VC_Overlay

BOOL
VC_Overlay(
    VCUSER_HANDLE vh,
    BOOL bOverlay
    );

The VC_Overlay function requests a kernel-mode video capture driver to enable or disable the hardware’s overlay capabilities, using the current rectangle and key color settings.

Parameters

vh

Handle to the kernel-mode driver, obtained from VC_OpenDevice.

bOverlay

Set TRUE to enable overlay, or FALSE to disable overlay.

Return Value

Returns TRUE if the operation succeeds. Otherwise returns FALSE.

Comments

User-mode video capture drivers using VCUser.lib should call the VC_Overlay function with bOverlay set to TRUE when processing a DVM_STREAM_INIT command for the VIDEO_EXTERNALOUT channel. They should call the function with bOverlay set to FALSE when processing a DVM_STREAM_FINI command for the VIDEO_EXTERNALOUT channel.

The VC_Overlay function calls DeviceIoControl (described in the Win32 SDK) to send either an IOCTL_VIDC_OVERLAY_ON or an IOCTL_VIDC_OVERLAY_OFF control code to the specified kernel-mode driver. When a kernel-mode driver using VCKernel.lib receives one of these control codes, its OverlayFunc function is called.

See Also

VC_SetOverlayRect