Study Of USB Video Capturing System Based On ARM

The video technology is used widely in the fields of medicine and sanitation, public security, video communication and so on. And the video signals can not be getted without a set of high-performance video capturing system. At the same time, video capturing is the basis of video processing, compressing and transmitting. At present the video capturing systems based on PC have lots of shortcomgings, such as large volume, high maintenance costs, not easy to extend and so on. But the embedded system which is developing quickly can solve these problems well. So the research on embedded video capturing system is full of practical value and meaning.Firstly, the development status of video capturing system and the advantage of USB transmission are introduced in this paper, and the system's design about USB video capturing system based on ARM processor is brought forward then. The system makes use of the dual-core processor development board OMAP3530-Mini produced by Beijing realtime science and technology CO. Ltd. as hardware platform, and chooses embedded Linux which is free available as the operating system. The application software implements these functions including video capturing and video displaying locally.Secondly, this paper builds the embeeded Linux development software platform for the OMAP3530-Mini development board. These steps include the establishment of the cross-compling environment, the transplant and compilation of Bootloader,the configuration and transplant of Linux kernel 2.6.22, the construction and transplant of JFFS2 root file system.Thirdly, the USB camera driver is designed on embedded Linux operating system in this paper. The USB camera driver is analyzed in two levels, including USB interface driver and device driver. And it is implemented finally in the framework of V4L2.Finally, the development process of the application software is research deeply in this paper, which includes the video capturing program, the video displaying program and Qt graphical user interface. The viedo capturing program captures video data from USB camera with V4L2 interface, and the video displaying program display the video data out. Then the two programs are combined together by graphical user interface program which is written with Qt to achieve the expectant purpose that the system gets the video data from the USB camera and displays it out.