Hello I am also not lucky with Mythtv and VAAPI on my two FE with a SandyBridge 2500K and a 2120T running Ubuntu 12.04 and all latest libva, liba-intel-driver. I have been testing with the special versioned mplayer which works fine as can be found in: https://bugs.freedesktop.org/show_bug.cgi?id=51061