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: 
dicklyon@561: function CF = CARFAC_Init(CF)
dicklyon@561: % function CF = CARFAC_Init(CF)
tom@516: %
dicklyon@561: % Initialize state for one or more ears of CF.
dicklyon@561: % This allocates and zeros all the state vector storage in the CF struct.
tom@516: 
dicklyon@561: n_ears = CF.n_ears;
tom@516: 
dicklyon@534: for ear = 1:n_ears
dicklyon@534:   % for now there's only one coeffs, not one per ear
dicklyon@561:   CF.ears(ear).CAR_state = CAR_Init_State(CF.ears(ear).CAR_coeffs);
dicklyon@561:   CF.ears(ear).IHC_state = IHC_Init_State(CF.ears(ear).IHC_coeffs);
dicklyon@561:   CF.ears(ear).AGC_state = AGC_Init_State(CF.ears(ear).AGC_coeffs);
dicklyon@534: end
dicklyon@523: 
dicklyon@534: 
dicklyon@534: function state = CAR_Init_State(coeffs)
dicklyon@534: n_ch = coeffs.n_ch;
dicklyon@534: state = struct( ...
dicklyon@534:   'z1_memory', zeros(n_ch, 1), ...
dicklyon@534:   'z2_memory', zeros(n_ch, 1), ...
dicklyon@534:   'zA_memory', zeros(n_ch, 1), ...
dicklyon@617:   'zB_memory', coeffs.zr_coeffs, ...
dicklyon@534:   'dzB_memory', zeros(n_ch, 1), ...
dicklyon@534:   'zY_memory', zeros(n_ch, 1), ...
dicklyon@534:   'g_memory', coeffs.g0_coeffs, ...
dicklyon@534:   'dg_memory', zeros(n_ch, 1) ...
dicklyon@534:   );
dicklyon@534: 
dicklyon@534: 
dicklyon@534: function state = AGC_Init_State(coeffs)
dicklyon@665: n_ch = coeffs(1).n_ch;
dicklyon@665: n_AGC_stages = coeffs(1).n_AGC_stages;
dicklyon@665: state = struct([]);
dicklyon@665: for stage = 1:n_AGC_stages
dicklyon@665:   % Initialize state recursively...
dicklyon@665:   state(stage).AGC_memory = zeros(n_ch, 1);
dicklyon@665:   state(stage).input_accum = zeros(n_ch, 1);
dicklyon@665:   state(stage).decim_phase = 0;  % integer decimator phase
dicklyon@665: end
dicklyon@534: 
dicklyon@534: 
dicklyon@534: function state = IHC_Init_State(coeffs)
dicklyon@534: n_ch = coeffs.n_ch;
dicklyon@556: if coeffs.just_hwr
dicklyon@556:   state = struct('ihc_accum', zeros(n_ch, 1));
dicklyon@556: else
dicklyon@556:   if coeffs.one_cap
dicklyon@556:     state = struct( ...
dicklyon@556:       'ihc_accum', zeros(n_ch, 1), ...
dicklyon@556:       'cap_voltage', coeffs.rest_cap * ones(n_ch, 1), ...
dicklyon@556:       'lpf1_state', coeffs.rest_output * ones(n_ch, 1), ...
dicklyon@565:       'lpf2_state', coeffs.rest_output * ones(n_ch, 1), ...
dicklyon@565:       'ac_coupler', zeros(n_ch, 1) ...
dicklyon@556:       );
dicklyon@556:   else
dicklyon@556:     state = struct( ...
dicklyon@556:       'ihc_accum', zeros(n_ch, 1), ...
dicklyon@556:       'cap1_voltage', coeffs.rest_cap1 * ones(n_ch, 1), ...
dicklyon@556:       'cap2_voltage', coeffs.rest_cap2* ones(n_ch, 1), ...
dicklyon@556:       'lpf1_state', coeffs.rest_output * ones(n_ch, 1), ...
dicklyon@565:       'lpf2_state', coeffs.rest_output * ones(n_ch, 1), ...
dicklyon@565:       'ac_coupler', zeros(n_ch, 1) ...
dicklyon@556:       );
dicklyon@556:   end
dicklyon@556: end
dicklyon@534: 
dicklyon@556: 
dicklyon@556: