Configurable variable length code with genetic algorithms

The variable length code (VLC) tables in MPEG-1/2/4 and H.26X are fixed and optimized for a limited range of bit-rates, and they cannot handle a variety of applications. The universal variable length code (UVLC) is a new scheme to encode syntax elements and has some configurable capabilities. It is being considered in the ITU-T H.26L. However, the configurable feature of UVLC has not been well explored. In this paper we describe a VLC scheme which uses configurations as parameters to adapt UVLC to different symbol distributions of different applications. We also propose a method to automatically determine the configuration parameters based on a genetic algorithm (GA). Experimental results show that our method can achieve very good coding efficiency while drastically simplifying the encoding and decoding process, and is applicable to a variety of applications.