Working codec2 support

libs/libcodec2/octave/phase.m

@@ -0,0 +1,56 @@
+% phase.m
+% David Rowe August 2009
+% experiments with phase for sinusoidal codecs
+
+function phase(samname, F0, png)
+  Wo=2*pi*F0/8000;
+  P=2*pi/Wo;
+  L = floor(pi/Wo);
+  Nsam = 16000;
+  N = 80;
+  F = Nsam/N;
+  A = 10000/L;
+  phi = zeros(1,L);
+  s = zeros(1,Nsam);
+  
+  for m=floor(L/2):L
+    phi_off(m) = -m*Wo*8;
+  end
+
+  for f=1:F
+    phi(1) = phi(1) + Wo*N;
+    phi(1) = mod(phi(1),2*pi);
+  
+    for m=1:L
+      phi(m) = m*phi(1);
+    end
+
+    x = zeros(1,N);
+    for m=1:L
+      x = x + A*cos(m*Wo*(0:(N-1)) + phi(m));
+    endfor
+    s((f-1)*N+1:f*N) = x;
+  endfor
+
+  figure(1);
+  clf;
+  plot(s(1:250));
+
+  fs=fopen(samname,"wb");
+  fwrite(fs,s,"short");
+  fclose(fs);
+
+  if (nargin == 3)
+      % 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
+