[mythtv] Debugging mythfrontend video freeze

Scott D. Davilla davilla at 4pi.com
Wed Feb 20 23:19:30 UTC 2008

>I'd like to get some help in debugging a frontend video freeze. I'm
>using svn version 14938 trunk builds. Setup is as follows;
>	Dedicated backend w/ two PVR-150 and a dual channel
>HDHomeRun. So 4 encoders. This is all mpeg2 encoding. Backend has
>plenty of resources (core2 du0 at 1.83 GHz with four SATA 500GB
>drives for video storage and 320GB boot. Runs same svn version.
>	1GHz Pentium-M with nvidia 7300 for mpeg2 hardware decoding.
>This setup works quite well in handling HD content from the
>HDHomeRun, video is nice and smooth and cpu percent is 60-70 when
>displaying 1080i or 720p ATSC HD content. The frontend has no problem
>displaying HD content besides the below problem.
>The problem is I get random frontend hangs where the video freezes.
>Escape key works in that the frontend tells the backend it is done
>but frontend must be killed to fully recover as it's still hung
>somewhere. The freeze is very random, sometimes in minutes, sometimes
>hours. Smells like a race condition.

Just to follow up on this issue, not a MythFrontEnd problem. 
MythFrontEnd was running just fine.

Problem is solved by underclocking the nvidia gpu from 360MHz to 
200MHz. Not heat related as nvidia temp is 58C idle and 61C doing 
xvmc decode.

As of now, MythFrontEnd has been doing continuous LiveTV of 1080i 
mpeg2 content under xvmc decode for over 14 hours and no hangs or 
video glitches and previous to this mplayer run for over 12 hours 
before switching to MythFrontEnd. Mplayer takes about 60 percent cpu, 
MythFrontEnd takes about 70 percent.


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