Patent ID: 8392006

Claim:
A computer-implemented method for determining whether a selected portion of an audio stream contains monophonic or polyphonic audio data, comprising: analyzing, with a processor, audio data in a selected portion of an audio stream; detecting, with the processor, a plurality of frequency peaks in the audio data, where each detected peak has a minimum predefined amplitude; determining, with the processor, whether the selected portion of the audio stream contains monophonic audio data, by selecting a greatest common divisor frequency inclusively between a threshold frequency and a fundamental frequency F 0 based on the plurality of detected frequency peaks, wherein the threshold frequency is less than the fundamental frequency F 0 , comparing the greatest common divisor frequency with a predetermined number of successive detected peaks of the plurality of detected frequency peaks, determining that the selected portion of the audio stream contains monophonic audio data if each successive detected peak is substantially an integer multiple of the greatest common divisor frequency, and determining that the selected portion of the audio stream contains polyphonic audio data if any one of the successive detected peaks is not substantially an integer multiple of the greatest common divisor frequency.