%Function EdgeDetect
%      Takes in the entire signal and outputs a vector of values
%      representing the number of notes played within each 40000 sample
%      window.

function [beatpersec] = EdgeDetect(guitar)

%Use Gaussian filter function to create filter
filter = GaussianFilter;%/norm(GaussianFilter,inf);

%Low Pass Filter the guitar signal to remove unnecessary noise
guitar = conv(guitar,ones(3000,1));
guitar = guitar(1500:(length(guitar)-1500));

%Use FFT convolution to apply gaussian edge-detector signal
extendedfilter = [filter; zeros(length(guitar)-3001,1)];
fftfilter = fft(extendedfilter);
fftsig = fft(guitar);
multsig = fftfilter.*fftsig;
fsig = abs(ifft(multsig));
normsig = fsig/norm(fsig,inf);

%Ignore all of signal below threshold
for n = 1:1:length(normsig)
    if normsig(n)>0.1
        normsig(n) = normsig(n);
    else
        normsig(n) = 0;
    end
end


%Create vector of zeros with ones where peaks occur
sigzeros = zeros(1,length(normsig));

for n = 2:1:length(normsig)
    if normsig(n) >= normsig(n-1)
        sigzeros(n) = 1;
        sigzeros(n-1) = 0;
    else
        sigzeros(n) = 0;
    end
end

%Count up number of beats within each 40000 sample window
divbeats = zeros(floor(length(normsig)/40001) + 1, 1);

n = 1;
while (n <= length(sigzeros))
    if (sigzeros(n) == 1)
        divbeats(ceil(n/40000)) = divbeats(floor((n/40001)) + 1) + 1;
        n = n + 7000;
    else
        n = n+1;
    end
end

%Output
beatpersec = divbeats;