[mythtv-users] Very variable CPU usage from X using bob deinterlace

Steven Adeff adeffs.mythtv at gmail.com
Mon Jan 29 13:55:38 UTC 2007


On 1/28/07, junk <junk at giantblob.com> wrote:
> Paul Bender wrote:
> > junk wrote:
> >
> >> Hi,
> >>
> >> I'm experiencing very high and very variable CPU usage from X during DVB
> >> playback with the 'bob' deinterlacer - sometimes X uses a few percent of
> >> the CPU, sometimes it uses nearly 90 percent. I do have cpufreq turned
> >> on with the ondemand governor but this is not enough to explain the
> >> variation I'm seeing (as much as a hundred fold difference in load).
> >> There is no apparent difference in playback quality when the load
> >> changes and the load changes up and down while watching a single
> >> program. Switching deinterlacing off or choosing a different
> >> deinterlacing algorithm results in consistent CPU load.
> >>
> >> Does anyone else see this? Is it expected behaviour? I understand that
> >> bob is CPU intensive, but it seems odd that it sometimes takes
> >> practically no CPU and other times it nearly swamps my machine.
> >>
> >> My setup is:
> >>    AMD Athlon 64 3000+ (1800MHz), 2GB memory, NForce motherboard (6500,
> >> I think?), using built in TV Out to PAL TV
> >>    Gentoo 2006.1
> >>    Linux 2.6.19.2, (vanilla kernel, not gentoo kernel)
> >>    modular X.Org server (from stable portage)
> >>    recent proprietory NVidia drivers (emerge ~x86)
> >>    recent MythTV (from SVN a few days ago)
> >>    'Standard' output (not XVMC as it seems to crash X and or the front end)
> >>
> >> Thanks,
> >> -- jeek
> >>
> >
> > Yes, I have seen this behavior. Adding
> >
> > Option "UseEvents" "true"
> >
> > to the nvidia device section in xorg.conf solved the problem.

UseEvents needs the new 9xxx series drivers.

The other reason could be that your modeline is using a refresh rate
that isn't what the video refresh is. This will cause X to spike in
CPU every time it has to mash frames to get things to work right.
(mash=I don't know exactly what its doing, but it doesn't like it and
is doing something to fix things)

-- 
Steve
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