A comparative study of the proposed high quality coding schemes for digital music

This paper deals with comparisons between various coding schemes for the digital transmission of high quality sound signals typical of what will be transmitted through a Direct Broadcast Satellite System (DBS). Several PCM coding techniques using instantaneous logarithmic coding laws [1] (A-law and µ-law) or near-instantaneous coding law (block coding scheme) such as the NICAM 3 system [2] as well as the Adaptive Delta Modulation (ADM) [3] are compared in this paper. Several pre-emphasis/de-emphasis laws are also proposed to optimally shape the spectrum of the sound program signal before encoding [1]. An investigation of the properties of these laws is carried out and an evaluation, both objective and subjective, of the impact of their utilisation in a codec is presented.