VDPAU (Video Decode and Presentation API for Unix) is an open source library (libvdpau) and API originally designed by Nvidia for its GeForce 8 series and later GPU hardware, targeted at the X Window System on Unix-Like operating systems (including Linux, FreeBSD, and Solaris). This VDPAU API allows video programs to offload portions of the video decoding process and video post-processing to the GPU video-hardware.
Currently, the portions capable of being offloaded by VDPAU onto the GPU are motion compensation (mo comp), inverse discrete cosine transform (iDCT), VLD (variable-length decoding) and deblocking for MPEG-1, MPEG-2, MPEG-4 ASP (MPEG-4 Part 2), H.264/MPEG-4 AVC and VC-1, WMV3/WMV9 encoded videos. Which specific codecs of these that can be offloaded to the GPU depends on the generation version of the GPU hardware; specifically, to also decode MPEG-4 ASP (MPEG-4 Part 2), Xvid/OpenDivX (DivX 4), and DivX 5 formats, a GeForce 200M (2xxM) Series (the eleventh generation of Nvidia's GeForce graphics processing units) or newer GPU hardware is required.
VDPAU can be described as the X Window System equivalent of the Microsoft's DxVA (DirectX Video Acceleration) API for Windows.
Device drivers and video controllers implementing VDPAU 
VDPAU is implemented in X11 software device drivers, but relies on acceleration features in the hardware GPU. (Currently, only the second generation PureVideo HD bit-stream processor in some of Nvidia's GeForce 8 series and later video controller hardware work as of Beta device driver version 180.06.) Video controllers for which VDPAU is not available from the GeForce 8 series includes the 8800GTS 320/640 MB editions and the 8800GTX. Later cards based on the G9x series cores (e.g., the 8400GS and the 8800GTS 512 MiB; G92 core) work with VPDAU. Nvidia currently has no plans to introduce VPDAU for the additional existing video controller products. All video controllers for which the driver implements VDPAU are listed in Nvidia PureVideo.
S3 Graphics added VDPAU to the Linux drivers of their Chrome 400 video cards. As of version 14.02.17 of its Linux device driver, VPDAU is available with the S3 Chrome 430 GT, S3 Chrome 440 GTX, S3 Chrome 530 GT and the S3 Chrome 540 GTX hardware.
ATI/AMD released an open source driver for RADEON 4000+ graphic cards featuring VDPAU acceleration.
Intel currently do not offer VDPAU. Nvidia hopes these GPU designers will make their products compatible with the open source VDPAU library and provide drivers with VDPAU acceleration by mentioning example names of hardware specific drivers for Intel and ATI: libvdpau_intel.so and libvdpau_ati.so. Intel has stated they are considering VDPAU.
Mesa as of v8.0 includes VDPAU for video cards that work with by Gallium3D.
Software that uses VDPAU 
VDPAU can also be used as a backend for the Video Acceleration API (VA API) which itself covers a subset of VDPAU's capabilities; so any software that uses the VA API is also partly capable of using VDPAU (e.g., VLC media player).
libvdpau standalone VDPAU library 
The libvdpau standalone VDPAU library is distributed by Nvidia independently of their proprietary Linux graphics driver in an effort to help the adoption of VDPAU by those outside of Nvidia. This open source library package contains a wrapper library and a debugging library allowing other manufacturers to implement VDPAU in their device drivers.
See also 
External links