A new digital surround processing system for general A/V sources

A new surround processing algorithm is proposed for the sensible reproduction of non-encoded conventional stereo sources as well as Dolby encoded ones. The proposed method synthesizes the additional sound channels to expand the output from the conventional two channels to four or five. The directivity of auditory events is enhanced by the direction enhancement algorithm whose performance can be optimized to both cases of Dolby encoded and non-encoded sources. Also, spectral balance among the channels is tuned up to minimize the defects arising from processes such as coloration of timbre. A surround processing system based on the proposed method was implemented using a custom DASP (digital audio signal processor) chip and showed a much satisfactory performance for the various non-encoded sources as well as Dolby encoded sources.