[MPlayer-dev-eng] hook for each frame drawn

[irixdude at gmail.com]

Where would I best add a hook into mplayer that would be called once
each time a frame is drawn (or ready to be drawn)? Initially I'm just
going to dump this to stdout (ie, frame 0, frame 1, frame 2, frame 3)
and later might have it throw a signal or something along those lines.
The way mplayer is currently, I can easily dropped frames as they
occur, but I would like the opposite, a way to track successful
frames, real-time.