A Novel Macro-block Layer Rate Control Algorithm in Low Bit-rate

A real-time single-pass bit rate control algorithm in low bit-rate of macro-block layer for H.264 is presented.In order to solve the drawback of rate control model in H.264,a new concept of average pixel information bit(APIB) and the novel rate control model based on it are represented at first;then the more precise bit allocation scheme is implemented according to the coding complexity of each macro-block,and the parameters of rate control model are updated by the change of APIB adaptively;finally,the complete rate control algorithm is proposed.This algorithm is implemented in JM85(H.264/AVC),the experimental results show that,compared to JVT-G012 in H.264,the proposed method gains 0.171kbps in control precision and 0.227dB in PSNR averagely,and controls the fluctuation on bit and PSNR precisely at the same time.