The Design And Implementation Of Embedded Video Surveillance System Based On3G

With the rapid development of information technology, embedded technology has become one of the largest technology hotspots in contemporary. Meanwhile, audio and video coding compression technology combined with network technology and multimedia technology has been more widely used in daily life. It makes long-distance transmission of large amounts of audio and video data become a reality. However, the traditional wired video surveillance at the time of long-distance transmission has some problems such as wiring difficulties, high cost and so on, which requires the introduction of3G technology to transmit video data. The development of3G networks is maturing, while more extensive coverage.3G technology combining with H.264encoding compression technology, can solve the problem of long-distance cable transmission such as wiring difficulties, high cost. And high-bandwidth3G networks can solve the problem of low transmission speed in2G network, and realize the real-time long-distance wireless video data transmission.This paper designs an embedded video surveillance system based on3G transmission, which uses client/server mode. Among them, the client-side is an embedded development board, which is surveillance terminal. The server-side is a computer with a fixed IP, which is the surveillance center. Surveillance terminal uses Video4Linux interface to acquire image, and encodes the image data with multi format codec to save bandwidth. Extracted from the encoded data, parameter set is repeatedly transmitted to the surveillance center to ensure proper decoding. Through3G module and using socket network programming, it transmits the image data by the WCDMA network from the client-side to the server-side. By image data packet division sent at regular intervals and packet reassembly in destination, it can make transmission more smoothly and reduce packet loss rate. After surveillance center receives the image data, it uses the FFMPEG library to decode the image and uses the SDL library to display the decoded image. Also, users can send control messages to control the surveillance terminal to work/pause.Firstly, the paper shows the composition of the hardware platform and the building process of the software platform. Secondly, a detailed discussion of the implementation of video capture and coding scheme is presented, mainly focusing on the camera driver added, using Video4Linux interface to capture images, the use of MFC for image compression coding by H.264standard, extraction parameters set and other key issues. And then, we discuss the implementation of client-side and server-side communications based on socket, the3G module dial-up Internet, image data packet division and reassembly, SMS control function,etc. And we show how to use FFMPEG library to decode received image data and to display the decoded image using SDL library. Finally, we evaluate the system as a whole by test. The test results show that the system can achieve the expected results and it can work properly.