共查询到20条相似文献,搜索用时 140 毫秒
1.
数字视频监控系统的设计与实现 总被引:4,自引:1,他引:3
研制综合数字视频监控系统的主要目的是利用计算机处理音视频和各种传感器信号,帮助管理者有效控制防区,提高安全防范能力。介绍了数字视频监控系统的设计方案,从采集、传输到终端控制实现了全过程数字化。该系统能提供远程访问能力,视频资料管理保存方便,可靠性高,而且便于开发升级。 相似文献
2.
数字视频网络传输层协议的选择 总被引:4,自引:0,他引:4
随着视频压缩技术的日益成熟,数字视频监控产品逐渐成为了市场的主流。人们迫切希望网络技术能够成功地应用于数字视频监控领域,以使人们能够通过网络实现异地监控。正是在这种背景下,“基于网络的数字视频传输”课题研究日显重要。本文围绕网络视频传输的实时性和传输质量两大重要指标,从“解决传输层协议问题”入手,通过对TCP和RTP的比较,提出了“基于UDP协议的RTP实时视频传输”的设计思想,较好地保证了数字视频传输的实时性和服务质量。 相似文献
3.
4.
在DVB数字视频广播系统中,能够用Eb/N0或C/N来表征系统基本性能,介绍Eb/N0和C/N的概念,并描述Eb/N0与C/N的代数关系。 相似文献
5.
6.
7.
DVB概述 总被引:1,自引:1,他引:0
1引言数字视频广播(DigitalVideoBroadcasting,DVB)是一种基于MPEG-2的国际标准传输技术,它包含了HDTV在内多种数字电视格式的的广播和传输。欧洲DVB规划的范围可用图1来表示。信源编码和系统复用都遵循MPEG国际标准。信道编码则根据信道不同有卫星传输、有线传输、地面开路广播几种。由于将来的DVB业务趋向于付费电视方式,因此,DVB系统还需要一个高度可靠的有条件接收系统。2DVB中的信源和信道编码方式DVB包含了信源和信道两部分标准。MPEG-2信源编码采用MPEG-2标准,利用了人体视、听觉的生理特性,把图… 相似文献
8.
9.
文章给出了一种设计实时移动视频监控系统的方案。实时移动视频监控系统包括:控制中心监视子系统、车站监视子系统、车载子系统和传输子系统。文章首先从结构和功能两个方面阐述了各个子系统,然后从技术层面说明了实时移动视频监控系统的优越性。该系统在重庆轻轨中得到应用,并取得了较好的实际效果。 相似文献
10.
11.
12.
13.
14.
15.
16.
支持多模块的DVB通用接口的实现 总被引:1,自引:0,他引:1
具有支持多模块的DVB通用接口是机顶盒的必然趋势。介绍DVB通用接口标准,阐述接口中各层的功能,给出一个实现支持多模块的DVB—CI接口的实例及最后的测试结果。 相似文献
17.
DVB—H是数字视频广播(DVB)组织为通过地面数字广播网络向便携/手持终端提供移动多媒体业务所制订的最新标准。对DVB—H系统的构成、关键新技术、技术的试验情况及技术专利情况进行了分析。 相似文献
18.
Profit‐based exclusive‐or coding algorithm for data retransmission in DVB‐H with a recovery network
下载免费PDF全文
![点击此处可从《International Journal of Communication Systems》网站下载免费的PDF全文](/ch/ext_images/free.gif)
You‐Chiun Wang 《International Journal of Communication Systems》2015,28(9):1580-1597
The digital video broadcasting‐handheld (DVB‐H) standard is developed by European Telecommunications Standards Institute to broadcast digital videos to handheld devices, but data loss is a critical issue due to the broadcast behavior. On the other hand, DVB‐Internet protocol datacasting (DVB‐IPDC) integrates DVB‐H with an Internet protocol‐based wireless network to provide bidirectional communication. We adopt this wireless network to deal with data retransmission and call it a recovery network. The paper argues that network coding can improve retransmission efficiency of the recovery network because DVB‐H packet loss often exhibits high correlation. In addition, DVB‐H packets may be heterogeneous in the sense that they have different importance. According to these two arguments, the paper considers that DVB‐H packets are associated with different profit depending on their importance and proposes an α‐maximum profit network coding problem. It asks the base station in the recovery network to use no more than α coded packets for handheld devices to retrieve the lost DVB‐H packets such that the overall profit is the maximum. An efficient exclusive‐or coding scheme, namely the profit‐based exclusive‐or network coding (PEN) algorithm, is proposed to solve this problem. Extensive simulation results also verify the effectiveness of the PEN algorithm. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
19.
Hartmut Brandt Charbel Abdel Nour Nader Alagha Hans Peter Lexow 《International Journal of Satellite Communications and Networking》2014,32(1):49-59
The digital video broadcasting, return channel via satellite second generation (DVB‐RCS2) linear modulation scheme offers significantly better performance than that of the first generation (DVB‐RCS) both at the physical layer and at the link layer. The DVB‐RCS2 design allows for optimizing the link margin by implementing adaptive coding and modulation (ACM) in the return link, controlled by the central system controller, resembling the ACM as supported for the DVB‐S2‐based forward link. The gain of the return link ACM complements performance improvements at layers 1 and 2. The performance enhancement of the DVB‐RCS2 comes with a higher computational complexity compared with that of the DVB‐RCS but mainly at the gateway, whereas the computational load increase of the terminal is minimal. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献