ICM_COMPRESS_BEGIN

See also ICM_COMPRESS, ICM_COMPRESS_END, ICM_DECOMPRESS_BEGIN, ICM_DRAW_BEGIN


wParam = (DWORD) (LPVOID) lpbiInput;
lParam = (DWORD) (LPVOID) lpbiOutput;

Notifies a video compression driver to prepare to compress data.

wParam

Address of a BITMAPINFO structure indicating the input format.

lParam

Address of a BITMAPINFO structure indicating the output format.

The driver should allocate and initialize any tables or memory that it needs for compressing the data formats when it receives the ICM_COMPRESS message.

VCM saves the settings of the most recent ICM_COMPRESS_BEGIN message. ICM_COMPRESS_BEGIN and ICM_COMPRESS_END do not nest. If your driver receives an ICM_COMPRESS_BEGIN message before compression is stopped with ICM_COMPRESS_END, it should restart compression with new parameters.