Patent ID: 7767897

Claim:
A beat matcher, comprising: (a) an input for a digital audio stream; (b) an input beat detector coupled to said input, said input beat detector including stability logic for adjusting detected beat rates of successive frames, the input detector detects an nth input beat rate for an nth input frame of samples of said input digital audio stream; (c) a reference beat rate source for finding beat locations for said nth reference frame using said nth reference beat rate and finding beat locations in said nth input frame using said nth input beat rate; (d) a conversion ratio computer coupled to said input beat detector and to said reference beat rate source for computing an nth conversion ratio from said beat locations for said nth reference frame and said beat locations in said nth input frame; and (e) a sampled-stream converter coupled to said input and to said conversion ratio computer, whereby a digital audio stream at said input can be beat matched to beats of said reference beat rate source for computing an nth hop number from the number of said beat locations for said nth reference frame and the number of said beat locations in said nth input frame, defining an nth hop window for said nth reference frame using said nth hop number, computing an nth set of output samples from samples of said nth input frame using said nth conversion ratio where the number of samples in said nth set of output samples corresponds to said nth hop window determining an (n+1)th reference frame with beginning as following the end of said nth hop window and determining an (n+1)th input frame in said input audio stream by advancing in said input audio stream from the start of said nth input frame by a number of sample locations equal to the product of said nth conversion ratio multiplied by said number of locations corresponding to said nth hop window.