Research On Digitization Terminal Of Audio Broadcast System Based On IP Network In Intelligent Building

The developments of intelligent buildings and networks have brought great impact on the tradition audio processing and transmission. Digital audio signal process gradually takes the place of the analog audio signal process and turn into mainstream. Because the tradition audio transmitting network has shortcomings such as hard to manage, complicated fabric, difficult to realize auto-switching, the digital networks will be the future of the audio networks with no doubt.This paper according to the development tendency of the intelligent building broadcast system, proposed one kind of new intelligence broadcast system, and emphasizes the design and development of this system digitized terminal. The terminal uses embedded processor ARM and Linux system to decode and play back MPEG audio. The, terminal has good performance on real-time and stability, it can the utilized on the broadcast system efficiently.The paper divides into five parts.In chapter 1, it introduces the background and the present situation of broadcast system of intelligent building, and the advantage of broadcast system based on network transmission.In chapter 2, it describes the design of the hardware of the terminal, and porting process of embedded Linux from u-boot, the compile and configurations of kernel, file system and so on in detail.Chapter 3 is the introduction about the Embedded Linux device driver, especially on the programming of audio device. Then it analyses the UDA1341 driver in detail. In chapter 4, it introduces the basic principle of MPEG encoding and decoding. According to the principle, decoding process and algorithms were described, and some optimize measures for ARM embedded processor were proposed.Chapter 5 describes the method of realize the network broadcast system on the embedded Linux. Then, we test the system in many ways to find.whether the system can work steadily.Finally, we make a practically test and find some shortcomings, so we propose further measures to improve the system, looking forward to be finished in the future.