[mythtv-users] mpeg2 video stuttering

[ojw at weilerfamily.com]

Quoting "R. G. Newbury" <newbury at mandamus.org>:

> ojw at weilerfamily.com wrote:
>> Quoting "Michael T. Dean" <mtdean at thirdcontact.com>:
>>
>>> On 09/23/2008 07:44 PM, ojw at weilerfamily.com wrote:
>>>> After having ditched the idea that a 1.8Ghz P4 can display

Minutiae deleted...

>>> http://www.mythtv.org/wiki/index.php/Troubleshooting:Prebuffering_pause
>>>
>>> And, if it turns out yours is not on there, but you are suffering from
>>> prebuffering pauses, please update the page once you find out the   
>>> cause.  :)

more stuff deleted by me showing no prebuffering error output
and xvmc stuff

> That chipset supports xvmc. Much more likely is that your setup is
> misconfigured.
>
> Are you using the nvidia video driver for your kernel?

Yes, version 173.14.12.  I couldn't get the HDMI output to
work without it.

> (With the most recent nvidia driver versions, all you actually need is
> the 'driver "nvidia"' line in the Device videocard0 section. The driver
> then pulls in everything it needs. This was NOT the case not too long ago.)

I do have 'Driver "nvidia"' in my xorg.conf

> This includes having an etc/X11/XvMCConfig file, with the line
> /usr/lib/libXvMCNVIDIA_dynamic.so.1

My /etc/X11/XvMCConfig has the above library listed but without
the /usr/lib/ as specified by the XvMC wiki page but I'll try
adding /usr/lib/ in front of it and see if that helps.

> # cat /var/log/Xorg.0.log | grep Motion
> (II) Loading extension XVideo-MotionCompensation

I did get the above output

> # cat /var/log/Xorg.0.log | grep XvMC
> (**) NVIDIA(0): Option "XvMCUsesTextures" "True"

The XvMC wiki page specified the XvMCUsesTextures option to be
false but I'll try setting it to true and see what happens.

> There is a small program called xvmcinfo which will confirm that you
> have xvmc set up correctly. I will find my copy of the source and post
> it on the wiki xvmc page. I want to see if I can find out who wrote it
> before I post it...I don't remember where/how I got referred to it.

That'd be great!

> Finally, does your mythtv setup enable xvmc? Try 'mythfrontend
> --version' in a console. You should see 'using_xvmc' in the output.
> Unless you compiled your own version and omitted that switch, it should
> be there on any precompiled version of myth.

When running mythfrontend --version, I get the following entries
with the string "xvmc" in it: using_xvmc using_xvmcw using_xvmc_vld

> Geoff

While this the above is all very good information, it does seem
to me that even without xvmc, a dual core 2.53Ghz intel processor
should be able to keep up with 1080i output.  Just as a sanity
check for me, does that seem reasonable to expect such a CPU
to do 1080i on mpeg2 data?

Oliver