Record webcam in a video file

Hello,

I am looking for some way to record the video and audio stream captured by getUserMedia.js and write it in a video file (.mp4 for example).

I don't find an easy way to do it, google results are somewhat tricky... Have somebody ever experienced with it? Have a beginning of solution?

My first idea was to get a frame every X milliseconds, and put it somewhere. But... where? How to build the final result? How to put audio and video together in a single output file? So many questions :(

Thank you for the help