Apparatus, method and computer program product for transcoding a coded multiplex sound and moving pictuture sequence

摘要

Herein disclosed is an apparatus (600,700,200) for transcoding a coded multiplexed sound and moving picture sequence comprising a rate converter, which is operated to compress only the video bit streams, which have extremely large information volume. The compression operation is carried out through the steps of (a) operating the MPEG-2 transport stream (TS) demultiplexer (610) to demultiplex the input MPEG-2 transport streams into video TS, audio TS, and system information TS; (b) operating the MPEG-2 video transcoder (640) to transcode the video TS to generate output video TS having information volume less than the video TS; (c) operating the system controller (650) to modify or not modify part of fixed codes of the system information TS in accordance with the output MPEG-2 transport streams; (d) operating the MPEG-2 TS multiplexer (620) to multiplex the video TS thus transcoded, the audio TS, and the eventually partly-modified or not modified system information TS into output MPEG-2 transport streams, and output the output MPEG-2 transport streams, thereby making it possible to control the output bit rate less than the input bit rate.