audio_decode library

Native Ogg Vorbis and MP3 decoding to raw PCM for Dart, backed by Sean Barrett's stb_vorbis and lieff's minimp3 over FFI.

The C decoders are compiled from source by a Dart build hook, so there is no prebuilt binary to ship and no platform plugin or system library to install beyond a C toolchain. Decoding runs in native code and copies the result into a Dart Int16List, so callers never manage native memory. The same code path runs in pure Dart (CLI, servers, tests) and in Flutter.

Decoding is deterministic for a given build, and the geometry it reports is the same everywhere. Sample values are not bit-identical across CPU architectures: the decoders compute in floating point, so around 0.03% of samples can differ by one least-significant bit between arm64 and x86-64. Do not compare checksums of decoded PCM across a mixed fleet.

This is a decoder, not a player: it turns encoded bytes into PCM samples for waveforms, analysis, resampling, machine-learning preprocessing, games and servers. For playback, pair it with a player package such as just_audio or flutter_sound. encodeWav writes the decoded PCM back out as a WAV file so the samples can be saved or handed to other tools.

import 'dart:io';
import 'package:audio_decode/audio_decode.dart';

void main() {
  final bytes = File('clip.mp3').readAsBytesSync();
  final pcm = decodeAudio(bytes);
  print('${pcm.sampleRate} Hz, ${pcm.channels} ch, ${pcm.duration}');
  File('clip.wav').writeAsBytesSync(encodeWav(pcm));
}

See decodeAudio, decodeOgg, decodeMp3, detectFormat, PcmAudio and encodeWav for the full API.