| With the development and progress of society, there has been an increasingly strong demand for security technology. The video surveillance system has been widely used in various fields, due to its accuracy, visualization and high efficiency. Traditional video surveillance system mostly adopts wired network, with complicated structures, poor mobility and high cost. With the take-off of network techniques and embedded technology, the video surveillance system has been miniaturized with the application of wireless network and reliable embedded technology.After an analysis of the future development and application prospect of the video surveillance system, this paper has put forward the general structure scheme of the system and designed a wireless video surveillance system by applying WIFI and embedded technologies.The hardware structure of the system expands the OV7740 CMOS camera, AR9271 WIFI network card and other peripheral equipment, with the S3C2440 A microprocessor as the core of hardware platform. The embedded Linux operating system has been chosen as the software platform. The main tasks of this paper are:(1)Setting up system development environment: such as building a cross-compiler environment, transplanting U-Boot, configuring and transplanting Linux kernel as well as building root file system; replacing both the NIC driver that comes with the original kernel and the LCD driver to support the system devices; building the virtual machine, the development board and the computer to ensure the transfer of data among the three.(2)The design of the application program: completing the procedure of video capture module based on the API interface function of V4L2 module; installing dhcp and hostapd and setting relevant configuration file to make the WIFI network card enter the AP mode, designing the script which enables the WIFI network card to enter self-starting mode; designing the framework of MJPG-streamer and transplanting the video server of MJPG-streamer, and then transmit the video images to the mobile phone via TCP/IP network protocol. Real-time monitoring of video images could be realized as long as the user enters the IP address through the mobile browser.The wireless video surveillance system based on ARM9+LINUX was tested in this paper, and the result showed that within 60 m on an open ground or 15 m with 3 walls in-between, the fluency and stability of the video data transmission as well as the clarity of the images are not affected. Therefore the design goal has been achieved and the design requirements have been met. |
