[mythtv-users] HD upgrade: new problems with playback

[Willy Boyd]

On 2/14/07, John <jharitos at yahoo.com> wrote:
> I'm using Nvidia driver 1.0-9746. I'm using
> mythtv-0.20-152 from atrpms.net. These settings are on
> nvidia: sync to vblank (Text adapter), open gl setting
> (allow flipping).
>
> Here's my xorg.conf. I'm outputting to a VGA monitor.
>
> (snipped)

Well, I thought I was really on to something today.  But I seem to
have been thwarted.

I spent my lunch hour at work reading all about pci latencies and how
changing them has been the magic pill for so many performance
problems.  Running "lspci -v" shows that most of my devices are at a
latency of zero.  Only the firewire device is at 32, and the ivtv
pvr250 card is at 64 since the insertion of that module increases it.
So I thought, surely giving a little more time to my video and IDE
controller for bursts of data would be a good thing.

But no, it appears I cannot change the PCI latency.  Running setpci
"seems" to work fine, but when I query the devices again, their still
set at zero.  I think this is because they're actually PCIe (PCI
Express), but I haven't found a definitive answer.  And just in case,
I checked and I get the same stuttering and freezing issues in the
frontend.

However, changing to streaming as opposed to local access (this is a
combined box), DOES appear to help with watching pre-recorded video.
Or maybe it was just a fluke, but I watched a recording in progress
and couldn't  generate any "prebuffering pause" or "WriteAudio: buffer
underrun" messages.  LiveTV on the other hand, is still bad.

So I have done my homework, but am still at a loss.  It's a shame too
because I know this hardware is up to snuff, especially for simply SD
livetv.  And vlc or mplayer kicks butt with even 1080p hd mpeg4.