[mythtv-users] My Perennial Problems with XvMC

Dylan Semler dylan.semler at gmail.com
Sun Sep 17 05:52:41 UTC 2006


On 9/16/06, Mathew Elliot <matelliot at internode.on.net> wrote:
> According to the nvidia forums the 6200 is not actually XvMC enabled under
> 8756 – or from what I can gather under 8774 either...  - I know because I've
> been struggling to get mine doing XvMC…
>
> Refer to this thread -
> http://www.nvnews.net/vbulletin/showthread.php?t=68030&highlight=XvmC+6200
>
> Mine produces the same errors as you've posted later and the same errors
> with mplayer as is in the linked thread.... damnit I bought this card cause
> it was the cheapest supposedly XvMC enabled PCIe card... and now it's not -
> apparently all the cards >6600 work fine with XvMC... ripped off!

A nice find, but I don't think it's related.  The symptoms they
describe are not what I am seeing.  Furthermore, XvMC works
*perfectly* in mplayer (SVN version--it does not work in the atrpms
version).  Based on this and the two other replies, it doesn't seem
like it's a hardware issue.  It seems like it's something in Myth, but
why it works for some and why not me I don't have the slightest idea.
Furthermore, the fact that it works so well with mplayer suggests that
it is not a configuration error, unless it is one that mplayer is
smart enough to correct but myth is not.

Give the latest svn of mplayer a shot and see if you can use xvmc with that.


Some new insight:
I've hosed my FC6T3 install and have gone to FC5.  I've once again
been through all of the configurations one-by-one.  I'm currently
running mythtv and the nvidia drivers from atrpms.  XvMC, of course,
acts exactly the same as it did with FC4 and FC6T3 in both mplayer
(svn) and myth (0.20).  For a while, I had a file XvMCConfig in
/etc/X11/ that was pointing to the old location of the xvmc libraries
(the one from the nvidia installer on FC6T3).   While this file
existed, I noticed playback was exactly the same as before, but the
OSD was in color (implying xvmc wasn't working).  However, I was still
getting tearing and XvMC errors in the frontend terminal.  When I
changed the file to point to the correct libraries, the only
noticeable difference was that the OSD was now black and white.  The
poor quality of the playback remained quite similar.  Maybe this will
spark an idea in someone who knows how this all works.  To summarize:

No XvMC :  longer stutters spaced farther apart.  Prebuffering Pause
is the only error that shows up in the frontend terminal.  No picture
degradation except for the pauses.  Color OSD.

XvMC with incorrect XvMCConfig file :  Short quick studders with many
Prebuffering Pauses in between rapid and severe picture degradation.
Many xvmc errors in frontend terminal as well.  Color OSD.

XvMC with correct XvMCConfig file :  Same as above except black and white OSD.

note:  I understand that XvMC causes the OSD to loose color.  I am
simply reporting what I observe to help debug.

I've also had a chance to test with SD (not analog) and the picture
deteriorates the same as with HD.

Cheers,
Dylan
-- 
Type faster.  Use Dvorak:
http://dvzine.org


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