I do know about that , but mp4 should be working with chrome, it does, if no action is set . anyways, performance when rewinding is really really poor, skipping a bunch of frames.
Thought about going with a setinterval, each 24, by animating the .playbackRate , as it is supposed to work, again , big fail.
very frustrated right now .. I use to do this in flash around 6 years ago, when h264 came out.