【作者】 张克新；

【导师】 谢胜利； 吴宗泽；

【作者基本信息】 华南理工大学 ， 信号与信息处理， 2012， 博士

【摘要】 可伸缩视频编码技术的发展为基于网络传输的视频应用带来了新的契机，随着网络规模的不断扩大，及网络上所承载的业务的多样化，互联网络固有的异构性及性能的动态变化性表现的愈发突出，与此同时加入网络中的终端也越来越多样化，这些都给基于网络传输的视频应用带来了挑战，传统的视频编码方案显然无法适应这种挑战，而可伸缩视频编码方案因其生成的码流具有多个截断点，能够根据具体的应用选取合适的码流进行传输，提供对异构网络和多样终端的适应性，得到了国内外众多学者的关注。本文首先分析现有视频传输系统所面临的问题，并对现有的可伸缩视频编码技术、立体视频编码技术、码率控制技术、网络带宽测量技术进行研究，进而提出所面临问题的解决方案，本文主要的创新点如下。1.提出一种完全可伸缩视频编码的实现方案，该方案实现了视频在时间维、质量维、空间维的分级编码，并根据平均运动矢量来判断视频序列的运动程度，进而采用相应的图像组结构，具有较强的实用价值。2.提出一种基于H.264/MVC的立体视频可伸缩编码方案，该方案充分考虑双目抑制效应，在现有立体视频编码标准H.264/MVC的基础上，对立体视频的左视点数据进行高质量的单层编码，而对视频的右视点数据进行分级编码，在尽可能保证视频立体效果的前提下，实现了对立体视频的可伸缩编码。3.提出一种新颖的适宜于H.264/SVC的码流选取方案，该方案根据码流片段所处的时间维层次及各时间维层次之间的依赖关系计算其时间维重要性系数，并根据码流片段所包含的不同频率系数来计算其质量维重要性系数，进而给出该该码流片段的重要性系数，最终根据目标码率和重要性系数排序结果选取特定的码流组合，实验结果表明，本文所提方案计算量较小，相较于H.264/SVC基本提取过程获得了性能的提高，尤其是在高码率的情况下。4.针对现有可用带宽测量机制的不足之处，提出一种快速准确的可用带宽测量方案，该方案通过测量一段媒体流由发送端到接收端所用的时间来获取前一个时间间隔的网络带宽，并采用基于高斯分布的预测模型预测下一个时刻的网络带宽，实验结果表明该方案能够在不影响当前媒体传输过程的情况下，快速准确地预测下一个时刻的网络带宽。5.提出一种适宜于家庭M2M网络的多媒体共享方案。该方案基于可伸缩视频编码，以适应网络和终端的差异性，采用家庭网关作为整个家庭网络的管理中心，并采用本文所提的带宽测量和预测机制来预测当前网络的可用带宽，实验结果表明本文所提方案解决了由网络异构性和终端多样性所带来的问题，实现了家庭M2M网络内部各个设备之间任意媒体信息的共享。更多还原

【Abstract】 The development of scalable video coding technology has brought new opportunities forvideo applications which are based on network transmission. With the continuous expansionof network scale and diversity of service provided in the network, the inherent heterogeneityof network becomes more prominent, at the same time more and more devices withdifferent hardware and software configuration join in the network, all of these bring greatchallenges to the traditional video transmission system, in this situation, the scalable videocoding scheme(SVC),in which the generated bit stream can be divided into base layer andenhancement layers, get the attention of many scholars at home and abroad.With SVC scheme,the appropriate multimedia data can be selected according to the network condition anddevice configuration, hence SVC can provide the ability to adapt to different machines andnetworks. In this thesis, firstly the problems of current video transmission system areanalyzed, then we study the SVC technology, stereo video coding technology, rate controltechnology and bandwidth measurement technology, at last the solution of the faced problemare given. The main innovations of this paper are summarized as follows.1. A full-scalable video coding system is realized, in the system, video can behierarchically coded in temporal, spatial and fidelity domain, at the same time, weuse average motion vectors to determine the movement of a video sequence, andthen adopt the suitable GOP structure to improve the coding efficiency.2. Scalable stereo video coding scheme based on H.264/MVC is proposed, the schemetakes full consideration of the binocular suppression theory, encodes the left view ofa stereoscopic video in single-layer, and the right view in multi-layers, generatesscalable stereoscopic bit stream, meanwhile maintains stereoscopic perception asgood as possible.3. Novel bit stream extraction strategy which is suitable for H.264/SVC is presented,the strategy calculates a weighting coefficient for each bit stream slice according toits temporal level and the contained DCT coefficients, then selects a particular combination of bit stream according to the weighting coefficient and target bit rate,Experimental results show that the proposed scheme can achieve qualityimprovement compared with the existing JSVM basic extractor,especially in highbit-rate situation.4. A fast and accurate available bandwidth measurement and prediction scheme isproposed, the scheme gets the available network bandwidth by measuring the timethat a piece of media data transmitted from server to client, then predicts theavailable bandwidth in the next moment according to the normal distributionprediction model, Experimental results show that the proposed scheme predictsavailable bandwidth quickly and accurately, and meanwhile has no influence on thetransmission of streaming media.5. Video sharing solution in home M2M networks is proposed. The solution is based onSVC, adopts home gateway as the home management center, and the availablebandwidth prediction scheme proposed in chapter5is employed to get the currentavailable bandwidth, the presented multimedia sharing system can effectively solvethe problems bring by various terminals and heterogeneous networks, and realize thesmooth sharing of multimedia in home M2M networks.更多还原