Re: VDPAU API and implementation issues
I did some more testing about the queuing issue. It still happens with 195.22 drivers. I noticed one extra bit of information: if I use hardware decoding, AND there is no OSD/subtitle content displayed in MPlayer, then things seem to work fine even when queuing multiple surfaces ahead.
However using vdp_video_surface_put_bits_y_cb_cr() with software decoding triggers problems - VDPAU_TRACE shows VDPAU spending a lot of time blocking in that function as mentioned in my earlier post.
OSD/subtitle content also causes problems, but it seems to depend on the number of textures drawn after video mixer rendering. The problems also occur with non-changing libass subtitles that do not cause any reuploads of texture data. Basically it looks like the operations become a lot slower with frames queued ahead, and a much smaller amount of extra rendering starts causing slowdown.