Original author(s) Written in C, C++ Type API
Library | Developer(s) freedesktop.org Operating system | |
Stable release 1.1.1 / August 31, 2015; 18 months ago (2015-08-31) | ||
Video Decode and Presentation API for Unix (VDPAU) is a royalty-free application programming interface (API) as well as its implementation as free and open-source library (libvdpau) distributed under the MIT License.
Contents
- Functional range of the interface
- History
- Device drivers and video controllers implementing VDPAU
- Generic VDPAU driver
- Software that supports VDPAU
- Nvidia VDPAU Feature Sets
- libvdpau standalone VDPAU library
- References
The VDPAU interface is to be implemented by device drivers, such as Nvidia GeForce driver, nouveau, amdgpu, to offer end-user software, such as VLC media player or GStreamer, a standardized access to available video decompression acceleration hardware in the form of application-specific integrated circuit blocks on graphics processing units (GPU), such as Nvidia PureVideo or Unified Video Decoder and make use of it.
VDPAU is targeted at Unix-like operating systems (including Linux, FreeBSD, Solaris).
Functional range of the interface
VDPAU allows video programs to access the PureVideo function blocks to offload portions of the video decoding process and video post-processing.
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.
History
VDPAU was originally designed by Nvidia for their PureVideo SIP block present on their GeForce 8 series and later GPUs.
On March 9, 2015, Nvidia released VDPAU version 1.0 which supports High Efficiency Video Coding (HEVC) decoding for the Main, Main 4:4:4, Main Still Picture, Main 10, and Main 12 profiles.
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 VDPAU. Nvidia currently has no plans to introduce VDPAU 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, VDPAU 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 HD 4000+ graphic cards featuring VDPAU acceleration.
Intel does not offer VDPAU drivers, they only support their VA-API. It is, however, possible to use Intel's VA-API drivers by way of libvdpau-va-gl.
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.
sunxi SoCs (Allwinner) have experimental VDPAU implementation.
Mesa as of v8.0 includes VDPAU for video cards that utilize Gallium3D.
Generic VDPAU driver
As of late 2013, there is an independently developed back-end driver that in turn uses OpenGL (for drawing and scaling), and VA-API if available (for decoding). It has been reported to work on some Intel graphics and Adobe Flash Player.
The accelerated scaling with just OpenGL functionality is needed mostly because of Flash player, which uses un-accelerated scaling if VDPAU is unavailable. Almost all other video software that runs on GNU/Linux supports Xv. It's essential for full-screen video on slower computers without native VDPAU support.
The VDPAU to VA-API translation for HW decoding is useful with recent Intel graphics hardware, as some software supports HW decoding through VDPAU but not VA-API.
Software that supports VDPAU
VDPAU can also be used as a backend for the VA-API and OpenMAX IL which themselves covers a subset of VDPAU's capabilities; so any software that uses the VA-API or OpenMAX IL is also partly capable of using VDPAU (e.g., VLC media player).
Nvidia VDPAU Feature Sets
Nvidia VDPAU Feature Sets are different hardware generations of GPU's supporting different levels of (Nvidia PureVideo) hardware decoding capabilities. For feature sets A, B and C, the maximum video width and height are 2048 pixels, minimum width and height 48 pixels, and all codecs are currently limited to a maximum of 8192 macroblocks (8190 for VC-1/WMV9). Partial acceleration means that VLD (bitstream) decoding is performed on the CPU, with the GPU only performing IDCT, motion compensation and deblocking. Complete acceleration means that the GPU performs all of VLD, IDCT, motion compensation and deblocking.
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.