ICM_DECOMPRESSEX_BEGIN
The
ICM_DECOMPRESSEX_BEGIN message notifies a video compression driver to prepare
to decompress data.
ICM_DECOMPRESSEX_BEGIN
wParam = (DWORD) (LPVOID) &icdex;
lParam = sizeof(ICDECOMPRESSEX);
Parameters
icdex
Address of a ICDECOMPRESSEX structure containing the
input and output formats.
lParam
Size, in
bytes, of ICDECOMPRESSEX.
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_DECOMPRESSEX messages efficiently.
If you want
the driver to decompress data directly to the screen, send the ICM_DRAW_BEGIN
message.
The
ICM_DECOMPRESSEX_BEGIN and ICM_DECOMPRESSEX_END messages do not nest. If your
driver receives ICM_DECOMPRESSEX_BEGIN before decompression is stopped with
ICM_DECOMPRESSEX_END, it should restart decompression with new parameters.
See Also