Video Acceleration API (VA-API) is an open source application programming interface that allows applications such as

VLC media player VLC media player (previously the VideoLAN Client and commonly known as simply VLC) is a free and open-source, portable, cross-platform media player software and streaming media server developed by the VideoLAN project. VLC is available for desk ...

GStreamer GStreamer is a pipeline-based multimedia framework that links together a wide variety of media processing systems to complete complex workflows. For instance, GStreamer can be used to build a system that reads files in one format, processes the ...

to use hardware video acceleration capabilities, usually provided by the

graphics processing unit A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, m ...

(GPU). It is implemented by the free and open-source

library A library is a collection of materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or digital access (soft copies) materials, and may be a physical location or a vir ...

, combined with a hardware-specific driver, usually provided together with the GPU driver. VA-API video decode/encode interface is platform and window system independent but is primarily targeted at

Direct Rendering Infrastructure The Direct Rendering Infrastructure (DRI) is the framework comprising the modern Linux graphics stack which allows unprivileged user-space programs to issue commands to graphics hardware without conflicting with other programs. The main use ...

(DRI) in

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wi ...

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...

-like

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...

s (including

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...

, FreeBSD, Solaris), and Android, however it can potentially also be used with direct

framebuffer A framebuffer (frame buffer, or sometimes framestore) is a portion of random-access memory (RAM) containing a bitmap that drives a video display. It is a memory buffer containing data representing all the pixels in a complete video frame. Mode ...

and graphics sub-systems for video output. Accelerated processing includes support for

video decoding A video decoder is an electronic circuit, often contained within a single integrated circuit chip, that converts base-band analog video signals to digital video. Video decoders commonly allow programmable control over video characteristics such ...

video encoding In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...

, subpicture blending, and rendering. The VA-API specification was originally designed by

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

for its GMA (Graphics Media Accelerator) series of

GPU A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobi ...

hardware with the specific purpose of eventually replacing the

XvMC X-Video Motion Compensation (XvMC), is an extension of the X video extension (Xv) for the X Window System. The XvMC API allows video programs to offload portions of the video decoding process to the GPU video-hardware. In theory this process shou ...

standard as the default Unix multi-platform equivalent of Microsoft Windows DirectX Video Acceleration (DxVA) API, but today the API is no longer limited to Intel-specific hardware or GPUs. Other hardware and manufacturers can freely use this open standard API for hardware accelerated video processing with their own hardware without paying a royalty fee.

Overview

The main motivation for VA-API is to enable hardware-accelerated video decode at various entry-points ( VLD, IDCT,

motion compensation Motion compensation in computing, is an algorithmic technique used to predict a frame in a video, given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video d ...

deblocking A deblocking filter is a video filter applied to decoded compressed video to improve visual quality and prediction performance by smoothing the sharp edges which can form between macroblocks when block coding techniques are used. The filter aim ...

) for the prevailing coding standards today ( MPEG-2,

MPEG-4 ASP MPEG-4 Part 2, MPEG-4 Visual (formally ISO/ IEC 14496-2) is a video compression format developed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC standards. It uses block-wise motion compensation and a discrete cosine ...

/ H.263, MPEG-4 AVC/H.264, H.265/HEVC, and VC-1/WMV3). Extending XvMC was considered, but due to its original design for MPEG-2 MotionComp only, it made more sense to design an interface from scratch that can fully expose the video decode capabilities in today's

Supported hardware and drivers

As of 2019, VA-API is natively supported by: *

Intel Quick Sync Intel Quick Sync Video is Intel's brand for its dedicated video encoding and decoding hardware core. Quick Sync was introduced with the Sandy Bridge CPU microarchitecture on 9 January 2011 and has been found on the die of Intel CPUs ever since. T ...

open-source drivers for Linux *

Mesa A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a ...

open-source drivers for AMD and NVIDIA graphics cards * AMDGPU-PRO drivers for AMD graphics cards on Linux * libva-vdpau-driver for cards supported by

VDPAU 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 () distributed under the MIT License. VDPAU is also supported by Nvidia. Th ...

Supported video codecs

VA-API currently supports these video codecs in the official mainline version, but note that exactly which video codecs are supported depends on the hardware and the driver's capabilities. * MPEG-2 decode acceleration Main Profile * VC-1 / WMV3 decode acceleration Advanced Profile * MPEG-4 Part 2 (H.263) (a.k.a. MPEG-4 SP / MPEG-4 ASP, more commonly known as

Xvid Xvid (formerly "XviD") is a video codec library following the MPEG-4 video coding standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP). It uses ASP features such as b-frames, global and quarter pixel motion compensation, lumi mas ...

) decode acceleration * H.264 AVC encode acceleration Main Profile * H.264 AVC decode acceleration High Profile ** H.264 / AVC Hardware Variable Length Decoding (VLD) - CABAC ** H.264 / AVC Hardware Variable Length Decoding (VLD) - CAVLC ** H.264 / AVC Hardware Inverse Transform (IT) ** H.264 / AVC Hardware Motion Compensation (HWMC) ** H.264 / AVC Hardware In-Loop Deblocking (ILDB) * H.265/HEVC encode acceleration * H.265/HEVC decode acceleration *

VP9 VP9 is an open and royalty-free video coding format developed by Google. VP9 is the successor to VP8 and competes mainly with MPEG's High Efficiency Video Coding (HEVC/H.265). At first, VP9 was mainly used on Google's video platform YouTube. ...

8-bit encode acceleration * VP9 8-bit and 10-bit decode acceleration *

AV1 AOMedia Video 1 (AV1) is an open, royalty-free video coding format initially designed for video transmissions over the Internet. It was developed as a successor to VP9 by the Alliance for Open Media (AOMedia), a consortium founded in 2015 th ...

8-bit and 10-bit decode acceleration

Processes that can be accelerated with VA-API

Video decoding and post-processing processes that can be offloaded and accelerated if both the device drivers and GPU hardware supports them: *

Motion compensation Motion compensation in computing, is an algorithmic technique used to predict a frame in a video, given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video d ...

* Inverse discrete cosine transform * In-loop

deblocking filter A deblocking filter is a video filter applied to decoded compressed video to improve visual quality and prediction performance by smoothing the sharp edges which can form between macroblocks when block coding techniques are used. The filter aims ...

* Intra-frame prediction * variable-length decoding, more commonly known as slice-level acceleration * Bitstream processing (

Context-adaptive variable-length coding Context-adaptive variable-length coding (CAVLC) is a form of entropy coding used in H.264/MPEG-4 AVC video encoding. It is an inherently lossless compression technique, like almost all entropy-coders. In H.264/MPEG-4 AVC, it is used to encode r ...

Context-adaptive binary arithmetic coding Context-adaptive binary arithmetic coding (CABAC) is a form of entropy encoding used in the H.264/MPEG-4 AVC and High Efficiency Video Coding (HEVC) standards. It is a lossless compression technique, although the video coding standards in which it i ...

)

Software architecture

The current interface is window system independent, so that it can potentially be used with graphics sub-systems other than the DRI (Direct Rendering Infrastructure) in

, such as direct with

, and it can work with third-party DRM (Direct Rendering Manager) libraries. In a nutshell, it is a scheme to pass various types of data buffers from the application to the

for decoding or encoding a compressed bit-stream.

Software supporting VA-API

Clutter Clutter and its derivations may refer to any of the following: Excessive physical disorder * Clutter, a confusing, or disorderly, state or collection, and possible symptom of compulsive hoarding * Clutter (marketing), numerous advertisements, a ...

toolkit *

Jellyfin Jellyfin is a free and open-source media server and suite of multimedia applications designed to organize, manage, and share digital media files to networked devices. Jellyfin consists of a server application installed on a machine running ...

media server
datarhei Restreamer
real-time live video streaming * Emby media server (starting from release 3.0.6400) * Helix media player (

) * ''ffmpeg'', a command line tool from the

FFmpeg FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of vid ...

project, supports VA-API encoding through CLI with version starting from 3.1 and also

libavcodec libavcodec is a free and open-source library of codecs for encoding and decoding video and audio data. libavcodec is an integral part of many open-source multimedia applications and frameworks. The popular MPV, xine and VLC media players use ...

(also part of the FFmpeg project) does contain code that other applications use to support hardware accelerated decoding, including VA-API.
Fluendo
* Gnash Flash / SWF player *

through * Kodi (formerly XBMC Media Center) (

) * Kodibuntu (formerly XBMC Live) (Linux Live CD/USB operating-system) *

MPlayer MPlayer is a free and open-source media player software application. It is available for Linux, OS X and Microsoft Windows. Versions for OS/2, Syllable, AmigaOS, MorphOS and AROS Research Operating System are also available. A port for DOS using ...

(v1 with patches) and its fork mpv (native) *

MythTV MythTV is a free and open-source home entertainment application with a simplified "10-foot user interface" design for the living room TV. It turns a computer with the necessary hardware into a network streaming digital video recorder, a digital ...

(starting from release 0.25)
OpenShot
*

(starting from release 1.1.0) * Bluecherry DVR client (starting from release 2.2.6) *

Xine xine is a multimedia playback engine for Unix-like operating systems released under the GNU General Public License. xine is built around a shared library (xine-lib) that supports different frontend player applications. xine uses libraries ...

(via "''xine-lib-vaapi''" library) since Version 1.2.3 *

OBS Studio OBS Studio (also Open Broadcaster Software or OBS, for short) is a free, open-source, and cross-platform screencasting and streaming app. It is available for Windows, macOS, Linux distributions, and BSD. The OBS Project raises funds on the ...

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current ...

(On Wayland since release 78 and on X11 since release 80)

References

External links

*
Intel Media and Audio for Linux

mobile-hw-decode

"VA API slowly -- but surely -- making progress"
– an overview from 2009
"MPlayer, FFmpeg Gain VA-API Support"
– from 2008 {{freedesktop.org Application layer protocols Application programming interfaces Freedesktop.org Video acceleration Video acceleration APIs available on Linux X Window extensions