Prism - H.264 decoder in pure javascript

Logo by Jiangnan Zhuang

Prism is a H.264 decoder written in javascript(ES5), which is used in browser to decode H.264 stream data into RGBA/YCbCr format frames.

Prism can run in browsers support javascript ES5 or higher standard, and support H.264 realtime decoding profile which contains I/P frames.

Prism is a project of CloudwareHub, aiming at providing cross platform video stream decoder.

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Build

Prism depends on Node.js, npm, gruntjs. Execute commands below to build prism, and the built file prism.min.js should be generated in build/ folder.

$ npm install
$ bower install
$ grunt

Usage

Prism uses requirejs/almod to package, and export window.prism if not in AMD context. The typical usage of prism should work with websocket, just read raw H.264 nal data from server via websocket and feed into prism, then prism will decode every frame into RGBA/YCbCr format pictures. Sample code is as follows:

ws.onmessage = function(msg) {
  prism.decodeNal(msg);
  console.log(prism.SL) // decoded frame luma in xy format
  console.log(prism.SCb, prism.SCr) //decoded frame chroma cb/cr in xy format
}

The demo of prism is available at CloudwareHub.

License

BSD-2-Clause

Resources

H.264 standard