Abstract: Variable length codewords representing high definition television image information are processed by a codeword analyzr for prioritizing codewords within a predetermined codeword group. A single FIFO rate buffer conveys codewords subject to analysis to the analyzer. A succeeding codeword group is written into the buffer when a current codeword group is being analyzed, at which time buffer read out is inhibited. In an illustrated embodiment, buffer read out is inhibited, and codeword analysis begins, when MPEG Picture Start or Slice Start codewords associated with the succeeding codeword group approach the buffer output. Buffer read out is enabled at the end of the analysis interval.

Abstract: 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.