在没有服务质量保证的无线传输环境中,按照传统视频编码标准压缩的码流很容易遭到破坏,这在Ⅰ帧中尤为突出.因此需要对传统视频压缩标准加以改进以提高在无线传输环境中的自身容错性能.针对这一问题提出了一种用于提高视频流Ⅰ帧容错能力的算法.该算法首先对视频流中不同部分对发生在自身的码位错误所引起误差传播的敏感度进行分析,然后以此分析结果和Ⅰ帧重建中码流信息的不同重要性作为决定Ⅰ帧码流中重要信息的原则,最终通过对这些Ⅰ帧中的重要信息加以保护、提取和集中,以减少发生帧内误差传播范围.通过H.263+baseline测试码流在加性高斯白噪声无线信道仿真实验的结果可以证明,该算法在增加少量冗余信息和计算复杂度的情况下,相比参考算法在主观和客观质量上都有较大幅度的提高.

In wireless environment without assurance of quality of service, the video stream compressed by conventional video compress standards is vulnerable, especially in intra coded frame. So it is necessary to make modification on structure of conventional video stream in order to enhance its error resilience performance inwireless environment. In this paper, one method is proposed to improve robustness of intra coded frame in wireless transmission, it firstly analyze the sensitivity to error propagation of different segment in video stream when there are channelbit errors. And thenwith this analysis results and respective role of different segments of video stream on reconstruction of intra coded frame, important information for intra coded frame is determined. Finally, the proposed method exploits protection, extraction and aggregation of determined important information in intra coded frame tomitigate the extent of error propagation inside frame reference on traditional data partition error resilience algorithms. Experimental resultswithH. 263+ baseline tested stream through addictive Gauss white noisewireless channel show that the proposed method outperforms reference method in subjective and objective quality obviously with little increasing of coding overhead and computation.