Research And Implementation Of An Embedded High-Definition Video Processing Terminal In Vehicle

With the rapid development of the urban rail transportation and the increasing of people’s dependence on rail transportation, how to ensure passenger’s safety and provide a better service has become one of the main content of the subway work. As a security and service system which interacts with passengers directly, car multimedia information system bears the most important responsibility, the safety and stable operation of the subway. Video processing system, one of the most important systems of the car multimedia information system, is a direct play to provide high quality services for passengers and deal with and identify responsibility in emergency situations.Through the research of Beijing subway lines, we discovered that video processing terminal has common problems, easy to crash and offers low image clarity. The problems may be caused by the operating system’s stability and the image’s resolution. To settle problems above, this thesis proposed a new high-definition video processing terminal using Linux operating system. It implements the high-definition video monitoring function.Through the analysis of the current mainstream embedded video processor, the design decided to use TMS320DM368, one of the multi-core processor of TI’s Davinci series, as the main processor, and using Linux2.6.18as the operating system, using CMOS image sensor as the high-definition video capture device, using H.264as the codec algorithm, using720P or1080P as the system resolution. The design also reserve HDMI and chromatism component video display interface for future integration and expansion of high-definition video display system. This thesis focuses on the design of the terminal’s hardware and the kernel boot program. For the hardware, the thesis will detailedly analyze the design process of each module circuit and PCB drawing. The hardware includes the DM368small system, high-definition capture circuit, high-definition video display circuit, Ethernet communication circuit, SD card memory circuit, etc. For the PCB, this thesis shows the process of the design and drawing of the8-layer motherboard and4-layer interface board. For the software, the thesis focuses on the analysis of the modification and transplantation of UBL and U-boot source code using in kernel boot procedure. While the establishment of the system development environment, the start-up procedure and the transplantation of kernel are also introduced in the same chapter. Finally, we verified the correctness of the design by experimentation and completed the reserved function of720P or1080P high-definition video monitoring.