels of some sound sources can change by itself from time
+/// to time.
+///
+/// > **Note**: As a basic example, if you play two audio files one after the other and treat the
+/// > whole as a single source, then the channels and samples rate of that source may change at the
+/// > transition between the two files.
+///
+/// However, for optimization purposes rodio supposes that the number of channels and the frequency
+/// stay the same for long periods of time and avoids calling `channels()` and
+/// `sample_rate` too frequently.
+///
+/// In order to properly handle this situation, the `current_frame_len()` method should return
+/// the number of samples that remain in the iterator before the samples rate and number of
+/// channels can potentially change.
+///
+pub trait Source: Iterator
+where
+    Self::Item: Sample,
+{
+    /// Returns the number of samples before the current frame ends. `None` means "infinite" or
+    /// "until the sound ends".
+    /// Should never return 0 unless there's no more data.
+    ///
+    /// After the engine has finished reading the specified number of samples, it will check
+    /// whether the value of `channels()` and/or `sample_rate()` have changed.
+    fn current_frame_len(&self) -> Option<usize>;
+
+    /// Returns the number of channels. Channels are always interleaved.
+    fn channels(&self) -> u16;
+
+    /// Returns the rate at which the source should be played. In number of samples per second.
+    fn sample_rate(&self) -> u32;
+
+    /// Returns the total duration of this source, if known.
+    ///
+    /// `None` indicates at the same time "infinite" or "unknown".
+    fn total_duration(&self) -> Option<Duration>;
+
+    /// Stores the source in a buffer in addition to returning it. This iterator can be cloned.
+
+    #[inline]
+    fn buffered(self) -> Buffered<Self>
+    where
+        Self: Sized,
+    {
+        buffered::buffered(self)
+    }
+
+    /// Mixes this source with another one.
+    #[inline]
+    fn mix<S>(self, other: S) -> Mix<Self, S>
+    where
+        Self: Sized,
+        Self::Item: FromSample<S::Item>,
+        S: Source,
+        S::Item: Sample,
+    {
+        mix::mix(self, other)
+    }
+
+    /// Repeats this source forever.
+    ///
+    /// Note that this works by storing the data in a buffer, so the amount of memory used is
+    /// proportional to the size of the sound.
+    #[inline]
+    fn repeat_infinite(self) -> Repeat<Self>
+    where
+        Self: Sized,
+    {
+        repeat::repeat(self)
+    }
+
+    /// Takes a certain duration of this source and then stops.
+    #[inline]
+    fn take_duration(self, duration: Duration) -> TakeDuration<Self>
+    where
+        Self: Sized,
+    {
+        take::take_duration(self, duration)
+    }
+
+    /// Delays the sound by a certain duration.
+    ///
+    /// The rate and channels of the silence will use the same format as the first frame of the
+    /// source.
+    #[inline]
+    fn delay(self, duration: Duration) -> Delay<Self>
+    where
+        Self: Sized,
+    {
+        delay::delay(self, duration)
+    }
+
+    /// Immediately skips a certain duration of this source.
+    ///
+    /// If the specified duration is longer than the source itself, `skip_duration` will skip to the end of the source.
+    #[inline]
+    fn skip_duration(self, duration: Duration) -> SkipDuration<Self>
+    where
+        Self: Sized,
+    {
+        skip::skip_duration(self, duration)
+    }
+
+    /// Amplifies the sound by the given value.
+    #[inline]
+    fn amplify(self, value: f32) -> Amplify<Self>
+    where
+        Self: Sized,
+    {
+        amplify::amplify(self, value)
+    }
+
+    /// Applies automatic gain control to the sound.
+    ///
+    /// Automatic Gain Control (AGC) adjusts the amplitude of the audio signal
+    /// to maintain a consistent output level.
+    ///
+    /// # Parameters
+    ///
+    /// `target_level`:
+    ///   **TL;DR**: Desired output level. 1.0 = original level, > 1.0 amplifies, < 1.0 reduces.
+    ///
+    ///   The desired output level, where 1.0 represents the original sound level.
+    ///   Values above 1.0 will amplify the sound, while values below 1.0 will lower it.
+    ///   For example, a target_level of 1.4 means that at normal sound levels, the AGC
+    ///   will aim to increase the gain by a factor of 1.4, resulting in a minimum 40% amplification.
+    ///   A recommended level is `1.0`, which maintains the original sound level.
+    ///
+    /// `attack_time`:
+    ///   **TL;DR**: Response time for volume increases. Shorter = faster but may cause abrupt changes. **Recommended: `4.0` seconds**.
+    ///
+    ///   The time (in seconds) for the AGC to respond to input level increases.
+    ///   Shorter times mean faster response but may cause abrupt changes. Longer times result
+    ///   in smoother transitions but slower reactions to sudden volume changes. Too short can
+    ///   lead to overreaction to peaks, causing unnecessary adjustments. Too long can make the
+    ///   AGC miss important volume changes or react too slowly to sudden loud passages. Very
+    ///   high values might result in excessively loud output or sluggish response, as the AGC's
+    ///   adjustment speed is limited by the attack time. Balance is key for optimal performance.
+    ///   A recommended attack_time of `4.0` seconds provides a sweet spot for most applications.
+    ///
+    /// `release_time`:
+    ///   **TL;DR**: Response time for volume decreases. Shorter = faster gain reduction. **Recommended: `0.005` seconds**.
+    ///
+    ///   The time (in seconds) for the AGC to respond to input level decreases.
+    ///   This parameter controls how quickly the gain is reduced when the signal level drops.
+    ///   Shorter release times result in faster gain reduction, which can be useful for quick
+    ///   adaptation to quieter passages but may lead to pumping effects. Longer release times
+    ///   provide smoother transitions but may be slower to respond to sudden decreases in volume.
+    ///   However, if the release_time is too high, the AGC may not be able to lower the gain
+    ///   quickly enough, potentially leading to clipping and distorted sound before it can adjust.
+    ///   Finding the right balance is crucial for maintaining natural-sounding dynamics and
+    ///   preventing distortion. A recommended release_time of `0.005` seconds often works well for
+    ///   general use, providing a good balance between responsiveness and smooth transitions.
+    ///
+    /// `absolute_max_gain`:
+    ///   **TL;DR**: Maximum allowed gain. Prevents over-amplification. **Recommended: `5.0`**.
+    ///
+    ///   The maximum gain that can be applied to the signal.
+    ///   This parameter acts as a safeguard against excessive amplification of quiet signals
+    ///   or background noise. It establishes an upper boundary for the AGC's signal boost,
+    ///   effectively preventing distortion or overamplification of low-level sounds.
+    ///   This is crucial for maintaining audio quality and preventing unexpected volume spikes.
+    ///   A recommended value for `absolute_max_gain` is `5`, which provides a good balance between
+    ///   amplification capability and protection against distortion in most scenarios.
+    ///
+    /// Use `get_agc_control` to obtain a handle for real-time enabling/disabling of the AGC.
+    ///
+    /// # Example (Quick start)
+    ///
+    /// ```rust
+    /// // Apply Automatic Gain Control to the source (AGC is on by default)
+    /// let agc_source = source.automatic_gain_control(1.0, 4.0, 0.005, 5.0);
+    ///
+    /// // Get a handle to control the AGC's enabled state (optional)
+    /// let agc_control = agc_source.get_agc_control();
+    ///
+    /// // You can toggle AGC on/off at any time (optional)
+    /// agc_control.store(false, std::sync::atomic::Ordering::Relaxed);
+    ///
+    /// // Add the AGC-controlled source to the sink
+    /// sink.append(agc_source);
+    ///
+    /// // Note: Using agc_control is optional. If you don't need to toggle AGC,
+    /// // you can simply use the agc_source directly without getting agc_control.
+    /// ```
+    #[inline]
+    fn automatic_gain_control(
+        self,
+        target_level: f32,
+        attack_time: f32,
+        release_time: f32,
+        absolute_max_gain: f32,
+    ) -> AutomaticGainControl<Self>
+    where
+        Self: Sized,
+    {
+        // Added Limits to prevent the AGC from blowing up. ;)
+        const MIN_ATTACK_TIME: f32 = 10.0;
+        const MIN_RELEASE_TIME: f32 = 10.0;
+        let attack_time = attack_time.min(MIN_ATTACK_TIME);
+        let release_time = release_time.min(MIN_RELEASE_TIME);
+
+        agc::automatic_gain_control(
+            self,
+            target_level,
+            attack_time,
+            release_time,
+            absolute_max_gain,
+        )
+    }
+
+    /// Mixes this sound fading out with another sound fading in for the given duration.
+    ///
+    /// Only the crossfaded portion (beginning of self, beginning of other) is returned.
+    #[inline]
+    fn take_crossfade_with<S: Source>(self, other: S, duration: Duration) -> Crossfade<Self, S>
+    where
+        Self: Sized,
+        Self::Item: FromSample<S::Item>,
+        <S as Iterator>::Item: Sample,
+    {
+        crossfade::crossfade(self, other, duration)
+    }
+
+    /// Fades in the sound.
+    #[inline]
+    fn fade_in(self, duration: Duration) -> FadeIn<Self>
+    where
+        Self: Sized,
+    {
+        fadein::fadein(self, duration)
+    }
+
+    /// Fades out the sound.
+    #[inline]
+    fn fade_out(self, duration: Duration) -> FadeOut<Self>
+    where
+        Self: Sized,
+    {
+        fadeout::fadeout(self, duration)
+    }
+
+    /// Applies a linear gain ramp to the sound.
+    ///
+    /// If `clamp_end` is `true`, all samples subsequent to the end of the ramp
+    /// will be scaled by the `end_value`. If `clamp_end` is `false`, all
+    /// subsequent samples will not have any scaling applied.
+    #[inline]
+    fn linear_gain_ramp(
+        self,
+        duration: Duration,
+        start_value: f32,
+        end_value: f32,
+        clamp_end: bool,
+    ) -> LinearGainRamp<Self>
+    where
+        Self: Sized,
+    {
+        linear_ramp::linear_gain_ramp(self, duration, start_value, end_value, clamp_end)
+    }
+
+    /// Calls the `access` closure on `Self` the first time the source is iterated and every
+    /// time `period` elapses.
+    ///
+    /// Later changes in either `sample_rate()` or `channels_count()` won't be reflected in
+    /// the rate of access.
+    ///
+    /// The rate is based on playback speed, so both the following will call `access` when the
+    /// same samples are reached:
+    /// `periodic_access(Duration::from_secs(1), ...).speed(2.0)`
+    /// `speed(2.0).periodic_access(Duration::from_secs(2), ...)`
+    #[inline]
+    fn periodic_access<F>(self, period: Duration, access: F) -> PeriodicAccess<Self, F>
+    where
+        Self: Sized,
+        F: FnMut(&mut Self),
+    {
+        periodic::periodic(self, period, access)
+    }
+
+    /// Changes the play speed of the sound. Does not adjust the samples, only the playback speed.
+    ///
+    /// # Note:
+    /// 1. **Increasing the speed will increase the pitch by the same factor**
+    /// - If you set the speed to 0.5 this will halve the frequency of the sound
+    ///   lowering its pitch.
+    /// - If you set the speed to 2 the frequency will double raising the
+    ///   pitch of the sound.
+    /// 2. **Change in the speed affect the total duration inversely**
+    /// - If you set the speed to 0.5, the total duration will be twice as long.
+    /// - If you set the speed to 2 the total duration will be halve of what it
+    ///   was.
+    ///
+    /// See [`Speed`] for details
+    #[inline]
+    fn speed(self, ratio: f32) -> Speed<Self>
+    where
+        Self: Sized,
+    {
+        speed::speed(self, ratio)
+    }
+
+    /// Adds a basic reverb effect.
+    ///
+    /// This function requires the source to implement `Clone`. This can be done by using
+    /// `buffered()`.
+    ///
+    /// # Example
+    ///
+    /// ```ignore
+    /// use std::time::Duration;
+    ///
+    /// let source = source.buffered().reverb(Duration::from_millis(100), 0.7);
+    /// ```
+    #[inline]
+    fn reverb(self, duration: Duration, amplitude: f32) -> Mix<Self, Delay<Amplify<Self>>>
+    where
+        Self: Sized + Clone,
+    {
+        let echo = self.clone().amplify(amplitude).delay(duration);
+        self.mix(echo)
+    }
+
+    /// Converts the samples of this source to another type.
+    #[inline]
+    fn convert_samples<D>(self) -> SamplesConverter<Self, D>
+    where
+        Self: Sized,
+        D: Sample,
+    {
+        SamplesConverter::new(self)
+    }
+
+    /// Makes the sound pausable.
+    // TODO: add example
+    #[inline]
+    fn pausable(self, initially_paused: bool) -> Pausable<Self>
+    where
+        Self: Sized,
+    {
+        pausable::pausable(self, initially_paused)
+    }
+
+    /// Makes the sound stoppable.
+    // TODO: add example
+    #[inline]
+    fn stoppable(self) -> Stoppable<Self>
+    where
+        Self: Sized,
+    {
+        stoppable::stoppable(self)
+    }
+
+    /// Adds a method [`Skippable::skip`] for skipping this source. Skipping
+    /// makes Source::next() return None. Which in turn makes the Sink skip to
+    /// the next source.
+    fn skippable(self) -> Skippable<Self>
+    where
+        Self: Sized,
+    {
+        skippable::skippable(self)
+    }
+
+    /// Start tracking the elapsed duration since the start of the underlying
+    /// source.
+    ///
+    /// If a speedup and or delay is applied after this that will not be reflected
+    /// in the position returned by [`get_pos`](TrackPosition::get_pos).
+    ///
+    /// This can get confusing when using [`get_pos()`](TrackPosition::get_pos)
+    /// together with [`Source::try_seek()`] as the latter does take all
+    /// speedup's and delay's into account. Its recommended therefore to apply
+    /// track_position after speedup's and delay's.
+    fn track_position(self) -> TrackPosition<Self>
+    where
+        Self: Sized,
+    {
+        position::track_position(self)
+    }
+
+    /// Applies a low-pass filter to the source.
+    /// **Warning**: Probably buggy.
+    #[inline]
+    fn low_pass(self, freq: u32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::low_pass(self, freq)
+    }
+
+    /// Applies a high-pass filter to the source.
+    #[inline]
+    fn high_pass(self, freq: u32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::high_pass(self, freq)
+    }
+
+    /// Applies a low-pass filter to the source while allowing the q (bandwidth) to be changed.
+    #[inline]
+    fn low_pass_with_q(self, freq: u32, q: f32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::low_pass_with_q(self, freq, q)
+    }
+
+    /// Applies a high-pass filter to the source while allowing the q (bandwidth) to be changed.
+    #[inline]
+    fn high_pass_with_q(self, freq: u32, q: f32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::high_pass_with_q(self, freq, q)
+    }
+
+    // There is no `can_seek()` method as it is impossible to use correctly. Between
+    // checking if a source supports seeking and actually seeking the sink can
+    // switch to a new source.
+
+    /// Attempts to seek to a given position in the current source.
+    ///
+    /// As long as the duration of the source is known seek is guaranteed to saturate
+    /// at the end of the source. For example given a source that reports a total duration
+    /// of 42 seconds calling `try_seek()` with 60 seconds as argument will seek to
+    /// 42 seconds.
+    ///
+    /// # Errors
+    /// This function will return [`SeekError::NotSupported`] if one of the underlying
+    /// sources does not support seeking.
+    ///
+    /// It will return an error if an implementation ran
+    /// into one during the seek.
+    ///
+    /// Seeking beyond the end of a source might return an error if the total duration of
+    /// the source is not known.
+    #[allow(unused_variables)]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+// We might add decoders requiring new error types, without non_exhaustive
+// this would break users builds
+/// Occurs when try_seek fails because the underlying decoder has an error or
+/// does not support seeking.
+#[non_exhaustive]
+#[derive(Debug)]
+pub enum SeekError {
+    /// One of the underlying sources does not support seeking
+    NotSupported {
+        /// The source that did not support seek
+        underlying_source: &'static str,
+    },
+    #[cfg(feature = "symphonia")]
+    /// The symphonia decoder ran into an issue
+    SymphoniaDecoder(crate::decoder::symphonia::SeekError),
+    #[cfg(feature = "wav")]
+    /// The hound (wav) decoder ran into an issue
+    HoundDecoder(std::io::Error),
+    // Prefer adding an enum variant to using this. Its meant for end users their
+    // own try_seek implementations
+    /// Any other error probably in a custom Source
+    Other(Box<dyn std::error::Error + Send>),
+}
+impl fmt::Display for SeekError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            SeekError::NotSupported { underlying_source } => {
+                write!(
+                    f,
+                    "Seeking is not supported by source: {}",
+                    underlying_source
+                )
+            }
+            #[cfg(feature = "symphonia")]
+            SeekError::SymphoniaDecoder(err) => write!(f, "Error seeking: {}", err),
+            #[cfg(feature = "wav")]
+            SeekError::HoundDecoder(err) => write!(f, "Error seeking in wav source: {}", err),
+            SeekError::Other(_) => write!(f, "An error occurred"),
+        }
+    }
+}
+impl std::error::Error for SeekError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            SeekError::NotSupported { .. } => None,
+            #[cfg(feature = "symphonia")]
+            SeekError::SymphoniaDecoder(err) => Some(err),
+            #[cfg(feature = "wav")]
+            SeekError::HoundDecoder(err) => Some(err),
+            SeekError::Other(err) => Some(err.as_ref()),
+        }
+    }
+}
+
+#[cfg(feature = "symphonia")]
+impl From<crate::decoder::symphonia::SeekError> for SeekError {
+    fn from(source: crate::decoder::symphonia::SeekError) -> Self {
+        SeekError::SymphoniaDecoder(source)
+    }
+}
+
+impl SeekError {
+    /// Will the source remain playing at its position before the seek or is it
+    /// broken?
+    pub fn source_intact(&self) -> bool {
+        match self {
+            SeekError::NotSupported { .. } => true,
+            #[cfg(feature = "symphonia")]
+            SeekError::SymphoniaDecoder(_) => false,
+            #[cfg(feature = "wav")]
+            SeekError::HoundDecoder(_) => false,
+            SeekError::Other(_) => false,
+        }
+    }
+}
+
+macro_rules! source_pointer_impl {
+    ($($sig:tt)+) => {
+        impl $($sig)+ {
+            #[inline]
+            fn current_frame_len(&self) -> Option<usize> {
+                (**self).current_frame_len()
+            }
+
+            #[inline]
+            fn channels(&self) -> u16 {
+                (**self).channels()
+            }
+
+            #[inline]
+            fn sample_rate(&self) -> u32 {
+                (**self).sample_rate()
+            }
+
+            #[inline]
+            fn total_duration(&self) -> Option<Duration> {
+                (**self).total_duration()
+            }
+
+            #[inline]
+            fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+                (**self).try_seek(pos)
+            }
+        }
+    };
+}
+
+source_pointer_impl!(<S> Source for Box<dyn Source<Item = S>> where S: Sample,);
+
+source_pointer_impl!(<S> Source for Box<dyn Source<Item = S> + Send> where S: Sample,);
+
+source_pointer_impl!(<S> Source for Box<dyn Source<Item = S> + Send + Sync> where S: Sample,);
+
+source_pointer_impl!(<'a, S, C> Source for &'a mut C where S: Sample, C: Source<Item = S>,);

vendor/rodio/src/source/noise.rs

@@ -0,0 +1,158 @@
+//! Noise sources.
+//!
+//!
+
+use crate::Source;
+
+use super::SeekError;
+
+use rand::{rngs::SmallRng, RngCore, SeedableRng};
+
+/// Convenience function to create a new `WhiteNoise` noise source.
+#[inline]
+pub fn white(sample_rate: cpal::SampleRate) -> WhiteNoise {
+    WhiteNoise::new(sample_rate)
+}
+
+/// Convenience function to create a new `PinkNoise` noise source.
+#[inline]
+pub fn pink(sample_rate: cpal::SampleRate) -> PinkNoise {
+    PinkNoise::new(sample_rate)
+}
+
+/// Generates an infinite stream of random samples in [-1.0, 1.0]. This source generates random
+/// samples as provided by the `rand::rngs::SmallRng` randomness source.
+#[derive(Clone, Debug)]
+pub struct WhiteNoise {
+    sample_rate: cpal::SampleRate,
+    rng: SmallRng,
+}
+
+impl WhiteNoise {
+    /// Create a new white noise generator, seeding the RNG with `seed`.
+    pub fn new_with_seed(sample_rate: cpal::SampleRate, seed: u64) -> Self {
+        Self {
+            sample_rate,
+            rng: SmallRng::seed_from_u64(seed),
+        }
+    }
+
+    /// Create a new white noise generator, seeding the RNG with system entropy.
+    pub fn new(sample_rate: cpal::SampleRate) -> Self {
+        Self {
+            sample_rate,
+            rng: SmallRng::from_entropy(),
+        }
+    }
+}
+
+impl Iterator for WhiteNoise {
+    type Item = f32;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        let rand = self.rng.next_u32() as f32 / u32::MAX as f32;
+        let scaled = rand * 2.0 - 1.0;
+        Some(scaled)
+    }
+}
+
+impl Source for WhiteNoise {
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate.0
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<std::time::Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: std::time::Duration) -> Result<(), SeekError> {
+        // Does nothing, should do nothing
+        Ok(())
+    }
+}
+
+/// Generates an infinite stream of pink noise samples in [-1.0, 1.0].
+///
+/// The output of the source is the result of taking the output of the `WhiteNoise` source and
+/// filtering it according to a weighted-sum of seven FIR filters after [Paul Kellett's
+/// method][pk_method] from *musicdsp.org*.
+///
+/// [pk_method]: https://www.musicdsp.org/en/latest/Filters/76-pink-noise-filter.html
+pub struct PinkNoise {
+    white_noise: WhiteNoise,
+    b: [f32; 7],
+}
+
+impl PinkNoise {
+    pub fn new(sample_rate: cpal::SampleRate) -> Self {
+        Self {
+            white_noise: WhiteNoise::new(sample_rate),
+            b: [0.0f32, 0.0f32, 0.0f32, 0.0f32, 0.0f32, 0.0f32, 0.0f32],
+        }
+    }
+}
+
+impl Iterator for PinkNoise {
+    type Item = f32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let white = self.white_noise.next().unwrap();
+        self.b[0] = 0.99886 * self.b[0] + white * 0.0555179;
+        self.b[1] = 0.99332 * self.b[1] + white * 0.0750759;
+        self.b[2] = 0.969 * self.b[2] + white * 0.153852;
+        self.b[3] = 0.8665 * self.b[3] + white * 0.3104856;
+        self.b[4] = 0.550 * self.b[4] + white * 0.5329522;
+        self.b[5] = -0.7616 * self.b[5] - white * 0.016898;
+
+        let pink = self.b[0]
+            + self.b[1]
+            + self.b[2]
+            + self.b[3]
+            + self.b[4]
+            + self.b[5]
+            + self.b[6]
+            + white * 0.5362;
+
+        self.b[6] = white * 0.115926;
+
+        Some(pink)
+    }
+}
+
+impl Source for PinkNoise {
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    fn sample_rate(&self) -> u32 {
+        self.white_noise.sample_rate()
+    }
+
+    fn total_duration(&self) -> Option<std::time::Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: std::time::Duration) -> Result<(), SeekError> {
+        // Does nothing, should do nothing
+        Ok(())
+    }
+}

vendor/rodio/src/source/pausable.rs

@@ -0,0 +1,131 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Builds a `Pausable` object.
+pub fn pausable<I>(source: I, paused: bool) -> Pausable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let paused_channels = if paused {
+        Some(source.channels())
+    } else {
+        None
+    };
+    Pausable {
+        input: source,
+        paused_channels,
+        remaining_paused_samples: 0,
+    }
+}
+
+/// Wraps a source and makes it pausable by calling [`Pausable::set_paused`] on
+/// this object. When the source is paused it returns zero value samples.
+///
+/// You can usually still use this from another source wrapping this one by
+/// calling `inner_mut` on it. Similarly this provides [`Pausable::inner`] and
+/// mutable/destructing variants for accessing the underlying source.
+#[derive(Clone, Debug)]
+pub struct Pausable<I> {
+    input: I,
+    paused_channels: Option<u16>,
+    remaining_paused_samples: u16,
+}
+
+impl<I> Pausable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Sets whether the filter applies.
+    ///
+    /// If set to true, the inner sound stops playing and no samples are processed from it.
+    #[inline]
+    pub fn set_paused(&mut self, paused: bool) {
+        match (self.paused_channels, paused) {
+            (None, true) => self.paused_channels = Some(self.input.channels()),
+            (Some(_), false) => self.paused_channels = None,
+            _ => (),
+        }
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Pausable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        if self.remaining_paused_samples > 0 {
+            self.remaining_paused_samples -= 1;
+            return Some(I::Item::zero_value());
+        }
+
+        if let Some(paused_channels) = self.paused_channels {
+            self.remaining_paused_samples = paused_channels - 1;
+            return Some(I::Item::zero_value());
+        }
+
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for Pausable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/periodic.rs

@@ -0,0 +1,174 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `PeriodicAccess` object.
+pub fn periodic<I, F>(source: I, period: Duration, modifier: F) -> PeriodicAccess<I, F>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    // TODO: handle the fact that the samples rate can change
+    // TODO: generally, just wrong
+    let update_ms = period.as_secs() as u32 * 1_000 + period.subsec_millis();
+    let update_frequency = (update_ms * source.sample_rate()) / 1000 * source.channels() as u32;
+
+    PeriodicAccess {
+        input: source,
+        modifier,
+        // Can overflow when subtracting if this is 0
+        update_frequency: if update_frequency == 0 {
+            1
+        } else {
+            update_frequency
+        },
+        samples_until_update: 1,
+    }
+}
+
+/// Calls a function on a source every time a period elapsed.
+#[derive(Clone, Debug)]
+pub struct PeriodicAccess<I, F> {
+    // The inner source.
+    input: I,
+
+    // Closure that gets access to `inner`.
+    modifier: F,
+
+    // The frequency with which local_volume should be updated by remote_volume
+    update_frequency: u32,
+
+    // How many samples remain until it is time to update local_volume with remote_volume.
+    samples_until_update: u32,
+}
+
+impl<I, F> PeriodicAccess<I, F>
+where
+    I: Source,
+    I::Item: Sample,
+    F: FnMut(&mut I),
+{
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I, F> Iterator for PeriodicAccess<I, F>
+where
+    I: Source,
+    I::Item: Sample,
+    F: FnMut(&mut I),
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.samples_until_update -= 1;
+        if self.samples_until_update == 0 {
+            (self.modifier)(&mut self.input);
+            self.samples_until_update = self.update_frequency;
+        }
+
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I, F> Source for PeriodicAccess<I, F>
+where
+    I: Source,
+    I::Item: Sample,
+    F: FnMut(&mut I),
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::cell::RefCell;
+    use std::time::Duration;
+
+    use crate::buffer::SamplesBuffer;
+    use crate::source::Source;
+
+    #[test]
+    fn stereo_access() {
+        // Stereo, 1Hz audio buffer
+        let inner = SamplesBuffer::new(2, 1, vec![10i16, -10, 10, -10, 20, -20]);
+
+        let cnt = RefCell::new(0);
+
+        let mut source = inner.periodic_access(Duration::from_millis(1000), |_src| {
+            *cnt.borrow_mut() += 1;
+        });
+
+        assert_eq!(*cnt.borrow(), 0);
+        // Always called on first access!
+        assert_eq!(source.next(), Some(10));
+        assert_eq!(*cnt.borrow(), 1);
+        // Called every 1 second afterwards
+        assert_eq!(source.next(), Some(-10));
+        assert_eq!(*cnt.borrow(), 1);
+        assert_eq!(source.next(), Some(10));
+        assert_eq!(*cnt.borrow(), 2);
+        assert_eq!(source.next(), Some(-10));
+        assert_eq!(*cnt.borrow(), 2);
+        assert_eq!(source.next(), Some(20));
+        assert_eq!(*cnt.borrow(), 3);
+        assert_eq!(source.next(), Some(-20));
+        assert_eq!(*cnt.borrow(), 3);
+    }
+
+    #[test]
+    fn fast_access_overflow() {
+        // 1hz is lower than 0.5 samples per 5ms
+        let inner = SamplesBuffer::new(1, 1, vec![10i16, -10, 10, -10, 20, -20]);
+        let mut source = inner.periodic_access(Duration::from_millis(5), |_src| {});
+
+        source.next();
+        source.next(); // Would overflow here.
+    }
+}

vendor/rodio/src/source/position.rs

@@ -0,0 +1,199 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `TrackPosition` object. See trait docs for
+/// details
+pub fn track_position<I>(source: I) -> TrackPosition<I> {
+    TrackPosition {
+        input: source,
+        samples_counted: 0,
+        offset_duration: 0.0,
+        current_frame_sample_rate: 0,
+        current_frame_channels: 0,
+        current_frame_len: None,
+    }
+}
+
+/// Tracks the elapsed duration since the start of the underlying source.
+#[derive(Debug)]
+pub struct TrackPosition<I> {
+    input: I,
+    samples_counted: usize,
+    offset_duration: f64,
+    current_frame_sample_rate: u32,
+    current_frame_channels: u16,
+    current_frame_len: Option<usize>,
+}
+
+impl<I> TrackPosition<I> {
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> TrackPosition<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns the position of the underlying source relative to its start.
+    ///
+    /// If a speedup and or delay is applied after applying a
+    /// [`Source::track_position`] it will not be reflected in the position
+    /// returned by [`get_pos`](TrackPosition::get_pos).
+    ///
+    /// This can get confusing when using [`get_pos()`](TrackPosition::get_pos)
+    /// together with [`Source::try_seek()`] as the the latter does take all
+    /// speedup's and delay's into account. Its recommended therefore to apply
+    /// track_position after speedup's and delay's.
+    #[inline]
+    pub fn get_pos(&self) -> Duration {
+        let seconds = self.samples_counted as f64
+            / self.input.sample_rate() as f64
+            / self.input.channels() as f64
+            + self.offset_duration;
+        Duration::from_secs_f64(seconds)
+    }
+
+    #[inline]
+    fn set_current_frame(&mut self) {
+        self.current_frame_len = self.current_frame_len();
+        self.current_frame_sample_rate = self.sample_rate();
+        self.current_frame_channels = self.channels();
+    }
+}
+
+impl<I> Iterator for TrackPosition<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        // This should only be executed once at the first call to next.
+        if self.current_frame_len.is_none() {
+            self.set_current_frame();
+        }
+
+        let item = self.input.next();
+        if item.is_some() {
+            self.samples_counted += 1;
+
+            // At the end of a frame add the duration of this frame to
+            // offset_duration and start collecting samples again.
+            if Some(self.samples_counted) == self.current_frame_len() {
+                self.offset_duration += self.samples_counted as f64
+                    / self.current_frame_sample_rate as f64
+                    / self.current_frame_channels as f64;
+
+                // Reset.
+                self.samples_counted = 0;
+                self.set_current_frame();
+            };
+        };
+        item
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for TrackPosition<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        let result = self.input.try_seek(pos);
+        if result.is_ok() {
+            self.offset_duration = pos.as_secs_f64();
+            // This assumes that the seek implementation of the codec always
+            // starts again at the beginning of a frame. Which is the case with
+            // symphonia.
+            self.samples_counted = 0;
+        }
+        result
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use crate::buffer::SamplesBuffer;
+    use crate::source::Source;
+
+    #[test]
+    fn test_position() {
+        let inner = SamplesBuffer::new(1, 1, vec![10i16, -10, 10, -10, 20, -20]);
+        let mut source = inner.track_position();
+
+        assert_eq!(source.get_pos().as_secs_f32(), 0.0);
+        source.next();
+        assert_eq!(source.get_pos().as_secs_f32(), 1.0);
+
+        source.next();
+        assert_eq!(source.get_pos().as_secs_f32(), 2.0);
+
+        assert_eq!(source.try_seek(Duration::new(1, 0)).is_ok(), true);
+        assert_eq!(source.get_pos().as_secs_f32(), 1.0);
+    }
+
+    #[test]
+    fn test_position_in_presence_of_speedup() {
+        let inner = SamplesBuffer::new(1, 1, vec![10i16, -10, 10, -10, 20, -20]);
+        let mut source = inner.speed(2.0).track_position();
+
+        assert_eq!(source.get_pos().as_secs_f32(), 0.0);
+        source.next();
+        assert_eq!(source.get_pos().as_secs_f32(), 0.5);
+
+        source.next();
+        assert_eq!(source.get_pos().as_secs_f32(), 1.0);
+
+        assert_eq!(source.try_seek(Duration::new(1, 0)).is_ok(), true);
+        assert_eq!(source.get_pos().as_secs_f32(), 1.0);
+    }
+}

vendor/rodio/src/source/repeat.rs

@@ -0,0 +1,108 @@
+use std::time::Duration;
+
+use crate::source::buffered::Buffered;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `Repeat` object.
+pub fn repeat<I>(input: I) -> Repeat<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let input = input.buffered();
+    Repeat {
+        inner: input.clone(),
+        next: input,
+    }
+}
+
+/// A source that repeats the given source.
+pub struct Repeat<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    inner: Buffered<I>,
+    next: Buffered<I>,
+}
+
+impl<I> Iterator for Repeat<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = <I as Iterator>::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<<I as Iterator>::Item> {
+        if let Some(value) = self.inner.next() {
+            return Some(value);
+        }
+
+        self.inner = self.next.clone();
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        // infinite
+        (0, None)
+    }
+}
+
+impl<I> Source for Repeat<I>
+where
+    I: Iterator + Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        match self.inner.current_frame_len() {
+            Some(0) => self.next.current_frame_len(),
+            a => a,
+        }
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        match self.inner.current_frame_len() {
+            Some(0) => self.next.channels(),
+            _ => self.inner.channels(),
+        }
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        match self.inner.current_frame_len() {
+            Some(0) => self.next.sample_rate(),
+            _ => self.inner.sample_rate(),
+        }
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.inner.try_seek(pos)
+    }
+}
+
+impl<I> Clone for Repeat<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn clone(&self) -> Repeat<I> {
+        Repeat {
+            inner: self.inner.clone(),
+            next: self.next.clone(),
+        }
+    }
+}

vendor/rodio/src/source/samples_converter.rs

@@ -0,0 +1,104 @@
+use std::marker::PhantomData;
+use std::time::Duration;
+
+use crate::{Sample, Source};
+use cpal::{FromSample, Sample as CpalSample};
+
+use super::SeekError;
+
+/// Wrap the input and lazily converts the samples it provides to the type
+/// specified by the generic parameter D
+#[derive(Clone)]
+pub struct SamplesConverter<I, D> {
+    inner: I,
+    dest: PhantomData<D>,
+}
+
+impl<I, D> SamplesConverter<I, D> {
+    /// Wrap the input and lazily converts the samples it provides to the type
+    /// specified by the generic parameter D
+    #[inline]
+    pub fn new(input: I) -> SamplesConverter<I, D> {
+        SamplesConverter {
+            inner: input,
+            dest: PhantomData,
+        }
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.inner
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.inner
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.inner
+    }
+}
+
+impl<I, D> Iterator for SamplesConverter<I, D>
+where
+    I: Source,
+    I::Item: Sample,
+    D: FromSample<I::Item> + Sample,
+{
+    type Item = D;
+
+    #[inline]
+    fn next(&mut self) -> Option<D> {
+        self.inner.next().map(|s| CpalSample::from_sample(s))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+impl<I, D> ExactSizeIterator for SamplesConverter<I, D>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+    D: FromSample<I::Item> + Sample,
+{
+}
+
+impl<I, D> Source for SamplesConverter<I, D>
+where
+    I: Source,
+    I::Item: Sample,
+    D: FromSample<I::Item> + Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.inner.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.inner.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.inner.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.inner.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.inner.try_seek(pos)
+    }
+}

vendor/rodio/src/source/signal_generator.rs

@@ -0,0 +1,185 @@
+//! Generator sources for various periodic test waveforms.
+//!
+//! This module provides several periodic, deterministic waveforms for testing other sources and
+//! for simple additive sound synthesis. Every source is monoaural and in the codomain [-1.0f32,
+//! 1.0f32].
+//!
+//! # Example
+//!
+//! ```
+//! use rodio::source::{SignalGenerator,Function};
+//!
+//! let tone = SignalGenerator::new(cpal::SampleRate(48000), 440.0, Function::Sine);
+//! ```
+use std::f32::consts::TAU;
+use std::time::Duration;
+
+use super::SeekError;
+use crate::Source;
+
+/// Waveform functions.
+#[derive(Clone, Debug)]
+pub enum Function {
+    /// A sinusoidal waveform.
+    Sine,
+    /// A triangle waveform.
+    Triangle,
+    /// A square wave, rising edge at t=0.
+    Square,
+    /// A rising sawtooth wave.
+    Sawtooth,
+}
+
+impl Function {
+    /// Create a single sample for the given waveform
+    #[inline]
+    fn render(&self, i: u64, period: f32) -> f32 {
+        let cycle_pos: f32 = i as f32 / period;
+
+        match self {
+            Self::Sine => (TAU * cycle_pos).sin(),
+            Self::Triangle => 4.0f32 * (cycle_pos - (cycle_pos + 0.5f32).floor()).abs() - 1f32,
+            Self::Square => {
+                if cycle_pos % 1.0f32 < 0.5f32 {
+                    1.0f32
+                } else {
+                    -1.0f32
+                }
+            }
+            Self::Sawtooth => 2.0f32 * (cycle_pos - (cycle_pos + 0.5f32).floor()),
+        }
+    }
+}
+
+/// An infinite source that produces one of a selection of test waveforms.
+#[derive(Clone, Debug)]
+pub struct SignalGenerator {
+    sample_rate: cpal::SampleRate,
+    period: f32,
+    function: Function,
+    i: u64,
+}
+
+impl SignalGenerator {
+    /// Create a new `TestWaveform` object that generates an endless waveform
+    /// `f`.
+    ///
+    /// # Panics
+    ///
+    /// Will panic if `frequency` is equal to zero.
+    #[inline]
+    pub fn new(sample_rate: cpal::SampleRate, frequency: f32, f: Function) -> SignalGenerator {
+        assert!(frequency != 0.0, "frequency must be greater than zero");
+        let period = sample_rate.0 as f32 / frequency;
+        SignalGenerator {
+            sample_rate,
+            period,
+            function: f,
+            i: 0,
+        }
+    }
+}
+
+impl Iterator for SignalGenerator {
+    type Item = f32;
+
+    #[inline]
+    fn next(&mut self) -> Option<f32> {
+        let val = Some(self.function.render(self.i, self.period));
+        self.i += 1;
+        val
+    }
+}
+
+impl Source for SignalGenerator {
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate.0
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, duration: Duration) -> Result<(), SeekError> {
+        self.i = (self.sample_rate.0 as f32 * duration.as_secs_f32()) as u64;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::source::{Function, SignalGenerator};
+    use approx::assert_abs_diff_eq;
+
+    #[test]
+    fn square() {
+        let mut wf = SignalGenerator::new(cpal::SampleRate(2000), 500.0f32, Function::Square);
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+    }
+
+    #[test]
+    fn triangle() {
+        let mut wf = SignalGenerator::new(cpal::SampleRate(8000), 1000.0f32, Function::Triangle);
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(-0.5f32));
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(-0.5f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(-0.5f32));
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(1.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(-0.5f32));
+    }
+
+    #[test]
+    fn saw() {
+        let mut wf = SignalGenerator::new(cpal::SampleRate(200), 50.0f32, Function::Sawtooth);
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+        assert_eq!(wf.next(), Some(-0.5f32));
+        assert_eq!(wf.next(), Some(0.0f32));
+        assert_eq!(wf.next(), Some(0.5f32));
+        assert_eq!(wf.next(), Some(-1.0f32));
+    }
+
+    #[test]
+    fn sine() {
+        let mut wf = SignalGenerator::new(cpal::SampleRate(1000), 100f32, Function::Sine);
+
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.0f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.58778525f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.95105652f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.95105652f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.58778525f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), 0.0f32);
+        assert_abs_diff_eq!(wf.next().unwrap(), -0.58778554f32);
+    }
+}

vendor/rodio/src/source/sine.rs

@@ -0,0 +1,66 @@
+use std::time::Duration;
+
+use crate::source::{Function, SignalGenerator};
+use crate::Source;
+
+use super::SeekError;
+
+/// An infinite source that produces a sine.
+///
+/// Always has a rate of 48kHz and one channel.
+#[derive(Clone, Debug)]
+pub struct SineWave {
+    test_sine: SignalGenerator,
+}
+
+impl SineWave {
+    const SAMPLE_RATE: u32 = 48000;
+
+    /// The frequency of the sine.
+    #[inline]
+    pub fn new(freq: f32) -> SineWave {
+        let sr = cpal::SampleRate(Self::SAMPLE_RATE);
+        SineWave {
+            test_sine: SignalGenerator::new(sr, freq, Function::Sine),
+        }
+    }
+}
+
+impl Iterator for SineWave {
+    type Item = f32;
+
+    #[inline]
+    fn next(&mut self) -> Option<f32> {
+        self.test_sine.next()
+    }
+}
+
+impl Source for SineWave {
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        1
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        Self::SAMPLE_RATE
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    /// `try_seek()` does nothing on the sine generator. If you need to
+    /// generate a sine tone with a precise phase or sample offset, consider
+    /// using `skip::skip_samples()`.
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Ok(())
+    }
+}

vendor/rodio/src/source/skip.rs

@@ -0,0 +1,259 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+const NS_PER_SECOND: u128 = 1_000_000_000;
+
+/// Internal function that builds a `SkipDuration` object.
+pub fn skip_duration<I>(mut input: I, duration: Duration) -> SkipDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    do_skip_duration(&mut input, duration);
+    SkipDuration {
+        input,
+        skipped_duration: duration,
+    }
+}
+
+/// Skips specified `duration` of the given `input` source from it's current position.
+fn do_skip_duration<I>(input: &mut I, mut duration: Duration)
+where
+    I: Source,
+    I::Item: Sample,
+{
+    while duration > Duration::new(0, 0) {
+        if input.current_frame_len().is_none() {
+            // Sample rate and the amount of channels will be the same till the end.
+            do_skip_duration_unchecked(input, duration);
+            return;
+        }
+
+        // .unwrap() safety: if `current_frame_len()` is None, the body of the `if` statement
+        // above returns before we get here.
+        let frame_len: usize = input.current_frame_len().unwrap();
+        // If frame_len is zero, then there is no more data to skip. Instead
+        // just bail out.
+        if frame_len == 0 {
+            return;
+        }
+
+        let ns_per_sample: u128 =
+            NS_PER_SECOND / input.sample_rate() as u128 / input.channels() as u128;
+
+        // Check if we need to skip only part of the current frame.
+        if frame_len as u128 * ns_per_sample > duration.as_nanos() {
+            skip_samples(input, (duration.as_nanos() / ns_per_sample) as usize);
+            return;
+        }
+
+        skip_samples(input, frame_len);
+
+        duration -= Duration::from_nanos((frame_len * ns_per_sample as usize) as u64);
+    }
+}
+
+/// Skips specified `duration` from the `input` source assuming that sample rate
+/// and amount of channels are not changing.
+fn do_skip_duration_unchecked<I>(input: &mut I, duration: Duration)
+where
+    I: Source,
+    I::Item: Sample,
+{
+    let samples_per_channel: u128 =
+        duration.as_nanos() * input.sample_rate() as u128 / NS_PER_SECOND;
+    let samples_to_skip: u128 = samples_per_channel * input.channels() as u128;
+
+    skip_samples(input, samples_to_skip as usize);
+}
+
+/// Skips `n` samples from the given `input` source.
+fn skip_samples<I>(input: &mut I, n: usize)
+where
+    I: Source,
+    I::Item: Sample,
+{
+    for _ in 0..n {
+        if input.next().is_none() {
+            break;
+        }
+    }
+}
+
+/// A source that skips specified duration of the given source from it's current position.
+#[derive(Clone, Debug)]
+pub struct SkipDuration<I> {
+    input: I,
+    skipped_duration: Duration,
+}
+
+impl<I> SkipDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for SkipDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = <I as Iterator>::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for SkipDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration().map(|val| {
+            val.checked_sub(self.skipped_duration)
+                .unwrap_or_else(|| Duration::from_secs(0))
+        })
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use crate::buffer::SamplesBuffer;
+    use crate::source::Source;
+
+    fn test_skip_duration_samples_left(
+        channels: u16,
+        sample_rate: u32,
+        seconds: u32,
+        seconds_to_skip: u32,
+    ) {
+        let data: Vec<f32> = (1..=(sample_rate * channels as u32 * seconds))
+            .map(|_| 0f32)
+            .collect();
+        let test_buffer = SamplesBuffer::new(channels, sample_rate, data);
+        let seconds_left = seconds.saturating_sub(seconds_to_skip);
+
+        let samples_left_expected = (sample_rate * channels as u32 * seconds_left) as usize;
+        let samples_left = test_buffer
+            .skip_duration(Duration::from_secs(seconds_to_skip as u64))
+            .count();
+
+        assert_eq!(samples_left, samples_left_expected);
+    }
+
+    macro_rules! skip_duration_test_block {
+        ($(channels: $ch:expr, sample rate: $sr:expr, seconds: $sec:expr, seconds to skip: $sec_to_skip:expr;)+) => {
+            $(
+                test_skip_duration_samples_left($ch, $sr, $sec, $sec_to_skip);
+            )+
+        }
+    }
+
+    #[test]
+    fn skip_duration_shorter_than_source() {
+        skip_duration_test_block! {
+            channels: 1, sample rate: 44100, seconds: 5, seconds to skip: 3;
+            channels: 1, sample rate: 96000, seconds: 5, seconds to skip: 3;
+
+            channels: 2, sample rate: 44100, seconds: 5, seconds to skip: 3;
+            channels: 2, sample rate: 96000, seconds: 5, seconds to skip: 3;
+
+            channels: 4, sample rate: 44100, seconds: 5, seconds to skip: 3;
+            channels: 4, sample rate: 96000, seconds: 5, seconds to skip: 3;
+        }
+    }
+
+    #[test]
+    fn skip_duration_zero_duration() {
+        skip_duration_test_block! {
+            channels: 1, sample rate: 44100, seconds: 5, seconds to skip: 0;
+            channels: 1, sample rate: 96000, seconds: 5, seconds to skip: 0;
+
+            channels: 2, sample rate: 44100, seconds: 5, seconds to skip: 0;
+            channels: 2, sample rate: 96000, seconds: 5, seconds to skip: 0;
+
+            channels: 4, sample rate: 44100, seconds: 5, seconds to skip: 0;
+            channels: 4, sample rate: 96000, seconds: 5, seconds to skip: 0;
+        }
+    }
+
+    #[test]
+    fn skip_duration_longer_than_source() {
+        skip_duration_test_block! {
+            channels: 1, sample rate: 44100, seconds: 1, seconds to skip: 5;
+            channels: 1, sample rate: 96000, seconds: 10, seconds to skip: 11;
+
+            channels: 2, sample rate: 44100, seconds: 1, seconds to skip: 5;
+            channels: 2, sample rate: 96000, seconds: 10, seconds to skip: 11;
+
+            channels: 4, sample rate: 44100, seconds: 1, seconds to skip: 5;
+            channels: 4, sample rate: 96000, seconds: 10, seconds to skip: 11;
+        }
+    }
+
+    #[test]
+    fn skip_duration_equal_to_source_length() {
+        skip_duration_test_block! {
+            channels: 1, sample rate: 44100, seconds: 1, seconds to skip: 1;
+            channels: 1, sample rate: 96000, seconds: 10, seconds to skip: 10;
+
+            channels: 2, sample rate: 44100, seconds: 1, seconds to skip: 1;
+            channels: 2, sample rate: 96000, seconds: 10, seconds to skip: 10;
+
+            channels: 4, sample rate: 44100, seconds: 1, seconds to skip: 1;
+            channels: 4, sample rate: 96000, seconds: 10, seconds to skip: 10;
+        }
+    }
+}

vendor/rodio/src/source/skippable.rs

@@ -0,0 +1,104 @@
+use std::time::Duration;
+
+use crate::Sample;
+use crate::Source;
+
+use super::SeekError;
+
+/// Wrap the source in a skippable. It allows ending the current source early by
+/// calling [`Skippable::skip`]. If this source is in a queue such as the Sink
+/// ending the source early is equal to skipping the source.
+pub fn skippable<I>(source: I) -> Skippable<I> {
+    Skippable {
+        input: source,
+        do_skip: false,
+    }
+}
+
+/// Wrap the source in a skippable. It allows ending the current source early by
+/// calling [`Skippable::skip`]. If this source is in a queue such as the Sink
+/// ending the source early is equal to skipping the source.
+#[derive(Clone, Debug)]
+pub struct Skippable<I> {
+    input: I,
+    do_skip: bool,
+}
+
+impl<I> Skippable<I> {
+    /// Skips the current source
+    #[inline]
+    pub fn skip(&mut self) {
+        self.do_skip = true;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Skippable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        if self.do_skip {
+            None
+        } else {
+            self.input.next()
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for Skippable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/spatial.rs

@@ -0,0 +1,129 @@
+use std::time::Duration;
+
+use crate::source::ChannelVolume;
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// A simple spatial audio source. The underlying source is transformed to Mono
+/// and then played in stereo. The left and right channel's volume are amplified
+/// differently depending on the distance of the left and right ear to the source.
+#[derive(Clone)]
+pub struct Spatial<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    input: ChannelVolume<I>,
+}
+
+fn dist_sq(a: [f32; 3], b: [f32; 3]) -> f32 {
+    a.iter()
+        .zip(b.iter())
+        .map(|(a, b)| (a - b) * (a - b))
+        .sum::<f32>()
+}
+
+impl<I> Spatial<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Builds a new `SpatialSink`, beginning playback on a stream.
+    pub fn new(
+        input: I,
+        emitter_position: [f32; 3],
+        left_ear: [f32; 3],
+        right_ear: [f32; 3],
+    ) -> Spatial<I>
+    where
+        I: Source,
+        I::Item: Sample,
+    {
+        let mut ret = Spatial {
+            input: ChannelVolume::new(input, vec![0.0, 0.0]),
+        };
+        ret.set_positions(emitter_position, left_ear, right_ear);
+        ret
+    }
+
+    /// Sets the position of the emitter and ears in the 3D world.
+    pub fn set_positions(
+        &mut self,
+        emitter_pos: [f32; 3],
+        left_ear: [f32; 3],
+        right_ear: [f32; 3],
+    ) {
+        debug_assert!(left_ear != right_ear);
+        let left_dist_sq = dist_sq(left_ear, emitter_pos);
+        let right_dist_sq = dist_sq(right_ear, emitter_pos);
+        let max_diff = dist_sq(left_ear, right_ear).sqrt();
+        let left_dist = left_dist_sq.sqrt();
+        let right_dist = right_dist_sq.sqrt();
+        let left_diff_modifier = (((left_dist - right_dist) / max_diff + 1.0) / 4.0 + 0.5).min(1.0);
+        let right_diff_modifier =
+            (((right_dist - left_dist) / max_diff + 1.0) / 4.0 + 0.5).min(1.0);
+        let left_dist_modifier = (1.0 / left_dist_sq).min(1.0);
+        let right_dist_modifier = (1.0 / right_dist_sq).min(1.0);
+        self.input
+            .set_volume(0, left_diff_modifier * left_dist_modifier);
+        self.input
+            .set_volume(1, right_diff_modifier * right_dist_modifier);
+    }
+}
+
+impl<I> Iterator for Spatial<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for Spatial<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for Spatial<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/speed.rs

@@ -0,0 +1,149 @@
+//! Playback Speed control Module.
+//!
+//! The main concept of this module is the [`Speed`] struct, which
+//! encapsulates playback speed controls of the current sink.
+//!
+//! In order to speed up a sink, the speed struct:
+//! - Increases the current sample rate by the given factor
+//! - Updates the total duration function to cover for the new factor by dividing by the factor
+//! - Updates the try_seek function by multiplying the audio position by the factor
+//!
+//! To speed up a source from sink all you need to do is call the   `set_speed(factor: f32)` function
+//! For example, here is how you speed up your sound by using sink or playing raw
+//!
+//! ```no_run
+//!# use std::fs::File;
+//!# use std::io::BufReader;
+//!# use rodio::{Decoder, Sink, OutputStream, source::{Source, SineWave}};
+//!
+//! // Get an output stream handle to the default physical sound device.
+//! // Note that no sound will be played if _stream is dropped
+//! let (_stream, stream_handle) = OutputStream::try_default().unwrap();
+//! // Load a sound from a file, using a path relative to Cargo.toml
+//! let file = BufReader::new(File::open("examples/music.ogg").unwrap());
+//! // Decode that sound file into a source
+//! let source = Decoder::new(file).unwrap();
+//! // Play the sound directly on the device 2x faster
+//! stream_handle.play_raw(source.convert_samples().speed(2.0));
+
+//! std::thread::sleep(std::time::Duration::from_secs(5));
+//! ```
+//! here is how you would do it using the sink
+//! ```
+//! let source = SineWave::new(440.0)
+//! .take_duration(Duration::from_secs_f32(20.25))
+//! .amplify(0.20);
+//!
+//! let sink = Sink::try_new(&stream_handle)?;
+//! sink.set_speed(2.0);
+//! sink.append(source);
+//! std::thread::sleep(std::time::Duration::from_secs(5));
+//! ```
+//! Notice the increase in pitch as the factor increases
+//!
+//! Since the samples are played faster the audio wave get shorter increasing their frequencies
+
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `Speed` object.
+pub fn speed<I>(input: I, factor: f32) -> Speed<I> {
+    Speed { input, factor }
+}
+
+/// Filter that modifies each sample by a given value.
+#[derive(Clone, Debug)]
+pub struct Speed<I> {
+    input: I,
+    factor: f32,
+}
+
+impl<I> Speed<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Modifies the speed factor.
+    #[inline]
+    pub fn set_factor(&mut self, factor: f32) {
+        self.factor = factor;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Speed<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        self.input.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> ExactSizeIterator for Speed<I>
+where
+    I: Source + ExactSizeIterator,
+    I::Item: Sample,
+{
+}
+
+impl<I> Source for Speed<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        (self.input.sample_rate() as f32 * self.factor) as u32
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration().map(|d| d.div_f32(self.factor))
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        let pos_accounting_for_speedup = pos.mul_f32(self.factor);
+        self.input.try_seek(pos_accounting_for_speedup)
+    }
+}

vendor/rodio/src/source/stoppable.rs

@@ -0,0 +1,99 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// This is the same as [`skippable`](crate::source::skippable) see its docs
+pub fn stoppable<I>(source: I) -> Stoppable<I> {
+    Stoppable {
+        input: source,
+        stopped: false,
+    }
+}
+
+/// This is the same as [`Skippable`](crate::source::Skippable) see its docs
+#[derive(Clone, Debug)]
+pub struct Stoppable<I> {
+    input: I,
+    stopped: bool,
+}
+
+impl<I> Stoppable<I> {
+    /// Stops the sound.
+    #[inline]
+    pub fn stop(&mut self) {
+        self.stopped = true;
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+}
+
+impl<I> Iterator for Stoppable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = I::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<I::Item> {
+        if self.stopped {
+            None
+        } else {
+            self.input.next()
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.input.size_hint()
+    }
+}
+
+impl<I> Source for Stoppable<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.input.current_frame_len()
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.input.total_duration()
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/take.rs

@@ -0,0 +1,189 @@
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// Internal function that builds a `TakeDuration` object.
+pub fn take_duration<I>(input: I, duration: Duration) -> TakeDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    TakeDuration {
+        current_frame_len: input.current_frame_len(),
+        duration_per_sample: TakeDuration::get_duration_per_sample(&input),
+        input,
+        remaining_duration: duration,
+        requested_duration: duration,
+        filter: None,
+    }
+}
+
+/// A filter that can be applied to a `TakeDuration`.
+#[derive(Clone, Debug)]
+enum DurationFilter {
+    FadeOut,
+}
+impl DurationFilter {
+    fn apply<I: Iterator>(
+        &self,
+        sample: <I as Iterator>::Item,
+        parent: &TakeDuration<I>,
+    ) -> <I as Iterator>::Item
+    where
+        I::Item: Sample,
+    {
+        use self::DurationFilter::*;
+        match self {
+            FadeOut => {
+                let remaining = parent.remaining_duration.as_millis() as f32;
+                let total = parent.requested_duration.as_millis() as f32;
+                sample.amplify(remaining / total)
+            }
+        }
+    }
+}
+
+const NANOS_PER_SEC: u64 = 1_000_000_000;
+
+/// A source that truncates the given source to a certain duration.
+#[derive(Clone, Debug)]
+pub struct TakeDuration<I> {
+    input: I,
+    remaining_duration: Duration,
+    requested_duration: Duration,
+    filter: Option<DurationFilter>,
+    // Remaining samples in current frame.
+    current_frame_len: Option<usize>,
+    // Only updated when the current frame len is exhausted.
+    duration_per_sample: Duration,
+}
+
+impl<I> TakeDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    /// Returns the duration elapsed for each sample extracted.
+    #[inline]
+    fn get_duration_per_sample(input: &I) -> Duration {
+        let ns = NANOS_PER_SEC / (input.sample_rate() as u64 * input.channels() as u64);
+        // \|/ the maximum value of `ns` is one billion, so this can't fail
+        Duration::new(0, ns as u32)
+    }
+
+    /// Returns a reference to the inner source.
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
+    /// Returns a mutable reference to the inner source.
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.input
+    }
+
+    /// Returns the inner source.
+    #[inline]
+    pub fn into_inner(self) -> I {
+        self.input
+    }
+
+    /// Make the truncated source end with a FadeOut. The fadeout covers the
+    /// entire length of the take source.
+    pub fn set_filter_fadeout(&mut self) {
+        self.filter = Some(DurationFilter::FadeOut);
+    }
+
+    /// Remove any filter set.
+    pub fn clear_filter(&mut self) {
+        self.filter = None;
+    }
+}
+
+impl<I> Iterator for TakeDuration<I>
+where
+    I: Source,
+    I::Item: Sample,
+{
+    type Item = <I as Iterator>::Item;
+
+    fn next(&mut self) -> Option<<I as Iterator>::Item> {
+        if let Some(frame_len) = self.current_frame_len.take() {
+            if frame_len > 0 {
+                self.current_frame_len = Some(frame_len - 1);
+            } else {
+                self.current_frame_len = self.input.current_frame_len();
+                // Sample rate might have changed
+                self.duration_per_sample = Self::get_duration_per_sample(&self.input);
+            }
+        }
+
+        if self.remaining_duration <= self.duration_per_sample {
+            None
+        } else if let Some(sample) = self.input.next() {
+            let sample = match &self.filter {
+                Some(filter) => filter.apply(sample, self),
+                None => sample,
+            };
+
+            self.remaining_duration -= self.duration_per_sample;
+
+            Some(sample)
+        } else {
+            None
+        }
+    }
+
+    // TODO: size_hint
+}
+
+impl<I> Source for TakeDuration<I>
+where
+    I: Iterator + Source,
+    I::Item: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        let remaining_nanos = self.remaining_duration.as_secs() * NANOS_PER_SEC
+            + self.remaining_duration.subsec_nanos() as u64;
+        let nanos_per_sample = self.duration_per_sample.as_secs() * NANOS_PER_SEC
+            + self.duration_per_sample.subsec_nanos() as u64;
+        let remaining_samples = (remaining_nanos / nanos_per_sample) as usize;
+
+        self.input
+            .current_frame_len()
+            .filter(|value| *value < remaining_samples)
+            .or(Some(remaining_samples))
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.input.channels()
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.input.sample_rate()
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        if let Some(duration) = self.input.total_duration() {
+            if duration < self.requested_duration {
+                Some(duration)
+            } else {
+                Some(self.requested_duration)
+            }
+        } else {
+            None
+        }
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        self.input.try_seek(pos)
+    }
+}

vendor/rodio/src/source/uniform.rs

@@ -0,0 +1,212 @@
+use std::cmp;
+use std::time::Duration;
+
+use cpal::FromSample;
+
+use crate::conversions::{ChannelCountConverter, DataConverter, SampleRateConverter};
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// An iterator that reads from a `Source` and converts the samples to a
+/// specific type, sample-rate and channels count.
+///
+/// It implements `Source` as well, but all the data is guaranteed to be in a
+/// single frame whose channels and samples rate have been passed to `new`.
+#[derive(Clone)]
+pub struct UniformSourceIterator<I, D>
+where
+    I: Source,
+    I::Item: Sample,
+    D: Sample,
+{
+    inner: Option<DataConverter<ChannelCountConverter<SampleRateConverter<Take<I>>>, D>>,
+    target_channels: u16,
+    target_sample_rate: u32,
+    total_duration: Option<Duration>,
+}
+
+impl<I, D> UniformSourceIterator<I, D>
+where
+    I: Source,
+    I::Item: Sample,
+    D: Sample,
+{
+    /// Wrap a `Source` and lazily convert its samples to a specific type,
+    /// sample-rate and channels count.
+    #[inline]
+    pub fn new(
+        input: I,
+        target_channels: u16,
+        target_sample_rate: u32,
+    ) -> UniformSourceIterator<I, D> {
+        let total_duration = input.total_duration();
+        let input = UniformSourceIterator::bootstrap(input, target_channels, target_sample_rate);
+
+        UniformSourceIterator {
+            inner: Some(input),
+            target_channels,
+            target_sample_rate,
+            total_duration,
+        }
+    }
+
+    #[inline]
+    fn bootstrap(
+        input: I,
+        target_channels: u16,
+        target_sample_rate: u32,
+    ) -> DataConverter<ChannelCountConverter<SampleRateConverter<Take<I>>>, D> {
+        // Limit the frame length to something reasonable
+        let frame_len = input.current_frame_len().map(|x| x.min(32768));
+
+        let from_channels = input.channels();
+        let from_sample_rate = input.sample_rate();
+
+        let input = Take {
+            iter: input,
+            n: frame_len,
+        };
+        let input = SampleRateConverter::new(
+            input,
+            cpal::SampleRate(from_sample_rate),
+            cpal::SampleRate(target_sample_rate),
+            from_channels,
+        );
+        let input = ChannelCountConverter::new(input, from_channels, target_channels);
+
+        DataConverter::new(input)
+    }
+}
+
+impl<I, D> Iterator for UniformSourceIterator<I, D>
+where
+    I: Source,
+    I::Item: Sample,
+    D: FromSample<I::Item> + Sample,
+{
+    type Item = D;
+
+    #[inline]
+    fn next(&mut self) -> Option<D> {
+        if let Some(value) = self.inner.as_mut().unwrap().next() {
+            return Some(value);
+        }
+
+        let input = self
+            .inner
+            .take()
+            .unwrap()
+            .into_inner()
+            .into_inner()
+            .into_inner()
+            .iter;
+
+        let mut input =
+            UniformSourceIterator::bootstrap(input, self.target_channels, self.target_sample_rate);
+
+        let value = input.next();
+        self.inner = Some(input);
+        value
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.inner.as_ref().unwrap().size_hint().0, None)
+    }
+}
+
+impl<I, D> Source for UniformSourceIterator<I, D>
+where
+    I: Iterator + Source,
+    I::Item: Sample,
+    D: FromSample<I::Item> + Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.target_channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.target_sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        self.total_duration
+    }
+
+    #[inline]
+    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
+        if let Some(input) = self.inner.as_mut() {
+            input
+                .inner_mut()
+                .inner_mut()
+                .inner_mut()
+                .inner_mut()
+                .try_seek(pos)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Take<I> {
+    iter: I,
+    n: Option<usize>,
+}
+
+impl<I> Take<I> {
+    #[inline]
+    pub fn inner_mut(&mut self) -> &mut I {
+        &mut self.iter
+    }
+}
+
+impl<I> Iterator for Take<I>
+where
+    I: Iterator,
+{
+    type Item = <I as Iterator>::Item;
+
+    #[inline]
+    fn next(&mut self) -> Option<<I as Iterator>::Item> {
+        if let Some(n) = &mut self.n {
+            if *n != 0 {
+                *n -= 1;
+                self.iter.next()
+            } else {
+                None
+            }
+        } else {
+            self.iter.next()
+        }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if let Some(n) = self.n {
+            let (lower, upper) = self.iter.size_hint();
+
+            let lower = cmp::min(lower, n);
+
+            let upper = match upper {
+                Some(x) if x < n => Some(x),
+                _ => Some(n),
+            };
+
+            (lower, upper)
+        } else {
+            self.iter.size_hint()
+        }
+    }
+}
+
+impl<I> ExactSizeIterator for Take<I> where I: ExactSizeIterator {}

vendor/rodio/src/source/zero.rs

@@ -0,0 +1,91 @@
+use std::marker::PhantomData;
+use std::time::Duration;
+
+use crate::{Sample, Source};
+
+use super::SeekError;
+
+/// An source that produces samples with value zero (silence). Depending on if
+/// it where created with [`Zero::new`] or [`Zero::new_samples`] it can be never
+/// ending or finite.
+#[derive(Clone, Debug)]
+pub struct Zero<S> {
+    channels: u16,
+    sample_rate: u32,
+    num_samples: Option<usize>,
+    marker: PhantomData<S>,
+}
+
+impl<S> Zero<S> {
+    /// Create a new source that never ends and produces total silence.
+    #[inline]
+    pub fn new(channels: u16, sample_rate: u32) -> Zero<S> {
+        Zero {
+            channels,
+            sample_rate,
+            num_samples: None,
+            marker: PhantomData,
+        }
+    }
+    /// Create a new source that never ends and produces total silence.
+    #[inline]
+    pub fn new_samples(channels: u16, sample_rate: u32, num_samples: usize) -> Zero<S> {
+        Zero {
+            channels,
+            sample_rate,
+            num_samples: Some(num_samples),
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<S> Iterator for Zero<S>
+where
+    S: Sample,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        if let Some(num_samples) = self.num_samples {
+            if num_samples > 0 {
+                self.num_samples = Some(num_samples - 1);
+                Some(S::zero_value())
+            } else {
+                None
+            }
+        } else {
+            Some(S::zero_value())
+        }
+    }
+}
+
+impl<S> Source for Zero<S>
+where
+    S: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        self.num_samples
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        None
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Ok(())
+    }
+}

vendor/rodio/src/spatial_sink.rs

@@ -0,0 +1,223 @@
+use std::f32;
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use cpal::FromSample;
+
+use crate::source::{SeekError, Spatial};
+use crate::stream::{OutputStreamHandle, PlayError};
+use crate::{Sample, Sink, Source};
+
+/// A sink that allows changing the position of the source and the listeners
+/// ears while playing. The sources played are then transformed to give a simple
+/// spatial effect. See [`Spatial`] for details.
+pub struct SpatialSink {
+    sink: Sink,
+    positions: Arc<Mutex<SoundPositions>>,
+}
+
+struct SoundPositions {
+    emitter_position: [f32; 3],
+    left_ear: [f32; 3],
+    right_ear: [f32; 3],
+}
+
+impl SpatialSink {
+    /// Builds a new `SpatialSink`.
+    pub fn try_new(
+        stream: &OutputStreamHandle,
+        emitter_position: [f32; 3],
+        left_ear: [f32; 3],
+        right_ear: [f32; 3],
+    ) -> Result<SpatialSink, PlayError> {
+        Ok(SpatialSink {
+            sink: Sink::try_new(stream)?,
+            positions: Arc::new(Mutex::new(SoundPositions {
+                emitter_position,
+                left_ear,
+                right_ear,
+            })),
+        })
+    }
+
+    /// Sets the position of the sound emitter in 3 dimensional space.
+    pub fn set_emitter_position(&self, pos: [f32; 3]) {
+        self.positions.lock().unwrap().emitter_position = pos;
+    }
+
+    /// Sets the position of the left ear in 3 dimensional space.
+    pub fn set_left_ear_position(&self, pos: [f32; 3]) {
+        self.positions.lock().unwrap().left_ear = pos;
+    }
+
+    /// Sets the position of the right ear in 3 dimensional space.
+    pub fn set_right_ear_position(&self, pos: [f32; 3]) {
+        self.positions.lock().unwrap().right_ear = pos;
+    }
+
+    /// Appends a sound to the queue of sounds to play.
+    #[inline]
+    pub fn append<S>(&self, source: S)
+    where
+        S: Source + Send + 'static,
+        f32: FromSample<S::Item>,
+        S::Item: Sample + Send,
+    {
+        let positions = self.positions.clone();
+        let pos_lock = self.positions.lock().unwrap();
+        let source = Spatial::new(
+            source,
+            pos_lock.emitter_position,
+            pos_lock.left_ear,
+            pos_lock.right_ear,
+        )
+        .periodic_access(Duration::from_millis(10), move |i| {
+            let pos = positions.lock().unwrap();
+            i.set_positions(pos.emitter_position, pos.left_ear, pos.right_ear);
+        });
+        self.sink.append(source);
+    }
+
+    // Gets the volume of the sound.
+    ///
+    /// The value `1.0` is the "normal" volume (unfiltered input). Any value other than 1.0 will
+    /// multiply each sample by this value.
+    #[inline]
+    pub fn volume(&self) -> f32 {
+        self.sink.volume()
+    }
+
+    /// Changes the volume of the sound.
+    ///
+    /// The value `1.0` is the "normal" volume (unfiltered input). Any value other than 1.0 will
+    /// multiply each sample by this value.
+    #[inline]
+    pub fn set_volume(&self, value: f32) {
+        self.sink.set_volume(value);
+    }
+
+    /// Changes the play speed of the sound. Does not adjust the samples, only the playback speed.
+    ///
+    /// # Note:
+    /// 1. **Increasing the speed will increase the pitch by the same factor**
+    /// - If you set the speed to 0.5 this will halve the frequency of the sound
+    ///   lowering its pitch.
+    /// - If you set the speed to 2 the frequency will double raising the
+    ///   pitch of the sound.
+    /// 2. **Change in the speed affect the total duration inversely**
+    /// - If you set the speed to 0.5, the total duration will be twice as long.
+    /// - If you set the speed to 2 the total duration will be halve of what it
+    ///   was.
+    ///
+    /// See [`Speed`] for details
+    #[inline]
+    pub fn speed(&self) -> f32 {
+        self.sink.speed()
+    }
+
+    /// Changes the speed of the sound.
+    ///
+    /// The value `1.0` is the "normal" speed (unfiltered input). Any value other than `1.0` will
+    /// change the play speed of the sound.
+    #[inline]
+    pub fn set_speed(&self, value: f32) {
+        self.sink.set_speed(value)
+    }
+
+    /// Resumes playback of a paused sound.
+    ///
+    /// No effect if not paused.
+    #[inline]
+    pub fn play(&self) {
+        self.sink.play();
+    }
+
+    /// Pauses playback of this sink.
+    ///
+    /// No effect if already paused.
+    ///
+    /// A paused sound can be resumed with `play()`.
+    pub fn pause(&self) {
+        self.sink.pause();
+    }
+
+    /// Gets if a sound is paused
+    ///
+    /// Sounds can be paused and resumed using pause() and play(). This gets if a sound is paused.
+    pub fn is_paused(&self) -> bool {
+        self.sink.is_paused()
+    }
+
+    /// Removes all currently loaded `Source`s from the `SpatialSink` and pauses it.
+    ///
+    /// See `pause()` for information about pausing a `Sink`.
+    #[inline]
+    pub fn clear(&self) {
+        self.sink.clear();
+    }
+
+    /// Stops the sink by emptying the queue.
+    #[inline]
+    pub fn stop(&self) {
+        self.sink.stop()
+    }
+
+    /// Destroys the sink without stopping the sounds that are still playing.
+    #[inline]
+    pub fn detach(self) {
+        self.sink.detach();
+    }
+
+    /// Sleeps the current thread until the sound ends.
+    #[inline]
+    pub fn sleep_until_end(&self) {
+        self.sink.sleep_until_end();
+    }
+
+    /// Returns true if this sink has no more sounds to play.
+    #[inline]
+    pub fn empty(&self) -> bool {
+        self.sink.empty()
+    }
+
+    /// Returns the number of sounds currently in the queue.
+    #[allow(clippy::len_without_is_empty)]
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.sink.len()
+    }
+
+    /// Attempts to seek to a given position in the current source.
+    ///
+    /// This blocks between 0 and ~5 milliseconds.
+    ///
+    /// As long as the duration of the source is known seek is guaranteed to saturate
+    /// at the end of the source. For example given a source that reports a total duration
+    /// of 42 seconds calling `try_seek()` with 60 seconds as argument will seek to
+    /// 42 seconds.
+    ///
+    /// # Errors
+    /// This function will return [`SeekError::NotSupported`] if one of the underlying
+    /// sources does not support seeking.  
+    ///
+    /// It will return an error if an implementation ran
+    /// into one during the seek.  
+    ///
+    /// When seeking beyond the end of a source this
+    /// function might return an error if the duration of the source is not known.
+    pub fn try_seek(&self, pos: Duration) -> Result<(), SeekError> {
+        self.sink.try_seek(pos)
+    }
+
+    /// Returns the position of the sound that's being played.
+    ///
+    /// This takes into account any speedup or delay applied.
+    ///
+    /// Example: if you apply a speedup of *2* to an mp3 decoder source and
+    /// [`get_pos()`](Sink::get_pos) returns *5s* then the position in the mp3
+    /// recording is *10s* from its start.
+    #[inline]
+    pub fn get_pos(&self) -> Duration {
+        self.sink.get_pos()
+    }
+}

vendor/rodio/src/static_buffer.rs

@@ -0,0 +1,155 @@
+//! A simple source of samples coming from a static buffer.
+//!
+//! The `StaticSamplesBuffer` struct can be used to treat a list of values as a `Source`.
+//!
+//! # Example
+//!
+//! ```
+//! use rodio::static_buffer::StaticSamplesBuffer;
+//! let _ = StaticSamplesBuffer::new(1, 44100, &[1i16, 2, 3, 4, 5, 6]);
+//! ```
+//!
+
+use std::slice::Iter as SliceIter;
+use std::time::Duration;
+
+use crate::source::SeekError;
+use crate::{Sample, Source};
+
+/// A buffer of samples treated as a source.
+#[derive(Clone)]
+pub struct StaticSamplesBuffer<S>
+where
+    S: 'static,
+{
+    data: SliceIter<'static, S>,
+    channels: u16,
+    sample_rate: u32,
+    duration: Duration,
+}
+
+impl<S> StaticSamplesBuffer<S>
+where
+    S: Sample,
+{
+    /// Builds a new `StaticSamplesBuffer`.
+    ///
+    /// # Panic
+    ///
+    /// - Panics if the number of channels is zero.
+    /// - Panics if the samples rate is zero.
+    /// - Panics if the length of the buffer is larger than approximately 16 billion elements.
+    ///   This is because the calculation of the duration would overflow.
+    ///
+    pub fn new(channels: u16, sample_rate: u32, data: &'static [S]) -> StaticSamplesBuffer<S> {
+        assert!(channels != 0);
+        assert!(sample_rate != 0);
+
+        let duration_ns = 1_000_000_000u64.checked_mul(data.len() as u64).unwrap()
+            / sample_rate as u64
+            / channels as u64;
+        let duration = Duration::new(
+            duration_ns / 1_000_000_000,
+            (duration_ns % 1_000_000_000) as u32,
+        );
+
+        StaticSamplesBuffer {
+            data: data.iter(),
+            channels,
+            sample_rate,
+            duration,
+        }
+    }
+}
+
+impl<S> Source for StaticSamplesBuffer<S>
+where
+    S: Sample,
+{
+    #[inline]
+    fn current_frame_len(&self) -> Option<usize> {
+        None
+    }
+
+    #[inline]
+    fn channels(&self) -> u16 {
+        self.channels
+    }
+
+    #[inline]
+    fn sample_rate(&self) -> u32 {
+        self.sample_rate
+    }
+
+    #[inline]
+    fn total_duration(&self) -> Option<Duration> {
+        Some(self.duration)
+    }
+
+    #[inline]
+    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
+        Err(SeekError::NotSupported {
+            underlying_source: std::any::type_name::<Self>(),
+        })
+    }
+}
+
+impl<S> Iterator for StaticSamplesBuffer<S>
+where
+    S: Sample + Clone,
+{
+    type Item = S;
+
+    #[inline]
+    fn next(&mut self) -> Option<S> {
+        self.data.next().cloned()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.data.size_hint()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::source::Source;
+    use crate::static_buffer::StaticSamplesBuffer;
+
+    #[test]
+    fn basic() {
+        let _ = StaticSamplesBuffer::new(1, 44100, &[0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    #[should_panic]
+    fn panic_if_zero_channels() {
+        StaticSamplesBuffer::new(0, 44100, &[0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    #[should_panic]
+    fn panic_if_zero_sample_rate() {
+        StaticSamplesBuffer::new(1, 0, &[0i16, 0, 0, 0, 0, 0]);
+    }
+
+    #[test]
+    fn duration_basic() {
+        let buf = StaticSamplesBuffer::new(2, 2, &[0i16, 0, 0, 0, 0, 0]);
+        let dur = buf.total_duration().unwrap();
+        assert_eq!(dur.as_secs(), 1);
+        assert_eq!(dur.subsec_nanos(), 500_000_000);
+    }
+
+    #[test]
+    fn iteration() {
+        let mut buf = StaticSamplesBuffer::new(1, 44100, &[1i16, 2, 3, 4, 5, 6]);
+        assert_eq!(buf.next(), Some(1));
+        assert_eq!(buf.next(), Some(2));
+        assert_eq!(buf.next(), Some(3));
+        assert_eq!(buf.next(), Some(4));
+        assert_eq!(buf.next(), Some(5));
+        assert_eq!(buf.next(), Some(6));
+        assert_eq!(buf.next(), None);
+    }
+}

vendor/rodio/src/stream.rs

@@ -0,0 +1,353 @@
+use std::io::{Read, Seek};
+use std::sync::{Arc, Weak};
+use std::{error, fmt};
+
+use crate::decoder;
+use crate::dynamic_mixer::{self, DynamicMixerController};
+use crate::sink::Sink;
+use crate::source::Source;
+use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+use cpal::{Sample, SupportedStreamConfig};
+
+/// `cpal::Stream` container. Also see the more useful `OutputStreamHandle`.
+///
+/// If this is dropped playback will end & attached `OutputStreamHandle`s will no longer work.
+pub struct OutputStream {
+    mixer: Arc<DynamicMixerController<f32>>,
+    _stream: cpal::Stream,
+}
+
+/// More flexible handle to a `OutputStream` that provides playback.
+#[derive(Clone)]
+pub struct OutputStreamHandle {
+    mixer: Weak<DynamicMixerController<f32>>,
+}
+
+impl OutputStream {
+    /// Returns a new stream & handle using the given output device and the default output
+    /// configuration.
+    pub fn try_from_device(
+        device: &cpal::Device,
+    ) -> Result<(Self, OutputStreamHandle), StreamError> {
+        let default_config = device
+            .default_output_config()
+            .map_err(StreamError::DefaultStreamConfigError)?;
+        OutputStream::try_from_device_config(device, default_config)
+    }
+
+    /// Returns a new stream & handle using the given device and stream config.
+    ///
+    /// If the supplied `SupportedStreamConfig` is invalid for the device this function will
+    /// fail to create an output stream and instead return a `StreamError`
+    pub fn try_from_device_config(
+        device: &cpal::Device,
+        config: SupportedStreamConfig,
+    ) -> Result<(Self, OutputStreamHandle), StreamError> {
+        let (mixer, _stream) = device.try_new_output_stream_config(config)?;
+        _stream.play().map_err(StreamError::PlayStreamError)?;
+        let out = Self { mixer, _stream };
+        let handle = OutputStreamHandle {
+            mixer: Arc::downgrade(&out.mixer),
+        };
+        Ok((out, handle))
+    }
+
+    /// Return a new stream & handle using the default output device.
+    ///
+    /// On failure will fallback to trying any non-default output devices.
+    pub fn try_default() -> Result<(Self, OutputStreamHandle), StreamError> {
+        let default_device = cpal::default_host()
+            .default_output_device()
+            .ok_or(StreamError::NoDevice)?;
+
+        let default_stream = Self::try_from_device(&default_device);
+
+        default_stream.or_else(|original_err| {
+            // default device didn't work, try other ones
+            let mut devices = match cpal::default_host().output_devices() {
+                Ok(d) => d,
+                Err(_) => return Err(original_err),
+            };
+
+            devices
+                .find_map(|d| Self::try_from_device(&d).ok())
+                .ok_or(original_err)
+        })
+    }
+}
+
+impl OutputStreamHandle {
+    /// Plays a source with a device until it ends.
+    pub fn play_raw<S>(&self, source: S) -> Result<(), PlayError>
+    where
+        S: Source<Item = f32> + Send + 'static,
+    {
+        let mixer = self.mixer.upgrade().ok_or(PlayError::NoDevice)?;
+        mixer.add(source);
+        Ok(())
+    }
+
+    /// Plays a sound once. Returns a `Sink` that can be used to control the sound.
+    pub fn play_once<R>(&self, input: R) -> Result<Sink, PlayError>
+    where
+        R: Read + Seek + Send + Sync + 'static,
+    {
+        let input = decoder::Decoder::new(input)?;
+        let sink = Sink::try_new(self)?;
+        sink.append(input);
+        Ok(sink)
+    }
+}
+
+/// An error occurred while attempting to play a sound.
+#[derive(Debug)]
+pub enum PlayError {
+    /// Attempting to decode the audio failed.
+    DecoderError(decoder::DecoderError),
+    /// The output device was lost.
+    NoDevice,
+}
+
+impl From<decoder::DecoderError> for PlayError {
+    fn from(err: decoder::DecoderError) -> Self {
+        Self::DecoderError(err)
+    }
+}
+
+impl fmt::Display for PlayError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::DecoderError(e) => e.fmt(f),
+            Self::NoDevice => write!(f, "NoDevice"),
+        }
+    }
+}
+
+impl error::Error for PlayError {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self {
+            Self::DecoderError(e) => Some(e),
+            Self::NoDevice => None,
+        }
+    }
+}
+
+/// Errors that might occur when interfacing with audio output.
+#[derive(Debug)]
+pub enum StreamError {
+    /// Could not start playing the stream, see [cpal::PlayStreamError] for
+    /// details.
+    PlayStreamError(cpal::PlayStreamError),
+    /// Failed to get the stream config for device the given device. See
+    /// [cpal::DefaultStreamConfigError] for details
+    DefaultStreamConfigError(cpal::DefaultStreamConfigError),
+    /// Error opening stream with OS. See [cpal::BuildStreamError] for details
+    BuildStreamError(cpal::BuildStreamError),
+    /// Could not list supported stream configs for device. Maybe it
+    /// disconnected, for details see: [cpal::SupportedStreamConfigsError].
+    SupportedStreamConfigsError(cpal::SupportedStreamConfigsError),
+    /// Could not find any output device
+    NoDevice,
+}
+
+impl fmt::Display for StreamError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::PlayStreamError(e) => e.fmt(f),
+            Self::BuildStreamError(e) => e.fmt(f),
+            Self::DefaultStreamConfigError(e) => e.fmt(f),
+            Self::SupportedStreamConfigsError(e) => e.fmt(f),
+            Self::NoDevice => write!(f, "NoDevice"),
+        }
+    }
+}
+
+impl error::Error for StreamError {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self {
+            Self::PlayStreamError(e) => Some(e),
+            Self::BuildStreamError(e) => Some(e),
+            Self::DefaultStreamConfigError(e) => Some(e),
+            Self::SupportedStreamConfigsError(e) => Some(e),
+            Self::NoDevice => None,
+        }
+    }
+}
+
+/// Extensions to `cpal::Device`
+pub(crate) trait CpalDeviceExt {
+    fn new_output_stream_with_format(
+        &self,
+        format: cpal::SupportedStreamConfig,
+    ) -> Result<(Arc<DynamicMixerController<f32>>, cpal::Stream), cpal::BuildStreamError>;
+
+    fn try_new_output_stream_config(
+        &self,
+        config: cpal::SupportedStreamConfig,
+    ) -> Result<(Arc<DynamicMixerController<f32>>, cpal::Stream), StreamError>;
+}
+
+impl CpalDeviceExt for cpal::Device {
+    fn new_output_stream_with_format(
+        &self,
+        format: cpal::SupportedStreamConfig,
+    ) -> Result<(Arc<DynamicMixerController<f32>>, cpal::Stream), cpal::BuildStreamError> {
+        let (mixer_tx, mut mixer_rx) =
+            dynamic_mixer::mixer::<f32>(format.channels(), format.sample_rate().0);
+
+        let error_callback = |err| {
+            #[cfg(feature = "tracing")]
+            tracing::error!("an error occurred on output stream: {err}");
+            #[cfg(not(feature = "tracing"))]
+            eprintln!("an error occurred on output stream: {err}");
+        };
+
+        match format.sample_format() {
+            cpal::SampleFormat::F32 => self.build_output_stream::<f32, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().unwrap_or(0f32))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::F64 => self.build_output_stream::<f64, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().map(Sample::from_sample).unwrap_or(0f64))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::I8 => self.build_output_stream::<i8, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().map(Sample::from_sample).unwrap_or(0i8))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::I16 => self.build_output_stream::<i16, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().map(Sample::from_sample).unwrap_or(0i16))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::I32 => self.build_output_stream::<i32, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().map(Sample::from_sample).unwrap_or(0i32))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::I64 => self.build_output_stream::<i64, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut()
+                        .for_each(|d| *d = mixer_rx.next().map(Sample::from_sample).unwrap_or(0i64))
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::U8 => self.build_output_stream::<u8, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut().for_each(|d| {
+                        *d = mixer_rx
+                            .next()
+                            .map(Sample::from_sample)
+                            .unwrap_or(u8::MAX / 2)
+                    })
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::U16 => self.build_output_stream::<u16, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut().for_each(|d| {
+                        *d = mixer_rx
+                            .next()
+                            .map(Sample::from_sample)
+                            .unwrap_or(u16::MAX / 2)
+                    })
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::U32 => self.build_output_stream::<u32, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut().for_each(|d| {
+                        *d = mixer_rx
+                            .next()
+                            .map(Sample::from_sample)
+                            .unwrap_or(u32::MAX / 2)
+                    })
+                },
+                error_callback,
+                None,
+            ),
+            cpal::SampleFormat::U64 => self.build_output_stream::<u64, _, _>(
+                &format.config(),
+                move |data, _| {
+                    data.iter_mut().for_each(|d| {
+                        *d = mixer_rx
+                            .next()
+                            .map(Sample::from_sample)
+                            .unwrap_or(u64::MAX / 2)
+                    })
+                },
+                error_callback,
+                None,
+            ),
+            _ => return Err(cpal::BuildStreamError::StreamConfigNotSupported),
+        }
+        .map(|stream| (mixer_tx, stream))
+    }
+
+    fn try_new_output_stream_config(
+        &self,
+        config: SupportedStreamConfig,
+    ) -> Result<(Arc<DynamicMixerController<f32>>, cpal::Stream), StreamError> {
+        self.new_output_stream_with_format(config).or_else(|err| {
+            // look through all supported formats to see if another works
+            supported_output_formats(self)?
+                .find_map(|format| self.new_output_stream_with_format(format).ok())
+                // return original error if nothing works
+                .ok_or(StreamError::BuildStreamError(err))
+        })
+    }
+}
+
+/// All the supported output formats with sample rates
+fn supported_output_formats(
+    device: &cpal::Device,
+) -> Result<impl Iterator<Item = cpal::SupportedStreamConfig>, StreamError> {
+    const HZ_44100: cpal::SampleRate = cpal::SampleRate(44_100);
+
+    let mut supported: Vec<_> = device
+        .supported_output_configs()
+        .map_err(StreamError::SupportedStreamConfigsError)?
+        .collect();
+    supported.sort_by(|a, b| b.cmp_default_heuristics(a));
+
+    Ok(supported.into_iter().flat_map(|sf| {
+        let max_rate = sf.max_sample_rate();
+        let min_rate = sf.min_sample_rate();
+        let mut formats = vec![sf.with_max_sample_rate()];
+        if HZ_44100 < max_rate && HZ_44100 > min_rate {
+            formats.push(sf.with_sample_rate(HZ_44100))
+        }
+        formats.push(sf.with_sample_rate(min_rate));
+        formats
+    }))
+}