A Novel R-λ Rate Control Algorithm for HEVC

In this paper, a novel R-lambda rate control algorithm is proposed. Firstly, different from the conventional R-lambda rate control for the predefined bit ratio of the frame level rate control, an adaptive bit allocation ratio, which is mainly determined by mean bi-directional frame difference, is proposed for more reasonable frame level bit allocation. Then, according to the rate distortion optimization (RDO) process, a special relationship between frame lambda and the mean coding tree unit (CTU) lambda can be built. Finally, a CTU lambda clipping method is proposed to get the optimal RDO of every CTU in a frame. The experimental results show that the coding quality of the proposed algorithm is increased by 0.35 dB at Random Access (RA) configuration and by 0.66 dB at Low Delay (LD) configuration.