The Design And Implementation Of Vehicle Wireless Multimedia System

With the rapid development of China's economic and the improvement of people's standards, the automobile has been popular among Chinese people. Thus it directly leads to the growth of automotive electronics industry and attracts more and more attention of the industry. The ter- minal which integrates multiple functions and is easy-to-use and high- quality will become the development trend of automotive telematics and entertainment systems in the future.In this paper, a vehicle wireless multimedia system which is feature- rich and easy to expand is designed and realized. According to the research status and development trend of vehicle wireless multimedia system, a scheme which uses 32-bit MIPS processor Au1200 as the core of the hardware is designed, based on embedded Linux. The system is composed of multimedia processing module, memory module, network module and HCI module and equipped with a CMOS camera, a USB wireless LAN adapter, an IDE hard disk, a VGA monitor and speakers. It has multiple functions such as mass storage, audio and video playback, video surveillance and wireless transmission. Also it provides a graphical user interface for operational control.On this basis, the hardware, relative driver and application layer are designed subsequently. In terms of hardware, the circuit is parti- tioned into modules according to the performance and interface characte- ristics of Aul200. Also a wide range of common interfaces are provided to support the expansion and upgrade of the system, such as audio interface, USB port, SD card interface and VGA interface; In terms of driver, the main work is the realization of key driver and porting of wireless LAN adapter driver; With regards to application layer, it is divided into four modules, wireless network, multimedia playback, video surveillance and HCI. Wireless network module uses wireless LAN adapter to realize point- to-multipoint wireless transmission. The media player is designed based on the Au1200 MAE and MAI package. It supports multiple audio and video formats with clear and smooth image playback and good sound quality; The video surveillance module uses CMOS camera for video capture and FFmpeg software for compression and coding, and stores the data into hard disk. The storage capacity is up to 120G. The HCI module's GUI is designed with QT/E and acts in concert with keys. Thus the HCI is kind and easy to operate.The actual tests show that the program design and implementation of vehicle wireless multimedia system has a series of advantages, such as multi-functional, high-tech-combined, system-integrated and network- based. It is an integrated platform with independent intellectual pro- perty rights and strong scalability and could be functional reorganized for different users and manufacturers. The flexibility and convenience make it a good application prospect in transport systems such as railways, underground railways and passenger cars.