An efficient MB level rate control for H.264/AVC hardware encoder implementation

Abstract

In this paper, we propose an effective macroblock (MB) layer rate control (RC) scheme with low complexity for efficient H.264/AVC video encoder hardware implementation. Linear mean absolute difference (MAD) prediction is crucial in H.264/AVC rate control. The MAD prediction accuracy in JVT G012 is imperfect with high complexity. Therefore we propose a new MAD prediction arithmetic which computes MAD by elaborately controlling the weight of the MADs for well-selected spatiotemporally neighboring MBs. The proposed scheme not only considers the problem of data dependencies due to MB level pipeline, but also the MB scan order of zigzag MB encoding which is used to improve the data reuse in hardware encoder implementation. Extensive experiments results show that the proposed RC algorithm can further improve the rate-distortion performance, and achieves an average PSNR gain of 0.15dB. Meanwhile the computational complexity is kept low compared to the JVT-G012 RC arithmetic adopted in JM10.2 reference software.