Video Acceleration API
Video Acceleration API (VA-API) is an open source application programming interface that allows applications such as VLC media player or GStreamer to use hardware video acceleration capabilities, usually provided by the graphics processing unit (GPU). It is implemented by the free and open-source library , 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 (DRI) in X Window System on Unix-like operating systems (including Linux, FreeBSD, Solaris), and Android, however it  can potentially also be used with direct framebuffer and graphics sub-systems for video output. Accelerated processing includes support for video decoding, video encoding, subpicture blending, and rendering. The VA-API specification was originally designed by Intel for its GMA (Graphics Media Accelerator) series of GPU hardware with the specific purpose of eventually replacing the XvMC 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, deblocking) for the prevailing coding standards today (MPEG-2, MPEG-4 ASP/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 GPUs. Supported hardware and drivers. As of 2019, VA-API is natively supported  by: 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. 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: 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 X Window System, such as direct with framebuffer , 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 GPU for decoding or encoding a compressed bit-stream.