An efficient VLC decompression scheme for user-defined coding tables

With the increase of information and data types, a high-throughput and flexible memory-based (variable length code) VLC decoder is required for user-defined coding tables to achieve a higher compression ratio. We present a memory-based VLC decoder which is quite suitable for the applications with user-defined tables. By parallel loading data into memories, the coding tables can be changed with much less time. The codeword-boundary prediction algorithm breaks the recursive dependency of the decoding procedures. As a result, the VLC decoder can be realized on a multiprocessor architecture and hence the decoding throughput is enhanced significantly. Additionally, the index-offset symbols that can recover all data with a pure VLC codeword and a smaller table size are presented. Simulation results show that the combination of the proposed VLC decoder and user-defined table can achieve a high decompression rate. As a result, it is quite suitable for high data rate applications with user-defined coding tables, such as MPEG-4.