Patent ID: 7756713
Filing Date: 2010-07-13
Classification: G10L

Abstract:
1. An audio signal decoding device which decodes a downmix channel signal obtained by downmixing audio channel signals, into the audio channel signals, said audio signal decoding device comprising: a downmix channel signal transformation unit that transforms the downmix channel signal into a time-frequency representation over plural frequency bands segmented along a frequency axis; an audio channel signal transformation unit that transforms the audio channel signals into time-frequency representations, each of the audio channel signals being coded after a part of the audio channel signal within a frequency range up to a predetermined upper frequency limit is quantized to a low-bit signal; a premixing unit that premixes, for each of the frequency bands, the transformed downmix channel signal and the transformed audio channel signals so as to generate premix channel signals, the premixing being performed within the frequency range up to the predetermined upper frequency limit; a mixing unit that mixes, for each of the frequency bands, the downmix channel signal, on which a predetermined process is performed based on spatial audio information which indicates a spatial property between the audio channel signals, with the generated premix channel signals so as to generate mixed channel signals, the mixing being performed in a frequency range higher than the predetermined upper frequency limit; and a mixed channel signal transformation unit that transforms the mixed channel signals into the audio channel signals.