Supporting Overlay Capabilities, Using VCKernel.lib

Kernel-mode video capture drivers support a device's overlay capabilities by providing a set of functions that VCKernel.lib can call in response to requests from a user-mode driver. If the hardware supports overlay capabilities, the driver must provide the following set of functions:

OverlayFunc

Enables overlay.

GetOverlayModeFunc

Returns overlay capabilities.

SetOverlayRectsFunc

Sets overlay display rectangles.

SetOverlayOffsetFunc

Sets the overlay offset rectangle that is used for panning.

GetKeyColourFunc

Returns the overlay area's current key color.

SetKeyPalIdxFunc

Sets the overlay area's key color to a palette index number.

SetKeyRGBFunc

Sets the overlay area's key color to an RGB value.