低码率应用中的一种视频码率控制方法

针对低码率视频应用,该文根据信源的线性模型,在满足码率约束的条件下,提出一种使宏块量化参数集中的优化策略。通过该方法,可以使宏块失真度分布更加集中,图像质量更加均匀,更符合人眼视觉特性;同时减少了编码码流中用于表征宏块间量化参数变化的句法比特数。仿真表明,在低码率及甚低码率的视频应用中,该方法能改善主客观视觉质量。

One rate control method for low rate video applications

Targeted to low rate video application, a new rate control scheme based on linear source model is proposed in this paper. The optimal criterion is to minimize the variance of MBs' quantize parameters while subject to the constraint of rate. This method makes the quantize parameters and MSEs more concentrating among MBs, which led to more consistent visual quality. At the same time, the overhead bits used to show the changes of quantize parameters between MBs are decreased dramatically, which is the desired feature in low bit rate applications. Simulation results show that our proposal can improve PSNR as well as subjective visual quality.