This driver specific messages for video compression and decompression drivers are covered by the three basic operations of these drivers: video compression, video decompression using the client-application, and video decompression directly to video hardware. Because video compression and decompression drivers typically use AVI files and bitmaps, this section includes a brief overview of the AVI RIFF format, the BITMAPINFO data structure, and the BITMAPINFOHEADER data structure.