The capSetCallbackOnStatus macro sets a status callback function in the application. AVICap calls this procedure whenever the capture window status changes. You can use this macro or explicitly call the WM_CAP_SET_CALLBACK_STATUS message.
BOOL capSetCallbackOnStatus(
hwnd,
fpProc
);
Returns TRUE if successful or FALSE if streaming capture or a single-frame capture session is in progress.
Applications can optionally set a status callback function. If set, AVICap calls this procedure in the following situations:
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Video Capture Overview, Video Capture Macros, WM_CAP_SET_CALLBACK_STATUS