Vista DVD playback jerky

I have a problem on released Windows Vista Media Center. On some DVDs
(not all), playing back a DVD causes the video to jerk every 1/2 second
or so. It is very repetitive and consistent. Audio is always fine.
It's the video. It looks like it slows down, speeds up, slows down,
speeds up, etc. All within this 1/2 second to 1 second period.

The system is plenty fast, dual core, nVidia 6800, 2 GB RAM, fast SATA
drives, etc.

What is strange is that if I play the DVD from Media Player, it works
fine. There is *NOTHING* else installed on the PC except for Windows
Vista with updated drivers.

I checked to make sure that it is using Microsoft's MPEG-2 decoder and
there are no other MPEG-2 decoders on the system.

I am thinking of trying the nVidia MPEG-2 decoder but I have not yet.
I saw a post from several months ago (during the Beta period) that
looked similar to this but I never saw a resolution. Has anyone heard
of this and, if so, what a resolution might be? Thank you.

I believe that the problem is caused by MCE using VMR9 rendering and Media
player using Overlay mode which puts much less of a load on the graphics
card. And it appears that the MS decoder does not invoke VMR rendering
support from the graphics card itself and instead does it in software using
the sysgem CPU.

"JR" <russet32@gmail.com> wrote in message
news:1166899533.339374.42290@80g2000cwy.googlegroups.com...
>I have a problem on released Windows Vista Media Center. On some DVDs
> (not all), playing back a DVD causes the video to jerk every 1/2 second
> or so. It is very repetitive and consistent. Audio is always fine.
> It's the video. It looks like it slows down, speeds up, slows down,
> speeds up, etc. All within this 1/2 second to 1 second period.
>
> The system is plenty fast, dual core, nVidia 6800, 2 GB RAM, fast SATA
> drives, etc.
>
> What is strange is that if I play the DVD from Media Player, it works
> fine. There is *NOTHING* else installed on the PC except for Windows
> Vista with updated drivers.
>
> I checked to make sure that it is using Microsoft's MPEG-2 decoder and
> there are no other MPEG-2 decoders on the system.
>
> I am thinking of trying the nVidia MPEG-2 decoder but I have not yet.
> I saw a post from several months ago (during the Beta period) that
> looked similar to this but I never saw a resolution. Has anyone heard
> of this and, if so, what a resolution might be? Thank you.
>

Some other interesting information. Switching to the nVidia driver
fixes the problem but then audio is very very bad when watching live
tv. So far my solution is to use the nVidia for the video and
Microsoft for the audio and it "generally" works ok. I have had some
hangs though.

Too bad, I was hoping this would be more stable as it is a "released"
OS.

Have you checked to see if there are newer Vista drivers for your actual
audio out interface?
The NVIDIA Decoder has lots of options for audio as described in the user's
guide have you tried different options?

"JR" <russet32@gmail.com> wrote in message
news:1166942152.579996.58920@42g2000cwt.googlegroups.com...
> Some other interesting information. Switching to the nVidia driver
> fixes the problem but then audio is very very bad when watching live
> tv. So far my solution is to use the nVidia for the video and
> Microsoft for the audio and it "generally" works ok. I have had some
> hangs though.
>
> Too bad, I was hoping this would be more stable as it is a "released"
> OS.
>