Priority processing of encoded video signal including insertion of datastream null words during priority analysis intervals

摘要

A system for processing a high definition television signal includes a codeword prioritizer responsive to a codeword datastream derived from an MPEG-like encoder. The prioritizer generates a flag to indicate a breakpoint between high priority and standard priority codewords within a given image data group. Null codewords are inserted into the codeword datastream during intervals when the prioritizer is analyzing codewords to determine where to establish the priority breakpoint. The null codewords are ignored by a following transport processor which packs codewords into cells.