Patent ID: 8019614
Filing Date: 2011-09-13
Classification: G10L,H04S

Abstract:
1. An energy shaping apparatus which performs energy shaping in decoding of a multi-channel audio signal, said energy shaping apparatus comprising: a splitting unit operable to split an audio signal in a sub-band domain into diffuse signals indicating a reverberating component and direct signals indicating a non-reverberating component, the audio signal being obtained by performing a hybrid time-frequency transformation; a downmix unit operable to generate a downmix signal by downmixing the direct signals; a filter processing unit operable to generate a bandpass downmix signal and bandpass diffuse signals by bandpassing the downmix signal and the diffuse signals per sub-band, the diffuse signals being split on the sub-band basis; a normalization processing unit operable to generate a normalized downmix signal and normalized diffuse signals, respectively, by normalizing the bandpass downmix signal and the bandpass diffuse signals with regard to respective energy; a scale factor computing unit operable to compute, for each of predetermined time slots, a scale factor indicating magnitude of energy of the normalized downmix signal with respect to the energy of the normalized diffuse signals; a multiplying unit operable to generate scale diffuse signals by multiplying each of the diffuse signals by a corresponding one of the scale factors; a high-pass processing unit operable to generate high-pass diffuse signals by highpassing the scale diffuse signals; an adding unit operable to generate addition signals by adding the high-pass diffuse signals and the direct signals; and a synthesis filter processing unit operable to apply synthesis filtering to the addition signals and transform the addition signals into time domain signals.