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

Address of a BITMAPINFO structure containing the input format.

lpbiOutput

Address of 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_DECOMPRESSd_BEGIN before decompression is stopped with ICM_DECOMPRESS_END, it should restart decompression with new parameters.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in vfw.h.

See Also

Video Compression Manager Overview, Video Compression Messages, BITMAPINFO, ICM_DECOMPRESS, ICDecompressBegin, ICM_DECOMPRESS_END, ICM_DRAW