基于窄变带宽的实时视频传输算法

根据视频流与实时监视应用的特点,提出一种基于TCP协议的动态双缓冲与双线程视频实时传输算法。在发送方设置视频数据缓存与数据发送缓存,并分别由视频数据输入线程与视频数据发送线程负责管理;视频数据输入线程根据预设的最大等待发送时间与实时计算的网络传输速率,动态调节缓存的大小以及在网络拥塞时有选择性地丢弃视频帧;视频数据发送线程实现视频数据发送与按帧从视频数据缓存获取数据,并实时计算出网络数据传输速率。实验结果表明,本算法能最大限度地利用动态变化的网络带宽,保证视频实时发送至接收方与平稳播放,可有效地应用于窄变带宽网络环境下实时视频监视。     

MS网络中基于策略的QoS视频会话研究

为了检验基于策略QoS机制在IP多媒体系统（IMS）中对媒体会话发起的应用情况,在构建的IMS平台上提出视频会话系统方案．并分析了基于策略QoS机制的视频会话发起中存在的问题以及改进建议。     

IMS网络中基于策略的QoS视频会话研究

为了检验基于策略QoS机制在IP多媒体系统(IMS)中对媒体会话发起的应用情况,在构建的IMS平台上提出视频会话系统方案,并分析了基于策略QoS机制的视频会话发起中存在的问题以及改进建议.     

基于MapReduce的大规模流量分析系统的设计

随着用户和网络规模的快速扩大以及精细化运营需求的增加,网络流量分析系统面临的数据规模及分析深度要求都在快速发展,针对传统技术在系统扩展性、建设成本以及分析深度方面已经很难满足目前需求这一问题,提出了一种基于MapReduce 技术的大规模流量分析系统技术方案,对数据存储、数据分析全部并行化处理,消除传统系统存在的若干瓶颈。     

一种以音频为基准的视频捕获丢帧补偿算法的研究

针对视音频捕获回放过程中视频超前、音频滞后的现象，提出了一种以音频为基准的视频捕获丢帧补偿算法，其利用稳定的音频数据作为同步基准，在视频帧数据写入流媒体文件时进行丢帧补偿处理，从而保证视音频捕获的同步。本算法已在西安交通大学网络教育示范系统中得到了应用。应用表明，本算法较好地解决了视音频捕获同步问题。     

基于Nb/Mc口的话音质量评估研究

随着移动通信日益普及,用户对服务品质和性能的要求也越来越高。话音业务作为用户最基本的业务,是评价用户感知质量的最重要方面。如何客观评估话音质量,高效地发现现网话音业务中存在的问题,定位问题的产生原因,都是移动通信网络维护面临的新课题。本文研究的内容,就是通过分析现网的话音媒体流,对用户通话的质量进行评估,定位话音降质的故障原因及故障点,并使媒体流的分析能够结合实际工作的需要,提供与话音质量相关的核心网、无线网支撑服务,即研究网络改造解决新方案。     

一种在原始视频帧中嵌入的鲁棒的数字水印

该文提出的在原始视频帧中的扩频水印方案,使用二值图像作为水印,采用每帧索引的办法,并且利用相邻帧的统计相关性来嵌入水印。对于丢帧、帧重组以及共谋攻击有很强的鲁棒性。水印提取时不需要用到原始视频。文中对该方案进行了详细的介绍,并给出了仿真实验结果。     

一种以音频为基准的视频捕获丢帧补偿算法的研究

针对视音频捕获回放过程中视频超前、音频滞后的现象,提出了一种以音频为基准的视频捕获丢帧补偿算法,其利用稳定的音频数据作为同步基准,在视频帧数据写入流媒体文件时进行丢帧补偿处理,从而保证视音频捕获的同步.本算法已在西安交通大学网络教育示范系统中得到了应用.应用表明,本算法较好地解决了视音频捕获同步问题.     

一种以音频为基准的视频捕获丢帧补偿算法的研究

针对视音频捕获回放过程中视频超前、音频滞后的现象 ,提出了一种以音频为基准的视频捕获丢帧补偿算法 ,其利用稳定的音频数据作为同步基准 ,在视频帧数据写入流媒体文件时进行丢帧补偿处理 ,从而保证视音频捕获的同步。本算法已在西安交通大学网络教育示范系统中得到了应用。应用表明 ,本算法较好地解决了视音频捕获同步问题     

软件企业大规模敏捷策略研究

大规模敏捷开发是软件企业的重要改进方向。文章对大型软件开发的特点进行了分析,并比较了几种业界常见的大规模敏捷开发方法,结合实践经验,提出了一系列针对性的策略,将有助于软件企业成功实施大规模敏捷。     

Parallel Scalability of Video Decoders

An important question is whether emerging and future applications exhibit sufficient parallelism, in particular thread-level parallelism, to exploit the large numbers of cores future chip multiprocessors (CMPs) are expected to contain. As a case study we investigate the parallelism available in video decoders, an important application domain now and in the future. Specifically, we analyze the parallel scalability of the H.264 decoding process. First we discuss the data structures and dependencies of H.264 and show what types of parallelism it allows to be exploited. We also show that previously proposed parallelization strategies such as slice-level, frame-level, and intra-frame macroblock (MB) level parallelism, are not sufficiently scalable. Based on the observation that inter-frame dependencies have a limited spatial range we propose a new parallelization strategy, called Dynamic 3D-Wave. It allows certain MBs of consecutive frames to be decoded in parallel. Using this new strategy we analyze the limits to the available MB-level parallelism in H.264. Using real movie sequences we find a maximum MB parallelism ranging from 4000 to 7000. We also perform a case study to assess the practical value and possibilities of a highly parallelized H.264 application. The results show that H.264 exhibits sufficient parallelism to efficiently exploit the capabilities of future manycore CMPs.

一种基于H.264/AVC的空域分级编码方案

提出了一种基于H.264/AVC的空域分级视频编码器方案,给出的实验结果表明,和不采用分级编码的H.264/AVC编码器相比,该方案的增强层编码器可以降低视频传输所需带宽约20%～30%,计及传输基本层后,总比特率也仅比不分级的比特率约增加不到10%.     

基于视频分析的电视视频监测技术

本文分析了当前广播电视安全播出中违法信息监测的重要性,对基于视频分析的电视节目内容监控的关键技术进行了分析,提出了视频、文字、音频等分类处理的方法.保障了广播电视节目的安全、可靠传输,提高了广播电视安全播出工作效率.     

Interactive Content-aware Video Streaming System with Fine Granularity Scalability

Video streaming with varying transmission bandwidth is becoming increasingly important. In this paper, an interactive video streaming system is proposed. Fine Granularity Scalability (FGS) is applied to be the streaming video format. The computational complexity of FGS coding is analyzed to explore an efficient FGS implementation. A new transmission model is proposed for the realization of a content-aware video streaming. At encoder side, the current MPEG-4 FGS coding flow is reordered such that the picture-level maximum can be acquired in advance and bit-plane data can be dynamically adapted. With these proposed hardware-oriented optimization approaches, a hardwired FGS block-level processing core is proposed to achieve a cost-effective solution to FGS implementation. The streaming server can adaptively decide quality-enhanced region by selective enhancement according to both object information from encoding side and user-defined region from receiver side. From the simulation results, it’s demonstrated that the proposed approach can provide better quality in users’ interest regions with no bit-rate or complexity overhead. Yung-Chi Chang was born in Kaohsiung, Taiwan, R.O.C., in 1975. He received the B.S., M.S., and Ph.D. degrees from the Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, R.O.C., in 1998, 2000, and 2005, respectively. He serves as senior engineer in SoC Solutions Dept., Vivotek Inc. now. His research interests include video coding algorithms and VLSI architectures for image/video processing. Chih-Wei Hsu was born in Taipei, Taiwan, in 1979. He received the B.S.E.E and M.S.E.E degrees from National Taiwan University (NTU), Taipei, in 2001 and 2003, respectively. He joined MediaTek, Inc., Hsinchu, Taiwan, in 2003, where he develops integrated circuits related to multimedia coding standard and digital consumer devices. His research interests include video coding, video processing and VLSI design. Wei-Min Chao was born in Taoyuan, Taiwan, R.O.C., in 1977. He received the B.S. and M.S. degrees from the Department of Electronics Engineering, National Taiwan University in 2000 and 2002 separately. His research interests include video coding algorithms and VLSI architecture for image and video processing. Liang-Gee Chen was born in Yun-Lin, Taiwan, in 1956. He received the B.S., M.S., and Ph.D. degrees in electrical engineering from National Cheng Kung University, Tainan, Taiwan, in 1979, 1981, and 1986, respectively. He was an Instructor (1981–1986), and an Associate Professor (1986–1988) in the Department of Electrical Engineering, National Cheng Kung University. In the military service during 1987 to 1988, he was an Associate Professor in the Institute of Resource Management, Defense Management College. In 1988, he joined the Department of Electrical Engineering, National Taiwan University. During 1993 to 1994 he was a Visiting Consultant of DSP Research Department, AT&T Bell Lab, Murray Hill. In 1997, he was a visiting scholar of the Department of Electrical Engineering, University of Washington, Seattle. During 2001 to 2004, he was the first director of the Graduate Institute of Electronics Engineering (GIEE) in National Taiwan University (NTU). Currently, he is a Professor of the Department of Electrical Engineering and GIEE in NTU, Taipei, Taiwan. He is also the director of the Electronics and Optoelectronics Research Laboratories in Industrial Technology Research Institute, Hsinchu, Taiwan. His current research interests are DSP architecture design, video processor design, and video coding systems. Dr. Chen has served as an Associate Editor of IEEE Transactions on Circuits and Systems for Video Technology since 1996, as Associate Editor of IEEE Transactions on VLSI Systems since 1999, and as Associate Editor of IEEE Transactions on Circuits and Systems II since 2000. He has been the Associate Editor of the Journal of Circuits, Systems, and Signal Processing since 1999, and a Guest Editor for the Journal of Video Signal Processing Systems. He is also the Associate Editor of the Proceedings of the IEEE. He was the General Chairman of the 7th VLSI Design/CAD Symposium in 1995 and of the 1999 IEEE Workshop on Signal Processing Systems: Design and Implementation. He is the Past-Chair of Taipei Chapter of IEEE Circuits and Systems (CAS) Society, and is a member of the IEEE CAS Technical Committee of VLSI Systems and Applications, the Technical Committee of Visual Signal Processing and Communications, and the IEEE Signal Processing Technical Committee of Design and Implementation of SP Systems. He is the Chair-Elect of the IEEE CAS Technical Committee on Multimedia Systems and Applications. During 2001–2002, he served as a Distinguished Lecturer of the IEEE CAS Society. He received the Best Paper Award from the R.O.C. Computer Society in 1990 and 1994. Annually from 1991 to 1999, he received Long-Term (Acer) Paper Awards. In 1992, he received the Best Paper Award of the 1992 Asia-Pacific Conference on circuits and systems in the VLSI design track. In 1993, he received the Annual Paper Award of the Chinese Engineer Society. In 1996 and 2000, he received the Outstanding Research Award from the National Science Council, and in 2000, the Dragon Excellence Award from Acer. He is a member of Phi Tan Phi.     

基于Spark平台的NetFlow流量分析系统

目前典型的NetFlow分析系统多为基于私有架构或平台的第三方系统,面临扩展性较低、开放性不足、扩容代价大、分析时延长等问题.大数据技术的快速发展尤其是内存式计算平台如Spark的出现为集中处理大规模NetFlow数据提供了可能,本文提出了基于Spark的NetFlow分析系统,验证了核心算法(如流量应用构成统计)在Spark平台的性能.实验表明,基于Spark的NetFlow分析系统具有很高的性能和很强的扩展能力,较之Hadoop MapReduce有显著的性能提升.     

场论说对非线性网络回路电流法一般形式方程的推导

本文从场论说的对非线性网络中积分形式的两组最基本的独立方程组出发能严格和简练地推导出从非线性网络到线性网络的回路电流法的一般形式的状态方程,并给出回路自复阻抗和回路间互复阻抗与复阻抗之间包括正负号关系在内的普遍关系式.     

计算任务与体系结构匹配的异构计算可扩展性分析

 扩展性是衡量高性能并行系统的一个关键要素,而扩展性的研究主要集中在同构的高性能系统上,异构系统研究的文献很少. 本文以异构系统为研究对象,根据实际应用任务,将计算任务分为三类:单任务模型、元任务池模型和fork-join任务队列模型,并给出这三类计算任务的定义. 提出描述基于计算任务和体系结构相匹配的异构计算系统匹配矩阵,给出异构计算的可扩展性定义. 针对上述三种计算任务模型以及异构匹配给出异构系统的可扩展性条件,为异构系统的可扩展性提供了理论依据. 用实例分析证实了这种方法的有效性.     

基于ATM的MPLS域的可扩展性研究

MPLS是最成功地把IP和ATM融合到一起的技术之一.对基于ATM的MPLS域的扩展性进行研究,介绍了改善 MPLS网络扩展性的几种方法,并重点对VC合并机制进行讨论.     

基于光码的标记扩展性分析

基于光码的多协议标记交换(OC-GMPLS),利用光码分复用(OCDM)技术,将基于波长的标记交换(MPλS)粒度进行了细分,扩大了标记空间;而二维光码增加了一个自由度,扩大了码容量.提出了标记扩展性分析模型,分析了MPλS和OC-GMPLS的标记空间扩展性,并对OC-GMPLS中两种二维光码的标记空间扩展性进行了对比分析.仿真结果表明,OC-GMPLS大大扩展了标记空间,合理选择编码方式可以扩大标记空间.     

基于MATLAB的大规模电路稳态分析

借助于MATLAB语言强大的矩阵变换与运算功能,利用混合节点法编制含有理想电压源和受控源的大规模电路稳态分析程序。程序具有通用自由的输入格式和直观形象的输出形式,为大规模线性电路稳态分析提供了一个便利且有效的辅助工具。文章介绍了程序总体框图和编程要点,最后给出应用实例,经分析得到各节点电压和各支路电流,并给出相应的相量图和时域波形图。