Symphonia is a pure Rust audio decoding and media demuxing library supporting AAC, OGG, FLAC, MP3, and WAV.
Symphonia's planned features are:
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.
The follow status classifications are used to determine the state of development for each format or codec.
| Status | Meaning | |-----------|--------------------------------------------------------------------------------------------------------------------------| | - | No work started or planned yet. | | Next | Is the next major work item. | | Viable | Many media streams play. Some streams may panic, error, or produce audible glitches. Some features may not be supported. | | Usable | Most media streams play. Inaudible glitches may be present. Most common features are supported. | | Compliant | All media streams play. No audible or inaudible glitches. All required features are supported. |
A classification of usable indicates the end of major development. Though bugs and smaller issues can occur, it would generally be safe to use in an application. Compliance testing according to standards will be delayed until most codecs and demuxers are implemented so it's expected that many will stay in the category for a while.
| Format | Status | Feature Flag | Default | Crate |
|----------|-----------|--------------|---------|---------------------------|
| ISO/MP4 | Usable | isomp4 | No | symphonia-format-isomp4 |
| MKV/WebM | - | mkv | Yes | symphonia-format-mkv |
| OGG | Usable | ogg | Yes | symphonia-format-ogg |
| Wave | Compliant | wav | Yes | symphonia-format-wav |
| Codec | Status | Feature Flag | Default | Crate |
|------------------------------|-----------|--------------|---------|---------------------------|
| AAC-LC | Usable | aac | No | symphonia-codec-aac |
| HE-AAC (AAC+, aacPlus) | - | aac | No | symphonia-codec-aac |
| HE-AACv2 (eAAC+, aacPlus v2) | - | aac | No | symphonia-codec-aac |
| FLAC | Compliant | flac | Yes | symphonia-bundle-flac |
| MP1 | - | mp3 | No | symphonia-bundle-mp3 |
| MP2 | - | mp3 | No | symphonia-bundle-mp3 |
| MP3 | Usable | mp3 | No | symphonia-bundle-mp3 |
| Opus | - | opus | Yes | symphonia-codec-opus |
| PCM | Compliant | pcm | Yes | symphonia-codec-pcm |
| Vorbis | Next | vorbis | Yes | symphonia-codec-vorbis |
| WavPack | - | wavpack | Yes | symphonia-codec-wavpack |
A symphonia-bundle-* package is a combination of a decoder and a native bitstream demuxer.
All metadata readers are provided by the symphonia-metadata crate.
| Format | Status | |-----------------------|-----------| | APEv1 | - | | APEv2 | - | | ID3v1 | Usable | | ID3v2 | Usable | | ISO/MP4 | Usable | | RIFF | Usable | | Vorbis comment (FLAC) | Compliant | | Vorbis comment (OGG) | Compliant |
In addition to the safety guarantees provided by Rust, Symphonia aims to:
symphonia-coreSymphonia 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:
```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 |
Please see symphonia-play for a simple music player example.
Symphonia provides the following tools for debugging purposes:
symphonia-play for probing files and playing back audio, as well as serving as a demo applicationThe primary author is Philip Deljanov.
symphonia-codec-aac)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!