Design Of Vehicle Mounted Video Broadcast System

With the continues development and improvement of automotive electronics technology, Electronic information technology automotive information entertainment systems, such as audio, video, navigation and telemetry become hot issues problems in today's research. This paper focuses on researching on the automotive video systems'relative theory and designing methods.To automotive video systems, the main problems to be solved are the large requisite storage room and clear video image owing to high-speed steering and long-time steering. Through the compare of existing automotive video systems, a highly clear video system based on embedded system is presented. On the basis of detailed analyzing the video data DCT advanced data compression arithmetic and MPEG4/H.264 standard, the design of the automotive video systems'hardware structure and software task flow are conveyed. In the facet of hardware design, microprocessor (ARM) of Philip Company is adopted as the main controller, realizing the video decode, cache and LCD display control. In the part of video decode, chip SAA7111A is adopted to decode the video image signal, enhancing the speed of image display. Based on the large required to car video system data, using advanced DCT compression arithmetic, embedded to the software of car video system, stored area of the large number of data is returned, which is broke the bottleneck of the playing speed. The format standard of H.264 in MPEG4 is adopted in designing software ,based on the consideration the definition of graph in car video system. The picture is clearly showed by TFT LCD screen.In the process of designing the application software,at the same time ,the resources of system is rationally allocated. combination with the reasonable procedure structure , effectively preventing the system inefficient, sharing conflict, and the termination of task and the system crashed, it is sure that system is real-time, efficient, reliable work.