Study And Design On Embedded Wireless Video Monitoring Terminal

With the coming of information age, computer network technology and image processing technology and the rapid development of communication technology greatly continuously promoted the development of monitoring technology. Wireless video surveillance which has many advantages compared with the traditional wired one, had been widely used in various fields of social life. To meet the application needs of wireless video surveillance cameras in the helmets of the police, this paper study and design embedded wireless video monitoring terminal. it in-depth study the video surveillance capture, coding and transmission.Through in-depth study on embedded technology and digital imaging technology andwireless network transmission technology, a precept of wireless video surveillance systemdesign program based on PXA 255 is presented.This issue focuses on the the research anddesign of the monitoring terminal.In terms of hardware, select the ZC0301 camera, embeddeddevelopment board which based on PXA255 processor and CDMA modem according to theneeds of video surveillance capture, coding and transmission. The embedded Linux operatingsystem is selected as software platform. According to the hardware platform and embeddedLinux,the thesis build a wireless video surveillance hardware and software framework for theterminal, and build development environment, for example, building the cross-compilerdevelopment environment based on the embedded systems, analysing the Bootloader startprocess, the Bootloader transplantation, ARM-Linux kernel configuration and migration forPXA255 target board. The paper designes the video capture and transmission modulesaccording to application software: in-depth analysis the H.264 main modules, on which thehigher complexity of motion estimation and intra prediction algorithm is improved andoptimized to improve the coding efficiency, so that the encoder meet the needs of embeddedapplications, through the integration of collection and coding procedures and transplantationencoder and optimized for the PXA255 platform to complete video capture and compressionmodule design; to study the transmission control method based on RTP, to send and receivewireless video data by socket to completed the design of video transmission module; Finally,building test environment to analysis results of the encoder performance.The test results showed that in the hardware and software environment ,the design of the control terminal of the QCIF resolution video capture and encoding according to H.264 standard, the optimized encoder speed can reach 18 per second, the basic quasi-real-time results can be achieved. To achieve real-time video surveillance, it also depends on further optimization for the Xscale platform and uses higher performance processors and other means.