Omix

A quiet little browser app for mixing background audio into a video.

Drop an .mp4, add any number of .mp3 or .wav tracks, set one shared background volume, mute what you do not want, and export a new .mp4 directly in the browser with ffmpeg.wasm.

Your media stays on your device. Processing happens in the browser and files are never uploaded anywhere.

What It Does

• Drag and drop video and audio files anywhere on the page
• Add multiple background tracks
• Mute individual tracks or mute/clear them all
• Set one volume for enabled background tracks
• Mix the original clip audio with enabled background tracks
• Download the final video without leaving the browser

Why It Exists

Sometimes you do not need a timeline editor.

Sometimes you just need:

• one clip
• a few audio layers
• simple volume control
• a fast export

That is Omix.

Run It

Option 1: Local Static Server

Install dependencies:

npm install

Serve the project from the repo root:

python3 -m http.server 4173

Then open:

http://127.0.0.1:4173

Do not open index.html via file://. ffmpeg.wasm needs a local server context.

Option 2: Docker

Build and run:

docker compose up --build

Then open:

http://127.0.0.1:4173

Tech

• Plain HTML, CSS, and JavaScript
• ffmpeg.wasm for in-browser export
• No backend
• No upload step

Notes

• Export runs locally in your browser, so large files can take time.
• The app keeps the original video audio and mixes enabled background tracks on top.
• The local static-server path expects node_modules to exist in the project root.

License

MIT