diff matlab/bmm/carfac/CARFAC_hacking.m @ 455:f8ba7ad93fa9

Added MATLAB code for Lyon's CAR-FAC filter cascade.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/matlab/bmm/carfac/CARFAC_hacking.m	Wed Feb 15 21:26:40 2012 +0000
@@ -0,0 +1,85 @@
+% 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.
+
+%% Test/demo hacking for CARFAC Matlab stuff:
+
+clear variables
+
+%%
+file_signal = wavread('plan.wav');
+
+% file_signal = file_signal(9000+(1:10000));  % trim for a faster test
+file_signal = file_signal(9300+(1:5000));  % trim for a faster test
+
+% repeat with negated signal to compare responses:
+file_signal = [file_signal; -file_signal];
+
+% make a long test signal by repeating at different levels:
+test_signal = [];
+for dB = -60:20:40  % -80:20:60
+  test_signal = [test_signal; file_signal * 10^(dB/20)];
+end
+
+%%
+CF_struct = CARFAC_Design;  % default design
+
+%% Run mono, then stereo test:
+
+agc_plot_fig_num = 6;
+
+for n_mics = 1  % :2
+  CF_struct = CARFAC_Init(CF_struct, n_mics);
+
+  [nap, CF_struct, nap_decim] = CARFAC_Run(CF_struct, ...
+    test_signal, agc_plot_fig_num);
+
+%   nap = deskew(nap);  % deskew doesn't make much difference
+
+  MultiScaleSmooth(nap_decim, 10);
+
+%   nap_decim = nap;
+%   nap_decim = smooth1d(nap_decim, 1);
+%   nap_decim = nap_decim(1:8:size(nap_decim, 1), :);
+
+  % Display results for 1 or 2 mics:
+  for mic = 1:n_mics
+    smooth_nap = nap_decim(:, :, mic);
+    if n_mics == 1
+      mono_max = max(smooth_nap(:));
+    end
+    figure(3 + mic + n_mics)  % Makes figures 5, ...
+    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.k_mod_decim
+  CF_struct.filter_state
+  CF_struct.AGC_state
+  min_max = [min(nap(:)), max(nap(:))]
+  min_max_decim = [min(nap_decim(:)), max(nap_decim(:))]
+
+  % For the 2-channel pass, add a silent second channel:
+  test_signal = [test_signal, zeros(size(test_signal))];
+end
+
+% Expected result:  Figure 3 looks like figure 2, a tiny bit darker.
+% and figure 4 is empty (all zero)