The x11 overlay contains a 'live' ebuild media-libs/mesa-9999, but it doesn't (yet?) set the proper flags. You need to add
myconf+="--enable-xvmc --enable-vdpau"
just before the econf line
(then, don't forget to update the manifest using 'repoman manifest').
With those settings i now have some new files installed on my r600 system:
/usr/lib64/libXvMCr600.so*
/usr/lib64/libXvMCsoftpipe.so*
/usr/lib64/vdpau/libvdpau_r600.so*
/usr/lib64/vdpau/libvdpau_softpipe.so*
As said previously, you need to set the env var VDPAU_DRIVER to your card (here : 'r600').
vdpauinfo and mplayer wont see the vdpau stuff until i also set
LD_LIBRARY_PATH=/usr/lib64/vdpau
With all of this, i have the following results
- vdpauinfo fails with "Failed to open VDPAU backend libvdpau_r600.so: cannot open shared object file: No such file or directory"
- mplayer -vo vdpau manages to display the video, but it has lot of problems, such as printing "[vdpau] Error when calling vdp_output_surface_put_bits_indexed: No backend implementation could be loaded.", having a green line at the bottom of the video, and using as much CPU as usual. So i guess it's a failure too, but i wonder about the green line.. ?
- using mplayer -vo xvmc fails with "vo_xvmc: No X-Video MotionCompensation Extension on :0"