【作者】 舒展；

【导师】 王宏远；

【作者基本信息】 华中科技大学 ， 通信与信息系统， 2006， 硕士

【摘要】 随着我国广电网络的数字化改造的逐步深入。对数字电视系统的监测越来越显得重要。而近年来,非法信号多次攻击广播电视卫星转发器,造成了许多不良影响。防止非法信号入侵也是广电系统很重视的一个部分。目前阻止非法信号入侵主要是在卫星地面站进行卫星信号的监测。而本文提出的DVB延时监测系统使得电视台前端能够防止非法信号的入侵与播出,是现有防范体系的一个很好的补充。本系统是基于对DVB的TS流分析的一个非法信号防范系统。能够实现多路TS流的实时监测和图像异常监测。并且具备模拟视音频输出和数字TS流输出接口。该系统具备延时播出功能,大大延长了出现问题后的反应时间。如果监测到卫星信号受到非法信号攻击,该系统可自动或手动将输出切换到备用节目源。延时监测系统的主要模块分为三个部分。第一部分是码流分析的监测和延时播出模块。文中重点介绍了码流分析的实现过程和延时播出技术。第二部分是多画处理模块,重点介绍了系统构成和静帧、黑场的检测。第三部分为通讯控制模块,文中对系统中定义的协议做了说明。实践证明,通过TS流监测来实现对非法信号的防范是完全可行的。本系统在实际测试过程中表现良好。在模拟多种不同故障情况下,DVB延时监测主机都有良好的表现。更多还原

【Abstract】 With the development of the Broadcasting & Video network, the Monitoring System on DVB(Digital Video Broadcasting) is becoming more and more important.In the recent years, some of the TV channels Broadcasted by satellite are attacked by unlawful signal. It is commonly prevent the unlawful signal from attacking on the RF(Radio Frequency) part in DVB system. The DVB Delaying Monitoring System is designed for the TV station’s broadcasting defending. It can block the forbidden information before it is broadcasted by the TV station devices.This system is a unlawful signal blocker based on the Transport Stream analysis. It can make realtime surveillance on several transport streams at the same time. It has anolog CVBS interface and Audio interface. The system also has the ASI(Asynchronous Serial Interface)for TS output. Once it has problems on the signal from satellites, the response time of the TV station can be prolonged when using the system, and it can change to the back program source automatically.The DVB Delaying Monitoring System has three main modules.The analys board is made for TS analysis and TS delay. The multi-pic board mixes the video signal from eight analys boards into one video and output. The freezing frame check and black screen check technology are used in this part. The control module is in charge of the communication and protocol translating.The TS analysis system has passed the test of NIM. It is helpful to the construction of the DVB security system.更多还原