The Software Design And Realization Of MP3Player Based On Embedded System

Accompanied by the popularity of computers and internet，and also the booming ofmicroelectronics technology in recent years，the embedded technology has been widelyused and developed from applying to a specific aspect to the current applying to manyaspects．And the products combined with embedded and linux have been widely used inmany industries，such as information appliance，network communication， consumerelectronics and industrial control．As a kind of audit format，MP3can compress theuntreated CD format music to only tenth of the size with maintaining the audio quality atthe same time．At present，this technology has been quite mature．But traditionalMP3players are mainly designed on the base of the chip， while ARM hasmore abundant peripheral resources and the more const-effective，which make it moresuitable for the manufacture of MP3player．Based on embedded technology，the paper designs and implements a MP3player．Thedesign uses development board with S3C2440processor and is achieved in the linuxenvironment． Before the design， demand analysis is carried on according tothe player required functions to form the final overall scheme of the MP3，includingbuilding of hardware and software platform and designing of software solutions．Thispaper is mainly consisted with the following components：1．Briefly describe subject background，embedded technology and development ofMP3．And based on the full analysis of the required hardware environment，ultimately theboard with S3C2440is selected as development board of the MP3player．2． Analyze the building of the software development environment in detail from thebuilding of cross compiler arm-linux-gcc， Bootloader transplantation， Linux kernelcustomization and making root file system．3． Expound the MP3file structure，coding principle and decoding principle indetail． The decoding principle can be divided into hardware decoding and softwaredecoding．On the basis of analyzing applications and differences between these two，finallya software decoding named madplay with open source and high-efficiency is selected．4． By designing the MP3player，the function framework is put forward，it dividesinto three modules which are player modules， key drivers module and the mainapplication module．And design each module in detail．Utilizing C language complete thecoding of the main application module， and control the music playing by using therelationship between sub-process and the grandson-process， finally implement music functions successfully such as start，pause，continue，stop and music track switching．5． Finally the played functions are tested， and the results show that the player wedesign has integrated functions with good sound quality． So the player well satisfies thedesign demands．...