#codec #media #decoder #multimedia #encoding

symphonium

An unofficial easy-to-use wrapper around Symphonia for loading audio files

4 releases

0.2.2 Oct 17, 2024
0.2.1 Oct 17, 2024
0.2.0 Oct 17, 2024
0.1.0 Oct 17, 2024

#365 in Audio

34 downloads per month

MPL-2.0 license

98KB
2K SLoC

Symphonium

Documentation Crates.io License

An unofficial easy-to-use wrapper around Symphonia for loading audio files. It also handles resampling at load-time.

The resulting DecodedAudio resources are stored in their native sample format whenever possible to save on memory, and have convenience methods to fill a buffer with f32 samples from any arbitrary position in the resource in realtime during playback. Alternatively you can use the DecodedAudioF32 resource if you only need samples in the f32 format.

Example

/// A struct used to load audio files.
let mut loader = SymphoniumLoader::new();

/// Load an audio file.
let audio_data = loader
    .load(
        // The path to the audio file.
        file_path,    
        // The target sample rate. If this differs from the
        // file's sample rate, then it will be resampled.
        // If you wish to never resample, set this to `None`.
        Some(sample_rate),
        // The quality of the resampling algorithm. Normal
        // is recommended for most applications.
        ResampleQuality::Normal,
        // The maximum size a file can be in bytes before an
        // error is returned. This is to protect against
        // out of memory errors when loading really long
        // audio files. Set to `None` to use the default of
        // 1 GB.
        None
    )
    .unwrap();

/// Fill a stereo buffer with samples starting at frame 100.
let mut buf_l = vec![0.0f32; 512];
let mut buf_r = vec![0.0f32; 512];
audio_data.fill_stereo(100, &mut buf_l, &mut buf_r);

/// Alternatively, if you don't need to save memory, you can
/// load directly to an `f32` format.
let audio_data_f32 = loader
    .load_f32(
        file_path, 
        Some(sample_rate),
        ResampleQuality::Normal,
        None
    )
    .unwrap();

/// Print info about the data (`data` is a `Vec<Vec<f32>>`).
println!("num channels: {}" audio_data_f32.data.len());
println!("num frames: {}" audio_data_f32.data[0].len());

Features

By default, only wav and ogg support is enabled. If you need more formats, enable them as features in your Cargo.toml file like this:

symphonium = { version = "0.2", features = ["mp3", "flac"] }

Available codecs:

  • aac
  • adpcm
  • alac
  • flac
  • mp1
  • mp2
  • mp3
  • pcm
  • vorbis

Available container formats:

  • caf
  • isomp4
  • mkv
  • ogg
  • aiff
  • wav

Alternatively you can enable the all feature if you want everything, or the open-standards feature if you want all of the royalty-free open-source standards.

Dependencies

~5MB
~149K SLoC