Statistical Multiplexing of Multiple MPEG-2 Video Programs in a Single Channel

This paper discusses rate control for statistically multiplexed (stat mux) systems and derives the fundamental equations governing encoder and decoder buffer fullness. An example of how these equations can be used to determine the sizes of the encoder and decoder buffers is presented. Two fundamental approaches to stat mux rate control are also discussed: the look-ahead approach and the feedback approach. In the look-ahead approach, statistics computed by a preprocessor are used to adjust the bit rate prior to coding the frames in question. In the feedback approach, statistics generated by the encoder as a by-product of the compression process are used to control the future bit-rate allocation. Finally, simulation results for one stat mux implementation are presented.