Stereo to the "Real Surround Sound" conversion algorithm

Abstract

The method of the extraction of spatial information from 2-channel audio signal is presented in the paper. The proposed algorithm will be used to recover true spatial acoustical field for 5.0 surround system from archival 2-channel stereo recordings. There is a lot of such recordings (digital as well) which can be more attractive, when post processed to 5.0-channel standard and reproduced in home theater systems. The idea of the proposed approach is based on special utilization of amplitude-phase dependencies in input audio signal. The author have created a nonlinear algorithm of spatial information which intelligently splits 2-channel sound to 5 output channels in DTS (or Dolby Digital) 5.0 format. The proposed algorithm is also compatible with analog Dolby Surround coding. The efficiency of the method is proven objectively and subjectively. Author has also presented simple method of graphic presentation of received results. Thanks to combination of diagrams it is possible to estimate fast a quality of spatial effect. Effectively of presented sound spatialization method has been compared to known matrix Dolby Surround system and recordings made in multi-channel Dolby Digital 5.0 system.