[mythtv] no video with 0.20-fixes p14649

[Daniel Kristjansson]

On Sat, 2007-10-13 at 11:14 -0400, Scott wrote:
> On Sat, 2007-10-13 at 15:55 +0200, Michael Haas wrote:
> 
> > Try disabling OpenGL vsync. One of the users of our weekly -fixes builds
> >  in Ubuntu is experiencing the same problems. I'll file a bug report now.
> 
> Yeah, that did it. I loaded up p14643 only and saw the same problem. I
> would guess that it should be this:
> 
> Index: branches/release-0-20-fixes/mythtv/libs/libmythtv/vsync.cpp
> ===================================================================
> --- Revision 11610
> +++ Revision 14643
> @@ -469,5, +469,13 @@
>       __GLXextFuncPtr glXGetProcAddress(const char * const procName) 
>       { 
> -         __GLXextFuncPtr ret = glXGetProcAddressARB((const GLubyte *) procName); 
> +         __GLXextFuncPtr ret = NULL; 
> +  
> + #if GLX_VERSION_1_4 
> +         X11S(ret = glXGetProcAddress(procName)); 
> + #elif GLX_ARB_get_proc_address 
> +         X11S(ret = glXGetProcAddressARB((const GLubyte *) procName)); 
> + #elif GLX_EXT_get_proc_address 
> +         X11S(ret = glXGetProcAddressEXT(procName)); 
> + #endif 
>    
>           if (!ret) 

If this is the issue my guess is that the GLX headers are incorrect
for whoever is compiling the packages. The headers probably say that
you have GLX 1.4, but the libraries actually don't have GLX 1.4 support.

What video drivers are you using? What version? What GLX headers were
used during the compile?

We could rewrite this to use glXQueryVersion() and glXQueryExtension()
which are GLX 1.0 functions. It would be a bit more complicated but
should allow this code to work for older GLX libraries that the headers
the code was compiled with.. If this is indeed the problem please open
up a ticket explaining the problem and I'll have a look at it.

-- Daniel