Patent ID: 6787689
Filing Date: 2004-09-07
Classification: G10H

Abstract:
A method of determining a rhythmic beat of a digital sound signal, said method comprising:(a) down sampling the digital signal by a predetermined factor to produce a decimated signal comprising a plurality of first data points; (b) grouping said plurality of first data points into groups each comprising a predetermined number of said first data points of said decimated signal and summing absolute values of said data points in each of said groups to produce a group-summed signal comprising a plurality of second data points; (c) dividing said plurality of second data points of said onset peak train into a plurality of successive frames of uniform duration; (d) determining for each of said frames a threshold value and detecting, within each of said frames, peak profiles each comprising successive ones of said second data points having values greater than said threshold value; (e) detecting, within each of said peak profiles, a peak point having a greatest value among said successive ones of said second data points; and (f) determining a match between (i) said peak point and ones of said second data points located at least one of before and after said peak point and (ii) one of a plurality of unit data pulse sequences, having different periods, in accordance with an algorithm, wherein said rhythmic beat is determined to correspond to the period of said one of said unit pulse sequences, wherein said threshold value is defined by a relation (A+Mâ€²)/2, where A is the average of the values of all of said second data points within one of said frames and Mâ€² is the maximum of the values of all of said second data points within said one of said frames.