Frequency domain pitch period based encoding and decoding in accordance with magnitude and amplitude criteria

摘要

A frequency-domain sample interval corresponding to a time-domain pitch period L corresponding to a time-domain pitch period code of an audio signal in a given time period is obtained as a converted interval T₁, a frequency-domain pitch period T is chosen from among candidates including the converted interval T₁ and integer multiples U×T₁ of the converted interval T₁, and a frequency-domain pitch period code indicating how many times the frequency-domain pitch period T is greater than the converted interval T₁ is obtained. The frequency-domain pitch period code is output so that a decoding side can identify the frequency-domain pitch period T.