annotate matlab/bmm/carfac/CARFAC_Init.m @ 611:0fbaf443ec82

Carfac C++ revision 3, indluding more style improvements. The output structs are now classes again, and have separate storage methods for each output structure along with flags in the Run and RunSegment methods to allow for only storing NAPs if desired.

% Copyright 2012, Google, Inc.
% Author: Richard F. Lyon
%
% This Matlab file is part of an implementation of Lyon's cochlear model:
% "Cascade of Asymmetric Resonators with Fast-Acting Compression"
% to supplement Lyon's upcoming book "Human and Machine Hearing"
%
% Licensed under the Apache License, Version 2.0 (the "License");
% you may not use this file except in compliance with the License.
% You may obtain a copy of the License at
%
%     http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS,
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
% See the License for the specific language governing permissions and
% limitations under the License.

function CF = CARFAC_Init(CF)
% function CF = CARFAC_Init(CF)
%
% Initialize state for one or more ears of CF.
% This allocates and zeros all the state vector storage in the CF struct.

n_ears = CF.n_ears;

for ear = 1:n_ears
  % for now there's only one coeffs, not one per ear
  CF.ears(ear).CAR_state = CAR_Init_State(CF.ears(ear).CAR_coeffs);
  CF.ears(ear).IHC_state = IHC_Init_State(CF.ears(ear).IHC_coeffs);
  CF.ears(ear).AGC_state = AGC_Init_State(CF.ears(ear).AGC_coeffs);
end


function state = CAR_Init_State(coeffs)
n_ch = coeffs.n_ch;
state = struct( ...
  'z1_memory', zeros(n_ch, 1), ...
  'z2_memory', zeros(n_ch, 1), ...
  'zA_memory', zeros(n_ch, 1), ...
  'zB_memory', coeffs.zr_coeffs, ...
  'dzB_memory', zeros(n_ch, 1), ...
  'zY_memory', zeros(n_ch, 1), ...
  'g_memory', coeffs.g0_coeffs, ...
  'dg_memory', zeros(n_ch, 1) ...
  );


function state = AGC_Init_State(coeffs)
n_ch = coeffs.n_ch;
n_AGC_stages = coeffs.n_AGC_stages;
state = struct( ...
  'AGC_memory', zeros(n_ch, n_AGC_stages), ...
  'input_accum', zeros(n_ch, n_AGC_stages), ...
  'decim_phase', zeros(n_AGC_stages, 1) ... % integer decimator phase
  );


function state = IHC_Init_State(coeffs)
n_ch = coeffs.n_ch;
if coeffs.just_hwr
  state = struct('ihc_accum', zeros(n_ch, 1));
else
  if coeffs.one_cap
    state = struct( ...
      'ihc_accum', zeros(n_ch, 1), ...
      'cap_voltage', coeffs.rest_cap * ones(n_ch, 1), ...
      'lpf1_state', coeffs.rest_output * ones(n_ch, 1), ...
      'lpf2_state', coeffs.rest_output * ones(n_ch, 1), ...
      'ac_coupler', zeros(n_ch, 1) ...
      );
  else
    state = struct( ...
      'ihc_accum', zeros(n_ch, 1), ...
      'cap1_voltage', coeffs.rest_cap1 * ones(n_ch, 1), ...
      'cap2_voltage', coeffs.rest_cap2* ones(n_ch, 1), ...
      'lpf1_state', coeffs.rest_output * ones(n_ch, 1), ...
      'lpf2_state', coeffs.rest_output * ones(n_ch, 1), ...
      'ac_coupler', zeros(n_ch, 1) ...
      );
  end
end