http://en.wikipedia.org/wiki/Nvidia_PureVideo
The Fourth Generation PureVideo HD
This implementation of PureVideo HD, VP4 added hardware to offload MPEG-4 (Advanced) Simple Profile bitstream decoding with the GT215, GT216 & GT218 GPUs (sold as GeForce GT 240, GeForce GT 220 & GeForce 210/G210)[7]. The H.264-decoder no longer suffers the framesize restrictions of VP3, and adds hardware-acceleration for MVC, a H.264 extension used on 3D Blu-ray discs. The same features are also supported by Geforce 400 GPUs.
The fourth generation PureVideo HD is sometimes called "PureVideo HD 4" or VP4, although this is not an official NVIDIA designation. It corresponds to Nvidia VDPAU Feature Set C (which due to a missing API currently does not support MVC)。