@audio/decode-avi

Decode the audio stream of AVI files to PCM float samples. A pure-JS RIFF/AVI demuxer (OpenDML AVIX extensions included) that skips the video stream and routes the audio to the matching codec package, loaded on demand.

import decode, { decoder } from '@audio/decode-avi'

let { channelData, sampleRate } = await decode(aviBytes)

let dec = await decoder()
let head = await dec.decode(chunk1)   // Promise on the chunk that completes the stream headers
let more = dec.decode(chunk2)         // synchronous from then on
let tail = await dec.flush()
dec.free()

Codecs

| wFormatTag | Codec | Decoded by | |---|---|---| | 0x0001, 0x0003 (and WAVE_FORMAT_EXTENSIBLE) | PCM 8–32 bit int, 32/64 bit float | built in | | 0x0006, 0x0007 | G.711 A-law, µ-law | built in | | 0x0055 | MP3 | @audio/decode-mp3 | | 0x00FF | AAC | @audio/decode-aac | | 0x2000 | AC-3 | @audio/decode-ac3 | | 0x2001 | DTS | @audio/decode-dts |

WMA and ADPCM streams throw an error naming the codec. The first auds stream is decoded.

Codec packages are imported dynamically, which is unavailable inside an AudioWorklet — decode in the main thread or a Worker.

API

decode(src: Uint8Array | ArrayBuffer): Promise<AudioData>

Decode a complete file.

decoder(): Promise<AVIDecoder>

Streaming decoder. decode(chunk) returns AudioData, or a Promise of it on the chunk that completes the stream headers while the codec module loads. flush() returns remaining samples and throws if no audio stream was found. free() releases codec resources.

AudioData

{ channelData: Float32Array[], sampleRate: number }

License

ॐ · MIT. Codec packages carry their own licenses.