Design And Implementation Of MP3 Codec Based On SOPC

AbstractAt present, the research of MP3 codec is focused mainly on audio codec on MCU about at home and abroad. The systems have limitations. The main defects are the poor extended function, high loss of power and non-compatible with popular function. With the fast development of the application needs and IT, the research based on SOPC system grows fast in the fields of audio codec. The aim of the thesis is to develop an MP3 codec based on the SOPC platform.In this paper, as the characteristics and application requirements in reality of SOPC system are considered, a set of MP3 codec based on Altera's CycloneⅡ2C35 processor is developed, which may mount USB device. Taking the CycloneⅡ2C35 as the core, the audio processing component based on SOPC is developed, which transform the audio data collected by the MIC to NiosII soft-core processor, and then those data are coded into mp3 file which are stored in the USB device by audio coding program in theμClinux OS, and the transformation of MP3 digital audio information to PCM data is realized by the decoding program. The system has the strong expandability and wide application andμClinux is transplanted, which is convenient to continue subsequent development for adding user's needs. So it improves the intelligence degree of device and has the practical engineering value.In this paper, the related modules of MP3 codec based on SOPC system are realized from two respects of software and hardware. The research of systematic hardware controlling platform mainly includes:the architecture of SOPC system based on NiosII soft-core processor, the function and structure of the audio process module, and the application requirements of DE2 development board; The research of systematic software operation platform mainly includes:the introduce ofμClinux OS, the design of MP3 codec, and how to transplant codec program under the environment ofμClinux etc. The paper introduced the structure of Avalon bus, NiosII system which constitutes hardware platform, and the MP3 algorithm principle, which are main related technology that are used in the development of MP3 codec based on SOPC. At last the paper gives the debuging results and lists the solutions of the problem. The experiment results show that the developed system are accurate to code and decode the audio data, and are easy to be operated, and meet the basic system requirements. It has been transplanted withμClinux OS, which is easy to continue subsequent development for adding user's needs. So the system has a wide application prospect.