Diego Alvarez-Estevez
38 linhas
1.3 KiB
Matlab
38 linhas
1.3 KiB
Matlab
% Created by Diego Alvarez-Estevez (http://dalvarezestevez.com)
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% Last modified 19/01/2018
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% Implements high pass filter from Polyman
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%% This program is free software: you can redistribute it and/or modify
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%% it under the terms of the GNU General Public License as published by
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%% the Free Software Foundation, either version 3 of the License, or
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%% (at your option) any later version.
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%% This program is distributed in the hope that it will be useful,
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%% but WITHOUT ANY WARRANTY; without even the implied warranty of
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%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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%% GNU General Public License for more details.
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%% You should have received a copy of the GNU General Public License
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%% along with this program. If not, see <http://www.gnu.org/licenses/>.
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function signalFilt = polymanHighPassFilter(signal, sr, gain, hpFreq)
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% Check for valid settings
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if ((hpFreq <= 0) || (hpFreq > sr/2))
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disp('Error');
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return;
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end
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r = 2 * pi * hpFreq * ((1/sr)/2);
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t = gain / (r + 1);
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b = [t, - t]; % b coeffs according to filter function description (for x(n))
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a = [1, -(r-1)/(r+1)]; % a coeffs according to filter function description (for y(n))
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% We multiply a(2:end)*(-1) because filter function is implemented as a direct
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% form II transposed structure
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a(2:end) = -a(2:end);
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signalFilt = filter(b, a, signal);
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