Compatibility of widescreen and non-widescreen television transmissions.

摘要

A widescreen television picture is sampled at a higher sampling rate so as to fit all of the information in the current 52.5 us active video line time. A selection signal is also incorporated with the widescreen picture signal, allowing non-widescreen television receivers to display a contiguous portion of the widescreen picture without geometric distortion. The widescreen television signal is transmitted either in MAC or widescreen NTSC format, and is received by a decoder. The decoder allows the entire widescreen picture to be displayed on a widescreen receiver, and makes use of the selection signal to display the selected portion of the picture on a standard receiver without geometric distortion. In another embodiment, a decoder allows television signals having the standard aspect ratio to be displayed on receivers having widescreen aspect ratios without geometric distortion.