The ICM_SETQUALITY message provides a video compression driver with a quality level to use during compression.
ICM_SETQUALITY 
wParam = (DWORD) (LPVOID) &dwICValue; 
lParam = 0; 
 Returns ICERR_OK if the driver supports this message or ICERR_UNSUPPORTED otherwise.
  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in vfw.h.
Video Compression Manager Overview, Video Compression Messages