There are currently three X11 Nvidia drivers available: a 2D-only open source but obfuscated driver maintained by Nvidia called nv, a proprietary binary driver by Nvidia, and an open source driver based on reverse engineering of the binary driver developed by the Linux community called Nouveau. Nouveau is not pursuing XvMC support, the 2D nv driver does not support XvMC, and the official proprietary binary driver by Nvidia only supports MPEG-2 offloading (mo comp and iDCT) on hardware up to and including the GeForce 7000 series.