采用DirectShow和IP组播技术定制音视频通信系统

本文基于Windows平台和面向对象编程技术,应用DirectShow软件开发包和Socket网络煽程技术,实现一个多媒体网络音视频通信系统.在网络传输方面,系统采用具有众多优点且目前使用最为广泛的IP组播技术.DirectShow和IP组播技术的使用,使得该系统具有开发周期短、程序结构良好、运行速度快、占用资源少等诸多优点.     

基于DM642的MPEG-4视频压缩PCI板卡的设计与实现

介绍了一种基于TITMS320DM642的4路MPEG-4视频压缩PCI板卡的设计与实现。分析了系统软硬件构成以及MPEG-4视频编码和优化。该板可以通过PCI总线直接与主机相连,将MPEG-4视频压缩流传输给主机,可方便地完成本地存储或远程传输,为实现远程视频监控提供了有效的硬件设备,有着广泛的应用前景。基于DM642的MPEG-4视频压缩PCI板卡的设计与实现@何泉$武汉大学电子信息学院研302班!湖北武汉430079 @熊炜$武汉大学电子信息学院研302班!湖北武汉430079     

DirectShow技术在网络视频压缩中的应用研究

在诸多视频压缩标准中,MPEG-4以其高压缩比和高性能倍受人们的青睐,成为网络视频应用中的主流视频压缩技术之一。在实际的应用研究中,考虑到MPEG-4算法的复杂性,本文依托VisualC＋＋的开发平台和Microsoft的Direct—Show技术,在DirectShow搭建的系统中加入DivX或XviDCodec编码器,来完成具有MPEG-4压缩功能的视频应用,既可以绕开MPEG-4复杂的算法,又可以取得很好的压缩效果,从而提高了开发的效率。     

基于MPEG-4的交互式多媒体设计

详细介绍了MPEG-4交互实现机制,针对MPEG-4基于对象编码可交互的特点设计了一个基于MPEG-4交互式多媒体系统的基本框架,并对该框架中的基本模块进行了详细的分析,最后利用DirectShow技术对各个组件进行了详细的设计.     

基于IP组播的网络电视播放技术

针对使用Tuner卡所附带的SDK或基于Video for Windows技术开发软件时依赖具体设备和成本高等问题,提出一种基于DirectShow和COM技术的网络电视播放系统。该系统采用IP组播技术实现数据的多点传输,节省了网络带宽资源,提高了数据传送的效率,并具有通用性。     

基DirectShow设计USB Source Filter

实现了在微软DirectX SDK基础上利用DirectShow和COM组件技术快速开发USB Source Filter。首先介绍了DirectShow体系结构和有关的USB知识,然后以USB Source Filter为例研究了如何开发DirectShow支持的Filter组件,以此为基础结合其它多媒体中间件即可快速构建远程监控、实时图像传输等流媒体系统。     

基于DirectShow设计USB Source Filter

实现了在微软DirectX SDK基础上利用DirectShow和COM组件技术快速开发USB Source Filter。首先介绍了DirectShow体系结构和有关的USB知识，然后以USB Source Filter为例研究了如何开发DirectShow支持的Filter组件，以此为基础结合其它多媒体中间件即可快速构建远程监控、实时图像传输等流媒体系统。     

基于DM642的视频压缩板卡的设计与实现

介绍了一种基于TI TMS320DM642的实时、4路MPEG-4视频压缩PCI板卡的设计与实现,对系统软硬件构成以及MPEG-4视频编码和优化进行了分析,试验结果表明该板卡可以实时对视频流进行压缩编码,并传输给主机,可以方便的完成本地存储或远程传输功能,为实现远程视频监控提供了有效的硬件支持。     

张鸿的VB教室（四）

Visual C#是微软公司推出的下一代程序开发语言,是微软,Net框架中的的一个重要组成部分,在推出Visual C#的过程中,微软公司还推出了与之相对应的一个软件开发包——Net FrameWork SDK。此软件开发包里面封装了许多类、对象。Visual C#就是通过调用这些类、对象来实现许多比较强大的功能。但是在Visual C#下没有像MFC直接     

基于DirectShow实现局域网实时视频传输

随着计算机网络和多媒体技术的发展,音频、视频等多媒体信息已在网络中越来越普遍,它们深深地影响了人们的生活。MPEG-4是时下一种流行的视频编解码模式,怎样在Intemet上实时地传输MPEG-4码流已经成为当前的一个热点;同样是未来网络方向的一个研究重点。文中在目前的视频传输系统的基础上,利用新的协议标准和传输方式来实现视频的实时传输,使传输的视频实时,没有马赛克。论文研究了DirectShow技术,分析了其体系结构的特点与组成,研究了利用DirectShow实现视频采集、压缩编码、网络传输以及解码播放技术,并给出了利用RTP／RTCP以及DirectShow实现MPEG-4视频数据的实时直播的方法和部分核心代码,有效地保证了高质量的实时视频传输。同时在应用程序内开发源Filter,简化了开发流程和程序的调试。测试证明系统有良好的网络适应性,视频经过传输后比较流畅,几乎没有马赛克。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.