[mythtv-users] NVP: prebuffering pause on older Athlon XP/NVidia machine

[Tom Greer]

On 7/2/07, Mark Knecht <markknecht at gmail.com> wrote:
> Hi,
>    I've got a very pokey old Athlon XP 1600+ machine that I sort of
> wanted to use as a mythfrontend machine if possible. I've built Myth
> and it runs but as soon as I try to display video, whether a program
> or even the thumbnail video in the listing guide, I get jerky video
> and NVP: prebuffering messages.
>
>    What causes this and how do I fix it?
>
>    I've emerged Myth with xvmc support but I'm not sure how to tell if
> it's working. I don't get error messages of any type in xorg.conf when
> I run Myth.
>
>    The video card is a somewhat older NVidia GeForce4 MX 4000 AGP 8x.
> Not the fastest but glxgears runs OK so I think Myth shouldn't be
> acting this bad.
>
>    What have I missed?
>
> Thanks,
> Mark

First off, are you using the nvidia?  In other words, check your
/etc/X11/xorg.conf file.   In the Device section, if it says Driver
"nv" then you are using the open source driver.  To install the nvidia
driver in Gentoo, see http://www.gentoo.org/doc/en/xorg-config.xml.

If you are already using the nvidia driver, then you might try some of
the tips listed here:
http://www.mythtv.org/wiki/index.php/Optimizing_Performance.  In
particular, since your motherboard has a VIA IDE chipset, see the
section on hard drive DMA setttings.  That vintage of motherboards had
DMA problems.

You may want to run the frontend in a real-time thread.  That is
covered in the above document as well.

Or, PCI latency settings might have an impact (probably not since you
are using an AGP video card).  But there are other components affected
by PCI latency settings.  See
http://www.mythtv.org/wiki/index.php/PCI_Latency.

You may want to turn on XVMC.  If you still have problems, then you
will want to activate xvmc.  See
http://www.mythtv.org/wiki/index.php/XvMC.

Good luck.

Tom