clear all;
clc;

% Define number of bands
numBands = 8;

% Read in the sample
%filename = 'NordwindSonne';
filename = 'aem2f010';
%[sample, sr] = audioread(filename);
[sample, sr] = wavread([filename '.wav']);


% Normalize
sample = sample ./ (max(abs(sample))*1.1);
%sound(sample, sr);


% Time vector
dt = 1/sr;
t = 0:dt:(length(sample)*dt) - dt;


% Setup 3x2 subplots
ha = tight_subplot(3,2,0.1);


% Plot input signal
%figure(4)
axes(ha(1)); plot(t, sample(:,1));
% xlabel('Time (s)'); ylabel('Amplitude');
title('Original Signal');


% Build an array of filtered samples
filterOrder = 6;
[bank, centralFreqs] = createFilterBank(sr, numBands, filterOrder);

% Perform the Filtering
for i = 1:numBands
    filteredSamples(:,i) = filter(bank(i), sample);
end


% Plot the largest and smallest bands
% Low
axes(ha(2)); plot(t, filteredSamples(:,1));
%xlabel('Time (s)'); ylabel('Amplitude');
title('Filtered Signal - Low');

% High
axes(ha(3)); plot(t, filteredSamples(:,numBands));
% xlabel('Time (s)'); ylabel('Amplitude');
title('Filtered Signal - High');


% Rectify signal array
filteredSamples = abs(filteredSamples);

% Create Envelope Array by Running Filtered Samples through LP
lpInit = fdesign.lowpass('N,F3db', 5, 400/(sr/2));
lpFilter = design(lpInit, 'butter');

for i = 1:numBands
    sampleEnvelopes(:,i) = filter(lpFilter, filteredSamples(:,i));
end


% Plot Envelopes of largest and smallest bands
% Low
axes(ha(4)); plot(t, sampleEnvelopes(:,1));
% xlabel('Time (s)'); ylabel('Amplitude');
title(' Filtered Signal Envelope - Low');

% High
axes(ha(5)); plot(t, sampleEnvelopes(:,numBands));
%xlabel('Time (s)'); ylabel('Amplitude');
title(' Filtered Signal Envelope - High');


% Generate Cosine waves for each band in the filter bank;
for i = 1:numBands
    cosineBank(:,i) = cos(2*pi*centralFreqs(i)*t);
end


% Scramble bands
scrambledBands = [ 1 2 3 4 5 6 7 8 ];
%scrambledBands = [ 1 2 6 5 4 3 7 8 ];
%scrambledBands = [ 8 7 6 5 4 3 2 1 ];
%amplifyBands   = [ 1 1 1 1 1 1 1 1 ];
amplifyBands   = [ 0 0 1 1 0 0 0 0 ];


% Amplitude modulate the samples using the cosine wave from scrambleBands
for i = 1:numBands
    j = scrambledBands(i);
    modulatedSignals(:,i) = modulate(amplifyBands(i).*sampleEnvelopes(:,i), centralFreqs(j), sr);
end


% Add all the signals together to generate output signal
%disp(size(modulatedSignals, 1));
%disp(size(modulatedSignals, 2));
%clear sum;
outputSignal = sum(modulatedSignals, 2);
axes(ha(6)); plot(t, outputSignal); title('Output Signal');

% Normalize the output signal
%outputSignal = outputSignal * sqrt(max(outputSignal)) / sqrt(sum(outputSignal.^2));
outputSignal = outputSignal ./ (max(abs(outputSignal))*1.1);
%disp(outputSignal);

% Play the output signal (and boost volume back up)
sound(outputSignal, sr);

% Write the altered signal to a wav file
%audiowrite('Cermh014Filtered.wav', outputSignal, sr);
wavwrite(outputSignal, sr, [filename '_sim.wav']);