| Microsoft DirectX 8.1 (C++) |
DirectX VA describes an Application Programming Interface (API) and a corresponding Device Driver Interface (DDI) for hardware acceleration of digital video decoding processing, with support of alpha blending for such purposes as DVD subpicture support. It provides an interface definition focused on support of MPEG-2 "main profile" video (formally ITU-T H.262 | ISO/IEC 13818-2), but is also intended to support other key video codecs (for example, ITU-T Recommendations H.263 and H.261, and MPEG-1 and MPEG-4).
Note: The DirectX VA specification is now located in the Microsoft Platform DDK. Developers of software decoders as well as device drivers should refer to that specification. The following section is primarily relevant for decoder developers. It provides detailed information on how a software MPEG-2 decoder uses the IAMVideoAccelerator Interface when communicating with a DXVA-enabled hardware device.