Research And Application On J2A Audio CODEC

Nowadays, with the development of computer technology, modern communication technology, network technology and information processing technology, the application of multimedia technology is becoming more and more popular. At present, the multimedia data source include text, audio, video, graphic, image, animation etc. The important issues in multimedia technology are how to deal with and organize these data, and how to improve the efficiency of data storage and transmission Among these multimedia data, the audio information is more and more huge; it is quite necessary to offer suitable compression technologies for audio data.Now there are already some standards and algorithms for audio CODEC. A new audio CODEC methods-J2A, which can be realized by ET83X432 chip, is studied and introduced in this paper. The J2A CODEC algorithm is based on standard JPEG2000 theory and the Percept Audio Coding technology. The theory foundation of standard JPEG2000 is Wavelet Transform, so the theories and properties of the Wavelet Transform and the JPEG2000 are introduced in the preface and Chapter two of this paper. The detailed introduction about the J2A algorithm is also discussed in this paper. A simple but highly efficient J2A audio player is implemented by applying the J2A CODEC technology. The design methods and implementation technologies for the J2A audio player are also discussed in this paper. A testing J2A audio player is presented as an application example. The hardware of the J2A player includes three chips. They are ET44M210 MCU chip, ET83X432 Audio CODEC chip and a 16M Nand flash chip respectively. The software of the J2A player includes three modules. They are audio processing module, signal controlling module and data storage module. The audio processing module performs data sampling, ADC/DAC, amplifying, compression and decompression etc; the control module performs demand controlling, timing controlling etc; the storage module performs the data storage.The J2A player is co-implemented by our research group and the ETOMS Co. The J2A player test machine is implemented by our research group; the J2A player sample machine is implemented by the ETOMS Co. In this paper, there is an investigation report about the. "J2A audio player with a USB".Our J2A audio player's features include: playing music, the compression ratio selection, USB communication function, etc. It is a low-power, low-cost system. It...