Intel GMA 900 & XVideo Accelleration (i810 drivers)

[galenz at zinkconsulting.com]

Hello,

I have a machine with the Intel GMA 900 graphics chipset. It works  
beautifully under Linux... except I'm still struggling to get video  
playback acceleration working with VLC.

I have three sample clips, played in VLC 0.8.4a under Fedora Core 5.  
One DVD-resolution and bitrate, and two HD bitrate clips, one 720p  
and another 1080i. With X11 Video output, the sample clips works  
perfectly, but are CPU intensive and/or choppy.

I want to use XVideo output, because my chipset supports XVideo and  
Xvideo motion compensation. I found the DVD resolution clip worked  
fine out of the box. But the HD clips didn't - VLC would segfault. As  
far as I can tell, VLC is fairly well coded, so things should  
generally work.

I turned to the video drivers, as I think they're likely to be the  
problem. After I increased the the CacheLines to 1100 in xorg.conf,  
the 720p worked superbly in VLC. But 1080i still segfaulted. I  
increased the CacheLines again and again, eventually to 9500, with no  
luck. I've also increased VideoRam to 131072 - in the off chance  
there was some sort of memory shortage going on.

But it still doesn't work... so... what do I do? The VLC segfault  
information doesn't seem very useful.

I have reviewed the data available here:
http://intellinuxgraphics.org/man.html

Thoughts anybody?

-Galen