add functions to create B format signals without going through the FIR filter

sphear_a_to_b_hf.m

@@ -0,0 +1,54 @@
+%%
+%% *SpHEAR Project
+%% sphear_fir_render: render impulse responses throught the FIR filter A2B matrix
+%%
+%% usage:
+%%   [] = sphear_fir_render(FIR, fmin, fmax, N, Npre)
+%%
+%% FIR: A2B matrix of FIR filters
+%% fmin, fmax: range of frequencies to use
+%% N: number of samples to filter
+%% Npre: number of samples before the main impulse peak
+%% Fs: sampling rate
+%% plt: plot response
+%%
+%% Copyright 2016, Fernando Lopez-Lezcano, All Rights Reserved
+%% nando@ccrma.stanford.edu
+%%
+%%  This program is free software: you can redistribute it and/or modify
+%%  it under the terms of the GNU General Public License as published by
+%%  the Free Software Foundation, either version 3 of the License, or
+%%  (at your option) any later version.
+%%
+%%  This program is distributed in the hope that it will be useful,
+%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%%  GNU General Public License for more details.
+%%
+%%  You should have received a copy of the GNU General Public License
+%%  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+function [bf Fs] = sphear_a_to_b_hf(m, A2B, N, Npre);
+  capnames = cellstr(['LF'; 'RF'; 'LB'; 'RB']);
+  %% read in capsule signals and apply FIR filter
+  for c = 1:4
+    [cs(c,:) Fs] = wavread(["../cal/2016.04.20/export/a-format-0" sprintf("%02.0f", m) "-" char(capnames(c)) ".wav"]);
+    if (c == 1)
+      %% find highest peak location and define sample range
+      [index, value] = findmaxpeak(cs(c,:)');
+      r_start = index - Npre;
+      r_end = r_start + N -1;
+      range = r_start:r_end;
+      printf("reference: peak %f at %d, sample range [%d %d], sampling rate: %d\n",
+	     value, index, r_start, r_end, Fs);
+    end
+    cr(c,:) = cs(c,:)(range);
+    for b = 1:4
+      bs(c,b,:) = A2B(c,b) * cr(c,:);
+    end
+  end
+  %% accumulate b format signals
+  for b = 1:4
+    bf(b,:) = bs(1,b,:) + bs(2,b,:) + bs(3,b,:) + bs(4,b,:);
+  end
+end

sphear_a_to_b_hf_render.m

@@ -0,0 +1,41 @@
+%%
+%% *SpHEAR Project
+%%
+%% sphear_a_to_b_hf_render: render impulse responses throught one A2B matrix
+%%
+%% usage:
+%%   [] = sphear_a_to_b_hf_render()
+%%
+%% optional parameters:
+%%
+%% Copyright 2016, Fernando Lopez-Lezcano, All Rights Reserved
+%% nando@ccrma.stanford.edu
+%%
+%%  This program is free software: you can redistribute it and/or modify
+%%  it under the terms of the GNU General Public License as published by
+%%  the Free Software Foundation, either version 3 of the License, or
+%%  (at your option) any later version.
+%%
+%%  This program is distributed in the hope that it will be useful,
+%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%%  GNU General Public License for more details.
+%%
+%%  You should have received a copy of the GNU General Public License
+%%  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+function [BFF] = sphear_a_to_b_hf_render(A2B, N, Npre)
+
+  for m = 1:16
+    %% render b format components
+    [bf(m,:,:) srate] = sphear_a_to_b_hf(m, A2B, N, Npre);
+    %% write soundfile with rendered B format signals
+    %%
+    %% if we write a 32 bit soundfile we need to scale by 256
+    %% if we want the same amplitude as when writing a 16 bit
+    %% per sample soundfile, otherwise we get nasty clipping
+    wavwrite(reshape(bf(m,:,:),4,[])' / 256, srate, 32, ["../cal/2016.04.20/export/b-format-" sprintf("%02.0f", m) ".wav"]);
+  end
+
+end
+