Research Of Perceptual Audio Coding Algorithm

With the gradual im provement in peopl e’s living, the trend of digital audio electronic products in dem and for people in China is going up, so royalties paid to foreign audio companies is increasing significantly. Although technology of AVS and DRA is to fill the gap of our digital audio processing technology to some extend, but further study is needed because of som e shortcomings in them. In the field of audio processing technology in China, the more research in institutions is on audio decoding algorithm and optim al implementation of algorithm , less on coding algorithm and Chinese audio coding standard DRA espe cially. The research in audio coding algorithm involved in DRA in this paper has important practical significance.In this paper, through analysis of DRA/AVS/AAC/MP3 audio coding standard and im prove in public algorithm on audio coding system, so that they could be applied in DRA audio coding system. In the pre-echo controlling aspects, through the study of transient signal detection algorit hms, a new method based on variance -flat measure is proposed and tested on the testi ng platform of DRA coding system , also simulated in MATLAB environm ent. In th e psycho-acoustic algorithm , refer to the previous algorithm based on DFT/ MDCT/CMDCT, a new mixed method with lower computational complexity and better perf ormance is presented and tested on DRA coding platform. In the codebooks selection, a cyclic codebooks allocation method on the basis of codebooks selection algorithm in MP3 is presented and sim ulated in MATLAB environment. In the last, refer to research on main modules in perceptual audio coding system and materials about DRA standard, a platform that could provide a test platform for further study on audio coding system is built.