Speech acoustic encoding apparatus, speech acoustic decoding apparatus, speech acoustic encoding method, and speech acoustic decoding method

摘要

While suppressing deterioration of the sound quality of the extension band, the amount of encoding bits allocated to encoding the extension band spectrum is reduced. The band compression unit (105) creates a combination of two subsamples in order from the low frequency side in the band compression target subband, and selects and selects a spectrum having a large absolute value amplitude from each combination. The resulting spectrum is arranged on the low frequency side on the frequency axis. The unit number recalculation unit (106) redistributes the bits saved in the band-compressed subband to the low band outside the extension band, and redistributes the number of units based on the redistributed bits.