@audio/encode-flac

Encode PCM audio samples to FLAC (lossless) format. WASM (libFLAC via libflacjs) — works in both node and browser.

import flac from '@audio/encode-flac';

const encoder = await flac({ sampleRate: 44100 });
const chunk = encoder.encode(channelData); // → Uint8Array (FLAC frames)
const tail = encoder.flush();              // → Uint8Array (remaining)
// concatenate chunk + tail for complete FLAC file

Options

| Option | Default | Description | |--------|---------|-------------| | sampleRate | — | Sample rate (required) | | channels | auto | 1 or 2. Auto-detected from first encode call. | | bitDepth | 16 | 16 or 24 | | compression | 5 | Compression level 0–8 (higher = smaller, slower) |

Streaming

const encoder = await flac({ sampleRate: 44100, compression: 8 });
const a = encoder.encode(chunk1);
const b = encoder.encode(chunk2);
const c = encoder.flush();
// complete FLAC = concat(a, b, c)
encoder.free();

Streaming output

After flush(), head() returns the first 42 bytes with the final STREAMINFO (total samples, MD5, frame sizes), which libFLAC only knows at the end: write it over the start. stream: true also puts meta into the metadata blocks ahead of the frames; frames (the exact length, known upfront) puts the sample count into STREAMINFO from the start.

License

MIT

ॐ