audio-file 0.4.0

A simple library to read and write audio files on your disk.
Documentation

audio-file

A simple library to read and write audio files on your disk.

The library can read many formats and can write only to wav files.

Quick Start

Read Audio

You can read most common audio formats. The default feature set enables all available codecs.

let audio = audio_file::read::<f32>("test_data/test_1ch.wav", audio_file::ReadConfig::default())?;
let sample_rate = audio.sample_rate;
let num_channels = audio.num_channels;
let samples = &audio.samples_interleaved;

With audio-blocks, you can read straight into an AudioBlock, which adds simple channel-based read helpers:

let (block, sample_rate) = audio_file::read_block::<f32>("test_data/test_1ch.wav", audio_file::ReadConfig::default())?;

Write Audio

You can only write wav files. The audio_file::write function expects interleaved samples.

let samples = [0.0, 1.0, 0.0, 1.0, 0.0, 1.0]; // interleaved
let num_channels = 2;
let sample_rate = 48000;
audio_file::write(
    "tmp.wav",
    &samples,
    num_channels,
    sample_rate,
    audio_file::WriteConfig::default(),
)?;

With the audio-blocks feature you can write any audio layout, e.g.:

let sample_rate = 48000;

let block = InterleavedView::from_slice(&[0.0, 1.0, 0.0, 1.0, 0.0, 1.0], 2);
audio_file::write_block("tmp.wav", block, sample_rate, audio_file::WriteConfig::default())?;

let block = SequentialView::from_slice(&[0.0, 0.0, 0.0, 1.0, 1.0, 1.0], 2);
audio_file::write_block("tmp.wav", block, sample_rate, audio_file::WriteConfig::default())?;

Supported Input Codecs

Default features enable all codecs (including royalty-encumbered formats) via all-codecs. To opt out, disable default features and enable only what you need.

Format Feature Flag
AAC aac
ADPCM adpcm
ALAC alac
FLAC flac
CAF caf
ISO MP4 isomp4
Matroska (MKV) mkv
MP1 mp1
MP2 mp2
MP3 mp3
Ogg ogg
PCM pcm
AIFF aiff
Vorbis vorbis
WAV wav

Feature flags:

  • all-codecs enables all Symphonia codecs (this is the default).
  • audio-blocks enables read_block and write_block.
  • Individual codec flags (above) enable specific formats.

Read and Write Options

Reading

When reading a file you can specify the following things:

  • Start and stop in frames or time
  • Start channel and number of channels
  • Optional resampling

The crate will try to decode and store only the parts that you selected.

Writing

For writing audio you can select from the following sample formats:

Format Description
Int8 8-bit integer
Int16 16-bit integer (default)
Int32 32-bit integer
Float32 32-bit float

Int16 is the default, for broader compatibility.

Some example configs:

  • resample to 22.05 kHz while reading
let audio = audio_file::read::<f32>(
    "test_data/test_1ch.wav",
    audio_file::ReadConfig {
        sample_rate: Some(22_050),
        ..Default::default()
    },
)?;
  • read the first 0.5 seconds
let audio = audio_file::read::<f32>(
    "test_data/test_1ch.wav",
    audio_file::ReadConfig {
        stop: audio_file::Position::Time(Duration::from_secs_f32(0.5)),
        ..Default::default()
    },
)?;
  • read from frame 300 to 400
let audio = audio_file::read::<f32>(
    "test_data/test_1ch.wav",
    audio_file::ReadConfig {
        start: audio_file::Position::Frame(300),
        stop: audio_file::Position::Frame(400),
        ..Default::default()
    },
)?;
  • read only the first two channels
let audio = audio_file::read::<f32>(
    "test_data/test_4ch.wav",
    audio_file::ReadConfig {
        num_channels: Some(2),
        ..Default::default()
    },
)?;
  • skip the first channel, reading channel 2 and 3
let audio = audio_file::read::<f32>(
    "test_data/test_4ch.wav",
    audio_file::ReadConfig {
        start_channel: Some(1),
        num_channels: Some(2),
        ..Default::default()
    },
)?;
  • write audio samples in Float32
audio_file::write(
    "tmp.wav",
    &samples_interleaved,
    num_channels,
    sample_rate,
    audio_file::WriteConfig {
        sample_format: audio_file::SampleFormat::Float32,
    },
)?;