Coding PCM with Opus in JavaScript?

I am trying to stream microphone sound using Socket.IO and looks like the best compression codec so far Opus .

I found this opus.js project , but have no idea how to use it, it's in a language that I can't even identify.

Does anyone know how to encode PCM with Opus right from the browser? In plays for a different client, not one big final file.

Or any other compression method? Until then, he works in JS.