add tool to convert speaker gains into minimum phase IR

scripts/spkgains2minphaseir.m

@@ -0,0 +1,34 @@
+function [mgains,vf,X,ir] = spkgains2minphaseir( layoutname, fs, fftlen )
+% spkgains2minphaseir
+%
+  doc = tascar_xml_open( layoutname );
+  hspk = tascar_xml_get_element( doc, 'speaker' );
+  csLabels = {};
+  vgains = [];
+  mgains = [];
+  for k=1:numel(hspk)
+    vf = str2num(tascar_xml_get_attribute( hspk{k}, 'eqfreq' ));
+    vg = str2num(tascar_xml_get_attribute( hspk{k}, 'eqgain' ));
+    l = char(tascar_xml_get_attribute( hspk{k}, 'label' ));
+    mgains(end+1,:) = vg;
+    if isempty(l)
+      l = num2str(k);
+    end
+    csLabels{end+1} = l;
+    g = str2num(tascar_xml_get_attribute( hspk{k}, 'gain' ));
+    vgains(end+1) = g;
+  end
+  mgains = mgains';
+  vf = vf';
+  X = realfft(zeros(fftlen,1));
+  nbins = numel(X);
+  vflin = linspace(0,0.5*fs,nbins)';
+  X = interp1([0;vf;fs],[mgains(1,:);mgains;mgains(end,:)],vflin,'linear','extrap');
+  X = 10.^(0.05*X);
+  plot(X)
+  phase = log(max(1e-10,X));
+  phase(end+1:fftlen,:) = 0;
+  phase = -imag(hilbert(phase));
+  X = X .* exp(i*phase(1:nbins,:));
+  ir = realifft(X,fftlen);
+end