ICM_DECOMPRESS_BEGIN
The ICM_DECOMPRESS_BEGIN message notifies a video decompression driver to prepare to decompress data. You can send this message explicitly or by using the ICDecompressBegin macro.
ICM_DECOMPRESS_BEGIN
wParam = (DWORD) (LPVOID) lpbiInput;
lParam = (DWORD) (LPVOID) lpbiOutput;
Parameters
lpbiInput
Pointer to a BITMAPINFO structure containing the input format.
lpbiOutput
Pointer to a BITMAPINFO structure containing the output format.
Return Values
Returns ICERR_OK if the specified decompression is supported or ICERR_BADFORMAT otherwise.
Remarks
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.
If you want the driver to decompress data directly to the screen, send the ICM_DRAW message.
The ICM_DECOMPRESS_BEGIN and ICM_DECOMPRESS_END messages 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.
Requirements
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
** Header:** Declared in Vfw.h.
See Also
Video Compression Manager, Video Compression Messages, BITMAPINFO, ICM_DECOMPRESS, ICDecompressBegin, ICM_DECOMPRESS_END, ICM_DRAW