ABSTRACT
At first this paper introduces the subject of the background and status of international
research, then pointed out that the traditional community broadcast system have been
unable to meet people’s quality of daily living and environmental requirements for a
variety of reasons. We have designed a solution for broadcast system based on
embedded Linux, which made use of the existing embedded technology, wireless
network technology, audio codectechnology and streaming media technology. That is
the public address system based on embedded and network, referred as the PASEN.
This article contains the following aspects of work:
(1) 、putting the idea of the specific design of this tipic, on the basis of
comprehensively discussing PASEN’s development status and related technical
principle analysis.
(2)、building an embedded Linux operating system based on ARM9 target board,
and its main duties include a lot, such as: boot loader porting, linux kernel cutting,
yaffs2 file system’s construction and shell’s custom. The system software is divided
into four parts: master process, communication thread, play thread and QT graphical
interaction thread, and at the same time gives the design methods.
(3)、transplanting the linux driver program of the audio chip uda1380, madplay audio
decoding library and jrtplib real-time transport protocol library, designing the
interactive graphics application.
PASEN uses C/S architecture, the server-side instead of using PC, the client-side
instead of designed streaming media player, and connect them using a wireless network.
This will be embedded technology, streaming media technology and audio codec
technology for embedded wireless networks intelligent community audio broadcasting
system, which reduce development costs, an increase of technical content, with
real-time performance, portability, and other excellent characteristics, tested and
achieved good results, there are some practical applications. In the end of this article, it
notes a number of areas for improvement.
Keywords: Embedded Linux System, audio coding and decoding,
real-time transport, graphic interactive, wireless network