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 'encode-audio';

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

Supported formats:

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

Whole-file encode

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

import encode from 'encode-audio';

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 });

Chunked encoding

Call with just options (no data) to create a streaming encoder:

import encode from 'encode-audio';

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

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

// explicit control: enc.flush(), enc.free()

TransformStream

import encodeStream from 'encode-audio/stream';

audioSource
  .pipeThrough(encodeStream('mp3', { sampleRate: 44100, bitrate: 128 }))
  .pipeTo(destination);

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 |

See also

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

License

MIT

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