低延时无线视频传输中的H.264码率控制算法  

A Rate Control Algorithm for H.264 Low-delay Video Transmission over Wireless Network

作　　者：费伟[1] 朱善安[1] 

机构地区：[1]浙江大学电气工程学院,杭州310027

出　　处：《中国图象图形学报》2008年第11期2099-2105,共7页Journal of Image and Graphics

摘　　要：针对基于ARQ机制下的低延时无线视频传输,提出了一种有效的信道信源联合码率控制方案。该方案首先利用Markov模型作为无线信道模型来预测估计信道的状态和带宽,并以基于Cauchy分布的率失真模型作为信源模型;然后在帧层设计了一种基于PID控制器的缓存控制算法,即根据预测信道带宽和缓存器状态来分配每帧目标比特数,以提高缓存的控制能力;对于宏块层则在监控缓存器状态的同时,利用基于Cauchy分布的率失真模型,最后通过Lagrange方法来优化分配目标比特数。实验结果证明,该算法不仅能显著提高平均峰值信噪比,并能大幅减少跳帧数目。In this paper, we proposed an efficient joint source-channel rate control algorithm for real-time wireless video transmission which use automatic repeat request scheme to retransmission the error packet. The two-state Markov model was used to simulate the wireless channel, and the Cauchy-distribution-based rate and distortion model were used as the source model. In the new scheme, at frame level, a PID-controller-based buffer control algorithm was developed to improve the buffer control ability which allocated frame target bit based on the channel bandwidth and buffer status; at macroblock level, the frame bit-budget was distributed among macroblocks using the new rate-distortion model and Lagrange optimization method. Experimental results show that, the proposed algorithm can improve the average PSNR and decrease the number of skipped frames significantly.

关 键 词：无线视频传输 码率控制 MARKOV模型 率失真模型 Cauchy分布 

分 类 号：TN919.81[电子电信—通信与信息系统]