PITCH PERIOD EXTRACTING METHOD

摘要

PURPOSE:To provide the pitch period extracting method which extracts a pitch period with the same precision over the entire frequency range without decreasing the precision of the pitch period in a low frequency range. CONSTITUTION:This pitch period extracting method which divides a digitized music signal into a 1st specific section, calculates an autocorrelation function by using a time difference as a variable in the 1st section, and extracts the time difference which maximizes the autocorrelation function as a pitch period. The digitized music signal in a 2nd specific section following the 1st specific section is prepared, and the autocorrelation function corresponding to one time difference is performed by regarding a constant section in the 1st and 2nd specific sections as an object and moving the object constant section in the 1st and 2nd specific sections according to variation in the time difference as the variable.