Logic Control for Parallel Video Processing in Program Switchers

Abstract

Studio program switchers are used to Select the proper picture(s) at the operator's discretion, either individually or in combination. Normally this is done by routing the video signals through different video devices, such as mixing amplifiers, special effects, etc. This delays the video signals, so the switchers must utilize secondary switching to put the processing devices in series or to substitute delay lines to maintain constant propagation delay through the system. To minimize the delay and to improve the quality of the picture, a new concept of parallel video processing has been developed. Time sharing and amplitude sharing are used to achieve MIX, WIPE, KEY, etc., leading to very good technical performance characteristics.