S3C2410-based Wireless Video Surveillance System

In recent years, embedded multimedia technology and network communication technology developed very quickly,and video applications based on embedded are more and more widely.The development in the field of multimedia video monitoring has experienced three stages.They are local analog video surveillance systems , PC-based video surveillance systems and embedded technology-based remote multimedia surveillance systems. What restricts its development of traditional wired video surveillance is high costs, poor mobility, the construction cycle length and other factors. Wireless Video Surveillance System, with its unique advantages of wireless transmission, breaks the transmission constraints of cable and optical fiber and becomes the mainstream market of video surveillance system. Under the background of the data transmission information growing wirelessly, wireless network technology in computer networks has become a critical component of wireless technology applications , and the field of wireless network technology application is growing rapidly , showing a gradual trend to replace the wired network. At the same time, with the continuous development of embedded technology, application of embedded system make monitoring systems have greater functionality, higher flexibility and better usability. Based on embedded technology, multimedia remote monitoring system will combine embedded technology and multimedia technology effectively to solve a PC-based multimedia monitoring systems that have problems such as complex structure, stability, low reliability, high cost, cumbersome operation and so on.In the embedded field, as, the embedded operating system which is the core of embedded systems is the key to the development of embedded applications. Linux system becomes the mainstream of the embedded operating system because of its open source code and hardware platforms supporting, powerful features of network characteristics. Relied on the linux open sources and free softwares, this paper trys to give a solution to design a wireless network monitoring systems for general using.As the representative in the ARM9 family of processors , S3C2410 has a relatively stable framework, the development of sophisticated technology and has advantages to collect data and information.S3C2410 is the preferred development platform of video monitoring system.Due to the above-mentioned advantages of ARM9 processor, this system uses the S3C2410 processor as the system-core processors of wireless video surveillance system.In accordance with the characteristics of wireless video surveillance system, this paper have studied the demand for surveillance systems and functions, divided the system function modules and summed up the specific functions of each module. By analyzing the working principle and work flow the paper determine the basic framework and specific programs of the system. The overall structure of the system has two major components: video image capture, video client and the receiving terminal such as the user platform. These two parts make connection with the wireless transmission protocol. Video capture client is responsible for collecting real-time camera to capture video data, storing the image data in memory, at the same time making encoded treatment, and sed to the receiver. Video image receiver will receive the video data , then decode into a original video and display on LCD monitor. According to the module, the system is divided into three modules.That is video capture module, wireless data transmission module and video data processing and display module.Main function of video image acquisition module is responsible for capturing the image data through camera or video capture cards and other hardware equipment. Then convert the analog signals to digital signals through ADC and store it in memory. USB camera and embedded processors are the composition of Video image acquisition module. USB camera is responsible for image data acquisition, while embedded processor is responsible for controlling the job status of video capture device. At the same time through data interface the video stream data collected will be encoded for network transmission. Based on Video4Linux which is compiled in the pattern of build-in or module in the linux kernel for video and radio program, this paper gives the flow chart of video image acquisition, the preparation of the image data acquisition procedures and implement the function of continuous frame capture. Video coding algorithm is MPEG-4 compression standard. Using the ffmpeg encoder to achieve data-encoding. ffmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes the leading audio/video codec library.Through camera equipment, images are compressed by ffmpeg for MPEG-4 video streaming. In order to achieve the purpose of remote monitoring and control, the system should take advantage of wireless networks. Through the Real-time Transport Protocol (RTP) and Real-time Transport Control Protocol (RTCP), wireless data transmission module provides real-time data transmission and Qos network services to meet requirements of delay and loss of packet. RTP is the best way to solve the problem of real-time transmission. This wireless transmission module used JRTPLBI library to achieve sending and receiving the wireless video streaming.Function of video data processing and display module is to store the MPEG-4 video streaming received in embedded FLASH memory or removable storage devices, decode video streams by ffmpeg + SDL decoder, and then displaye the video on the LCD screen. SDL is a cross-platform multimedia library, provides a simple API to draw graphics on the screen, and output video image. This system uses UP-NETARM2410-S experimental development platform as a video display terminal ,video processor is S3C2410, which is responsible for converting the compressed video data through the decoding algorithm into original image.Based on embedded hardware platforms and Linux development environment, wireless video surveillance system uses SAMSUNG S3C2410 processor as a standard platform support Linux,. Just to make easy changes to the kernel and configuration without other patch, the system can run very well on the goal board S3C2410. First of all set up embedded cross compiler environment, install cross compiler tools; transplant Linux2.6.14 core on the development platform. The main change to kernel is to add the information of NAND Flash. And make linux configuration properly. Finally create root file system for embedded linux, burn it to S3C2410 platform so that complete the system.This paper focused on functional requirements, the overall framework and hardware components of wireless video monitoring system. Make module division of the system, sum up the specific functions of each module, and provide system solutions. Using existing equipment to implement the program, this paper completed the basic functions of each module, and verified the feasibility of the program.It provides a reference for in-depth study on wireless video monitoring system research.