audio-encode

Encode raw audio samples to any format.
JS / WASM – no ffmpeg, no native bindings, works in both node and browser.
Small API, minimal size, near-native performance, stream encoding.

import encode from 'audio-encode';

const buf = await encode.wav(channelData, { sampleRate: 44100 });

Supported formats:

Format	Package	Engine
WAV	@audio/wav-encode	JS
MP3	@audio/mp3-encode	WASM
OGG Vorbis	@audio/ogg-encode	WASM
Opus	@audio/opus-encode	WASM
FLAC	@audio/flac-encode	WASM
AIFF	@audio/aiff-encode	JS

Whole-file encode

Specify the format as method name. Input is Float32Array[] (one per channel) or a single Float32Array (mono).

import encode from 'audio-encode';

const wav  = await encode.wav(channelData, { sampleRate: 44100 });
const aiff = await encode.aiff(channelData, { sampleRate: 44100 });
const mp3  = await encode.mp3(channelData, { sampleRate: 44100, bitrate: 128 });
const ogg  = await encode.ogg(channelData, { sampleRate: 44100, quality: 5 });
const flac = await encode.flac(channelData, { sampleRate: 44100 });
const opus = await encode.opus(channelData, { sampleRate: 48000, bitrate: 96 });

Stream encoding

For chunk-by-chunk encoding, use .stream():

import encode from 'audio-encode';

const encoder = await encode.mp3.stream({ sampleRate: 44100, bitrate: 128 });

const a = await encoder.encode(chunk1);  // Uint8Array
const b = await encoder.encode(chunk2);
const c = await encoder.encode();        // end of stream — flush + free

// explicit methods
// encoder.flush(), encoder.free()

Options

Option	Description	Applies to
sampleRate	Output sample rate (required)	all
bitrate	Target bitrate in kbps	mp3, opus
quality	Quality 0–10 (VBR)	ogg, mp3
channels	Output channel count	all
bitDepth	Bit depth: 16 or 32 (wav), 16 or 24 (aiff, flac)	wav, aiff, flac
compression	FLAC compression level 0–8	flac
application	'audio', 'voip', or 'lowdelay'	opus

Custom encoders

The encode registry is extensible:

import encode from 'audio-encode';
encode.myformat = Object.assign(
  async (data, opts) => { /* ... */ },
  { stream: async (opts) => ({ encode: chunk => ..., free() {} }) }
);

See also

• audio-decode – decode any audio format to raw samples.
• wasm-media-encoders – compact WASM MP3 & Vorbis encoders.
• AudioEncoder – native WebCodecs encoder API.
• ffmpeg.wasm – full encoding/decoding library.

License

MIT

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