Video Overlay

The placement of a full-motion video window on the display screen. There are various techniques used to display video on a computer’s screen, depending on whether the video source has been digitized or is still in analog NTSC format.

Since computer monitors are generally analog, NTSC video can be merged with signals coming from the video adapter. Increasingly, faster computer buses (PCI, VL-bus, etc.) and faster video busses (Advanced Feature Connector, VM Channel, etc.), allow for analog video to be digitized and stored with other binary data for output. Then the video adapter turns it into analog scan lines for the monitor.