【摘要】 根据无线信道的特点,提出了一种基于场景统计模型的联合信源信道编码和网络拥塞控制的多媒体鲁棒传输系统。首先进行场景统计模型和特性分析,采用MPEG-4分级编码将所有的层划分成几类,接着由码流对网络拥塞和重建视频质量的影响将其分成两个传输优先级队列。在传输过程中,依据信道误码率和网络丢包率进行自适应的信源不同保护等级编码和网络拥塞控制策略。试验数据表明,本方案与以前文献中提出的IPB等方案相比,能够明显的提高重建视频质量。更多还原

【Abstract】 Streaming video over wireless channel is a challenging task because the networks present not only packet losses,but also residual bit errors.These losses and errors have severe adverse effect on the reconstructed video.To solve this problem,we propose a new scheme combining source channel with source modeling and network congestion control.Based on the scene modeling and characteristic analysis,all layers encoded by MPEG-4 scalable coding are firstly classified into several types.Second,two queuing are made respectively according to their contribution to network congestion and the quality of reconstructed video.Then the source rate,protection level and congestion control strategy are dynamically adjusted according to different error status in which the packet loss is caused by network congestion or unreliable transmission in wireless channel.Finally,the experimental results show that the proposed scheme achieves performance improvement over the conventional schemes in wireless channel.更多还原