A 610 Mbin/s CABAC decoder for H.265/HEVC level 6.1 applications

This paper presents a high-throughput decoder of HEVC context-based adaptive binary arithmetic coding (CABAC). A multi-sub-engine arithmetic decoder (MSE-AD) design is proposed to increase the average number of bins delivered per clock cycle by adaptively processing different patterns of upcoming bins with balanced critical path delay. A syntax element (SE) grouping scheme is proposed to maximize the utilization of MSE-AD under the SE parsing order specified in the standard. We also employ a prediction-based pipeline to alleviate the data hazard problem. The proposed CABAC decoder delivers 2.36 bins per clock cycle and achieves a maximum clock frequency of 258MHz in 90nm technology. The resulting performance is 610 Mbin/s which is enough for H.265/HEVC level 6.1 (8K×4K@60fps) applications.