基于异构网络的视频流数据传输

发布时间：2018-02-20 18:20

本文关键词： 视频流可靠路径视频传输负载均衡　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着网络速率的不断提高,在智能手机上各种视频相关应用不断出现,功能也越来越强大,对视频流的传输质量要求也越来越高。为了获得更高的传输质量,研究如何更有效地在异构网络上进行视频流传输显得十分必要。对视频质量的优化通常是从视频编码的角度进行的,而不关心视频流数据在网络中的具体传输情况。视频编码过后的I帧数据对视频质量有较大影响,因此在传输过程中保证I帧尽量完整地传输能够最大幅度提高视频传输质量。本文提出了RPS算法,用于在有多个约束条件的异构网络拓扑中找出最可靠的一条路径来保证I帧的可靠传输。算法主要以丢包率、延迟、数据速率三个因素为约束条件进行建模,并以丢包率为主要约束条件求解多约束条件最优路径选择问题。通过实验验证了在以丢包率为主要差别的不同路径上进行传输得到的视频质量会有较大差别,最大差别达到路径丢包率每增加一个百分点,会导致视频客观质量PSNR值下降最高约10dB。在当前复杂的网络拓扑中往往可以找到多条较可靠的路径。为了均衡地使用可靠路径更有效传输视频流数据,本文提出了IFPWRR算法。算法通过对视频流数据的帧类型加以区分,并按照I帧优先和每帧首数据包优先的原则,将数据包按丢包率加权分配到多条可靠路径上优化传输,保障视频解码过程中最重要的数据能够得到最完整地传输,同时也兼顾到了各路径上的负载均衡,并最终提高视频流传输质量。然后通过在三条不同质量的可靠路径上进行实验对比,证明IFPWRR算法比传统的轮循算法、配额算法更能提高视频的总体传输质量,幅度相比最高达20%。最后,本文结合RPS算法和IFPWRR算法设计并实现了一个基于ns-3的仿真系统,该系统能够在多个角度展现视频流在异构网络中的具体传输细节。
[Abstract]:With the improvement of network rate, various video related applications on smart phones are emerging, the functions are becoming more and more powerful, and the quality of video stream transmission is becoming more and more high. It is necessary to study how to transmit video stream more effectively over heterogeneous networks. The optimization of video quality is usually carried out from the point of view of video coding. I frame data after video coding has great influence on video quality. Therefore, in the process of transmission, I frame can be transmitted as completely as possible to improve the video transmission quality. In this paper, RPS algorithm is proposed. This algorithm is used to find the most reliable path in heterogeneous network topology with multiple constraints to guarantee the reliable transmission of I frame. The algorithm is modeled with three constraints: packet loss rate, delay and data rate. With packet loss rate as the main constraint condition, the optimal path selection problem with multiple constraints is solved. The experimental results show that the quality of video transmitted on different paths with packet loss rate as the main difference will be quite different. The biggest difference is that for each increase in the path packet loss rate, The objective quality of video can be reduced by up to 10 dB. More reliable paths can be found in the current complex network topology. In this paper, IFPWRR algorithm is proposed. The algorithm distinguishes the frame types of video stream data, and according to the principle of I frame priority and the first packet priority of each frame, the packets are allocated to multiple reliable paths weighted by packet loss rate. To ensure that the most important data in the video decoding process can be transmitted in the most complete way, and at the same time, the load balance on each path is also taken into account. Finally, the transmission quality of video stream is improved. Then, by comparing three reliable paths with different quality, it is proved that IFPWRR algorithm can improve the overall quality of video transmission better than the traditional role-based algorithm, and the quota algorithm can improve the overall quality of video transmission. At last, this paper designs and implements a simulation system based on ns-3 combined with RPS algorithm and IFPWRR algorithm. The system can display the details of video stream transmission in heterogeneous network from many angles.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.8

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