XvMC support came to
Gallium3D through a Google Summer of Code project for 2008 that involved getting X-Video Motion Compensation running atop the Nouveau driver with NVIDIA hardware. We described this work in
The State Of Gallium3D Video Decoding and subsequently in
Nouveau's Gallium3D Driver Gets Video Boost. In 2009 this XvMC work using GPU shaders
moved into the X.Org state tracker. XvMC in Gallium3D hasn't been too much of a focus as developers are still working on driver support and other state trackers like for OpenGL 3.x and OpenCL. More users are also interested in
VDPAU and its superior support and decoding abilities than the antiquated XvMC. However, AMD's Cooper Yuan has been toying around with this Gallium3D-XvMC code for the R300 Gallium3D driver.
Cooper Yuan is one of the few AMD developers that focuses on the open-source code and documentation process and in the past few days has
committed new code to port the XvMC "video stuff" to the mesa/pipe-video branch. According to AMD's John Bridgman that
commented in our forums, Cooper is working on driver-level XvMC work while taking advantage of the existing higher-level XvMC support that originated with the GSoC project.
There really isn't anything too exciting at the moment, but we'll keep an eye on his commits.