58 lines
1.8 KiB
Mathematica
58 lines
1.8 KiB
Mathematica
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%% Inicialização do ambiente
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clear; close all; clc
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%% >Exercício 8<
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%% Input
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[y, Fs] = audioread("Canto1.mp3"); % Signal and Sampling Frequency
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signal = y(:,1); % Discard second channel
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Fn = Fs/2; % Nyquist Frequency (Hz)
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L = length(signal); % Signal Length
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%% Find the noise
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dft_signal = fft(signal)./L; % Fourier Transform
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Fv = linspace(0, 1, fix(L/2)+1)*Fn; % Frequency Vector
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%% Filter
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%signal_filtered = filter(DiogoEliseu_TP3_8_butterworth_2nd_order_filter,signal);
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signal_filtered = filter(DiogoEliseu_TP3_8_butterworth_filter,signal);
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%% Filtered signal
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dft_signal_filtered = fft(signal_filtered)/L; % Fourier Transform
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%% Output
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signal_power = abs(dft_signal(1:(L/2+1)));
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figure(1)
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subplot(2,3,1)
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hold on
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plot(Fv, signal_power)
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grid
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marks = [2850, 3020, 7000, 7150];
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plot(2850, signal_power(2850), 'r*')
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plot(3020, signal_power(3020), 'r*')
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plot(7000, signal_power(7000), 'r*')
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plot(7150, signal_power(7150), 'r*')
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xlabel("Frequência (Hz)"); ylabel("|H_{1}(f)|"); title("DFT do Sinal")
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hold off
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subplot(2,3,4)
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plot(Fv, abs(dft_signal_filtered(1:(L/2+1))))
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grid
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xlabel("Frequência (Hz)"); ylabel("|H_{1}(f)|"); title("DFT do Sinal Filtrado")
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subplot(2,3,2)
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plot(Fv, signal(1:(L/2+1)))
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grid
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xlabel("Frequência (Hz)"); ylabel("Amplitude"); title("Sinal")
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subplot(2,3,5)
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plot(Fv, signal_filtered(1:(L/2+1)))
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grid
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xlabel("Frequência (Hz)"); ylabel("Amplitude"); title("Sinal Filtrado")
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subplot(2,3,3)
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plot(Fv, mag2db(signal_power))
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grid
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xlabel("Frequência (Hz)"); ylabel("Ganho (dB)"); title("Ganho do Sinal")
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subplot(2,3,6)
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plot(Fv, mag2db(abs(dft_signal_filtered(1:(L/2+1)))))
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grid
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xlabel("Frequência (Hz)"); ylabel("Ganho (dB)"); title("Ganho do Sinal Filtrado")
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%sound(signal_filtered, Fs);
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%audiowrite('canto1_butterworth.flac', signal_filtered, Fs);
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