SCALABLE ENCODING APPARATUS AND SCALABLE ENCODING METHOD

摘要

A scalable encoding apparatus wherein stereo audio signals can be scalable encoded by use of a CELP encoding to improve the encoding efficiency. In the apparatus, an adder (101) and a multiplier (102) obtain an average of first and second channel signals (CH1,CH2) as a monophonic signal (M). A CELP encoding part (103) performs a CELP encoding of the monophonic signal (M). A first channel difference information encoding part (104) performs an encoding of the first channel signal (CH1) in conformance with the CELP encoding and obtains a difference between a resulting encoded parameter and an encoded parameter outputted from the CELP encoding part (103). The first channel difference information encoding part (104) then encodes this difference and outputs the resulting encoded parameter.