Novel Multiple Bypass Bin Scheme and Low-power Approach for HEVC CABAC Binary Arithmetic Encoder

Abstract

HEVC is one of the most recent video coding standards, designed to face a new age of video processing challenges, such as higher video resolutions and limited traffic share bandwidth. The HEVC standard is divided into multiple steps, whereas the entropy encoding is the final stage before the coded bitstream generation. The CABAC (Context Adaptive Binary Arithmetic Coding) is the sole algorithm used for the entropy encoding at HEVC, providing reduced final bitstream generation, at the cost of increasing computational complexity and difficulties for parallelism opportunities. One of the novelties of the CABAC for the HEVC is the increase of certain types of input data (called bins), which have smaller dependencies among them (i.e. bypass bins), thus leading to the possibility to process multiples of them in parallel at once. The present work introduces a novel scheme for multiple bypass bins processing at once, leading to increasing bins-per-cycle throughput compared to related works. Moreover, the new technique is suitable for achieving a BAE (Binary Arithmetic Encoder) architecture (the CABAC critical part) able to process 8K UHD videos. Along with the multiple bypass bins technique, a low-power approach is achieved, based on statistical analysis of the recommended test video sequences, accomplishing around 15%of power savings.