This week's WWN pointed out a mailing list post by Michael Müller stubbing out the DxVA API functions. The intention of this work is to get a browser plugin to work that depends upon the DxVA library that in turn is also used by applications like VLC, Flash, and Silverlight. Michael Müller has managed to get some video support in place with VLC playing a MPEG-2 movie with GPU acceleration using DXVA2. His implementation layers DXVA2 atop VA-API, the Video Acceleration API mainly supported by Intel's open-source Linux graphics driver, but also works with Radeon and Nouveau via the Gallium3D state tracker.
Besides being limited to the VA-API native Linux video acceleration interface (as opposed to say VDPAU), this early Wine DXVA2 implementation also only handles MPEG-2 video decoding; implementing support for other video formats will require a lot more work. The patches are still being cleaned-up and need to be tested on more graphics hardware, but this MPEG-2 DxVA implementation for Wine is forthcoming and powered via VA-API.
More details can be found via the mailing list post.