Patent Document ID: 9378719
Application ID: 13956165
Patent Status: 1

Claim One:
1. An apparatus for analyzing a rhythm structure of a music audio data set, comprising: a beat position acquisition section configured to acquire beat position information indicating individual estimated beat positions of the music audio data set to be analyzed; a division section configured to: divide the music audio data set into a plurality of first possible pattern segments on the basis of provisional beat positions coinciding with the beat positions indicated by the acquired beat position information, each of the plurality of first possible pattern segments constituted by a number of the provisional beat positions, and provide a plurality of sets of first possible pattern segments by dividing the music audio data set in accordance with first individual division models of a plurality of division models so that a first beat position of each of the first possible pattern segments is shifted with respect to each other; divide the music audio data set into a plurality of second possible pattern segments on the basis of beat positions indicated by the beat position information equal in number to an integral multiple of the number of the provisional beat positions constituting the first possible pattern segments, and also provide a plurality of sets of second possible pattern segments by dividing the music audio data set in accordance with second individual division models of the plurality of division models so that a first beat position of each of the second possible pattern segments is shifted with respect to each other; and divide the music audio data set into a plurality of third possible pattern segments on the basis of beat positions indicated by the beat position information equal in number to an integral submultiple of the number of the provisional beat positions constituting the first possible pattern segments, and also provide a plurality of sets of third possible pattern segments by dividing the music audio data set in accordance with third individual division models of the plurality of division models so that a first beat position of each of the third possible pattern segments is shifted with respect to each other; a reference performance pattern acquisition section configured to acquire a plurality of reference performance patterns; a matching section configured to make comparisons between individual possible pattern segments with individual reference performance patterns for each of the sets of first, second, and third possible pattern segments and, on the basis of each comparison, determine, for each of the possible pattern segments of the set, at least one respective reference performance pattern that matches the possible pattern segment; a selection section configured to identify at least one combination of reference performance patterns on the basis of the at least one respective reference performance pattern determined by said matching section for each of the possible pattern segments, wherein each of the possible pattern segments within each of the sets of first, second, and third possible pattern segments is associated with one respective reference performance pattern, and the selection section further configured to select one optimal combination of reference performance patterns from among the at least one combination of reference performance patterns identified for the sets of first, second, and third possible pattern segments; and a beat position correction section configured to correct the beat positions in response to the selection of the one optimal combination of reference performance patterns by the selection section, wherein the beat positions are indicated by the beat position information acquired by said beat position acquisition section, and wherein said beat position correction section is configured to correct the beat positions if the one optimal combination of reference performance patterns selected by said selection section is a combination related to the second or third possible pattern segments.