pkg load signal

%load & plot audio file modulator
%modulator = fullfile('sound', 'modulator22.wav');
[audio_data sampling_freq]= audioread('modulator22.wav');

figure;
plot(audio_data);
xlabel('Time (s)');
ylabel('Amplitude');
title('Modulator22');

%spectral anlysis
if (1)
  t = 5;
  %average
  for i=1:t
    %FFT
    
    [power, duration]=frequencySpectrum(audio_data,sampling_freq,1);
    duration_fft(i) = duration;

    %DFT
    
    [power, duration]=frequencySpectrum(audio_data,sampling_freq,0);
    duration_dft(i) = duration;
   
    sum_fft =0; 
    sum_dft =0;
    
    sum_fft = sum_fft + duration_fft(i);
    sum_dft = sum_fft + duration_dft(i);
  
  endfor

%estimate the duration of FFT
average_fft = sum_fft/t
average_dft = sum_dft/t
end

%Compute and display spectrogram
if(0)
  spectrogram(audio_data,sampling_freq,5,5);
  %spectrogram(audio_data,sampling_freq,30,5);

  wan = audio_data(0.37*sampling_freq:1.17*sampling_freq);
  tu = audio_data(1.24*sampling_freq:1.75*sampling_freq);
  tri = audio_data(1.84*sampling_freq:2.19*sampling_freq);

  frequencySpectrum(wan,sampling_freq,1);
  frequencySpectrum(tu,sampling_freq,1);
  frequencySpectrum(tri,sampling_freq,1);
end