ICM_DECOMPRESS_BEGIN message
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_PTR) (LPVOID) lpbiInput;
lParam = (DWORD_PTR) (LPVOID) lpbiOutput;
Parameters
-
lpbiInput
-
Pointer to a BITMAPINFO structure containing the input format.
-
lpbiOutput
-
Pointer to a BITMAPINFO structure containing the output format.
Return Value
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
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|