Chris@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0: % Generating filter bank of filters corresponding MIDI pitches
Chris@0: %
Chris@0: % Pitches 21-59, fs = 882
Chris@0: % Pitches 60-95, fs = 4410
Chris@0: % Pitches 96-120, fs =22050
Chris@0: %
Chris@0: % Q                  (center frequency) / bandwidt, Q > 30 separates notes
Chris@0: % stop:              pass_rel = 1/(2*Q); stop_rel = stop*pass_rel;
Chris@0: % Rp                 loses no more than Rp dB in the passband
Chris@0: % Rs                 attenuation in the stopband in dB
Chris@0: %
Chris@0: % For details to filter desgin use MATLAB help function
Chris@0: %                    e.g., "help ellipord" and "help ellip"
Chris@0: %
Chris@0: % Attention: Construction of [b,a] may fail if the
Chris@0: %                   filter specification are too restrictive
Chris@0: %
Chris@0: %
Chris@0: % License:
Chris@0: %     This file is part of 'Chroma Toolbox'.
Chris@0: % 
Chris@0: %     'Chroma Toolbox' is free software: you can redistribute it and/or modify
Chris@0: %     it under the terms of the GNU General Public License as published by
Chris@0: %     the Free Software Foundation, either version 2 of the License, or
Chris@0: %     (at your option) any later version.
Chris@0: % 
Chris@0: %     'Chroma Toolbox' is distributed in the hope that it will be useful,
Chris@0: %     but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@0: %     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@0: %     GNU General Public License for more details.
Chris@0: % 
Chris@0: %     You should have received a copy of the GNU General Public License
Chris@0: %     along with 'Chroma Toolbox'. If not, see <http://www.gnu.org/licenses/>.
Chris@0: % 
Chris@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0: 
Chris@0: clear;
Chris@0: 
Chris@0: semitoneOffsets = [0, -0.25, -1/3, -0.5, -2/3, -0.75];
Chris@0: nameSuffixes = {''; '_minusQuarter'; '_minusThird'; '_minusHalf'; '_minusTwoThird'; '_minusThreeQuarters'};
Chris@0: 
Chris@0: for k=1:length(semitoneOffsets)
Chris@0:     
Chris@0:     
Chris@0:     midi = (1:128);                     % midi notes
Chris@0:     midi_freq = 2.^((midi-69+semitoneOffsets(k))/12)*440;  % computing frequencies of midi notes
Chris@0:     nameSuffix = nameSuffixes{k};
Chris@0:     h(120)=struct('a',[],'b',[]);
Chris@0:     
Chris@0:     disp(['Generating Filterbank: ',nameSuffix]);
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     % fs = 22005, pitches 96-120
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     fs = 22050;
Chris@0:     nyq = fs/2;
Chris@0:     midi_min = 96;
Chris@0:     midi_max = 120;
Chris@0:     Q = 25; stop = 2; Rp = 1; Rs = 50;
Chris@0:     pass_rel = 1/(2*Q);
Chris@0:     stop_rel = pass_rel*stop;
Chris@0:     
Chris@0:     for k = midi_min:midi_max;
Chris@0:         pitch = midi_freq(k);
Chris@0:         Wp = [pitch-pass_rel*pitch pitch+pass_rel*pitch]/nyq;
Chris@0:         Ws = [pitch-stop_rel*pitch pitch+stop_rel*pitch]/nyq;
Chris@0:         [n Wn]=ellipord(Wp,Ws,Rp,Rs);
Chris@0:         [h(k).b,h(k).a]=ellip(n,Rp,Rs,Wn);
Chris@0:     end
Chris@0:     num = midi_max-midi_min+1;
Chris@0:     h_fvtool = cell(2*num,1);
Chris@0:     for i = 1:num
Chris@0:         h_fvtool{2*i-1}=h(midi_min+i-1).b;
Chris@0:         h_fvtool{2*i}=h(midi_min+i-1).a;
Chris@0:     end
Chris@0:     fvtool(h_fvtool{:});
Chris@0:     
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     % fs = 4410, pitches 60-95
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     fs = 4410;
Chris@0:     nyq = fs/2;
Chris@0:     midi_min = 60;
Chris@0:     midi_max = 95;
Chris@0:     Q = 25; stop = 2; Rp = 1; Rs = 50;
Chris@0:     pass_rel = 1/(2*Q);
Chris@0:     stop_rel = pass_rel*stop;
Chris@0:     
Chris@0:     for k = midi_min:midi_max;
Chris@0:         pitch = midi_freq(k);
Chris@0:         Wp = [pitch-pass_rel*pitch pitch+pass_rel*pitch]/nyq;
Chris@0:         Ws = [pitch-stop_rel*pitch pitch+stop_rel*pitch]/nyq;
Chris@0:         [n Wn]=ellipord(Wp,Ws,Rp,Rs);
Chris@0:         [h(k).b,h(k).a]=ellip(n,Rp,Rs,Wn);
Chris@0:     end
Chris@0:     num = midi_max-midi_min+1;
Chris@0:     h_fvtool = cell(2*num,1);
Chris@0:     for i = 1:num
Chris@0:         h_fvtool{2*i-1}=h(midi_min+i-1).b;
Chris@0:         h_fvtool{2*i}=h(midi_min+i-1).a;
Chris@0:     end
Chris@0:     fvtool(h_fvtool{:});
Chris@0:     
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     % fs = 882, pitches 21-59
Chris@0:     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0:     fs = 882;
Chris@0:     nyq = fs/2;
Chris@0:     midi_min = 21;
Chris@0:     midi_max = 59;
Chris@0:     Q = 25; stop = 2; Rp = 1; Rs = 50;
Chris@0:     pass_rel = 1/(2*Q);
Chris@0:     stop_rel = pass_rel*stop;
Chris@0:     
Chris@0:     for k = midi_min:midi_max;
Chris@0:         pitch = midi_freq(k);
Chris@0:         Wp = [pitch-pass_rel*pitch pitch+pass_rel*pitch]/nyq;
Chris@0:         Ws = [pitch-stop_rel*pitch pitch+stop_rel*pitch]/nyq;
Chris@0:         [n Wn]=ellipord(Wp,Ws,Rp,Rs);
Chris@0:         [h(k).b,h(k).a]=ellip(n,Rp,Rs,Wn);
Chris@0:     end
Chris@0:     num = midi_max-midi_min+1;
Chris@0:     h_fvtool = cell(2*num,1);
Chris@0:     for i = 1:num
Chris@0:         h_fvtool{2*i-1}=h(midi_min+i-1).b;
Chris@0:         h_fvtool{2*i}=h(midi_min+i-1).a;
Chris@0:     end
Chris@0:     fvtool(h_fvtool{:});
Chris@0:     
Chris@0:     
Chris@0:     save(['MIDI_FB_ellip_pitch_60_96_22050_Q25',nameSuffix],'h','-V6');
Chris@0:     
Chris@0: end
Chris@0: