Stream Recorder szerző: megacamz

This extension can record streams and videos from different players and save it on your computer.
You can also pause and resume your recording in process if you want to save only some chosen moments.
After you stop recording it will save the video with a timestamp and site name in title.

It currently doesn't work on Youtube.
Installation and usage
http://megacamz.com/guides/stream_recorder_installation_and_usage/
You can also download it manually here - https://github.com/megacamz/Stream-Recorder