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

Paul Bender pebender at san.rr.com
Sun Jan 28 20:22:16 UTC 2007

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, (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.

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