function [outsig, obj] = hohmann2002_process(obj, insig)
%HOHMANN2002_PROCESS Process input signal by filterbank object
% Usage: [outsig, obj] = hohmann2002_process(obj, insig);
%
% Input parameters:
% obj : An object created within the HOHMANN2002 filterbank framework by
% one of the following funtions: HOHMANN2002,
% HOHMANN2002_FILTER, HOHMANN2002_DELAY,
% HOHMANN2002_SYNTH, HOHMANN2002_MIXER.
% insig : Input signal to be processed [time channels].
%
% Output parameters:
% outsig : A matrix containing the processed output signals [time channels].
% The columns correspond to the filter bands.
% obj : The original object with updated filter states.
%
% HOHMANN2002_PROCESS applies the processing given by obj retrieved from the
% HOHMANN2002 filterbank framework to the input signal.
%
% See also: exp_hohmann2002 demo_hohmann2002
%
% References:
% V. Hohmann. Frequency analysis and synthesis using a gammatone
% filterbank. Acta Acustica united with Acoustica, 88(3):433--442, 2002.
%
%
% Url: http://amtoolbox.org/amt-1.3.0/doc/modelstages/hohmann2002_process.php
% #StatusDoc: Perfect
% #StatusCode: Perfect
% #Verification: Verified
% #Author : Universitaet Oldenburg, tp (2002 - 2007)
% #Author : Piotr Majdak (2016)
% Adapted from function gfb_*_process
% This file is licensed unter the GNU General Public License (GPL) either
% version 3 of the license, or any later version as published by the Free Software
% Foundation. Details of the GPLv3 can be found in the AMT directory "licences" and
% at <https://www.gnu.org/licenses/gpl-3.0.html>.
% You can redistribute this file and/or modify it under the terms of the GPLv3.
% This file is distributed without any warranty; without even the implied warranty
% of merchantability or fitness for a particular purpose.
if ~isfield(obj,'type'), error('Type of the object missing'); end
switch(obj.type)
case 'gfb_Filter'
factor = obj.normalization_factor;
% for compatibility of the filter state with the MEX extension, we
% have to multiply the filter state with the filter coefficient before the
% call to filter:
filter_state = obj.state * obj.coefficient;
insig=insig.';
for i = 1:obj.gamma_order
[insig, filter_state(i)] = ...
filter(factor, [1, -obj.coefficient], ...
insig, filter_state(i));
factor = 1;
end
outsig = insig;
% for compatibility of the filter state with the MEX extension, we
% have to divide the filter state by the filter coefficient after the
% call to filter:
obj.state = filter_state / obj.coefficient;
outsig=outsig.';
case 'gfb_analyzer'
if (obj.fast)
% use matlab extension for fast computation.
% [outsig, obj] = gfb_analyzer_fprocess(obj, insig);
warning('fast computation not available');
end
% insig=insig';
number_of_bands = length(obj.center_frequencies_hz);
outsig = zeros(size(insig,1), number_of_bands);
for band = 1:number_of_bands
[tmp, obj.filters(band)] = hohmann2002_process(obj.filters(band), insig(:, min(band,size(insig,2))) );
outsig(:,band) = tmp;
end
% outsig=outsig';
case 'gfb_Delay'
insig=insig.';
[number_of_bands, number_of_samples] = size(insig);
if (number_of_bands ~= length(obj.delays_samples))
error('Input rows must match the number of bands');
end
outsig = zeros(number_of_bands, number_of_samples);
for band = 1:number_of_bands
if (obj.delays_samples(band) == 0)
outsig(band,:) = real(insig(band,:) * obj.phase_factors(band));
else
tmp_out = [obj.memory(band,1:obj.delays_samples(band)), ...
real(insig(band,:) * obj.phase_factors(band))];
obj.memory(band,1:obj.delays_samples(band)) = tmp_out(number_of_samples+1:length(tmp_out));
outsig(band,:) = tmp_out(1:number_of_samples);
end
end
outsig=outsig.';
case 'gfb_Synthesizer'
[outsig, obj.delay] = hohmann2002_process(obj.delay, insig);
[outsig, obj.mixer] = hohmann2002_process(obj.mixer, outsig);
case 'gfb_mixer'
insig=insig.';
outsig = obj.gains * insig;
outsig=outsig.';
otherwise
error('Unknown type of HOHMANN2002 filter object');
end