基于Cauchy分布的H.264/AVC码率控制优化算法  

Rate control optimization algorithm based on Cauchy distribution for H. 264 /AVC

作　　者：王科技[1] 康志伟[1] 刘新焕[1] 陈步真[1] 

机构地区：[1]湖南大学计算机与通信学院,长沙410082

出　　处：《计算机应用》2010年第9期2444-2448,共5页journal of Computer Applications

基　　金：国家自然科学基金资助项目(60702065);湘潭市科技计划重点项目(ZJ20071008)

摘　　要：由于通信信道带宽有限,有必要对视频编码的输出码率进行控制。通过引入能量均方误差(EMSE),进行视频序列统计分析,建立了一种简单的线性图像失真模型,并基于编码器中量化系数的概率分布特性,提出了改进的Cauchy分布码率模型,然后利用Lagrangian方法实现了率失真优化的位分配。实验结果表明,与H.264参考软件所采用的JVT-G012算法相比,该算法提高了码率控制精度和峰值信噪比,从而改善了解码图像的质量。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.

关 键 词：H.264/AVC 码率控制 率失真优化 Cauchy分布 比特分配 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]