Comment 2 for bug 162664

By the way, there is a patch that (almost) fixes this for MPlayer, there's some info at http://smspillaz.wordpress.com/2007/10/18/unlocking-the-full-video-potential-of-your-video-card/

It's not perfect (maximizing breaks the aspect ratio, and if you make the window transparent you can see the (useless) blue rectangle of XV through it), but it's a start. It should probably be included in Ubuntu's mplayer.

There are also a few hints on how to bypass Xv on other players at http://thedarkmaster.wordpress.com/2007/08/10/solving-video-playback-problems-in-compiz-fusion-beryl/

But this doesn't work great in VLC, because of scaling issues (as described above).