webm/mp4 Encoder

An FFmpeg based webm/mp4 encoder using Wasm binaries compiled by Emscripten.

This webm/mp4 encoder was created inspired by PaulKinlan's article: "Running FFMPEG with WASM in a Web Worker".

Internally, media transcoding is performed by the wasm/js output pair of ffmpeg.js compiled by Emscripten (specifically, mp4-to-webm conversion is done by ffmpeg-webm.{wasm,js}, and webm-to-mp4 by ffmpeg-mp4.{wasm,js}).

This in-browser app will help you casually transcode video files at hand, but for videos with a larger size, it might be too slow due to FFmpeg itself not running in a multi-threaded mode. Give it a try :)

Additional Resources

• Running FFMPEG with WASM in a Web Worker
• ffmpeg.js repo