Working codec2 support

libs/libcodec2/octave/phase2.m

@@ -0,0 +1,50 @@
+% phase2.m
+% David Rowe Sep 2009
+% experiments with phase for sinusoidal codecs, looking at phase
+% of excitation with real Am samples from hts1
+
+function phase2(samname, png)
+  N = 16000;
+
+  f=45;
+  model = load("../src/hts1a_model.txt");
+  phase = load("../src/hts1a_phase_phase.txt");
+  Wo = model(f,1);
+  P=2*pi/Wo;
+  L = model(f,2);
+  A = model(f,3:(L+2));
+  phi = phase(f,1:L);
+  phi = zeros(1,L);
+  for m=L/2:L
+    phi(m) = 2*pi*rand(1,1);
+  end
+
+  s = zeros(1,N);
+
+  for m=1:L
+    s_m = A(m)*cos(m*Wo*(0:(N-1)) + phi(m));
+    s = s + s_m;
+  endfor
+
+  figure(1);
+  clf;
+  plot(s(1:250));
+
+  fs=fopen(samname,"wb");
+  fwrite(fs,s,"short");
+  fclose(fs);
+
+  if (nargin == 2)
+      % small image to fit blog
+
+      __gnuplot_set__ terminal png size 450,300
+      ss = sprintf("__gnuplot_set__ output \"%s.png\"", samname);
+      eval(ss)
+      replot;
+
+      % for some reason I need this to stop large plot getting wiped
+      __gnuplot_set__ output "/dev/null"
+  endif
+
+endfunction
+