ffmpeg.wasm

ffmpeg.wasm is a pure Webassembly / Javascript port of FFmpeg. It enables video & audio record, convert and stream right inside browsers.

Transcode

Source Code

Browsers support

Chrome
last 2 versions

Examples:

Name	Demo	Source Code
Webcam		Link

Supported External Libraries

Check HERE

Installation

$ npm install @ffmpeg/ffmpeg @ffmpeg/core

As we are using the latest experimental features, you need to add few flags to run in Node.js

$ node --experimental-wasm-threads --experimental-wasm-bulk-memory transcode.js

Or, using a script tag in the browser (only works in Chrome):

<script src="https://unpkg.com/@ffmpeg/ffmpeg@0.9.2/dist/ffmpeg.min.js"></script>
<script>
  const { createFFmpeg } = FFmpeg;
  ...
</script>

Usage

ffmpeg.wasm provides simple to use APIs, to transcode a video you only need few lines of code:

const fs = require('fs');
const { createFFmpeg, fetchFile } = require('@ffmpeg/ffmpeg');

const ffmpeg = createFFmpeg({ log: true });

(async () => {
  await ffmpeg.load();
  ffmpeg.FS('writeFile', 'test.avi', await fetchFile('./test.avi'));
  await ffmpeg.run('-i', 'test.avi', 'test.mp4');
  fs.writeFileSync('./test.mp4', ffmpeg.FS('readFile', 'test.mp4'));
  process.exit(0);
})();

Multi-threading

Multi-threading need to be configured per external libraries, only following libraries supports it now:

x264

Run it multi-threading mode by default, no need to pass any arguments.

libvpx / webm

Need to pass -row-mt 1, but can only use one thread to help, can speed up around 30%

Documentation

• API