clc
clear all
close all

[son1 Fe]= audioread('signal_B.wav');
taille = [1:length(son1)]/Fe;


absfft = abs(fft(son1, Fe));

figure
plot(absfft)



denumTetaC = pi/(24000/3700);
i = 1;
for n=-42:42
    if n==0
        filtrePassBas(i) = denumTetaC/pi;
    else
        filtrePassBas(i) = (sin(denumTetaC*n))/(pi*n);
    end
    i = i+1;
end

filtrePassBas = kaiser(85, 3.7)'.*filtrePassBas;
monson = [son1' zeros(1, 42)];

result = filter(filtrePassBas, 1, monson);
result = result(43:end);

signal = result(1:6:end);

figure
plot(abs(fft(signal)))


%butterworth%
% dirac =
% epsi =
% omegs =
% omegp =
%
% ordre = log( ((1/((dirac.^2)-1)) / (epsi.^2 ))  / (2* log(omegs/omegp)))

[b1 a1] = butter(1, [420 580]/4000);
sign1 = filter(b1, a1, signal);

[b2 a2] = butter(1, [920 1080]/4000);
sign2 = filter(b2, a2, signal);

[b3 a3] = butter(1, [1420 1580]/4000);
sign3 = filter(b3, a3, signal);

[b4 a4] = butter(1, [1920 2080]/4000);
sign4 = filter(b4, a4, signal);

[b5 a5] = butter(1, [2420 2580]/4000);
sign5 = filter(b5, a5, signal);

[b6 a6] = butter(1, [2920 3080]/4000);
sign6 = filter(b6, a6, signal);

figure
subplot(611)
plot(abs(fft(sign1)))
subplot(612)
plot(abs(fft(sign2)))
subplot(613)
plot(abs(fft(sign3)))
subplot(614)
plot(abs(fft(sign4)))
subplot(615)
plot(abs(fft(sign5)))
subplot(616)
plot(abs(fft(sign6)))