As soon as the player is getting in charge of the media element (video or audio), one expect from it a bit more than just playing or pausing them
Here are some example of actions I would expect to see in the javascript API :
setting the sound balance
setting the sound volume
setting the rate (normal = 1, 0.2 = slow motion, 2 = twice faster, -1 = rewind, -10 = quite a fast rewind...)
going to any frame (setting the current frame trough a timecode like 00:03:26:12
: hh:mn:ss:frameNumber)
Similarly, one could expect to receive various event related to the beaviour of the player : when the end of the video is reched, when th eloading of the video is progressing or is done, when the video stated, paused or changed rate ....