BAND EXTENSION METHOD, BAND EXTENSION DEVICE, PROGRAM, INTEGRATED CIRCUIT, AND AUDIO DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a band extension method capable of reducing calculation amount for extending the band and preventing degradation of the quality of the extended band.

SOLUTION: The band extension method includes steps of: generating a first low-frequency QMF spectrum by converting low-frequency band signals into a QMF region (S11); generating plural signals with a pitch shifted by applying a shift coefficient different from each other to the low-frequency band signal (S12); generating a high-frequency QMF spectrum by time-extending in the QMF region (S13); correcting the high-frequency QMF spectrum (S14); and coupling the corrected high-frequency QMF spectrum and a first low-frequency QMF spectrum (S15).

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