55 lines
1.6 KiB
Matlab
55 lines
1.6 KiB
Matlab
%% Inicialização do ambiente
|
|
clear; close all; clc
|
|
|
|
%% >Exercício 8<
|
|
|
|
%% Input
|
|
[y, Fs] = audioread("Canto1.mp3"); % Signal and Sampling Frequency
|
|
signal = y(:,1); % Discard second channel
|
|
Fn = Fs/2; % Nyquist Frequency (Hz)
|
|
L = length(signal); % Signal Length
|
|
|
|
%% Compute the DFT
|
|
dft = fft(signal)./L;
|
|
magnitude = 10.*log10(abs(dft).^2); % power is squared, thus 10
|
|
Fv = linspace(0, 1, L)*Fn; % Frequency Vector
|
|
|
|
%% High-pass Filter
|
|
not_to_cutoff_indices = magnitude > -96;
|
|
dft_filtered = not_to_cutoff_indices.*dft;
|
|
magnitude_filtered = not_to_cutoff_indices.*magnitude;
|
|
signal_filtered = ifft(dft_filtered.*L);
|
|
|
|
%% Output
|
|
Fv_half = linspace(0, 1, fix(L/2)+1)*Fn;
|
|
y = abs(dft(1:(L/2+1)));
|
|
y_filtered = abs(dft_filtered(1:(L/2+1)));
|
|
figure(1)
|
|
subplot(2,3,1)
|
|
plot(Fv_half, y)
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("|H_{1}(f)|"); title("DFT do Sinal")
|
|
subplot(2,3,4)
|
|
plot(Fv_half, y_filtered)
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("|H_{1}(f)|"); title("DFT do Sinal Filtrado")
|
|
subplot(2,3,2)
|
|
plot(Fv_half, signal(1:(L/2+1)))
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("Amplitude"); title("Sinal")
|
|
subplot(2,3,5)
|
|
plot(Fv_half, signal_filtered(1:(L/2+1)))
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("Amplitude"); title("Sinal Filtrado")
|
|
subplot(2,3,3)
|
|
%plot(Fv, magnitude);
|
|
plot(Fv_half, mag2db(y))
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("Ganho (dB)"); title("Ganho do Sinal")
|
|
subplot(2,3,6)
|
|
plot(Fv_half, mag2db(y_filtered))
|
|
grid
|
|
xlabel("Frequência (Hz)"); ylabel("Ganho (dB)"); title("Ganho do Sinal Filtrado")
|
|
|
|
%sound(signal_filtered, Fs);
|
|
%audiowrite('canto1_high_pass.flac', signal_filtered, Fs); |