The MCIWNDM_GET_ACTIVETIMER message retrieves the update period used when the MCIWnd window is the active window. You can send this message explicitly or by using the MCIWndGetActiveTimer macro.
MCIWNDM_GETACTIVETIMER
wParam = 0;
lParam = 0L;
Returns the update period in milliseconds. The default is 500 milliseconds.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
MCIWnd Window Class Overview, MCIWnd Messages, MCIWndGetActiveTimer