[mythtv-users] XvMC and skipping forward locks frontend

[Alen Edwards]

Brian Sanders wrote:
> Hey everyone, been using Mythtv for a while now, and finally ran into a 
> spot where I might need some help from the list.  So as the subject 
> might suggest, I am working on getting XvMC working on my frontend to 
> make HD playback an option.  I have read over all the Nvidia/Wiki/google 
> material I can find, but I seem to be having a mythtv centered playback 
> problem. 
> 
> I can play files with mplayer using xvmc, and I can even play video 
> files from my videos directory if I tell mythtv to use mplayer.  When I 
> try and use "Internal" the playback does start seemingly smoothly, but 
> as soon as I try and skip forward or back, the entire system freezes 
> requiring a power cycle.  I am using this video file as a test before I 
> start trying to record HD programs and find out I can't play them.  I am 
> assuming that recorded programs need to use the internal player for 
> commercial skipping, plus I never saw an option to set what player is 
> used for recorded programs.
> 
> So, I can play with xvmc if I launch mplayer from the terminal, OR if 
> mythtv is told to use mplayer.  Skipping around in the video is very 
> smooth and quick.  Since it plays with one application but not MythTV I 
> am hoping someone can help me out here.  This is an old machine (hence 
> the xvmc) so perhaps I will end up upgrading this machine and bypassing 
> the entire xvmc need... but honestly I keep fighting with this b/c I 
> believe it "should" work :)
> 
> 
> Just incase this might help someone... here are some things I learned 
> about my setup while getting xvmc to even work at all.
> 
> If AGP is enabled (kernel or nvidia) standard recordings still play, but 
> xvmc fails to do anything.  I have tried setting both "NvAGP" for "1" 
> and "2" to force the module I was testing at the time, nothing works.  I 
> now run with AGP disabled "NvAGP" "0", and xvmc works with mplayer and 
> tries to work with myth.  While trying to make this work I have 
> re-complied the nvidia drivers to adjust the AGP speed down from 4x to 
> 2x, and 1x.  I tested all three modes (4x,2x,1x) with both Nvidia and 
> kernel drivers with no better results using any combination.  I 
> confirmed that AGP setting where being detected by using "cat 
> /proc/drivers/nvidia/agp/status" which confirmed I was actually running 
> with the modules and speeds I was trying to test.  I now accept that no 
> AGP is the only way to get xvmc to run on my machine.
> 
> Setup:
> Pentium 4 1.7Ghz
> Gentoo with latest kernel (upgraded this as well trying to get xvmc agp 
> to work)
> Nvidia Geforce 6200
> 
> My xorg.conf settings
> Section "Device"
>     Identifier     "Card0"
>     Driver         "nvidia"
>     VendorName     "nVidia Corporation"
>     BoardName      "NV20 [GeForce 6200]"
>     Option         "UseEvents" "true"
>     Option         "XvmcUsesTextures" "false"
>     Option         "NvAGP" "0"
> EndSection
> 
> Section "Extensions"
>         Option "Composit" "Disabled"
> EndSection
> 
> 
> Thanks for any suggestions
> Brian
> 
> -- 
> "Faithless is he, who says 'farewell', when the path darkens
> "you just keep on trying till you run out of cake"
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
When I ran XvMC on my P4 2.4GHz (6200 video as well) I used Option 
"NVAGP" "1" with the other options you have and it almost worked.  I 
came to the conclusion that my computer was just too slow.  I could 
watch an hour of HDTV and the sound would skip every 10 minutes or so. 
Annoying to say the least.

I would be surprised it it worked with your CPU.  I bought a new system 
and found that XvMC didn't even work that well on that so switched the 
config to CPU++ and it is much better.

Something to consider.

Allen