added matlab

2025-08-21 07:27:52 +02:00
parent fd522e1b99
commit 64c6745c76
50 changed files with 2516 additions and 0 deletions
@@ -0,0 +1,68 @@
+function eval_blit()
+L = 64000;
+Nb = 137;
+Nphases = 256;
+fs = 48000;
+fstart = 110*4;
+fend = 110*4;
+df = (fend-fstart)/L;
+fcut = 16000;
+
+x = (0:Nb*Nphases-1) - (Nb*Nphases-1)/2;
+H = sinc(2*fcut/fs.*x/Nphases);%.*Kaiser(Nphases*Nb, 8)';
+Hw = Kaiser(Nb, 18)';
+
+for ii=0:Nphases-1,
+    for jj=0:Nb-1
+        Hs(ii+1,jj+1) = H(Nphases-ii+Nphases*jj);
+    end
+end;
+
+
+f = fstart;
+Pic = 1;
+blit(1:L) = zeros(1, L);
+blit_bp(1:L) = zeros(1, L);
+pol = 1;
+for n = Nb:L,
+	P = fs/f;
+	Pi = floor(P);
+	Pf = 1+fix(Nphases*(P - Pi));
+
+	if Pic >= Pi,
+		blit(n-Nb+1:n) = blit(n-Nb+1:n) + Hs(Pf,:).*Hw;
+		blit_bp(n-Nb+1:n) = blit_bp(n-Nb+1:n) + pol*Hs(Pf,:).*Hw;
+		Pic = 0;
+		pol = -pol;
+	end;
+	Pic = Pic + 1;
+	f = f + df;
+end;
+
+mean_blit = 0.0034;
+mean_saw =  0.00;
+
+saw(1:L) = zeros(1, L);
+sqr(1:L) = zeros(1, L);
+y_saw = 0;
+y_sqr = 0;
+for n = 2:L,
+	y_saw = y_saw + blit(n)-mean_blit;
+	y_sqr = y_sqr + blit_bp(n);
+	saw(n) = -y_saw -1;
+	sqr(n) = y_sqr;
+end;
+
+saw_nodc = filter([1 -1], [1 -0.995], saw);
+sqr_nodc = filter([1 -1], [1 -0.995], sqr);
+
+close all;
+plot(saw); grid;
+
+figure;
+plot(saw_nodc); grid;
+
+wavwrite(0.8*blit, fs, 'blit.wav');
+wavwrite(0.7*saw_nodc, fs, 'saw.wav');
+wavwrite(0.5*sqr_nodc, fs, 'sqr.wav');
+