[mythtv-users] VDPAU performance issue with 1 specific video

[Ronald Frazier]

I've got a mythtv 0.22 system with a nvidia GT210 card running VDPAU.
Normally everything works fine with this setup. I routinely rip bluray
movies to m2ts files and play then without a hitch. I also take my
blurays and transcode them to mkv files so I can keep them on the
system without using so much space (about 4-6GB per movie). I do the
transcoding with handbrake, using the "high profile" with a constant
quality setting of 24. These transcoded files also work perfectly
fine.

However, I recently ran into a problem with one BluRay...Rush: Beyond
the Lighted Stage (it's a documentary of the band's history). I've
ripped the video to an m2ts and it plays beautifully. I then did the
transcoding with handbrake, same as I always do. It is this resulting
video that I have a lot of trouble with. When it hits certain scenes
in the video (mostly the really old, poor quality footage, but
sometimes even the newer HD footage) suddenly playback becomes REALLY
choppy, and playback slows down. While this is happening, I can see
that my cpu load for mythfrontend is running at 110% (it's a core 2
duo system). These same scenes are perfect on the M2TS file...about
20-30% CPU usage. This same mkv plays back perfectly fine in VLC on my
windows box.

I've upgraded my nvidia drivers from 190.x to the latest 260.x and
there was no difference. Results are identical no matter whether I use
the slim, normal, or high quality VDPAU  playback profiles. Using a
non-VDPAU profile, the video plays without the choppiness or slowdown
(though it does pause briefly every 1-2 seconds because the CPU can't
keep up).

Any idea what may be causing this problem? Are there any particular
encoding feature that handbrake could be using (ex: certain
types/combinations of keyframes or something) which would cause VDPAU
to fall back to software decoding?