[mythtv-users] Problem with MythTV/HDTV/nVidia

[Steve Meyers]

Jerry Rubinow wrote:
> On 2/18/06, Steve Meyers <steve-lists-mythtv at spamwiz.com> wrote:
> 
>>I've got a Pentium 4 2.8GHz with an nVidia FX 5500 in my frontend
>>machine.  I'm having a little bit of trouble playing HDTV on it.
>>
>>If I don't enable XvMC, but use libmpeg2, I can play 720p without many
>>problems, but 1080i stutters every 1-2 seconds.  Even 720p stutters once
>>every 10-15 seconds or so.
> 
> 
> This sounds like a bandwidth or CPU problem.  What's your CPU usage on
> the frontend when you're playing back?  Are the FE/BE on separate
> computers, and if so, how are they connected?  Are your drives using
> DMA?  Is your video card PCI or AGP?

Since it works fine with XvMC, I don't think it's a network bandwidth
problem.  For the record, it's a separate FE/BE with 100Mbit ethernet
connection, the drives (on the BE) use DMA, and the video card is AGP.

My CPU usage with pure ffmpeg (no XvMC) is about 95%, with stuttering
every second.  With libmpeg2, it is about 85%, with stuttering every 2
seconds.  With ffmpeg + XvMC, it is 30-40%.

>>If I turn off libmpeg2 and enable XvMC, it plays back with no
>>stuttering.  However, within a 1-5 minutes, it goes berserk.  The vast
>>majority of the screen (90-95%) becomes a blocky purple or green.  If I
>>let that continue, it completely freezes X within 30 seconds.  A
>>ctrl-alt-backspace will get me out of X, so the computer isn't
>>completely frozen.
> 
> This I have no idea on.

I made some other changes over the weekend, and this doesn't happen
anymore.  The tweaks I made were from this thread:

http://www.gossamer-threads.com/lists/mythtv/users/133727?search_string=%2Bxvmc%20%2Bnvidia%20%2Bagpgart;

I'm still tweaking it a little bit, but it's working well for now.  I'm
going to try some of these suggestions to get the picture quality up:

http://www.gossamer-threads.com/lists/mythtv/users/84507?search_string=%2Bxvmc%20%2Bdeint%20%2Bkernel;