Study On Algorithms Of Low Bit Rate Hi-Fi Audio Coding

ABSTRACTAlthough high bit rate channels and networks have become more easily accessible, low bit rate coding of digital audio has retained its importance. The main motivations for low bit rate audio coding are needed to minimize transmission costs or provide costefficient storage. The problem of audio coding or audio compression is to achieve a low bit rate in the digital representation of an input audio signal with minimum perceived loss of quality, and the ultimate criterion of signal quality is usually that judged or measured by the human receiver. So it is imperative that the coding algorithms designed must minimize the perceptually meaningful signal distortion. Any finite energy signal can be expanded or decomposed in terms of compactly supported orthogonal wavelet bases, it is very important to the development of fast and high efficient audio coding algorithm. A Hi-Fi audio coding algorithm based on orthogonal wavelet transform, psychoacoustic model and adaptive bit allocation is designed. The 1411 .2kbitls stereo Hi-Fi audio signals can be compressed to the bit rate as low as 64kbitls by this algorithm with good audio quality.