by Justin Hunt.
Right. You wouldn't be able to do that. A cross platform solution to this would be the best. I came across this:
http://www.w3schools.com/tags/av_prop_playbackrate.asp
Though I haven't tried it. This could be good because it will work on most browsers/os and devices. I don't know if setting the playback speed in real time will work. Needs a bit of research.