SCALABLE ENCODING DEVICE AND SCALABLE ENCODING METHOD

摘要

There is provided a scalable encoding device capable of realizing a band scalable LSP encoding of high performance by improving the conversion performance from a narrow band LSP to a wide band LSP. The device includes: a self correlation coefficient conversion unit (301) for converting the narrow band LSP of Mn degree to a self correlation coefficient of Mn degree; an inverse lag window unit (302) for multiplying the lag window applied to the self correlation coefficient by an inverse characteristic window (inverse lag window); an extrapolation unit (303) for subjecting the self correlation coefficient multiplied by the inverse lag window to extrapolation so as to extend the degree of the self correlation coefficient to (Mn + Mi) degree; an up-sample unit (304) for performing an up-sample process in the self correlation area equivalent to an up-sample process in a time area for the self correlation coefficient of the (Mn +Mi) degree so as to obtain a self correlation coefficient of Mw degree; a lag window unit (305) for applying a lag window to the self correlation coefficient of Mw degree; and an LSP conversion unit (306) for converting the self correlation coefficient to which the lag window is applied, into an LSP.