Libva is an implementation of VA-API. VA-API (Video Acceleration API, full name Video and Audio API) is an open source library and API specification that provides graphics hardware acceleration for video processing, and is provided by each supported hardware vendor. Main library and driver-specific acceleration backend.

The main motivation of VA-API (Video Acceleration API) is to enable hardware accelerated video decoding and encoding ASP/H at various entry points (VLD, IDCT, Motion Compensation, etc.) for popular encoding standards (MPEG-2, MPEG-4) .263, MPEG-4 AVC/H.264, VC-1/VMW3 and JPEG, HEVC/H265, VP8, VP9) and video pre/post processing.

Doxygen files are regularly updated via Github Pages, available via libva pages direct interview.

All VAAPI functions implemented in libva are thread-safe. For any VAAPI function that needs to implement a backend (such as a hardware driver), the backend must ensure that its implementation is also thread-safe. If the backend implementation of a VAAPI function is not thread safe, it should be considered a bug against the backend implementation.

It is assumed that no VAAPI functions will be called from the signal handler.In this context, thread safety means that when multiple concurrent threads call the VAAPI, it will not crash or hang the operating system, and the VAAPI internal data structures will not be corrupted.

When multiple threads operate on the same VAAPI object, the application is responsible for synchronizing these operations to produce the expected results.