Patent ID: 7012183

Claim:
Apparatus for analyzing an audio signal with regard to rhythm information of the audio signal by using an autocorrelation function, comprising: means for dividing the audio signal into at least two sub-band signals; means for examining at least one sub-band signal with regard to a periodicity in the at least one sub-band signal by an autocorrelation function, to obtain rhythm raw-information for the sub-band signal, wherein a delay is associated to a peak of the autocorrelation function; means for postprocessing the rhythm raw-information for the sub-band signal determined by the autocorrelation function, to obtain postprocessed rhythm raw-information for the sub-band signal, so that in the postprocessed rhythm raw-information an ambiguity in an integer multiple of a delay, to which an autocorrelation function peak is associated, is reduced compared to the rhythm raw-information before post processing, or a signal portion is added at an integer fraction of a delay, the integer fraction being determined by dividing “1” by an integer, to which an autocorrelation function peak is associated; and means for establishing the rhythm information of the audio signal by using the postprocessed rhythm raw-information of the sub-band signal and by using another sub-band signal of the at least two sub-band signals.