The Design And Implementation Of Video Decoder In IPCAM System

Video monitoring systems has been widely used and deployed in variety cases in recent years. To enhance the performance and QoS of the video monitoring system further, a automatic machine-based video monitoring fashion, as a replacement of the traditional video monitoring scheme operated by man, has received much concern in both researcher's and industrial community. Nowadays, the video monitoring scheme has changed into network-based style from the conventional analog monitoring and digital-analog mixed monitoring. Among network-based monitoring schemes, IPCAM is a very promising one and has significant application prospects. IPCAM is composed of three parts:video decoder, video compressing, network transfer. The video decoder is the key component used to conduct A/D converting such that analog video signal can be converted into digital signal with the format of ITU-R BT.601/BT.656 in IPCAM.Based on the analysis of the traditional and modern video monitoring technologies, by researching the analog and digital video technologies, and also according to the system's applying environment, the thesis addresses the issues of video decoder in IPCAM and implements it in real systems. The thesis first reviews analog and digital video format standards, and then uses the standards to design the hardware of the video decoder. After that, according to the Linux 2.6 kernel criterion, a driver of video decoder module is developed to resolve the problems of IPCAM, i.e. converting the video signal format. Moreover, the thesis describes the principle and main functions of video decoder in detail, and proposes the architecture for video decoder and its driver. The testing results show that the presented hardware and software technologies can solve the existing problems in current video monitoring systems to a large extent.