基于CDMA2000 1X的H.264远程视频传输方案

介绍了基于CDMA2000 1X的视频远程传输的设计思想,结合当前领先的视频压缩标准H.264,分别介绍了系统硬件、硬件、网络结构等,对其中的关键技术进行了研究,并给出了远程网络传输控制策略。实验结果表明,该系统充分利用了CDMA传输带宽,达到了实时传输的要求。     

网络视频教学支撑系统的设计与实现

分析了教学环境中视频传输的特点,比较研究了纯软件、纯硬件和软硬件结合等当前的主要几种开发方案,在此基础上采用软硬件结合的方式设计实现了局域网视频教学支撑系统,并介绍了系统实现的关键技术--视频编码、视频传输和视频传输的控制技术.使用情况表明,该系统能够满足日常的教学需要.     

无线网络链路传输调度策略研究综述

无线网络链路传输调度策略确定各个时间槽内进行传输的链路集合,这些链路互不冲突,能够同时进行传输.对于当前的无线网络链路传输调度策略建立一个全面的了解有助于对无线网络的性能做出客观评估,并且成为网络设计的基本依据之一.文章总结了当前主流的无线网络链路传输调度策略,并且给出了这一领域的后续发展趋势和主要挑战.在具体的介绍过程中,本文重点介绍了基于吞吐量的调度策略、基于链路服务质量的调度策略、基于应用的服务策略,以及应对于在线视频传输的策略.在后续挑战的介绍中,文章主要归纳了基于应用的调度策略的实施前提要求和挑战.     

市级广电专用SDH传输网络的设计与建设

本文通过对宁德市广电专用SDH传输网络在设计和建设中必须考虑到的问题的介绍．讨论了在当前广电节目传输从模拟向数字过渡中SDH传输网络建设的要求、组网原则、设计方案、设备的选用等几方面的内容。     

卫星通信在因特网中的应用

因特网正在以迅猛的速度飞速发展，卫星作为一种重要的通信手段，其传输的因特网业务也日益增加。本针对卫星信道的长延时特点对TCP办议在卫星信道上的传输效率进行了分析，同时对当前的各种解决方案作了简单介绍，最后介绍了下一代卫星宽带多媒体网络。     

对数字有线电视传输工程常用技术的思考

电视信号传输技术经过几十年的发展,已经发生了翻天覆地的变化。其中有线电视传输技术从过去的电缆传输发展到光纤传输,无论在传播速度还是覆盖范围上都发生了质的飞跃,对人们精神文化生活水平的改善起到了积极促进作用。而随着人类信息传输技术的不断进步,未来数字有线电视传输领域也将会取得更多突破。本文介绍了当前数字有线电视传输工程中的相关技术及其具体应用,进而对其技术发展进行了展望。     

卫星宽带IP技术研究

卫星IP网络是当前研究的热点之一。进一步发展Internet业务需要增大带宽并且要有移动性,因而卫星网与IP网结合成了热门话题。TCP协议是TCP/IP协议栈的主要传输协议,它在网络中的传输效率是影响IP网络传输性能的关键因素之一。首先介绍卫星IP特点,针对卫星网的信道差错率高、传播延迟长和信道不对称等特点,对TCP协议在卫星网络中的传输性能进行了分析,提出了相应的改进措施。     

基于5G的超高清视频传输方案和应用场景研究

5G超高清视频传输是当前5G应用的重要场景,首先介绍了5G的特点以及媒体应用的场景。详细分析了5G超高清视频传输的技术方案和该技术方案对5G网络的技术要求。提出了两种典型媒体应用场景。最后对5G在新媒体领域的应用进行了展望。     

网上监控系统中音视频实时传输研究

通过对网络视频监控系统进行分析，对网络传输中音视频压缩、传输进行重点研究，提出了合理设计方案，介绍了在此基础上开发的一个网上考试监控系统。     

网络流媒体技术及应用

本介绍了网络流媒体服务系统构架及其组件，并阐述了应用于流媒体系统的各种技术，包括传输质量控制、防火墙穿透、网络传输与控制协议等，最后对当前网络上流行的三种流媒体服务系统做了比较。     

Bandwidth allocation strategies for transporting variable bit ratevideo traffic

Large-scale deployment and successful commercialization of digital video services over computer networks strongly depend on the cost effectiveness of these services. Network bandwidth is one of the major factors that impact the cost of a video service. We survey various approaches to reducing the bandwidth requirement for transporting compressed video traffic over high-speed networks     

城域网承载流媒体业务统计特征及承载建议

新一代基于SDH的城域网采用了GFP,VC,LCAS等技术以有效地传送数据业务,目前仍然是城域骨干网络的主流部署方案,但是新兴的以视频业务为代表的流媒体业务给整个城域网络系统带来了严峻的带宽和服务考验,通过对流媒体业务的分析提出了适当的流媒体业务模型,依据该流媒体业务模型分析了在不同的传输速率及数据源的条件下流媒体业务的流量特征,并以该分析为基础参考SDH的特点提出了一种城域网承载流媒体业务方案,最后分析了该方案的实用性.     

基于DSP的交通信息视频检测系统的设计

介绍了一种基于DSP的交通信息视频检测系统.该系统能实时采集道路上的视频信号,经DSP芯片实时处理得到用户需要的交通信息.详细叙述了其硬件结构和软件的设计方案,并阐述了信息检测程序的设计原理.     

IP与SDH结合的原理和实现

ＩＰ ｏｖｅｒ ＳＤＨ技术高速、简单,有效,是一种适应Ｉｎｔｅｒｎｅｔ骨干网上ＩＰ业务的新技术。介绍了ＳＤＨ上直接传送ＩＰ的技术背景和实现方法。     

交通路况视频采集系统的开发与应用

本文介绍河南广播电视台自主研发的交通路况视频采集系统的项目建设背景、技术方案以及实际应用等方面的情况,为交通类广播多媒体直播间提供了一种创新应用。     

基于ARM的视频采集与处理系统的开发

介绍了一种基于S3C2440硬件平台,在Linux 2.6.32内核操作系统下采用V4L2架构进行视频采集与处理的总体设计方案,通过移植开源的H.264视频编解码器对视频信号进行压缩编码,并采用RTP流媒体传输协议传输给客户端,完成对现场的网络视频监控任务。实验结果表明,该系统采集到的图像清晰,显示比较流畅,经H.264编码的视频帧数据量小,网络传输异常情况下的视频存储正常,可以适用于不同场合尤其是对带宽要求比较高的场合。     

Smoothing and transporting video in QoS IP networks

Real‐time traffic such as voice and video, when transported over the Internet, demand stringent quality of service (QoS) requirements. The current Internet as of today is still used as a best effort environment with no quality guarantees. An IP‐based Internet that supports different QoS requirements for different applications has been evolving for the past few years. Video streams are bursty in nature due to the instant variability of the video content being encoded. To help mitigate the transport of bursty video streams with minimal loss of information, rate‐adaptive shapers (RASs) are usually being used to reduce the burstiness and therefore help preserve the desired quality. When transporting video over a QoS IP network, each stream is classified under a specific traffic profile to which it must conform, to avoid packet loss and picture quality degradation. In this paper we study, evaluate and propose RASs for the transport of video over a QoS IP network. We utilize the encoding video parameters for choosing the appropriate configuration needed to support the real‐time transport of Variable Bit Rate (VBR) encoded video streams. The performance evaluation of the different RASs is based on the transport of MPEG‐4 video streams encoded as VBR. The performance is studied based on looking at the effect of various parameters associated with the RASs on the effectiveness of smoothing out the burstiness of video and minimizing the probability of packet loss. Copyright © 2005 John Wiley & Sons, Ltd.     

车辆视频监控系统的构建及设计要点

针对客：运/货运车辆的车载无线视频监控系统是车联网技术的一个发展方向,通过该系统,除了可以监控车辆的移动轨迹和运行情况外,还能够实时获取车内以及道路的音视频信息,对公交客运、交通管理、运政执法、银行押运等行业的支持尤为重要。针对移动多媒体数据流的传输问题从传输效率和传输质量这两方面进行了分析,介绍了一种车辆视频监控系统的组织架构,并针对设计要点进行了阐述。     

Lossless aggregation: a scheme for transmitting multiple stored VBRvideo streams over a shared communications channel without loss of imagequality

This paper introduces a new concept called lossless aggregation for the transmission of video information. It is a scheme for the delivery of variable bit-rate (VBR) video streams from a video server to a group of users over a shared channel. No data are dropped at the source during the adaptation process that reshapes the VBR video traffic to conform to the channel bit-rate characteristics. The transmission schedules of individual video streams evolve in a dynamic way that depends on their relative traffic characteristics. Receiver buffer underflow and overflow are prevented. Therefore, the data delivery process does not cause any loss of image quality. We show that very significant receiver-buffer reduction can be achieved with aggregation compared with the independent transmission of individual video streams over separate channels. Several bandwidth allocation methods for aggregation are studied extensively. The frame equalization algorithm stands out in terms of its simplicity and optimality     

Toward an improvement of H.264 video transmission over IEEE 802.11e through a cross-layer architecture

The recently developed H.264 video standard achieves efficient encoding over a bandwidth ranging from a few kilobits per second to several megabits per second. Hence, transporting H.264 video is expected to be an important component of many wireless multimedia services, such as video conferencing, real-time network gaming, and TV broadcasting. However, due to wireless channel characteristics and lack of QoS support, the basic 802.11-based channel access procedure is merely sufficient to deliver non-real-time traffic. The delivery should be augmented by appropriate mechanisms to better consider different QoS requirements and ultimately adjust the medium access parameters to the video data content characteristics. In this article we address H.264 wireless video transmission over IEEE 802.11 WLAN by proposing a robust cross-layer architecture that leverages the inherent H.264 error resilience tools (i.e., data partitioning); and the existing QoS-based IEEE 802.11e MAC protocol possibilities. The performances of the proposed architecture are extensively investigated by simulations. Results obtained indicate that compared to 802.11 and 802.11e, our cross-layer architecture allows graceful video degradation while minimizing the mean packet loss and end-to-end delays.