Design And Implementation Of Embedded Wireless Video Surveillance Equipment Based On

In today’s society, people gradually enhance security awareness.Bacause of urgent need for public safety, real-time video surveillance system has been widely used in every aspects of the social life, like road traffic, business management, district defend, campus monitoring, financial safeguard, etc. Nowadays, the most commonly used are digital cable monitoring system based on video server, whose signal sometimes was accessed the internet to facilitate remote monitoring for some special occasions. Operation of this video monitoring system is safe, stable, and image is clear. But it also brings some problems,like higher price, complex wiring, strong dependence on hardware, which restricted the popularity and application of the cable monitoring system to some extent.In recent years, data access methods have more options with the popularity of wireless communication method like Wifi,4G.Meanwhile,the design and implementation of video monitoring has have more options with the advance of embedded technology. Video-surveillance equipment is turning toward low-cost, smaller and easy installation direction develops, the laying position is not constrained by the harsh cabling requirements. These advantages just offer an ideal choice for some applications that has a moderate requirement to image quality, and has many installation nodes.This paper proposes and implements a design scheme of embedded video monitoring equipment, which integrating the image acquisition, data compression, and wireless network to a whole. Mobile devices can see real-time video images by Firefox over wifi connections.The system hardware platform adopts ARM developed board based on S3C2440 processor, with 64 M SDRAM and 256 M Nanndflash. We used the USB interface camera as video capturing equipment, USB interface Wifi card as wireless transmitting equipment.In relation to the software, using the open-source, cuttable linux as the system software.To simplify kernel and speed up execution, the author own write and optimize camera driver and Nandflash driver.Porting Uboot as the bootstrap, making root file system by busybox. For application layer, the task of data collection and transmission is completed by porting Mjpg-streamer, and in whose process video data is encoded as JPEG by libjpeg library. To solve the overloaded CPU problems caused by software compression, the author carried out optimization and innovation on discrete cosine transform(DCT)、 Huffman coding、quantitative criterion in JPEG coding algorithm.Testing result shows that the system runs stably, and real-time video imagery can be displayed crisply and reliably by smartphone or PC.If improved slightly, this device have generality certain promotional meaning when microprocessors and material have a whole generation switch, and that will certainly take a seat on the real-time video monitoring field.