webm-decode

Decode WebM audio (Opus and Vorbis) to PCM float samples. EBML demuxer in pure JS, codec decoding via WASM.

Part of audio-decode.

Install

npm i @audio/webm-decode

Usage

import decode from '@audio/webm-decode'

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

Streaming

import { decoder } from '@audio/webm-decode'

let dec = await decoder()
let result = await dec.decode(chunk)
let flushed = await dec.flush()
dec.free()

API

decode(src): Promise<AudioData>

Whole-file decode. Accepts Uint8Array or ArrayBuffer.

decoder(): Promise<WebmDecoder>

Creates a decoder instance.

• dec.decode(data) — decode chunk, returns Promise<AudioData>
• dec.flush() — flush remaining data
• dec.free() — release resources

Note: decode() and flush() are async (unlike the sync PCM decoders) because Opus decoding happens in WASM.

Codecs

• Opus — via opus-decoder
• Vorbis — via @wasm-audio-decoders/ogg-vorbis (raw frames wrapped in OGG pages)

License

MIT

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