"In the open-source realm there has been talk of extending XvMC to support video formats besides MPEG-2, but that hasn't yet amounted to anything. Today though another video API is now on scene with VA-API finally being implemented in MPlayer and FFmpeg.
"VA-API (short for Video Acceleration API) is a software API that has the backing of Intel and is designed to accelerate video decoding, sub-picture blending, and rendering on the graphics processor. The hopes with VA-API are to ultimately replace X-Video Motion Compensation as being the predominate video API for Linux systems. Unlike XvMC that is limited to MPEG-2 and IDCT / Motion Compensation, VA-API is designed to support other standards such as MPEG-4 and VC-1 along with accelerating IDCT, Motion Compensation, VLC, bitstream processing, spatial-temporal deinterlacing, inverse quantization, and other functions."