A codec for HDTV signal transmission through terrestrial and satellite digital links

A codec for digital transmission of HDTV signals designed to operate with the 1125/60 and 1250/50 interlaced studio systems is described. The codec is based on the application of discrete cosine transforms (DCT), combined with temporal differential pulse-code modulation (DPCM) on blocks of 8×8 samples for both luminance and color differences. The line bit rate can range from a minimum of about 60 Mb/s up to more than 140 Mb/s. This range includes the standard digital CCITT hierarchies of 2×34 Mb/s, 2×45 Mb/s, and 140 Mb/s. For higher bit rates the full studio quality (1920 pixels/line) can be transmitted, while for lower bit rates, a horizontal resolution of about 1440 pixels/line is a better compromise, in order not to stress the compression algorithm. Applications of the codec to various transmission links, including satellite transmission, are discussed