Broadband Network Delivery of Interactive Digital Video Using ATM

The integrated digital multimedia video service can be delivered via different network media such as Hybrid Fiber Coax (HFC) and Fiber to the Curb (FTTC). Asynchronous Transfer Mode (ATM) can be used as an effective transport mechanism for the digital video services, such as MPEG-2. Both the lower layer physical network topology/characteristics and network protocols impose special technical constraints on the overall digital video system design.The system issues on network delivery of digital video discussed in this paper include: (1) Overall network impact and system protocol stack for HFC and FTTC video delivery; (2) Interactivity of digital video and its signaling; (3) Quality of Service (QoS) impact on digital video coding algorithm.Finally, the future directions on the networked video field are discussed and implementation choice and migration strategy are briefly analyzed.     

智能集成VBR MPEG视频流量预测模型

作为数字媒体网络视频通信的主要方式,VBR MPEG视频流量的预测能力是直接关系缓冲区设计、动态带宽分配及拥塞控制等提高网络服务质量的关键因素.因此针对MPEG视频流的复杂特性,充分利用人工智能方法的优势,提出并建立了基于模糊神经网络的智能集成VBR MPEG 视频流量预测模型.采用模糊预测模型提高预测精度,利用神经网络解决预测的实时性问题.实验结果表明,与标准AR预测模型相比,该模型预测的准确度和可靠性显著提高,且算法简单易于推广到其他方法中使用.     

新型DVI数字视频接口电路的研究

随着各种平板显示器的广泛应用,高画质视频接口技术的研究凸显重要.采用基于DVI接口解码芯片SiI161硬件电路设计方案,进行了高分辨率平板显示嚣视频接口电路的试验研究,实现了平板显示器可用高质量数字视频 数据的解码输出.该设计方案已在液晶显示器等接口电路系统中得到验证,为系统提供优质稳定的数字视频源,最高图像显示分辨率...     

重视IEEE1394技术在电视领域的应用

IEEE1394数据传输的开放式技术标准广泛应用于视音频领域，不仅支持数码相机、数字摄像机及数字录像机等设备，而且还应用于计算机网络互连和硬盘等方面。通过IEEE1394创建高速局域网络，能够进行声音、图像信息高质量的实时传送。应当重视推进IEEE1394技术在电视领域里的应用。     

基于嵌入式Linux与S3C2410平台的视频采集

针对数字网络视频监控系统的需求,设计一种基于MPEG-4网络视频服务器。使用基于MPG440的MPEG-4实时视频压缩卡压缩采集到的音视频数据,利用循环队列实现音视频数据的压缩,同时运用多线程技术以及传输机制解决网络数据的传输,从而有效克制了画面不清晰、音视频不同步、马赛克等现象,保证客户监看时音视频实时性和同步性。经过实验证明,该方案经济高效,可应用在多种需要音视频监控的场合。     

基于PXA270芯片的嵌入式数字视频采集系统

数字化的嵌入式视频采集系统成为当前视频采集的的主流。该嵌入式视频采集系统以Microsoft Windows CE 5.0操作系统和基于PXA270芯片的硬件平台为核心,实现了对现场的实时视频采集。系统在嵌入式端既可以进行视频的显示也可以进行图像的抓拍,同时视频数据在嵌入式端进行压缩之后通过局域网络传输到PC端,PC作为服务器端,在PC端的软件实现了对视频分析、存储和显示等功能。系统可广泛应用于视频监控的场合。     

视频会议系统音视频质量评价体系研究

音视频质量评价是视频会议系统建设的重点和难点,也是用户体验的关键点.分析了视频会议关键技术,系统梳理了影响音视频质量的各个环节,在此基础上提出了新的质量评价综合体系,将评价过程划分为网络编码码流、重建音视频流和会场音视频现场质量评价三个层次,供各级视频会议系统建设参考.     

一种基于NS的网络视频QoS分析方法

为了建立网络中视频传输的QoS分析平台,在分析EvalVid工具集的基础上,选取NS-2作为仿真环境,提出一种网络视频的QoS分析方法。该方法首先从视频流中提取仿真用的trace文件,注入模拟的网络中传输,然后利用结果trace文件将原压缩视频文件中由于传输丢失和延时超过限制的分组丢弃,产生新的视频文件,解码后可进行质量的评价。通过实例证实提出的方案完全可行,并可以作为设计与研究视频传输问题的试验平台。     

A hybrid architecture for analog video broadcast and B-ISDNservices in customer premises networks

The use of SCM (subcarrier multiplexing) transmission to deliver broadcast analog video signals within a CPN (customer premises network) as an overlay to an all-digital B-ISDN (broadband integrated services digital network) is considered. The feasibility of a proposal where the analog and digital signals are carried on different wavelengths is shown. An architecture for an optical CPN, termed H-Bus and incorporating emerging broadband SONET and ATM (asynchronous transfer mode) standards, is taken as a baseline for the delivery of switched digital, two-way voice, data, and video services. An optical overlay for the distribution of analog, broadcast video services using subcarrier multiplexing is considered. Several key alternatives associated with the delivery of broadcast video services are assessed, including signal quality, number of simultaneous channels, number of user terminals to be served, and modulation format. These issues are considered in terms of their impact on the interface with the public local exchange network and on the complexity, topology, and cost of the CPN     

基于PC104无人机网络视频系统的构建

无人机网络视频系统是无人机的重要组成部分,现在提出了一种基于PC104工控机的网络视频系统构建方案,从视频数据采集、压缩及传输等多个方面探讨无人机网络视频系统的构建过程并给出了网络视频系统主要部分的软件实现方案。最终实现了无人机网络视频系统的构建,实验结果表明,基于PC104无人机网络视频系统具有可靠的数据处理、传输、显示质量,可应用于监控、勘测等领域。     

Human motion quality assessment toward sophisticated sports scenes based on deeply-learned 3D CNN model

Video may be subject to various distortions during acquisition, processing, compression, storage, transmission, and reproduction, and it results in reduced visual quality. In complex sports scenes under big data environment, the human body's movements are even more so. The quality of human motion can intuitively affect the human visual experience. Therefore, it is necessary to determine an intelligent quality assessment model to evaluate human motion in complex motion scenarios under big data environment. It can be used to dynamically monitor and adjust video quality, and it can be used for algorithms and parameter settings in motion image processing systems. With the popularity of deep learning, convolutional neural networks have become a very important method in the field of computer vision research. Based on the 2D-CNN algorithm, we propose a 3D convolutional neural network model for human motion quality assessment in complex motion scenarios. The model captures the pose characteristics, motion trajectory, video brightness and contrast in time and space. The model feeds back the reference and distorted video pairs into the network, with each output layer acting as a feature map. The local similarity between the feature maps obtained from the reference video and the distorted video is then calculated and combined to obtain a global image quality score. Experiments show that the model can achieve competitive performance in big data environment for video quality assessment.     

Transmission of FDM wideband data and video channels over asingle-mode fibre using 1300 nm LED

The transmission of two frequency-division-multiplexed full motion network quality video channels and one digital ISDN-H1 channel over a repeaterless single-mode fibre in excess of eleven kilometres using a LED operating at 1300 nm wavelength is demonstrated. Transmitted video quality, and bit error rate performance of the digital channel are reported. Experimental system components and procedures are described in detail     

An evolvable ATM-based video network design supporting multipleaccess network technologies

This article describes an overall video network architecture with primary focus on the ATM subnetwork. The ATM subnetwork provides efficient switching capability for providing constant bit rate and variable bit rate video communication services. The ATM subnetwork can support multiple access networks like hybrid fiber coax (HFC), asymmetric digital subscriber line (ADSL), and fiber to the curb (FTTC). A broadband network controller is presented as the external controller for the ATM subnetwork which performs the functions of the session/network manager and the ATM-based connection management. The initial deployment of video is likely to be permanent virtual connection (PVC)-based, so a dynamic PVC-based scenario is described. The ATM switch architecture presented here has been optimized to support video applications. An evolution to the switched virtual connection environment and support of multiple services over the ATM subnetwork is also addressed. Traffic management schemes are discussed which provide the negotiated quality of service to the connections     

Advances in Efficient Resource Allocation for Packet-Based Real-Time Video Transmission

Multimedia applications involving the transmission of video over communication networks are rapidly increasing in popularity. Such applications can greatly benefit from adapting video coding parameters to network conditions as well as adapting network parameters to better support the application requirements. These two dimensions can both be viewed as allocating source and network resources to improve video quality. We highlight recent advances in optimal resource allocation for real-time video communications over unreliable and resource constrained communication channels. More specifically, we focus on point-to-point coding and delivery schemes in which the sequences are encoded on the fly. We present a high-level framework for resource-distortion optimization. The framework can be used for jointly considering factors across network layers, including source coding, channel resource allocation, and error concealment. For example, resources can take the form of transmission energy in a wireless channel, and transmission cost in a DiffServ-based Internet channel. This framework can be used to optimally trade off resource consumption with end-to-end video quality in packet-based video transmission. After giving an overview of this framework, we review recent work in two areas-energy efficient wireless video transmission and resource allocation for Internet-based applications.     

Scalable video transmission over multi-hop wireless networks with enhanced quality of experience using swarm intelligence

In this work, we take the advantages of the particle swarm optimization method which belongs to the family of swarm intelligence algorithms to find improved solutions for delivering digital video content with enhanced quality of experience to the end users over error-prone multi-hop wireless networks. In video transmission over such wireless networks, many network-based (packet loss, delay, etc.) and source-based (encoding quantization level, etc.) parameters can impair the perceived video quality. The main contributions of the proposed work are twofold. At first, an optimal bandwidth allocation framework is being developed based on the particle swarm optimization algorithm in which by incorporating an accurate video quality metric, the total weighted quality of experience of some competing video sources is being optimized. Secondly, these optimal rates have been used for differentiated quality of experience enforcement between multiple competing scalable video sources. The resulting optimal rates can be used as rate-feedbacks for on-line rate adaptation of a moderate scalable video encoder such as H.264/MPEG4 AVC. The aforementioned weight parameters are selected based on the importance of each video sequence's quality and can be associated with some previous service level agreement based prices. Some guidelines about the practical implementation of the proposed algorithm are given. Numerical analysis has been performed to validate the theoretical results and to verify the claims.     

高集成度H.261全数字化视频编解码系统的设计

介绍一个自行设计和研制的基于Ｈ．２６１的全数字化视频编解码系统。该系统采用了视频专用芯片、中规模ＰＬＤ芯片、虚拟缓存器控制策略，设计规模小，功能强，工作可靠，图象质量和视觉效果优良，可以方便地应用于数字视频领域中的各种场合。     

提高数字视频监控系统图像质量的技术措施

主要从视频图像的摄取、传输与再传输、处理、显示和回放等环节,讨论了摄像机、传输线、监视器和显示器等设备的选择以及视频图像的压缩、网络传输等关键问题,提出了一些相关技术和要求,保证了视频图像的高清晰、高品质,从而使数字视频监控系统的视频图像质量更佳。     

Traffic shaping, bandwidth allocation, and quality assessment forMPEG video distribution over broadband networks

This article provides an overview of residential video delivery systems and presents the applications, benefits, and challenges of using VBR MPEG video encoding in broadband video distribution networks. The network resources required to transmit stored variable-rate MPEG can be reduced by properly analyzing and smoothing the video stream before transmission. A scheduling technique is presented which selects a traffic contract for a pre-encoded MPEG video stream with the criteria of minimizing network resources and maintaining video quality. Several effective bandwidth metrics are discussed and used to model the potential savings in network resources for the shaped streams     

Alternative technologies and delivery systems for broadband ISDNaccess

Switched on-demand video is expected to become a major consumer of bandwidth. Two-way video offers televisting, tele-education, and telecommuting services, which together could represent a further substantial bandwidth demand. High-speed data services to provide the fiber distributed data interface (FDDI) between locations, or even operate a computer-aided design (CAD) terminal remotely from its local area network (LAN), are likely new applications for broadband integrated services digital networks (B-ISDN). The video quality evolution and digital modulation techniques that are making broadband digital delivery of TV signals possible are reviewed. Cable TV B-ISDN delivery, short twisted pair B-ISDN delivery, and TV broadcast digital delivery are discussed     

基于DM642的网络视频系统的设计与实现

为满足现代实时网络视频应用的需求,提出并实现了一种基于TI公司多媒体DSP芯片TMS320DM642的实时网络视频系统,给出了网络视频节点的硬件及软件的详细设计方案。结果证明,该系统能对视频图像进行实时压缩编码,并在各网络节点之间传输,且传榆速率稳定,图像质量可调,能满足现代各种实时监控系统的要求。