WM_CAP_SET_OVERLAY

The WM_CAP_SET_OVERLAY message enables or disables overlay mode. In overlay mode, video is displayed using hardware overlay. You can send this message explicitly or by using the capOverlay macro.

WM_CAP_SET_OVERLAY 
wParam = (WPARAM) (BOOL) (f); 
lParam = 0L; 
 

Parameters

f

Overlay flag. Specify TRUE for this parameter to enable overlay mode or FALSE to disable it.

Return Values

Returns TRUE if successful or FALSE otherwise.

Remarks

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.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in vfw.h.

See Also

Video Capture Overview, Video Capture Messages, CAPDRIVERCAPS, capOverlay, CAPSTATUS