H . 264 iso iec 14496 - 10 avc . itu - t sg16 q . 6 vceg and iso iec jtc 1 sc 29 wg 11 mpeg , jvt - g050r1 , may 2003 , pattaya . 3 li r , zeng b , liou m l . a new three - step search algorithm for block motion estimation 为了降低运动估计的复杂度，研究者们已经提出了很多方法，例如三步搜索算法，基于块的梯度下降算法，钻石型搜索算法，六边形搜索算法，这些算法都基于这样一个假设:离起始搜索点越近，越有可能搜索到最佳运动矢量。
Simulation results show that both objective gains measured in psnr ( peak signal - to - noise ratio ) and visual improvements of reconstructed video can be achieved by utilizing introduced methods . chapter 5 gives the implementation of jvt - based nwarq technique 实验结果表明，各改进算法能不同程度地提高和改善重建图像的峰值信噪比( psnr )和主观质量；第五章研究、实现并测试了基于jvt视频编码标准的无等待arq技术。
In march 2003 , jvt ( joint video team ) of itu - t vceg ( video coding experts group ) & iso / iec mpeg ( motion picture experts group ) published a video compression coding international standard , which will be two identical standards : part 10 of iso / iec mpeg4 and itu - t h . 264 Itu - t的vceg和iso / iec的mpeg联合组成了jvt共同研究制定了新型视频压缩国际标准h . 264 ,于2003年3月正式发布。目前,对h . 264的研究与实现已经成为图像通信研究领域的一个热门课题。
In this paper , research on such video error recovery and concealment techniques as decoder - side error concealment ( ec ) and feedback - based retransmission without waiting ( nwarq ) is carried out based on the test modal reference software jm1 . 4 of the developing iso / iec mpeg and itu - t vceg video coding standard jvt ( joint video team ) 本论文以新一代视频压缩标准jvt ( jointvideoteam )测试模型jm1 . 4为基础，重点研究了视频差错恢复和掩盖技术，其中包括解码器端差错掩盖技术和基于编码器解码器交互的无等待arq技术。
Scalable video coding ( such as mpeg - 4 fgs and jvt svc ) and streaming is one of the most promising technologies . in this thesis , we investigate the key problem of scalable video coding and streaming : rate - distortion analysis and approximation , with which we also design some simple and effective smooth quality reconstruction algorithms of video streaming 本文主要的内容和创新点包括:由于广义高斯分布ggd ( generalizedgaussiandistribution )的高度灵活性,理论上和实际中它都可以非常好地描述离散余弦变换( dct )和小波变换( wavelettransform )的编码系数( transformcoefficients ) 。
In chapter 1 a brief introduction to problems resulting from video compression and transmission and solutions to the stated problems is addressed . detailed descriptions of jm1 . 4 ' s newly adopted algorithms are presented in chapter 2 . chapter 3 discusses various video error recovery and concealment techniques , including error resilient encoding schemes , receiver - side post - processing and several feedback - based error control techniques , etc . knowledge in these chapters forms the theoretical basis of our research 本文内容安排如下：第一章简要介绍了视频压缩带来的问题及相应的解决办法；第二章和第三章分别详细介绍了jvt视频编码标准中引进的新算法及目前视频差错恢复和掩盖技术的内容、方法和发展现状。
The itu - t and iso / iec are responsible for all previous international video compression standards . h . 264 / avc is the current video standardization project of the itu - t video coding experts group ( vceg ) and the iso / iec moving picture experts group ( mpeg ) . the main goals of this standardization effort are to develop a simple and straightforward video coding design , with enchnced compression performance 目前最新制定的视频编码标准是由iso和itu建立的联合视频工作组( jointvideoteam ,简称jvt )制定的jvt视频编码标准,它在iso中的正式名称是mpeg - 4标准的第十部分,在itu中的正式名称是h . 264 。
However , the complexity of h . 264 dramatically increases due to the adoption of a number of new video coding tools . how to cut down the complexity of h . 264 and make it be practical has been a popular issue . this paper study and improve motion estimation which is the most complexity component in video coding 论文在对视频编码原理和h . 264整体进行剖析的基础上,结合h . 264运动估计的新特性及jvt已采纳的两个快速搜索的提案f017和g016 ,对多参考帧与可变块搜索算法进行了优化。
In chapter 4 the emphasis of our research is mainly concentrated on ec technique . several theoretically useful improvements over current ec techniques " deficiencies are introduced , such as side matching , preprocessing and motion vector extrapolation , and search at decoder side is proposed . all methods presented in this chapter are implemented and tested based on modified jm1 . 4 codec of jvt 这些知识是进行本论文研究的基础；第四章重点研究解码器端差错掩盖技术，并针对目前差错掩盖技术本身存在的一些不足，引入了边框匹配sm 、预处理prep和运动向量外插mve ，提出了搜索search等相应的改进算法；然后以jm1 . 4为实验平台，实现并测试了这些改进算法。
