A digital alternative to a video decoder

New video transmission systems such as the satellite D2-MAC/packet system and second-generation local area networks for video-communications will use digital coding and decoding of video signals. To develop reliable and low-cost receivers, it appears necessary to implement the main functions using CMOS technology. Therefore many analog functions must be replaced by the equivalent digital ones before implementation. Digital circuits are described for the final video postprocessing, i.e. video postfiltering and dematrixing. An NMOS digital filter for Y, CR, and CB oversampling is presented. R, G, and B components are obtained using a CMOS matrix operator, also described. These two circuits are used in a 108-Mb/s experimental video decoder.