视频带宽

Firstly, the thesis introduced the development of VOD, the background and meaning of the program, then the author introduced the associated technology, mainly including the feature of multimedia, video compression technology and the protocols SCTP and RTP. Considering the ambulant of host , fluctuation of bandwidth,high error rate data in wireless networks ,the author proposed some QoS strategy in the wireless networks such as RTP/SCTP protocol stack , connection control of the server, two buffers in the client end point.,TFC congestion control algorithms ,etc. Based these strategies, the team members gives the software and hardware solution of the wireless video-on-demand system and gives the main modules design of the software system. The system adopted the C/S structure including two parts: server and client ,using the Mpeg-2 which is apporiate for networks as the supported format. The thesis emphatically researches on the video-serving module of the server and the sink module, player module of client.

本文首先介绍了视频点播系统的发展现状、课题的研究背景和意义；接着对课题的相关技术进行概述主要包括了多媒体特点，压缩技术，传输协议SCTP以及RTP；针对无线环境的节点移动性，带宽波动性，数据错误率高等三大特点，作者研究设计了无线环境下的QoS策略：RTP/SCTP协议栈，服务器准入控制机制，客户端双缓冲区，TFRC拥塞控制机制等；在这些策略的基础上设计了系统的软硬件解决方案，并对软件体系结构的主要模块进行了设计，整个视频点播系统采用C/S结构，由服务器，客户端2个部分组成，使用适合网络传输的流媒体格式Mpeg-2作为系统支持的格式，文中重点研究了服务器的视频服务模块以及客户端的接收模块和播放器模块，并利用线程池技术对系统进行实现。

However, most of the current wireless networks still work in low bandwidths, and mobile devices still suffer from weak computational power, short batt

但目前许多通信设备终端还无法进行像图像序列编解码这样高复杂度的计算，也无法显示传统解码后的24位真彩色视频，更致命的是传输带宽往往也无法提供高质量的流媒体传输服务。为此，本论文在传统H.26x和MPEG-x等视频编解码技

But the huge video data and limited network bandwidth are always choke point.

但是，视频数据量大和网络带宽有限一直是限制着视频监控网络化的瓶颈。

The main objective of this project is to research and develop a novel and high efficient video codec framework based on wavelet techniques, especially to address the heterogeneousness of video networks, the fluctuation of transmission bandwidth and the diversity of video-stream receivers. The system will have some basic characteristics of the next video coding standard, such as high compression efficiency, high scalability and high error resiliency. This project will provide a software prototype of wavelet video codec with full scalability, construct a verification platform for wavelet video on demand service, and furthermore, design some VLSI IP cores of the key module in the codec system

本项目研究的主要目的就是着眼于下一代视频编解码标准的基本特征（高效压缩，高可伸缩，高容错），以小波技术为核心构建新型高效的视频编解码系统；特别针对当前视频传输网络的异构性，网络带宽的波动性以及用户视频接收终端的多样性，实现一个码流高度可伸缩同时兼顾压缩效率的小波视频编解码软件原型，并且构建基于异构IP网络的小波视频服务的技术验证平台；进一步还将基于VLSI技术，对小波视频编解码系统的关键模块进行IP核设计

Based on careful analysis to the users' requirements of real-time interactive multi-view video service, this paper tackles several key practical technologies. To provide flexibility to special video snapshot decoding, the images from different views are predictively re-encoded based on the view correlation. Both the unicast and IP multicast techniques are employed in our system to provide interactive video service based on different system requirements.

然后本文根据系统开发的关键问题，对关键技术进行了深入研究，系统采用了transcoding实时编码技术以解决特效视频快照的解码效率问题；提出了分别基于单播和IP组播技术的系统交互策略，用以在不同应用环境下为用户提供可交互的多视角视频服务；提出了特效视频的automatic组播策略和on-demand组播策略，以达到高度可交互性与合理带宽占用的平衡。

Fast bandwidth for the application of the family, but also quite optimistic about the industry,"the development of broadband in the world's best countries - Japan's practice, to provide bandwidth for the bandwidth and then to develop more applications, In fact, as long as it is to provide high-speed data, voice, video services, reflect the triple play of services, users can bring."

对于百兆带宽下的家庭应用，也有业内人士颇为乐观，"以世界上发展宽带最好的国家--日本的做法来看，先提供带宽，然后再为这些带宽开发出更多的应用，事实上，只要是提供高速数据、语音、视频服务，体现三网融合的业务，就可以带来用户。"

Instead of prioritizing bandwidth allocation, users can inexpensively overprovision bandwidth when they need to support delay-sensitive traffic such as voice and video.

当用户需要支持对延迟敏感的流量，如声音和视频图象时，他们可以廉价地获得很大的带宽，而不用对带宽进行优先等级分配。

Instead of prioritizing bandwidth allocation, users can inexpensively overprovision band-width when they need to support delay-sensitive traffic such as voice and video.

当用户需要支持对延迟敏感的流量，如声音和视频图象时，他们可以廉价地获得很大的带宽，而不用对带宽进行优先等级分配。

Instead of prioritizing bandwidth allocation, users can inexpensively overprovision bandwidth when they need to support delay-sensitive traffic such as voice and video .

当用户需要支持对延迟敏感的流量，如声音和视频图形时，他们可以廉价地获得很大的带宽，而不用对带宽进行优先等级分配。

BACE algorithm has the desired property that does not reduce the encoding efficiency of the CABAC entropy encoder compared to the CIME algorithm for CAVLC entropy encoder. Both CIME and BACE algorithms can adapt to the content security level by choose the amount and different key parts of the video stream to be encrypted, the theoretical and experimental results show that both these algorithms can effectively encrypt the video content. Due to the ability of encrypting the video content without violating the syntax, the BIME and BACE algorithms can be employed used for many advanced H.264/AVC coding options without first decrypting the video stream, like Data Partition and UnEqualized Protection for the enhancement of transmission robustness, and the scalable coding in order to match the different channel capacity.

上述两种结合了H.264/AVC熵编码器特征的内容选择性加密算法，由于其加密后的视频码流的句法结构完全符合H.264/AVC视频编码标准，与传统的基于块数据的块加密算法相比较，本文提出的两种内容加密算法可以使得加密后码流在无需解密的情况下，实现H.264/AVC视频编码标准为移动视频应用而设计的诸多特性，如：增强传输鲁棒性的数据分割技术和非均衡保护技术，以及直接做匹配信道带宽的分级编码操作等，具有更高的灵活性和计算效率，从而可以灵活运用于各种应用场合。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。