丢包网络中鲁棒的视频码率控制算法

Robust Video Rate Control Algorithm over Packet Loss Network

在率失真统计分析的基础上,提出了一种丢包网络中联合控制图像级量化参数和最佳宏块编码模式选择的优化算法.该算法克服了以往码率控制方法和误码复原技术互不关联的弊病,利用Lagrange数乘理论,在给定的受限码率下求得最优的图像量化参数和帧内刷新率,使得视频信源编码和信道传输总失真最小.实验结果表明,本算法能够获得比传统算法更高的性能增益.

This paper presented a statistics analysis of the picture distortion caused by quantization, channel errors and subsequent error propagation, and proposed rate-distortion estimation models which are functions of two parameters, i.e. quantization scale and intra refreshing ratio. Based on the proposed R-D models, a joint optimal quantization scale and intra refreshing ratio selection algorithm was developed by using Lagrange multiplier theory. Then it is integrated in this rate control scheme to minimize the overall picture distortion under bit rate constraint. The extensive simulation results show that the proposed algorithm can make the encoder adapting itself in time to the variation of the channel bandwidth, and significantly improve the video quality over packet loss network.