An adaptive bit mismatch rectification algorithm for intra frame rate control in HEVC

Rate control is an integral part of high-fidelity video coding. Since the first call for proposal, many rate control algorithms have been incorporated into the HEVC standard to prepare for its practical use in the future. The state of the art SATD based intra frame rate control strategy (SATDRC) achieves stable controlling performance. However, the average bit mismatch on the frame level (BMF) reaches 0.62%, with the highest 1.47%, which may lead to unsteady video services in bandwidth constrained applications. In this paper, an adaptive frame level bit mismatch rectification scheme (AFBMR) is proposed for SATDRC to reduce the gap between allocated bits and generated bits. BMF is utilized to adjust bits allocated to a frame adaptively in accordance with sequence characteristics. Experimental results show that the proposed method reduces bit inconsistency by 37.33% on average, enhancing bit rate accuracy as well as providing steadier bit streams without introducing extra computational complexity and loss of video quality.