High Efficient Context-Based Variable Length Coding with Parallel Orientation

Entropy coding is one of the most important techniques in video codec. Two main criteria to assess an entropy coder are coding efficiency and friendly realization characteristic. In the recent development of the H.264/AVC standard, a sophisticated entropy coder, named Context-based Adaptive Variable Length Coding (CAVLC), has been invented, which supplies higher coding efficiency than other VLC-based entropy coders in previous video coding standards. But due to its algorithm’s inherit traits CAVLC must be executed in a sequential manner, which results in relative low throughput rate. In this paper, a new well-designed context-based VLC entropy coder for transform coefficients is presented. It exploits coefficient block’s inner context information to obtain high coding efficiency, and at the same time context models for successive coding elements are designed to be dependent-free so that the coder is more apt to be parallel. Experimental results show that the proposed entropy coder can exhibit the same coding efficiency as CAVLC. Therefore, a new high performance entropy coder with characteristics of parallel orientation and high coding efficiency is supplied.