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

摘要

When a number of samples smaller than a first reference value is smaller than a second reference value or not greater than the second reference value and if a subtraction value calculated by subtracting a value corresponding to a quantized normalized value from a value corresponding to the size of a value of each sample is positive, and the value of each sample is positive, the subtraction value is selected as a quantization target value. If the subtraction value is positive and the value of each sample is negative, the sign of the subtraction value is inverted before being selected as the quantization target value for each sample. A second encoding method is then selected in which a plurality of quantization target values are gathered and vector quantized, and a vector quantisation index is obtained. If the second encoding method is not selected, an alternative, first encoding method is selected.