Network Camera Hardware Platform Design And Research

IP camera is new generation equipment for visual surveillance. There are two normal kinds of architecture for IP camera system: ASIC+MCU based and DSP based system. The former is made up of an ASIC (Application Specific Integrated Circuit) within video encoder, and a MPU (Microprocessor Unit). It is easy to design, but the video compression algorithm is not able to update. The later can be implemented by a multi-media processor (a DSP designed for multi-media processing). It is more flexible and easy to update the algorithm. The programmable design method using multi-media processor is focused on in this paper.Around the IP camera system design based on multi-media processor, the paper is divided into three parts. In the first part, we introduce the implementation and the application of IP camera in nowadays, and summarize the normal methods of IP camera system design. We also detailedly describe the architecture of the TMS320DM642 based system.Secondly, we discuss all the function modules of the camera, including power module, start up configuration module, SDRAM and Flash memory module, CPLD logical control module, video capture module, audio transmission module, Ethernet and RS-485 communication module. We also discuss the key technology in high speed PCB design in theory and actual application.In the third part, we expound the means of board supporting software for IP camera, including the driver for hardware, the interpolation method of color in the image captured by CMOS image sensor, auto white balance and Y regulation algorithm. We also discuss the implementation of these algorithms to DM642.The paper adopts a system design approach based on multi-media processor, and therefore the design time is shortened. We use modularized design, so the architecture is reduced, and it is convenient for fix and debugging. The IP camera uses programmable multi-processor for implementing different function module to enhance the flexibility of system.