METHOD AND APPARATUS FOR SPECTRAL EXPONENT RESHAPING IN A TRANSFORM CODER FOR HIGH QUALITY AUDIO

摘要

A method and apparatus for coding audio data in a frequency transform digital audio coder employing differential frequency coefficient exponent coding. Differential coding of exponents places constraints on possible values an exponent can take, which can lead to distortion in the decoded and reconstructed audio signal. The method and apparatus herein can overcome this restriction by mapping the input exponent set to a new set of values which satisfy the differential constraint as well as reducing information loss, thereby minimising overall signal distortion due to coding restrictions.