Basic consideration of MPEG-2 coded file entropy and lossless re-encoding

Re-encoding of once compressed files is one of the difficult challenges in measuring the efficiency of coding methods. Variable length coding with a variable source delimiting scheme is a promising method for improving re-encoding efficiency. Analyses of coded files with fixed length delimiting and with variable length delimiting are reviewed. Motion vector codes of MPEG-2 encoded files are modified as a variable-to-variable coding point of view. Length, bit-rates, and varieties of videos are examined. The largest file is 16 seconds of D1 full size at 720 ×480 among five video files. By entropy evaluation, an improvement of almost 20% in coding efficiency over the conventional MPEG-2 is obtained.