This is very odd. Going full screen should require less resources than a Windowed approach. We do back buffer flipping in full screen rather than blting which is supposed to be easier.
Can we get a copy of your /etc/X11/xorg.conf, /var/log/Xorg.0.log, and look at ‘top’ to see which process (X server, video, or OGL) is eating up the majority of the CPU. This will help us locate the resource hog.
Here is my setup:
1) Using mplayer with VAAPI support.
2) libva is version 0.31.0-sds4
If I set mplayer to playback a H264 720P video fullscreen (-fs flag), everything functions properly. MPlayer is using approximately 12\% CPU and Xorg is using 122\%. Next, if I start an instance of gnome-terminal over top of the video, the video continues to playback smooth. Now if I maximize that same instance of gnome-terminal, both processes continue to use the same amount of CPU, and I can see no other process contributing to CPU load, but the video starts to become very choppy.
Let me know if you need any additional information.
Thanks for the help