The capOverlay macro enables or disables overlay mode. In overlay mode, video is displayed using hardware overlay. You can use this macro or explicitly call the WM_CAP_SET_OVERLAY message.
BOOL capOverlay(
hwnd,
f
);
Returns TRUE if successful or FALSE otherwise.
Using an overlay does not require CPU resources.
The fHasOverlay member of the CAPDRIVERCAPS structure indicates whether the device is capable of overlay. The fOverlayWindow member of the CAPSTATUS structure indicates whether overlay mode is currently enabled.
Enabling overlay mode automatically disables preview mode.
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, CAPDRIVERCAPS, CAPSTATUS, WM_CAP_SET_OVERLAY