SCALABLE ENCODING APPARATUS, SCALABLE DECODING APPARATUS, AND METHODS THEREOF

摘要

A scalable encoding apparatus capable of reducing the bit rates of encoded parameters and also capable of efficiently encoding even audio signals in which a plurality of harmonic structures are coexistent. In the apparatus, an MDCT analyzing part (111) MDCT analyzes an audio signal (S15) for converting/encoding processes. A pitch frequency converting part (112) determines the inverse of a pitch period to calculate a pitch frequency. A selecting part (113) selects spectra located at frequencies that are integral multiples of the pitch frequency. A second layer encoding part (106) encodes the selected spectra.