Patent ID: 9489957
Filing Date: 2016-11-08
CPC Classification: G10L,H04S

Claim Text:
1. A decoding method in a multi-channel audio processing system for reconstructing M encoded channels, wherein M>2, comprising the steps of: receiving N waveform-coded downmix signals comprising spectral coefficients corresponding to frequencies between a first and a second cross-over frequency, wherein 1<N<M; receiving M waveform-coded signals comprising spectral coefficients corresponding to frequencies up to the first cross-over frequency, each of the M waveform-coded signals corresponding to a respective one of the M encoded channels; downmixing the M waveform-coded signals into N downmix signals comprising spectral coefficients corresponding to frequencies up to the first cross-over frequency; combining each of the N waveform-coded downmix signals comprising spectral coefficients corresponding to frequencies between a first and a second cross-over frequency with a corresponding one of the N downmix signals comprising spectral coefficients corresponding to frequencies up to the first cross-over frequency into N combined downmix signals; extending each of the N combined downmix signals to a frequency range above the second cross-over frequency by performing high frequency reconstruction, whereby each extended downmix signal comprises spectral coefficients corresponding to a range extending below the first cross-over frequency and above the second cross-over frequency; performing a parametric upmix of the N frequency extended combined downmix signals into M upmix signals comprising spectral coefficients corresponding to frequencies above the first cross-over frequency, each of the M upmix signals corresponding to one of the M encoded channels; and combining the M upmix signals comprising spectral coefficients corresponding to frequencies above the first cross-over frequency with the M waveform-coded signals comprising spectral coefficients corresponding to frequencies up to the first cross-over frequency.