WM_CAP_SET_OVERLAY

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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.

Requirements

**  Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
**  Windows 95/98/Me:** Included in Windows 95 and later.
**  Header:** Declared in Vfw.h.

See Also

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