We last talked about the state of Gallium3D video decoding back in September when Manton's video decoding method was working, but at an awfully slow pace. Now with his work on the Gallium3D-based Nouveau driver for NVIDIA hardware, he has achieved more promising results.
Thanks to the latest code in Gallium3D and an improvement in Nouveau's winsys layer, those using this community-developed driver can now play 1080p video clips. Additionally, those working on the Nouveau video playback improvements have been able to implement swizzled surfaces. As opposed to linear surfaces, swizzled surfaces offer greater performance when it comes to motion compensation during video playback. Using swizzled surfaces allows for smoother video playback atop Gallium3D, but more optimizations are still planned.
For more on the latest Gallium3D video work, check out Manton's blog post. He is also exploring an open-source implementation of NVIDIA's VDPAU video API.