Powerpc-based Embedded Linux Video Surveillance Network System Design And Development,

Based on Linux platform on POWER, an embedded video capture and monitor network system in client/server architecture is designed and discussed in this thesis. As key parts in the project, the realization of server end programs, the shifting operating environment from Windows to Linux and Embedded Linux, and the porting of applications from x86 platform to a different hardware architecture POWER are mainly studied in detail. The system performs major functions as follows: firstly, the server end on embedded Linux captures the video signals via a special video capture card, and the card encodes and compresses the video data according to MPEG4 standard;secondly, the compressed data are transmitted through the network on TCP/IP protocol to the client end programs;finally, the software in the client end reads the information source from the network, decodes the compressed data and displays the video information in the screen.In the thesis, the whole design of the system architecture is particularly discussed, including the essential hardware support and the design of the client end, server end, software interface, and installation program for applications. Furthermore, the changing developing environment on embedded Linux is studied on the one hand, and the differences of porting applications between x86 and POWER architectures are emphasized on the other hand, both of which are discussed combining our current project accomplished successfully. In addition, the performance of the system in simulation test is provided in the thesis. The entire system combines advanced techniques, such as the MPEG4 standard, the Directshow programming, and the especially chosen platform of embedded Linux. Testing results demonstrate that the system designed and realized in the thesis can not only arrive at a satisfying frame rate at 45 fps, but also render wonderful pictures that accord with the video quality of national highest digital harddisk video recording standard Dl(704×576pixel), performing excellently when capturing all the close, medium and distant scene, or monitoring both still and moving objects. In a word, this subject is quite worth studying and has great significance.