A Research And Realization For Video Signal Acquisition And Network Transmission System

With the rapid development of the network communication technology and multimedia technology,there is an increasing demand for video surveillance, and the application of video surveillance systems are increasingly being used. After the analog system of the first generation and the digital local system of the second generation, the video surveillance system is developing towards to the direction of embedded, digital, networking and intelligent.A network video signal acquisition and transmission system based on embedded system was designed by studying the previous video surveillance system and combining with the latest research focus.In this paper, a network video signal acquisition and transmission system was designed by studying and researching the theory of video signal processing and network transmission.The microprocessor mini2440 development platform based on Samsung S3C2440 was used as the embedded video server in the video image capture module. A USB webcam was used as the video capture device, and programmed the application of real-time video data acquisition based on V4L2, completed the function of converting the analog video signal to the the digital video signals of the MJPEG format.In the video network transmission control module, mjpg-streamer of the command line procedures was used as the core module of data processing, completed the function of converting the MJPEG format files to streaming media.Considering the application requirements of different users, the network transmission part of the paper was design as the wired network transmission and wireless network transmission. The client can moniter the dynamic image that are collected by the USB camera in a web browser via the internal wired and wireless LAN. After completing the design of the software and hardware of the system, a field test was made in the ATM combined with the demand for practical application,and every wireless signal strength was tested.The test results show that the development board and the client computers can communicate with each other by the wired and wireless LAN. The users can moniter the dynamic image that collected by the USB camera in a web browser,and the images transmitted through the wired LAN are much clearer than those through the wireless LAN.