| Video surveillance system is a hot topic in the monitoring field. It’s easily to be seen indaily life, such as examination, super market, cross road, ATM of the bank and so on. With therapid development of the mobile terminal, the video surveillance system has entered in thetime of networks.And wireless video surveillance system is highly praised by most users forits flexibility, easy to fix, cost effective etc. Now the wireless video surveillance system iswidely used in transportation, public security, fire fighting, scenic region. The research forwireless video surveillance has been hot for a long time. There are three main periods for thedevelopment of video surveillance system.It comes through from analog video surveillancesystem, based on the composition of PC to the embedded video surveillance system threemain periods. With the continuous progress of the technology, video surveillance system isdeveloping in the direction of wireless, intelligent, HD, digital, networks etc.Wireless video surveillance system is more convenient, for the tradition videosurveillance system has the trouble of arranging wires. The places where the system can beused are more flexible, not only can be used in fixed environment but also can be used inmobile environment such as automobile etc. Multi-channel video surveillance system widethe perspective of the monitor.More importantly, it can free the user from the boringsurveillance room. The monitor can hold the terminal and walk freely within the coveringrange of Wi-Fi.The wireless video surveillance system which the article talks about applies for the trendof the development of technology. And it’s the third generation of the video surveillancesystem. This system is based on ARM9S3C2440mirco processor. It is divided for three parts,including serval video collecting terminal and a monitoring terminal. Every video collectingterminal uses a camera to collect the video signal, and then sending the signal to the receivingend by the wireless network card. The receiving end can not only receive the multi-channelsignal but also can choose the specific channel to play in full screen mode.The user etiher can choose multi-channel mode or one channel mode. If somethingspecious happens, the terminal can be played in full screen and record in real-time for thechannel. It’s easy to change the channel of the system. The file management and the tool boxwhich are the assistant functions of the monitoring terminal can help the monitor to captureand record conveniently.In the future, we will realize to send the voice signal to the specificvideo collecting side either in multi-channel mode or one channel mode.You can see the picture collecting by the video collecting end at the receiving end in real-time. It is convenient for the monitor to collect and record the picture. Wireless videosurveillance system has a set of characteristics such as real-time, easy to erect the network,small voltage, easy to take, cost-effective and so on. The most important is that this systemcan free the monitor in the monitoring room. He can take the monitor terminal freely withinthe range of the network covers.This article makes analysis requirements on the video surveillance system, making thegeneral design for the system. It divides the modules and designs the hardware and softwareof the system. The system uses S3C2440A processor which is made by Samsung. Thisprocessor was based on the kernel of ARM920T, that is supported for32bit ARM and16bitThumb RISC. The memory includes64M SDRAM and a Flash which has1G Nand Flash and2M Nor Flash. The video collecting device is a CMOS camera with zc301chip. Thetransporting device is Ralink rt3070wireless network card and the screen is7’’ Turbo whichis a resistive touch screen LCD. According to its hardware structure and design the overallsoftware process, the article chooses embedded Linux as the operating system.Comparing with the main wireless transportation technology, we choose RTP/RTCP asthe transport protocol. The system realizes the function that is sending and receiving the videosignal. We apply for a method to use multi-thread technology at the receiving end, so it canreceive the signal from several video collecting terminals at the same time. We not onlyanalyse the function of the RTP/RTCP timestamp but also design the function which can testthe frame rate in the wireless video transportation. According to the frame rates which we testin one channel and multi-channel at different transportation ranges, we compare the framerates and analyse the reason why it changes.According to the requirements of the video surveillance system, I design the UI of themonitoring terminal for the system, choosing Qt as our UI development tool. We alsoconfigure the Qt-x11environment which is a version works on PC and Qt/Embedded which isa version works on embedded development board. After developing UI, we cross compile theprogram file and transplant it to the development board. At last we configure the rcS fileparameters to realize the auto start of the Qt UI program that we have made. Clicking thebutton of UI can change different function of the system. Because that the kernel2.6.29of thesystem has already support the camera and the LCD, and it doesn’t support the wirelessnetwork card Ralink rt3070. So we have to reconfigure the kernel2.6.29to make it supportfor Ralink rt3070. At last we transplant the kernel we have reconfigured to the developmentboard. |
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