Creating and Using a DirectX VA 2.0 Extension Device
The Microsoft Direct3D runtime calls the user-mode display driver's CreateExtensionDevice function to create an extension device for DirectX VA 2.0. When the Direct3D runtime is finished with the device, it calls the user-mode display driver's DestroyExtensionDevice function.
The Direct3D runtime calls the user-mode display driver's DecodeExtensionExecute function to decode video on a nonstandard decode device between a begin-frame and end-frame time period and on a specific render target surface. For a general discussion about decoding video, see Decoding Video.
The Direct3D runtime calls the user-mode display driver's ExtensionExecute function to perform nonstandard DirectX VA 2.0 operations on an extension device.