A High Throughput Multi Symbol CABAC Framework for Hybrid Video Codecs

Abstract

Summary form only given. This paper proposes a Multi-Symbol Context Adaptive Binary Arithmetic Coding (CABAC) Framework in Hybrid Video Coding. Advanced CABAC techniques have been employed in popular video coding technologies like H264-AVC, HEVC. The proposed framework aims at extending these technique by providing symbol level scalability in being able to code one or multi-symbols at a time without changing the existing framework. Such a coding not only can exploit higher order statistical dependencies on a syntax element level but also reduce the number of coded bins. New syntax elements and their Probability modeling are proposed as extensions to achieve Multi-Symbol coding. An example variant of this framework, that is coding only maximum of two symbols at a time for quantized coefficient Indices, was implemented on top of JM18.3-H264 CABAC. This example extension when tested with on HEVC test Sequences shows significant throughput improvement (i.e., significant reduction in number of bins to be coded) and at the same time reduces Bit-rate significantly. The Frame-work can be seamlessly extended to code Multiple Symbols greater than two.