Slow motion

Currently, there are x2, x4, x8 buttons available, and the API has the fastForward command function which accepts limited input values (2, 4, 8). However, I can't find a way to reduce the speed of a video so that it plays in slow motion.

Admittedly, I haven't really played with the API. Is there a way to reduce the speed currently?

I'd like to propose a new command function for this. Perhaps "slowMotion".

Or better yet, generalize the whole thing with "changeSpeed" to change the speed arbitrarily fast or slow, perhaps even allowing negative numbers for going backwards (a.k.a. rewind).