The Research And The Realization Of Embedded Broadcast System Based On MPEG-4

The development of streaming media technology, network technology and embedded system technology renders streaming media player based on network and embedded systems possible, therefore, in the myriad of applications broadcasting technology of client and server serves as the new direction of people's research. This paper proposes a design scheme for streaming media play system based on wireless network on the basic of streaming media player. The significance is the research of the key technology system streaming media player based on wireless network, and research the specific applications based on the basic functions.This paper analysis of the current situation and development trend of the streaming media technology and embedded system technology, gives the progress and program in the field of embedded media player, and gives the conclusion that using the high embedded system realize software decoder and the feasibility and with the wireless network to advantage of the wireless network media play system and the necessity and significance of the research of the key technology.The paper introduces the standard MPEG-4 video decoder theory and the key technologies and familiar with the basic idea and the video codec algorithm, and also analysis of the key technology and process.On the basis of comparison of different programs,the paper chose the Intel Xscale architecture processor named PXA270 and uses it as the core to design the hardware of the system. This paper gives the overall structure of the system hardware and the details of external circuit interface and the connecting bus and designs the circuit of the memory, LCD, power management, wireless network. Then the paper gives the design of software process of the server and client including server management, the transmission, reception and client interface design, streaming decoding module based on the familiar with the embedded operating system The paper elaborats the part of the realization of video decoder and used the IPP library to optimize the system.and through the IPP function optimization, increase the efficiency of decoders realized and the system.The paper realizes the system by the test of software and hardware.At the end of the paper, the major function units of the measurement system are tested and validated, then presents a test method and explained the system adjusting process and finally gets the experimental achievements and reached the conclusion through analyzing. Through the data comparison,the paper gets the conclusion that the efficiency of decoder improved by nearly 50% and meet the design objectives.