[mythtv-users] hardware considerations: fast CPU vs nvidia/vdpau?

[Joey Morris]

Raymond Wagner <raymond at wagnerrp.com> wrote on Sat, Jul 30, 2011 at 10:09:58PM -0400:
> The big question is can it handle the OpenGL video renderer?  The Xv
> blitter has some serious limitations, and should only be used as a last
> resort.  Benchmarks put the Intel HD graphics at plenty powerful to run
> OpenGL, but there have been mixed reports about driver difficulties in
> Linux.

I've been testing out OpenGL on my i3-540 today, and the results
aren't great. I'm not sure whether the problems are the chip, the
drivers, a misconfiguration on my part, or some combination of the
three. In any case, CPU decoding with OpenGL isn't really usable for
me.

Frequently I'd see rapid flashing during playback, with the screen
cycling between dark and bright. I also saw diagonal lines during the
flashing, which I suspect was the theme background (Mythbuntu theme).
After exiting playback, I'd continue to see similar flashing when
changing UI screens. Restarting mythfrontend would get things back to
normal.

I tested with several different deinterlacers. Yadif and Yadif (2X)
were very choppy. Eyeballing it, I'd guess they were displaying the
video at about 1-2 frames per second. CPU usage was only in the 30%
range, though. The hardware accelerated versions of Yadif were choppy
as well, and in addition everything was either purple or green. Bob
(2X) and Bob (2X, HW) were also choppy, maybe 5 fps, at about 20% CPU
usage. Kernel (2X) was slightly choppy, maybe 10-15 fps. Kernel,
Linear blend, and Linear blend (HW) seemed to be OK. I didn't test any
other deinterlacers.

After switching to xv-blit, I didn't see any of these issues. Also,
everything looked fine using VDPAU on a G210 card.