The Design And Realization For Network Video Monitoring Machine Based On ARM

With the development of video monitoring technology, computer network technology, embedded technology, the video monitor has developed from analog video monitor to digital video monitor and now the digital video monitor based on embedded system.The network video monitoring machines based on embedded system were used widely for their features of small size, high reliability, low power consumption, and the convenience of carrying. Now it not only can be used for traditional monitoring areas such as community, office, supermarkets, but also can be used for the cross-regional remote video monitoring through the internet, such as remote child care and the remote unattended communication room monitoring.The title of this paper comes from a project named Content-Based Retrieval of Network Video Monitoring Machine .It is supported by the Development of Information Industry of Jilin Province. This project is an intelligent network video monitoring system based on embedded system.The function is detecting the moving objects and making recognition. In order to improve the resource utilization and the stability.It is necessary to transplant an operating system.The monitoring software running on the operating system has shown the merit of stability.At the same time it has shorten the development cycle of the software.It can be concluded that transplanting a simplified but stable operating system do a lot of things in the development of embedded system.This paper presents a network video monitoring machine proposal. This proposal adopt the the method of embedded system capture-embedded system monitor.This proposal of network video monitoring system presented in this paper take the mini2440 experimental board as the hardware platform .Then transplanting a simplified operating system onto the board. Furthermore we build the driver of LCD and the applications of network video monitoring machine.This paper introduces the process of constructing an embedded operating system and the development of driver and the application sequentially.This paper focuses on how to build a stable operating system.The process of constructing the embedded operating system can be divided into three parts.They are the transplantation of the Bootloader,the transplantation of the kernel and the construction of the filesystem.This paper selects the U-boot as the Bootloader after analyzed the function of the Bootloader and several kinds of Bootloader. This paper analyzed the constitution and the booting process of the U-boot in detail firstly, Then made some configuration and modification based on the configuration of smdk2410 in order to make the U-boot can be run on the mini2440 board.At the same time this paper introduce the modification of the driver of flash after study the operating principle of the SST39VF1601 NORFLASH.Then analyzed the modification of the U-boot in order to make the U-boot can be booted from the NORFLASH.This booting method can enhance the stability of the system.At last of the transplantion of U-boot this paper show the methods of adding the function of programming the yaffs1 filesystem and the NANDFLASH.The linux kernel is the most important part in the linux operating system, it provides the function of the device management.During the transplantation of the linux kernel.This paper analyzed the construction and the booting process of the linux kernel firstly.Then this paper show how to configure, simplify and modify linux kernel according the hardware platform in order to make it can be booted on the board successfully. Furthermore this paper gives the methods of adding the driver of the ZC301 Camera and the driver of wireless network card.At the same time this paper show the method of adding the yaffs1 file system.The file system is the carrier of applications in the embedded system.The embedded system is incomplete without a file system. There are two methods of constructing File system usually .The first one is cutting out an integrate file system until it meets our requirement.The second one is constructing file system from zero.This paper adopt the second method with the help of busybox.When the comannds have been made by the busybox this paper show the methods of adding the library file, configuration file and the device file until the file system can be mounted by kernel successfully.The most important part in the development of the embedded system is constructing operating system.It is easy to develop the driver and the application with the help of the operating system.After constructing an embedded operating system this paper analyze the framework and the operating principle of the driver of character firstly, then designed a new driver of LCD with the function of modification of the screensize dynamically after studying the principle of the LCD. This paper describes the application from two aspects.The first aspect is about the video capture. The second aspect is about the video data transmit.When it comes to the first aspect this paper show the method of video capture based on video4linux.In order to program easily this paper show the method of pakeage the function of Video4Linux.When researching the process of the video captures this paper anaylyzed the mechanism of Buffer queue. This mechanism can make the capturing and the transmitting video data simultaneously. It can make the client receive video data fluently.When it comes to the transmiting this paper adopt the the method of server/client mode.The server will be run on the embedded system.It will accept the request of the client and then capture the video data, transmit the video data to the client continuously. When it comes to the client this paper describe the method of requesting by the socket program and receiving the video data and displaying.This system make full use of SDL(Simple DirectMedia Layer) for efficiency and convenient. Simple DirectMedia Layer is a cross-platform multimedia library.This system makes use of the function of display only.The operating system, the driver of the LCD and the application have been completed according to the method this paper proposed.In order to test the stability of the system, Some tests have been done.The results of the test show that the network video monitoring machine based on ARM has achived the purpose of monitoring.But there is still a drawback.That is we cannot do some complex image processing on the server or the client.