- refactored

- remove DC

matlab/osc/blip/eval_blit.m

@@ -1,24 +1,22 @@
 function eval_blit()
 
-sinc_use_lut = 0
+sinc_use_lut = 1
 
 L = 96000;
 fs = 48000;
-fstart = 440;
-fend = 440;
+fstart = 220;
+fend = 880;
 df = (fend-fstart)/L
 
 # for saw 
-rho = 0.95;
+rho = 1.0;
 
 nhw = 4096;
 Hw = kaiser(nhw, 8)';
 
 max_m = fix((fs/fstart/2.0)) + 1
 
-sinc_table_calc = sinc_use_lut;
-
-if sinc_table_calc == 1
+if sinc_use_lut == 1
     nharm = max_m
     nsin = 1024;
     xx = (0:nsin)/nsin - 0.5;
@@ -38,6 +36,7 @@ saw = 0.0;
 tri = 0.0;
 a = 1;
 b = 1;
+
 for n = 1:L,
 
 	if x >= 0.5,
@@ -51,22 +50,18 @@ for n = 1:L,
         nn = (x+0.5)*nsin + 1;
         ni = fix(nn);
         nf = nn - ni;
-        bbi = (bb(m, ni+1) - bb(m, ni))*nf + bb(m, ni);     % Fractional delay (linear interpolation)
-        aai = (aa(ni+1) - aa(ni))*nf + aa(ni);              % Fractional delay (linear interpolation)
-        if (aai ~= 0)
-            blit = fraq* bbi / aai  * Hw(fix((x+0.5)*nhw)+1);
-        else
-            blit = fraq;
-        end
+        b = (bb(m, ni+1) - bb(m, ni))*nf + bb(m, ni);     % Fractional delay (linear interpolation)
+        a = (aa(ni+1) - aa(ni))*nf + aa(ni);              % Fractional delay (linear interpolation)
     else
         b = sin(m*x*pi);
         a = sin(x*pi);
+    end
+
     if (a ~= 0)
         blit = fraq * b/a * Hw(fix((x+0.5)*nhw)+1);
     else
         blit = fraq;
     end
-    end
     
 	saw = rho*saw + (fraq - blit);
 	sqr = sqr + z*blit;
@@ -85,8 +80,11 @@ close all
 figure;
 plot(1:L, vsaw, 1:L, vblit); grid;
 
-wavwrite(0.5*vtri, fs, 'tri.wav');
-wavwrite(0.5*vsqr, fs, 'sqr.wav');
-wavwrite(0.5*vsaw, fs, 'saw.wav');
+N_UNDC = fs/100;
+
+a, b = undcc(N_UNDC);
+wavwrite(0.5*filter(b, a, vtri), fs, 'tri.wav');
+wavwrite(0.5*filter(b, a, vsqr), fs, 'sqr.wav');
+wavwrite(0.5*filter(b, a, vsaw), fs, 'saw.wav');
 wavwrite(0.5*vblit, fs, 'blit.wav');