wParam = (DWORD) (LPVOID) &icdex;
lParam = sizeof(ICDECOMPRESSEX);
Notifies a video compression driver to decompress a frame of data directly to the screen, decompress to an upside-down DIB, or decompress images described with source and destination rectangles.
This message is similar to ICM_DECOMPRESS except that it uses the ICDECOMPRESSEX structure to define its decompression information.
If you want the driver to decompress data directly to the screen, send the ICM_DRAW message.
The driver returns an error if this message is received before the ICM_DECOMPRESSEX_BEGIN message.
ICDecompressEx, ICM_DECOMPRESSEX_BEGIN, ICM_DECOMPRESSEX_END, ICM_DRAW_BEGIN