ENCODING METHOD, ENCODING DEVICE, PERIODIC FEATURE AMOUNT DETERMINATION METHOD, PERIODIC FEATURE AMOUNT DETERMINATION DEVICE, PROGRAM AND RECORDING MEDIUM

摘要

There is provided an encoding technique that improves the quality of encoding of a sound signal at a low bit rate with a less amount of processing. The technique includes an interval determination step of determining an interval T between samples that correspond to a periodicity of the audio signal or to an integer multiple of a fundamental frequency of the audio signal from a set S of candidates for the interval T and a side information generating step of encoding the interval T determined at the interval determination step to obtain side information. The interval determining step determines the interval T from a set S made up of Y candidates (where Y Z) including Z 2 candidates (where Z 2 Z) selected from among Z candidates for the interval T representable with the side information without depending on a candidate subjected to the interval determination step in a previous frame a predetermined number of frames before the current frame and including a candidate subjected to the interval determination step in the previous frame the predetermined number of frames before the current frame.