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.
See Also