ICM_DRAW_SUGGESTFORMAT

The ICM_DRAW_SUGGESTFORMAT message queries a rendering driver to suggest a decompressed format that it can draw.

ICM_DRAW_SUGGESTFORMAT 
wParam = (DWORD) (LPVOID) &icdrwSuggest; 
lParam = sizeof(ICDRAWSUGGEST); 
 

Parameters

icdrwSuggest

Address of an ICDRAWSUGGEST structure.

lParam

Size, in bytes, of ICDRAWSUGGEST.

Return Values

Returns ICERR_OK if successful. If the lpbiSuggest member of the ICDRAWSUGGEST structure is NULL, this message returns the amount of memory required to contain the suggested format.

Remarks

The driver should examine the format specified in the lpbiIn member of the ICDRAWSUGGEST structure and use the lpbiSuggest member to return a format it can draw. The output format should preserve as much data as possible from the input format.

Optionally, the driver can use the installable compressor handle passed in the hicDecompressor member of ICDRAWSUGGEST to make more complex selections. For example, if the input format is 24-bit JPEG data, a renderer could query the decompressor to find out if it can decompress to a YUV format (which might be drawn more efficiently) before selecting the format to suggest.

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, ICDRAWSUGGEST