Research On Digital Audio Public Broadcast System Based On JMF

Along with the rapid development of computer technology, multimedia technology and network technology, and the incessantly deepening to the intellectualization and informatization of building, audio technology used in building is now developing towards the field of intelligence, digitization and networking. Digital network audio technology refers to the technology used for amplifier system and public broadcasting to process, transmit and control audio all in digitization, by using internet and its relevant equipment (hardware and software). Digital network audio broadcasting could get rid of the disadvantage of traditional broadcasting system, which is difficult to manage, too complex and expensive for wiring, and too simplex in transmit mode. It has lots of advantages, which makes the wiring easy and flexible, the setting of wire extension more convenient, and plug and play at once. It is now becoming a hot topic in the audio transmission of intelligent building.After research on the recent technology of network broadcasting system, this paper puts forward the topic of digital audio public broadcasting based on JMF and begins the research on it. In this paper, broadcasting program of server is designed based on JMF from Sun Company, and the network terminals integrate into audio mode in the ARM-Linux platform. Streaming media is used in the whole system. Broadcasting program can transmit audio data at real time under the RTP protocol, and those data would be received by terminals and decoded to play.There are five chapters in this paper.Chapter one focuses on the limitation of traditional public broadcasting system in intelligent building, and extends to introduce the background and recent research status of digital audio public broadcasting system. This system has great advantage in practical use.Chapter two mainly explains some relevant knowledge of stream media, and roughly designs the working procedure of broadcasting program and network terminals. Chapter three analyses the support from Java Media Framework based on RTP protocol to achieve the real time transmit in network, and probe into the design of broadcasting program's function mode.Chapter four describes the hardware developing platform characteristic of network terminals, and introduces the transplant process of embedded Linux system on developing platform in detail.Chapter five introduces the debugging situation of broadcasting program and network terminal audio module in digital audio public broadcasting system, and goes further to explain the implement of network terminal based on the debugging result.