[mythtv-users] XvMC Wrapper not being recognized?

R. G. Newbury newbury at mandamus.org
Wed Apr 5 18:56:48 UTC 2006

Warren wrote:
> Chad wrote:
>>Hello there fellow Mythers!
>>I'm working up a new frontend and have been hitting large snags along
>>the way.  The current snag is getting XvMC working with MythTV.  Let
>>me start off with my hardware:
>>Biostar Socket 478 with onboard Via P4M800CE chipset output over VGA
>>CeleronD 310 (~2.2Ghz I think)
>>512MB Ram
>>Network boot (no Hard Drive)
>>Ok, so I'm trying to get XvMC working for the High Def playback as the
>>system is too underpowered (on purpose as I planned on using XvMC for
>>High Def) for HD mpeg2 playback (I have no problem using Xv to
>>playback mpeg4 720x480 content).  I've finally gotten the Openchrome
>>drivers working, and they claim to enable XvMC (in my
>>/var/log/Xorg.0.log it agrees).  So I've got:
>>/usr/local/lib/libviaXvMCPro.so AND libviaXvMC.so
>>My understanding is that I should be using the Pro as this chipset is
>>a UnichromePro chipset.  Either way, whichever lib I plug into
>>/etc/X11/XvMCConfig When I fire up myth I get an error message from
>>XvMC Wrapper saying it cannot load libviaXvMC.so.1 (which I don't even
>>have in the Wrapper XvMCConfig file).  So it would seem like it's a
>>hard linked library, even though I thought the whole idea behind the
>>Wrapper was to not have hard links.

Do you have that file? Or maybe a link is broken. Check the sym-link and 
run ldconfig ??????

>>In the end, I really don't care how I get XvMC working on MythTV, I
>>just am hoping to get it working *at all*.
>>I'm running gentoo, Xorg-7, and have compiled DRM and Openchrome by
>>hand and placed them in their /usr/local equivilents.

> OpenChrome XvMC has a max resolution of approximately 1024x768.  Don't
> expect to get HiDef working on a VIA chipset with the current software. 
> I do not know if it is a hardware or software limitation.

You'll have to scrounge around the Via web-site to determine exactly, 
but I think the P4M800 chipset has the VT1623 TV-out chipset capability. 
According to Via this chip is good for 1024x1024 TV out. The newer 
Vt1625 chipset will apparently do up to 1980x1080 TV out, but that 
chipset appears to be available only on the nano-itx N and NL 
motherboards (with the Luke(?) cpu). So you cannot actually do full HD. 
You can get to ED I guess....

As to software limitations, the openchrome guys have not yet reached the 
stage of dealing with the VT1625 and HD.

I suspect that the main problem is that the openchrome coders do not 
have access to either that hardware or a source of HD material to test 
their coding... and that assumes that they do have access to sufficient 
information about the chip to code for it. I've looked at the code and 
....it gives me a headache. I just hope that they can continue the good 

And it appears that their efforts to date are included in the Xorg 7.0 
modular build tree, and are included natively in Fedora Core 5. I put 
FC5 onto this laptop (on an old hard drive) and it appears that 
everything is there. This Thinkpad does not have xvmc so I cannot really 
tell, but the install set includes a libviaxvmc rpm (going from memory).



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