Slowness in compositor

[John Coppens]

Hello people.

Feeling slightly adventurous, I enabled the compositor for the first
time. I know it has been there for a while, but for some reason I never
got around to using it.

Beautiful!

... but, when playing video with mplayer, the slowness interferes.
Opening a movie in a smaller window still runs more or less acceptable,
but full screen is impossible to watch. I have:

# NVidia GeForce card with binary driver (latest version)
# An AMD64 processor at 2.2GHz
# mplayer set with -vo gl2
   (-vo xv is worse)
# xorg 7.4

I had google look around in the xfce.org site, and found no solution. (A
similar problem with mplayer was reported, but never answered).

Any suggestion would be appreciated. Is it possible to disable compositor
just while viewing video in fullscreen?

John