关键词: H.264/AVC, 码率控制, 率失真优化, Cauchy分布, 比特分配

Abstract: Due to the limited bandwidth of communication channel, it is necessary to control the bit rate output of video coding. First, by introducing Energy Mean Squared Error (EMSE) and analyzing the statistics of extensive video sequence, the authors developed a simple linear distortion-quantization model. Then, based on quantization coefficients' probability distribution characteristic of H.264 encoder, an improved Cauchy-distribution-based rate-quantization model was proposed. Finally, the Lagrangian method was adopted to derive a bit allocation solution to the optimization of rate distortion. The experimental results demonstrate that, compared with the rate control scheme JVT-G012 applied to H.264 reference software, the proposed rate control algorithm enhances the accuracy of rate control and the Peak Signal Noise Ratio (PSNR), and improves the subjective video quality as well.

Key words: H.264/AVC, rate control, rate-distortion optimization, Cauchy distribution, bit allocation