The Research And Development Of The Embedded Multimedia System Based On I.MX21

With the development of multimedia processing technology and embedded technology, the multimedia technology based on embedded system has been applied widely。The products, such as the CD players, automotive entertainment terminal and MP4 and so on, are typical application of embedded multimedia technology.Meanwhile. as result of the rapid development of network technology,The embedded multimedia transmission technology must be a good prospects for application and development.It can be widely used in image communications.video surveillance,Network streaming media and so on. Currently using technology to achieve the image embedded multimedia communications, video surveillance, video on demand and video conferencing and other functions has become a hot topic.This paper-based MC9328MX21 (i.MX21) processor and supports multi-purpose embedded Linux system development platform for embedded multimedia embedded systems research and development, focused on the use of embedded multimedia system, MPEG-4 Technical standards for hardware encoding and decoding methods and real-time transport protocol RTP (Realtime Transport Protocol) and real-time transmission control agreement RTCP (Realtime Transport Constrol Protocol) network transmission technology such as multimedia data transmission method. In the actual research and development process, mainly to complete the following tasks:(1) Analysis of the functional requirements of embedded multimedia systems, hardware and software architecture and key technologies, a multimedia-based i.MX21 embedded system architecture.(2) of the FFmpeg software-related technologies and platforms in the principles of the hardware module, in combination with hardware features, a FFmpeg software in the hardware encoding and decoding method, and in the actual environment to achieve the Code decoding methods.(3) MPEG-4 for the existing packaging strategy,analysis can be used as basis for calculating the priority VOP are two important factors (VOP location and content), made some improvements, and proposed future priorities to improve the specific calculation.(4) of the dynamic buffering strategies were discussed, proposed a new strategy for the adjustment of the buffer, and the strategy in details.(5) on the receiving end of dropped frames analyzed the situation, put forward a package priority based frame dropping strategy approach and method of real-time playback.Finally, the main work of this paper summarizes the main problems identified and proposed to improve the basic idea.