[mythtv-users] Openchrome XvMC problems in mythfrontend

Ronald Pijnacker pijnacker at dse.nl
Fri Jun 12 13:32:06 UTC 2009


> >Peter Holmes wrote:
> >>> Ronald Pijnacker wrote:
> >>>> Hi all,
> >>>>
> >>>> This week I tried to upgrade my mythfrontend to mythbuntu jaunty.
> >>>> Running mythfrontend gives an error about not being able to create an XvMC Surface.
> >>>> The hardware I'm running on is a VIA EPIA M1000, the bug report can be found here:
> >>>>
> >>>> https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-openchrome/+bug/371512
> >>>>
> >>>> Initially I filed a bug report under the openchrome video driver, but after
> >>>> a suggestion from the openchrome irc group, I ran xine with XvMC enabled.
> >>>> This worked without any problems.
> >>>> So the question now is, why I'm running into problems with mythtv. Any ideas?
> >>>>
> >>> As a quick hack, I modified the udev rules so that udev renames 
> >>> /dev/dri/card0 to /dev/dri/card1, which causes MythTV ot not use DRM 
> >>> vblank. Instead it uses usleep with busy wait. After that, no more stutter.
> >>>
> >>> Therefore, it appears that the problem is with DRM vblank. However, I do 
> >>> not know whether this is a bug in DRM or in MythTV.
> >> 
> >> Could you provide information about the change you made. I would like to try this 
> >> to see if it fixes my problem (see [mythtv-users] Video Jerky on a Epic Via Sp8000 board)
> >> 
> >You will need to find your where the udev rules are located on your 
> >system. Newer systems will likely have the rules in /lib/udev/rules.d/. 
> >If not, they will likely be in /etc/udev/rules.d/.
> >
> >Next you will want to create a udev rules file 99-user.rules in the 
> >rules directory with the line
> >KERNEL=="card*", NAME="dri/card1%n"
> >The reason for naming the file 99-user.rules is to ensure that it runs 
> >after the rules file the normally puts card* devices in the dri directory.
> >
> >Finally, you will want to trigger the udev rules. On some systems, you 
> >will use the command
> >udevtrigger
> >on other systems you will use
> >udevadm trigger
> >
> >After that, the /dev/dri/ should not contain any card0 entries. Since 
> >MythTV's DRM sync looks for /dev/dri/card0, it will fail and move on to 
> >the next sync method.
> 
> Well I tried all that but I still had /dev/dri/card0, so I modified the mythcode and told it not to use dri.
> Retested it and now it works fine.

I still have /dev/dri/card0 too. What did you change in mythtv to disable DRI?

Thanks,

Ronald


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