DECORRELATOR STRUCTURE FOR PARAMETRIC RECONSTRUCTION OF AUDIO SIGNALS

摘要

An encoding system encodes multiple audio signals (X) as a downmix signal (Y) together with wet and dry upmix coefficients (P, C). In a decoding system, a pre-multiplier (101) computes an intermediate signal (W) by mapping the downmix signal linearly in accordance with a first set of coefficients (Q); a decorrelating section (102) outputs a decorrelated signal (Z) based on the intermediate signal; a wet upmix section (103) computes a wet upmix signal by mapping the decorrelated signal linearly in accordance with the wet upmix coefficients; a dry upmix section (104) computes a dry upmix signal by mapping the downmix signal linearly in accordance with the dry upmix coefficients; a combining section (105) provides a multidimensional reconstructed signal (X) by combining the wet and dry upmix signals; and a converter (106) computes the first set of coefficients based on the wet and dry upmix coefficients and supplies this to the pre-multiplier.

主权项

1. A method for reconstructing a plurality of audio signals, comprising:
receiving a time/frequency tile of a downmix signal together with associated wet and dry upmix coefficients, wherein the downmix signal comprises fewer channels than the number of audio signals to be reconstructed; computing an intermediate signal as a linear mapping of the downmix signal, wherein a first set of coefficients is applied to the channels of the downmix signal; generating a decorrelated signal by processing one or more channels of the intermediate signal; computing a wet upmix signal as a linear mapping of the decorrelated signal, wherein a second set of coefficients is applied to one or more channels of the decorrelated intermediate signal; computing a dry upmix signal as a linear mapping of the downmix signal, wherein a third set of coefficients is applied to the channels of the downmix signal; and combining the wet and dry upmix signals to obtain a multidimensional reconstructed signal corresponding to a time/frequency tile of said plurality of audio signals to be reconstructed, wherein said second and third sets of coefficients coincide with, or are derived from, the received wet and dry upmix coefficients, respectively, wherein the method comprises computing said first set of coefficients based on the received wet and dry upmix coefficients such that the intermediate signal, which is to be processed into the decorrelated signal, is obtained by a linear mapping of the dry upmix signal.