There are 2 types of keying supported by decklink cards : internal keying and external keying
In internal keying mode the CG software will set the Decklink card to superimpose the graphics over incoming signal
In external keying mode the CG software will set the Decklink card to generate video and key SDI signals and the keying will be made by an external keyer
The following table displays hardware which supports the keyer functionality
