@strangeape/ffmpeg-audio-wasm

Audio-only FFmpeg compiled to WebAssembly. No native binaries, no postinstall scripts, works everywhere Node runs.

1.4MB WASM, single-threaded, no SharedArrayBuffer required.

Supported codecs

| | Encode | Decode | |---|--------|--------| | AAC | yes | yes | | MP3 | | yes | | Vorbis | | yes | | Opus | | yes | | FLAC | | yes | | PCM (various) | yes | yes |

Usage

import { createFFmpegAudio } from '@strangeape/ffmpeg-audio-wasm';

const ffmpeg = await createFFmpegAudio();

// Write input file to virtual FS
ffmpeg.writeFile('/input.wav', wavBuffer);

// Run ffmpeg command
const code = await ffmpeg.exec(['-y', '-i', '/input.wav', '-c:a', 'aac', '-q:a', '0.4', '/output.m4a']);

// Read output
const result = ffmpeg.readFile('/output.m4a');

Each createFFmpegAudio() call creates a fresh WASM instance to avoid state issues between runs.

Building the WASM from source

Requires Docker.

bash build/build.sh

Built from FFmpeg 4.4.5 with Emscripten 3.1.50.