The ICDecompressBegin macro notifies a video decompression driver to prepare to decompress data. You can use this macro or explicitly call the ICM_DECOMPRESS_BEGIN message.
DWORD ICDecompressBegin(
hic,
lpbiInput,
lpbiOutput
);
Returns ICERR_OK if the specified decompression is supported or ICERR_BADFORMAT otherwise.
When the driver receives this message, it should allocate buffers and do any time-consuming operations so that it can process ICM_DECOMPRESS messages efficiently.
The ICDecompressBegin and ICDecompressEnd macros do not nest. If your driver receives ICM_DECOMPRESS_BEGIN before decompression is stopped with ICM_DECOMPRESS_END, it should restart decompression with new parameters.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Video Compression Manager Overview, Video Compression Macros, BITMAPINFO, ICDecompressEnd, ICM_DECOMPRESS, ICM_DECOMPRESS_BEGIN, ICM_DECOMPRESS_END