[mythtv-users] Is my rig "on the limit" without XVMC?

Ray Whiteman ray.whiteman at consultant.com
Sat Aug 9 11:41:48 UTC 2008


Hello,

I have been trailing, tweaking and enjoying my combined BE/FE for about 
6 months now, and the results have been fantastic.

Here is my box

3 x Leadtek DTV 1000 T's
1 x Hauppague PVR-150
ASUS P-800 E
Intel Prescott P4 2.8Ghz (533Mhz FSB)
AGP Generic Nvidia 6600 (NOT a GT)
1 x Seagate 250GB SATA I (music, system, ancillary stuff)
1 x Seagate 1TB SATA II

I'm using Ubuntu Gutsy (7.10) , with backports enabled to take me to  
0.21, Nvidia Drivers 169.12. For TV Playback I use DVI out  @ 1280x720. 
I have found the best results without XVMC with 2x Bob as the 
deinterlacer. Currently that is the setup I am using as my default. I am 
using RTC for timing. I transcode some stuff after hours, and offload 
comm flagging to another slave backend.

Everything is perfect until I get to MPEG2 HDTV and H.264 playback from 
high bitrate BlRray rips. The BluRay I can park as a problem for a while 
but the HDTV is annoying. I get periods while watching recordings  where 
all I see is the occasional "jump" then everything is ok for a while, if 
I jump back and rewatch it, then I see no issues normally, or a jump in 
a different spot. I also occasionally see prebuffer pauses in my FE 
logs, I have not isolated the reason for this but my suspicion is that 
the issue is related.

I know that from my point of view the hardware is delivering above an 
beyond the call of duty, (my mates at work think I am insane for pushing 
the old girl like this). I guess my question is, am I pushing the 
hardware, particularly the CPU and Vid card past it's capability without 
XVMC?  How can I measure this? CPU utilisation tops out during HDTV 
playback currently depending on the content.... But under the 
circumstances..... It is expected :)

I have tried to get XVMC working a few times, (added the Option "NVAGP" 
"1" to my xorg.conf etc), but that totally upsets the system, HD is 
unwatchable, XVMC use crashes the FE, and other problems......

I would just simply toss more money at it and re platform to something 
faster, but I have invested in 4 PCI cards, and PCI motherboards are 
hard to get these days.

Any guidance? Particularly on getting XVMC running.



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