DWORD
VC_GetKeyColour(
VCUSER_HANDLE vh
);
The VC_GetKeyColour function requests a kernel-mode video capture driver to return the device’s current key color.
If the hardware supports a key color, the function returns the key color. Otherwise the function returns zero. See the following Comments section.
Before calling VC_GetKeyColour, the driver should call VC_GetOverlayMode and test the VCO_KEYCOLOUR_RGB flag to determine if, based on the current data format, the kernel-mode driver has stored the key color as an RGB color or as a palette index number. The VC_GetKeyColour function’s return value is either an RGBQUAD type or a palette index number, based on the VCO_KEYCOLOUR_RGB flag.
The VC_GetKeyColour function calls DeviceIoControl (described in the Win32 SDK) to send an IOCTL_VIDC_GET_KEY_COLOUR control code to the specified kernel-mode driver. When a kernel-mode driver using VCKernel.lib receives this control code, its GetKeyColourFunc function is called.