beat.zip_back_beat_beat audio_beat detection

function [p,m,S] = ifptrack(d,w,sr,fminl,fminu,fmaxl,fmaxu) % [p,m,S] = ifptrack(d,w,sr,fminl,fminu,fmaxl,fmaxu) % Pitch track based on inst freq. % Look for adjacent bins with same inst freq. % d is the input waveform. sr is its sample rate % w is the basic STFT DFT length (window is half, hop is 1/4) % S returns the underlying complex STFT. % fmin,fmax define ramps at edge of sensitivity % 2006-05-03 dpwe@ee.columbia.edu % Copyright (c) 2006 Columbia University. % % This file is part of LabROSA-coversongID % % LabROSA-coversongID is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License version 2 as % published by the Free Software Foundation. % % LabROSA-coversongID is distributed in the hope that it will be useful, but % WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU % General Public License for more details. % % You should have received a copy of the GNU General Public License % along with LabROSA-coversongID; if not, write to the Free Software % Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA % 02110-1301 USA % % See the file "COPYING" for the text of the license. % downweight fundamentals below here if nargin < 4; fminl = 150; end if nargin < 5; fminu = 300; end % highest frequency we look to if nargin < 6; fmaxl = 2000; end if nargin < 7; fmaxu = 4000; end % Calculate the inst freq gram [I,S] = ifgram(d,w,w/2,w/4,sr); % Only look at bins up to 2 kHz maxbin = round(fmaxu * (w/sr) ); %maxbin = size(I,1) minbin = round(fminl * (w/sr) ); % Find plateaus in ifgram - stretches where delta IF is < thr ddif = [I(2:maxbin, :);I(maxbin,:)] - [I(1,:);I(1:(maxbin-1),:)]; % expected increment per bin = sr/w, threshold at 3/4 that dgood = abs(ddif) < .75*sr/w; % delete any single bins (both above and below are zero); dgood = dgood .* ([dgood(2:maxbin,:);dgood(maxbin,:)] > 0 | [dgood(1,:);dgood(1:(maxbin-1),:)] > 0); % check it out %p = dgood; % reconstruct just pitchy cells? %r = istft(p.*S,w,w/2,w/4); p = 0*dgood; m = 0*dgood; % For each frame, extract all harmonic freqs & magnitudes for t = 1:size(I,2) ds = dgood(:,t)'; lds = length(ds); % find nonzero regions in this vector st = find(([0,ds(1:(lds-1))]==0) & (ds > 0)); en = find((ds > 0) & ([ds(2:lds),0] == 0)); npks = length(st); frqs = zeros(1,npks); mags = zeros(1,npks); for i = 1:length(st) bump = abs(S(st(i):en(i),t)); frqs(i) = (bump'*I(st(i):en(i),t))/(sum(bump)+(sum(bump)==0)); mags(i) = sum(bump); if frqs(i) > fmaxu mags(i) = 0; frqs(i) = 0; elseif frqs(i) > fmaxl mags(i) = mags(i) * max(0, (fmaxu - frqs(i))/(fmaxu-fmaxl)); end % downweight magnitudes below? 200 Hz if frqs(i) < fminl mags(i) = 0; frqs(i) = 0; elseif frqs(i) < fminu % 1 octave fade-out mags(i) = mags(i) * (frqs(i) - fminl)/(fminu-fminl); end if frqs(i) < 0 mags(i) = 0; frqs(i) = 0; end end % then just keep the largest at each frame (for now) % [v,ix] = max(mags); % p(t) = frqs(ix); % m(t) = mags(ix); % No, keep them all %bin = st; bin = round((st+en)/2); p(bin,t) = frqs; m(bin,t) = mags; end %% Pull out the max in each column %[mm,ix] = max(m); %% idiom to retrieve different element from each column %[nr,nc] = size(p); %pp = p((nr*[0:(nc-1)])+ix); %mm = m((nr*[0:(nc-1)])+ix); % r = synthtrax(pp,mm,sr,w/4); %p = pp; %m = mm;