[mythtv-users] XvMC_VLD on EPIA M10K

[Paul Bender]

Axel Thimm wrote:
> On Thu, Feb 21, 2008 at 08:00:41PM -0500, Bruce Taber wrote:
>> An update on this thread: Evidently, the SVN version 6133 fixes the XVMC 
>> on the Via Epia 10K. Everything seems to be back in working order using 
>> this version. SVN 6131 on atrpms-bleeding does not have the capability 
>> to use XVMC on the unit, however, running with minimyth has restored XVMC.
> 
> Indeed, the configure step changed to
> 
>  XvMC support              yes
> -XvMC VLD support          yes
> -XvMC pro support          yes
> +XvMC VLD support          no
> +XvMC pro support          no
>  XvMC OpenGL sup.          no
> 
> So you're saying that 16133 will restore it?

No it does not.

Looking into the problem, it appears that the XvMC-VLD detection logic 
was changed with changeset 15555 
<http://svn.mythtv.org/trac/changeset/15555/trunk/mythtv/configure>. 
Now, the logic will disable xvmc_vld and xvmc_pro when libviaXvMC and 
libXvMCPro are not on the build system. In my opinion, this is a bug 
since you they are not needed to build MythTV with XvMC-VLD support.

When this change was introduced, it broke MiniMyth because I use the 
newer Openchrome drivers in MiniMyth. The newer Openchrome drivers 
rename libviaXvMC -> libchromeXvMC and libviaXvMCPro -> 
libchromeXvMCPro. As a result, the configure script did not find them 
and disabled XvMC-VLD support.

When I discovered this, I patched the configure script to look for 
libchromeXvMC and libchromeXvMCPro as well. This fixed the problem for 
MiniMyth since the libraries are present in MiniMyth's build environment.

In addition, I reported the bug and provided my patch My patch was added 
to SVN.

Unfortunately, while my patch fixes it for MiniMyth, it is not correct. 
I believe the correct fix is to not disable XvMC-VLD based on the libraries.

I believe that the issue results from the overloading of xvmc_vld. At 
times the configure script uses xvmc_vld to mean the libviaXvMC library 
just as xvmc_pro means the libviaXvMCPro driver. However, other times 
the configure script uses it to mean enable xvmc_vld just as xvmc means 
enable xvmc. Since XvMC-VLD can be supported through the libXVMCW 
library, there should be separate variables to indicate the libviaXvMC 
library and the XvMC-VLD functionality.