Short answer .. use --enable-proc-opt
Theodore Murdock sent me this helpful note.
I suppose I should also mention that anyone who wants to compile MythTV also *must* use --enable-proc-opt
If you don't, MythTV will try to compile for a generic x86 processor, --enable-proc-opt allows it to compile for a specific processor architecture, which is something we need when we're compiling for PPC.
He also notes that using --enable-xvmc helps to avoid complaints about missing xvmc files ... however another user has posted in the google groups forum that:
Just thought I would point out that you can compile MythTV without XvMC support, and as there is no hope of it working at the moment that might be the way to go.
I think you will need to remove the XvMC libraries as it gets enabled automatically (usually) if the files are present. Relevant info:
"If you have the libXvMCW wrapper installed, then it will be automatically enabled by the configure program and all of the available library assets will be utilized. However, double-check your ./configure output during MythTV configuration state whether it says "yes" after "XvMC support" (or XvMC pro support) or not, since some distributions do not enable XvMC automatically regardless of XvMC library found in /usr/lib."
taken from: http://www.mythtv.org/wiki