annotate matlab/bmm/carfac/CARFAC_hacking.m @ 610:01986636257a

Second check-in of Alex Brandmeyer's C++ implementation of CARFAC. Addressed style issues and completed implementation of remaining functions. Still needs proper testing of the output stages against the MATLAB version, and runtime functions need improvements in efficiency.

% Copyright 2012 Google Inc. All Rights Reserved.
% 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.

%% Test/demo hacking for CARFAC Matlab stuff:

clear variables

%%

use_wav_file = 1;
dB_list = -40;  % -60:20:40

if use_wav_file
  wav_fn = 'plan.wav';
  
  wav_fn
  file_signal = wavread(wav_fn);
  file_signal = file_signal(:, 1);  % Mono test only.
else
  % A tone complex.
  flist = 1400 + (1:4)*200;
  alist = [1, 1, 1, 1];
  sine_signal = 0;
  times = (0:9999)' / 22050;
  for fno = 1:length(flist)
    sine_signal = sine_signal + alist(fno)*sin(flist(fno)*2*pi*times);
  end
  growth_power = 0;  % use 0 for flat, 4 or more for near exponential
  file_signal = 1.0 * (sine_signal .* (times/max(times)).^growth_power);
end

% make a long test signal by repeating at different levels:
% dB = dB_list(1);
% test_signal =  10^(dB/20)* file_signal(1:4000) % lead-in [];
test_signal = [];
for dB =  dB_list
  test_signal = [test_signal; file_signal * 10^(dB/20)];
end

%% Run mono, then stereo test:

agc_plot_fig_num = 6;

for n_ears = 1:2
  
  CF_struct = CARFAC_Design(n_ears);  % default design
  
  if n_ears == 2
    % For the 2-channel pass, add a silent second channel:
    test_signal = [test_signal, zeros(size(test_signal))];
  end
  
  CF_struct = CARFAC_Init(CF_struct);
  
  [CF_struct, nap_decim, nap] = CARFAC_Run(CF_struct, test_signal, ...
    agc_plot_fig_num);
    
  smoothed = filter(1, [1, -0.995], nap(:, :, :));
  
  % only ear 1:
  smoothed = max(0, smoothed(50:50:end, :, 1));
  MultiScaleSmooth(smoothed.^0.5, 1);
  
  figure(1)
  starti = 0;  % Adjust if you want to plot a later part.
  imagesc(nap(starti+(1:15000), :)');
  
  % Display results for 1 or 2 ears:
  for ear = 1:n_ears
    smooth_nap = nap_decim(:, :, ear);
    if n_ears == 1
      mono_max = max(smooth_nap(:));
    end
    figure(3 + ear + n_ears)  % Makes figures 5, 6, 7.
    image(63 * ((max(0, smooth_nap)/mono_max)' .^ 0.5))
    title('smooth nap from nap decim')
    colormap(1 - gray);
  end
  
  % Show resulting data, even though M-Lint complains:
  CF_struct
  CF_struct.ears(1).CAR_state
  CF_struct.ears(1).AGC_state
  min_max_decim = [min(nap_decim(:)), max(nap_decim(:))]
  
end

% Expected result:  Figure 3 looks like figure 2, a tiny bit darker.
% and figure 4 is empty (all zero)