ENCODING METHOD, DECODING METHOD, ENCODER, DECODER, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To reduce musical noise even if a signal becomes deficient after decoding because of the lack of number of necessary bits.SOLUTION: An encoding method has: a first vector quantization step; an extraction step; and a second vector quantization step. In the extraction step, a second signal to be encoded is generated only with a first signal to be encoded corresponding to a first quantization signal whose value is 0. In the second vector quantization step, the second signal to be encoded or a signal corresponding to the signal is subjected to vector amount quantization to find a second vector quantization index. The decoding method has: a first vector decoding step, an M value calculation step; a second vector decoding step; and a reconfiguration step. In the M-value calculation step, the number M of first signals to be decoded whose values are 0 is obtained. In the second vector decoding step, a second decoded quantization signal is obtained. In the reconfiguration step, a decoded signal is obtained by employing the value of the second decoded quantization signal when the value of the first decoded quantization signal is 0.