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

摘要

PROBLEM TO BE SOLVED: To reduce musical noise suitably in accordance with a type of first signals to be encoded even when a sufficient code bit length can not be secured.SOLUTION: A vector comprising a predetermined number of first signals to be encoded or a predetermined number of signals corresponding thereto as elements is quantized, and first quantization signals corresponding to the first signals to be encoded and first quantization indexes for specifying the quantization signals are generated and outputted. On the basis of a decision value specifying the number of first signals to be encoded which have amplitude values smaller than reference value or the number of first signals to be encoded whose amplitude values are equal to or smaller than the reference value among the predetermined number of first signals to be encoded, an encoding system corresponding to the predetermined number of first signals to be encoded is selected, and mode information specifying the selected encoding system is generated and output to performing encoding processing at least using the first quantization signals according to the selected encoding system.