ENCODING METHOD, ENCODING DEVICE, DECODING METHOD, DECODING DEVICE, PROGRAM AND RECORDING MEDIUM

摘要

An encoding method comprises: normalised signal encoding processing; global gain encoding processing; classification processing; and gain correction amount encoding processing. In the normalised signal encoding processing, a normalised signal code and a quantised normalised signal sequence corresponding to the normalised signal code are obtained. The normalised signal code is obtained by encoding a sequence based on a signal in which input signal samples contained in the input signal sequence are normalised. The global gain encoding processing obtains a quantised global gain corresponding to the input signal sequence and a global gain code corresponding to the quantised global gain. The classification processing classifies the quantised normalised signal sequence into three or more ranges. The gain correction amount encoding processing obtains a gain correction amount code for specifying the gain correction amount at which correlation is a maximum or the error is a minimum. This correlation is the correlation of the input signal sequence and a signal sequence obtained by multiplying the gain obtained by correcting the quantised global gain by at least one gain correction amount in respect of each of the ranges obtained by the aforementioned classification by each of the sample values of the quantised normalised signal sequence.