Patent ID: 7318035
Filing Date: 2008-01-08
Classification: G10L

Abstract:
1. A method for encoding a plurality of input audio signals, wherein the method comprises: receiving the plurality of input audio signals and obtaining therefrom one or more baseband signals and one or more residual signals, wherein spectral components of a baseband signal represent spectral components of a respective input audio signal in a first set of frequency subbands and spectral components in an associated residual signal represent spectral components of the respective input audio signal in a second set of frequency subbands that are not represented by the baseband signal; obtaining energy measures of at least some spectral components of one or more synthesized signals to be generated during decoding, wherein the one or more synthesized signals have spectral components within the second set of frequency subbands; obtaining energy measures of at least some spectral components of each residual signal; obtaining from the plurality of input audio signals a coupled-channel signal having spectral components representing a composite of spectral components of two or more of the input audio signals in a third sec of frequency subbands; obtaining energy measures of at least some spectral components of the coupled-channel signal; obtaining energy measures of at least some of the spectral components of the two or more input audio signals represented by the coupled-channel signal in the third set of frequency subbands; calculating coupling scale factors by obtaining square roots of ratios of the energy measures of spectral components in the two or more input audio signals to the energy measures of spectral energy in the coupled-channel signal, square roots of ratios of the energy measures of spectral energy in the coupled-channel signal to the energy measures of spectral components in the two or more input audio signals, ratios of square roots of the energy measures of spectral components in the two or more input audio signals to square roots of the energy measures of spectral energy in the coupled-channel signal, or ratios of square roots of the energy measures of spectral energy in the coupled-channel signal to square roots of the energy measures of spectral components in the two or more input audio signals; calculating scale factors by obtaining square roots of ratios of the energy measures of spectral components in the residual signals to the energy measures of spectral components in the one or more synthesized signals, square roots of ratios of the energy measures of spectral components in the one or more synthesized signals to the energy measures of spectral components in the residual signals, ratios of square roots of the energy measures of spectral components in the residual signals to square roots of the energy measures of spectral components in the one or more synthesized signals, or ratios of square roots of the energy measures of spectral components in the one or more synthesized signals to square roots of the energy measures of spectral components in the residual signals; and assembling signal information and scaling information into an encoded signal, wherein the signal information represents the spectral components in the one or more baseband signals and the spectral components in the coupled-channel signal, and wherein the scaling information represents the scale factors and the coupling scale factors.