Originally Posted by Stephen Warren
d) Is your application using timestamps when queueing pictures into the VDPAU presentation queue? Without this, every picture is displayed ASAP; i.e. beginning with the very next VSYNC. With 30fps content on a 60fps display, pictures should all be displayed for 2 VSYNCS each, but small variations in the timing of when VDPAU APIs are called, complexity differences in different pictures, etc. could cause some pictures to be displayed for 1 VSYNC and hence others for 3 VSYNCs, which probably would cause symptoms like you're seeing. I know MPlayer doesn't do this either, at least not in the versions I tested with nor the standard SVN repo (although there are some other experimental branches that do). Passing timestamps to vdp_presentation_queue_display, you should be able to avoid this issue.
out of curiosity, where can i find those mplayer branches?