Joint rate control with look-ahead for multi-program video coding

In this paper, we present a new joint rate control algorithm for a multi-program video compression system using MPEG-2 compatible video encoders. The proposed joint rate control is based on both the feedback and look-ahead approaches. It dynamically distributes the channel bandwidth among the program encoders according to the relative complexities of the programs using picture and coding statistics. As opposed to previous works in this area, our algorithm does not restrict the encoders to operate with identical group of pictures (GOP) structures, i.e. the GOP boundaries need not be synchronized among the different encoders. The proposed algorithm allows adaptive distribution of the channel bandwidth among the programs, even at the start of encoding. Furthermore, it assures quick reaction to scene changes, where a feedback approach requires an unavoidable delay. Experimental results show that the proposed joint rate control with look-ahead results in improved picture quality in comparison with a pure feedback approach.