Symphonia is a pure Rust audio decoding and media demuxing library supporting OGG, FLAC, MP3, and WAV.
Symphonia's planned features are:
- Decode support for the most popular audio codecs
- Reading the most common media container formats
- Probing and guessing the correct format and decoder combination(s) for playback or inspection
- Reading metadata
- Providing a set of audio primitives for manipulating audio data efficiently
- Providing a C API for integration into other languages
- Providing a WASM API for web usage
Support for individual audio codecs and media formats is provided by separate crates. By default, Symphonia selects support for FOSS codecs and formats, but others may be included via the features option.
| Format | Status | Feature Flag | Default | Crate |
|---|---|---|---|---|
| ISO/MP4 | - | isomp4 |
No | symphonia-format-isomp4 |
| MKV | - | mkv |
Yes | symphonia-format-mkv |
| OGG | Functional | ogg |
Yes | symphonia-format-ogg |
| Wave | Complete | wav |
Yes | symphonia-format-wav |
| WebM | - | webm |
No | symphonia-format-webm |
| Codec | Status | Feature Flag | Default | Crate |
|---|---|---|---|---|
| FLAC | Complete | flac |
Yes | symphonia-bundle-flac |
| MP1 | Paused | mp3 |
No | symphonia-bundle-mp3 |
| MP2 | Paused | mp3 |
No | symphonia-bundle-mp3 |
| MP3 | Complete | mp3 |
No | symphonia-bundle-mp3 |
| AAC | - | aac |
No | symphonia-codec-aac |
| Opus | Next | opus |
Yes | symphonia-codec-opus |
| PCM | Complete | pcm |
Yes | symphonia-codec-pcm |
| Vorbis | - | vorbis |
Yes | symphonia-codec-vorbis |
| WavPack | - | wavpack |
Yes | symphonia-codec-wavpack |
All metadata readers are provided by the symphonia-metadata crate.
| Format | Status |
|---|---|
| ID3v1 | Complete |
| ID3v2 | Complete |
| Vorbis comment (OGG) | In Work |
| Vorbis comment (FLAC) | Complete |
| RIFF | Complete |
| APEv1 | - |
| APEv2 | - |
In addition to the safety guarantees provided by Rust, Symphonia aims to:
- Decode files as well as the leading free-and-open-source software decoders
- Provide a powerful, consistent, and easy to use API
- Have absolutely no unsafe blocks outside of
symphonia-core - Have very minimal dependencies
- Prevent denial-of-service attacks
- Be fuzz-tested
Symphonia aims to be equivalent in speed to popular open-source C-based implementations.
Symphonia does not include explicit SIMD optimizations, however the auto-vectorizer is leveraged as much as possible and the results have been excellent. As Rust support for packed SIMD grows, Symphonia will include explicit SIMD optimizations where necessary.
These benchmarks compare the single-threaded decoding performance of both Symphonia and FFmpeg with various audio files.
The benchmarks were executed on an Arch Linux system with a Core i7 4790k and 32GB of RAM, for a minimum of 20 runs each. Hyperfine was used to execute the test. The full benchmark script is as follows:
#!/bin/bash
IN="${1@Q}"
hyperfine -m 20 "ffmpeg -threads 1 -benchmark -v 0 -i ${IN} -f null -" "symphonia-play --decode-only ${IN}"| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
| Symphonia | 306.2 ± 3.0 | 301.8 | 312.5 | 1.1 |
| FFmpeg | 272.7 ± 4.3 | 267.6 | 285.3 | 1.0 |
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
| Symphonia | 355.1 ± 8.4 | 348.2 | 376.2 | 1.1 |
| FFmpeg | 316.0 ± 3.5 | 308.8 | 322.8 | 1.0 |
| Decoder | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
| Symphonia | 453.6 ± 2.9 | 449.3 | 462.4 | 1.0 |
| FFmpeg | 501.9 ± 4.3 | 496.4 | 512.7 | 1.1 |
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
| Symphonia | 324.0 ± 8.9 | 315.4 | 346.3 | 1.0 |
| FFmpeg | 331.0 ± 7.4 | 323.6 | 354.5 | 1.0 |
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|---|---|---|---|---|
| Symphonia | 84.5 ± 1.8 | 81.8 | 89.1 | 1.0 |
| FFmpeg | 129.8 ± 3.4 | 123.4 | 136.1 | 1.5 |
Symphonia provides the following tools for debugging purposes:
symphonia-playfor probing files and playing back audio, as well as serving as a demo application
Rust makes a lot of sense for multimedia programming, particularly when accessing that media over the network. However, currently it is difficult to do something as simple as play a FLAC file. Rust does not have a library like FFMpeg, and even if one uses the FFI, FFMpeg is a difficult library to use and you'd have none of the protections afforded to you by Rust. Symphonia is therefore an attempt to fill-in that gap.
Personally, this is a project to learn Rust and experiment with signal processing.
The primary author is Philip Deljanov.
Symphonia is provided under the MPL v2.0 license. Please refer to the LICENSE file for more details.
Symphonia is an open-source project and contributions are very welcome! If you would like to make a large contribution, please raise an issue ahead of time to make sure your efforts fit into the project goals, and that there's no duplication of effort. Please be aware that all contributions must also be licensed under the MPL v2.0 license to be accepted.
When submitting a pull request, be sure you have included yourself in the CONTRIBUTORS file!