The ICM_GETDEFAULTKEYFRAMERATE message queries a video compression driver for its default (or preferred) key-frame spacing. You can send this message explicitly or by using the ICGetDefaultKeyFrameRate macro.
ICM_GETDEFAULTKEYFRAMERATE
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, ICGetDefaultKeyFrameRate