tom@516: % Copyright 2012, Google, Inc.
tom@516: % Author: Richard F. Lyon
tom@516: %
tom@516: % This Matlab file is part of an implementation of Lyon's cochlear model:
tom@516: % "Cascade of Asymmetric Resonators with Fast-Acting Compression"
tom@516: % to supplement Lyon's upcoming book "Human and Machine Hearing"
tom@516: %
tom@516: % Licensed under the Apache License, Version 2.0 (the "License");
tom@516: % you may not use this file except in compliance with the License.
tom@516: % You may obtain a copy of the License at
tom@516: %
tom@516: %     http://www.apache.org/licenses/LICENSE-2.0
tom@516: %
tom@516: % Unless required by applicable law or agreed to in writing, software
tom@516: % distributed under the License is distributed on an "AS IS" BASIS,
tom@516: % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
tom@516: % See the License for the specific language governing permissions and
tom@516: % limitations under the License.
tom@516: 
tom@516: function CF_struct = CARFAC_Init(CF_struct, n_mics)
tom@516: % function CF_struct = CARFAC_Init(CF_struct, n_mics)
tom@516: %
tom@516: % Initialize state for n_mics channels (default 1).
tom@516: % This allocates and zeros all the state vector storage in the CF_struct.
tom@516: 
tom@516: % TODO (dicklyon): Review whether storing state in the same struct as
tom@516: % the design is a good thing, or whether we want another
tom@516: % level of object.  I like fewer structs and class types.
tom@516: 
tom@516: if nargin < 2
tom@516:   n_mics = 1;  % monaural
tom@516: end
tom@516: 
tom@516: % % this is probably what I'd do in the C++ version:
tom@516: % if CF_struct.n_mics ~= n_mics;
tom@516: %   % free the state and make new number of channels
tom@516: %   % make a struct arrray, one element per mic channel, numbered:
tom@516: %   for k = 1:n_mics
tom@516: %     CF_struct.state(k)  = struct('mic_number', k);
tom@516: %   end
tom@516: % end
tom@516: % But this code doesn't work because I don't understand struct arrays.
tom@516: 
tom@516: % For now I don't ever free anything if n_mics is reduced;
tom@516: % so be sure to respect n_mics, not the size of the state struct array.
tom@516: 
tom@516: AGC_time_constants = CF_struct.AGC_params.time_constants;
tom@516: n_AGC_stages = length(AGC_time_constants);
tom@516: 
tom@516: CF_struct.n_mics = n_mics;
tom@516: CF_struct.k_mod_decim = 0;  % time index phase, cumulative over segments
tom@516: 
tom@516: % This zeroing grows the struct array as needed:
tom@516: for mic = 1:n_mics
tom@516:   CF_struct.filter_state(mic).z1_memory = zeros(CF_struct.n_ch, 1);
tom@516:   CF_struct.filter_state(mic).z2_memory = zeros(CF_struct.n_ch, 1);
tom@516:   % cubic loop
tom@516:   CF_struct.filter_state(mic).zA_memory = zeros(CF_struct.n_ch, 1);
tom@516:   % AGC interp
tom@516:   CF_struct.filter_state(mic).zB_memory = zeros(CF_struct.n_ch, 1);
tom@516:   % AGC incr
tom@516:   CF_struct.filter_state(mic).dzB_memory = zeros(CF_struct.n_ch, 1);
tom@516:   CF_struct.filter_state(mic).zY_memory = zeros(CF_struct.n_ch, 1);
tom@516:   CF_struct.filter_state(mic).detect_accum = zeros(CF_struct.n_ch, 1);
tom@516:   % AGC loop filters' state:
tom@516:   % HACK init
tom@516:   CF_struct.AGC_state(mic).AGC_memory = zeros(CF_struct.n_ch, n_AGC_stages);
tom@516:   CF_struct.AGC_state(mic).AGC_sum = zeros(CF_struct.n_ch, 1);
tom@516:   % IHC state:
tom@516:   if CF_struct.IHC_coeffs.just_hwr
tom@516:     CF_struct.IHC_state(mic).ihc_accum = zeros(CF_struct.n_ch, 1);
tom@516:   else
tom@516:     CF_struct.IHC_state(mic).cap_voltage = ...
tom@516:       CF_struct.IHC_coeffs(mic).rest_cap * ones(CF_struct.n_ch, 1);
tom@516:     CF_struct.IHC_state(mic).cap1_voltage = ...
tom@516:       CF_struct.IHC_coeffs(mic).rest_cap1 * ones(CF_struct.n_ch, 1);
tom@516:     CF_struct.IHC_state(mic).cap2_voltage = ...
tom@516:       CF_struct.IHC_coeffs(mic).rest_cap2 * ones(CF_struct.n_ch, 1);
tom@516:     CF_struct.IHC_state(mic).lpf1_state = ...
tom@516:       CF_struct.IHC_coeffs(mic).rest_output * zeros(CF_struct.n_ch, 1);
tom@516:     CF_struct.IHC_state(mic).lpf2_state = ...
tom@516:       CF_struct.IHC_coeffs(mic).rest_output * zeros(CF_struct.n_ch, 1);
tom@516:     CF_struct.IHC_state(mic).ihc_accum = zeros(CF_struct.n_ch, 1);
tom@516:   end
tom@516: end
tom@516: 
tom@516: