#################
#Created By: Loann Rio
#Created :20/04/2023 08:27:54
#
#Last modified: 02/03/2023 08:28:32
#
#################

pkg load signal;

clc;
close all;
clear all;


signal = csvread ('unknownsignal.csv');

figure;
plot(signal);
title("raw Signal");
xlabel("time");
ylabel("Amplitude");

% set signal of interest
SStart = 100;
SEnd = 400;

Fs = 300;

lenDomain = 1 + (SEnd - SStart);

windowed_signal= zeros(lenDomain);

% using blackman , we get the signal of interest
windowed_signal = signal(SStart:SEnd) .* blackman(lenDomain)';

figure;
plot(SStart: SEnd, windowed_signal);
title("Blackman signal windowing");
xlabel("samples");
ylabel("Amplitude");

frequencySpectrum(windowed_signal, Fs, 0);

%spectrogram(windowed_signal, Fs, 1/Fs, 1000*length(signal)/Fs);

% filter using filter and butter

[val, ind] = max(windowed_signal);

figure;
[b, a] = butter(6, 10/Fs);
s = filter(b, a, 10*log10(windowed_signal/windowed_signal(ind)));
plot(50:300, s(50:300));


audiowrite("sound.wav", signal, Fs);