[mythtv-users] XvMC Angst with 0.20 on Ubuntu with GeForce FX5200

Sam Hathaway mythtv-users.list at munkynet.org
Sat Oct 7 20:47:04 UTC 2006


Hi All,

I've been trying to get XvMC working on my Ubuntu Dapper (6.06.1) box  
with myth 0.20 (from superm's packages, version 0.20-0.2ubuntu1). I  
finally got XvMC enabled, by setting /etc/X11/XvMCConfig to  
libXvMCNVIDIA_dynamic.so.1.

The problem is, playback is slow and choppy, sound cuts in and out,  
and I get these messages (with --verbose playback on):

2006-10-07 12:02:46.352 WriteAudio: buffer underrun
2006-10-07 12:02:46.588 NVP: Video is 3.51891 frames behind audio  
(too slow), skipping A/V wait.
2006-10-07 12:02:46.696 NVP: Video is 4.02533 frames behind audio  
(too slow), skipping A/V wait.
2006-10-07 12:02:46.804 NVP: Video is 4.39013 frames behind audio  
(too slow), skipping A/V wait.
2006-10-07 12:02:46.912 NVP: Video is 4.64874 frames behind audio  
(too slow), skipping A/V wait.
2006-10-07 12:02:47.004 NVP: Video is 3.62141 frames behind audio  
(too slow), skipping A/V wait.
2006-10-07 12:02:47.104 NVP: Video is 3.2855 frames behind audio (too  
slow), skipping A/V wait.

These repeat continuously for the duration of playback. This is with  
1080i ATSC source material. I'm pretty sure it's not the CPU -- CPU  
usage is under 50%.

I have an Asus A7V8X-X motherboard and an Athlon XP 2500+ CPU. My GPU  
is an AGP NVidia GeForce FX5200. I'm using kernel 2.6.15 (Ubuntu  
package linux-image-2.6.15-27-k7) and version 1.0.8762 of the NVidia  
driver (Ubuntu package 1.0.8762+2.6.15.11-5).

/proc/driver/nvidia/agp/status looks like this:
         Status:          Enabled
         Driver:          NVIDIA
         AGP Rate:        8x
         Fast Writes:     Enabled
         SBA:             Enabled

Driver section in xorg.conf looks like this:
         Identifier      "nVidia GeForce FX 5200"
         Driver          "nvidia"
         BusID           "PCI:1:0:0"
         Option          "NvAgp" "1"
         Option          "ConnectedMonitor" "CRT-0"

It seems like I've tried every combination of all the settings that  
people recommend trying on this list and elsewhere, to no avail. Here  
are some changes i've tried that haven't fixed the problem:

* Turn on deinterlacing with "Bob" algorithm - raises CPU usage a  
little, but problem persists.
* Turn on "Enable OpenGL vertical sync for timing" - no effect.
* Turn on "Use video as timebase" - no effect.
* Turn off "Extra audio buffering" - no effect.
* Change "NvAGP" to "2" in xorg.conf - no effect.
* Stop blacklisting via_agp kernel module - no improvement, and hard  
freeze.
* Load nvidia_agp in /etc/modules - no improvement.
* Set "XvMCUsesTextures" to "1" in xorg.conf - no improvement, and  
hard freeze. also, getting messages like this mixed in with the  
normal ones:
         2006-10-07 12:24:27.298 VideoOutputXv: Frame E is in use by  
avlib and so is being held for later discarding.
         2006-10-07 12:24:27.298 NVP: prebuffering pause
         2006-10-07 12:24:27.299 VideoOutputXv: Frame E is in use by  
avlib and so is being held for later discarding.
         2006-10-07 12:24:27.299 NVP: Waiting for prebuffer.. 0 dLDDdDAA

Does anyone know of anything else I can try? If you have working XvMC  
and similar hardware, would you be willing to share your  
configuration with me? Thanks for your help... this is driving me crazy!
-sam



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