From ac7c48b4dee99d4c772f133d70d8d1b38262fcd2 Mon Sep 17 00:00:00 2001
From: Author Name <david@rowetel.com>
Date: Fri, 7 Jul 2023 12:20:59 +0930
Subject: shallow zip-file copy from codec2 e9d726bf20

---
 misc/timpulse.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 misc/timpulse.c

(limited to 'misc/timpulse.c')

diff --git a/misc/timpulse.c b/misc/timpulse.c
new file mode 100644
index 0000000..8227c0d
--- /dev/null
+++ b/misc/timpulse.c
@@ -0,0 +1,128 @@
+/*
+  timpulse.c
+  David Rowe Dec 2019
+
+  Generate a synthetic speech signal from a sum of sinusoids.  Generates a known test
+  signals for phaseNN and ampNN projects.
+*/
+
+#include <assert.h>
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <getopt.h>
+
+#define FS 8000
+
+int main(int argc, char *argv[]) {
+    short buf[FS] = {0};
+    float f0 = 60.0;
+    float n0 = 0.0;
+    int   Nsecs = 1;
+    int   randf0 = 0;
+    int   filter = 0;
+    int   rande = 0;
+    
+    int o = 0;
+    int opt_idx = 0;
+    while( o != -1 ) {
+        static struct option long_opts[] = {
+            {"help",   no_argument,       0, 'h'},
+            {"n0",     required_argument, 0, 'n'},
+            {"f0",     required_argument, 0, 'f'},
+            {"secs",   required_argument, 0, 's'},
+            {"randf0", no_argument, 0, 'r'},
+            {"rande",  required_argument, 0, 'e'},
+            {"filter", no_argument, 0, 'i'},
+            {0, 0, 0, 0}
+        };
+        
+        o = getopt_long(argc,argv,"hn:f:s:r",long_opts,&opt_idx);
+        
+        switch(o) {
+        case 'n':
+	    n0 = atof(optarg);
+            break;
+        case 'f':
+            f0 = atof(optarg);
+	    break;
+        case 's':
+            Nsecs = atoi(optarg);
+	    break;
+        case 'r':
+            randf0 = 1;
+	    break;
+        case 'i':
+            filter = 1;
+	    break;
+        case 'e':
+            rande = atoi(optarg);
+	    break;
+        case '?':
+        case 'h':
+	    fprintf(stderr,
+		    "usage: %s\n"
+		    "[--f0 f0Hz]          fixed F0\n" 
+                    "[--n0 samples]       time offset\n" 
+                    "[--secs Nsecs]       number of seconds to generate\n"
+	            "[--randf0]           choose a random F0 every second\n"
+	            "[--rande Ndiscrete]  choose a random frame energy every second, Ndiscrete values\n"
+		    "\n", argv[0]);
+	    exit(1);      
+	break;
+        }
+    }
+
+    int t = 0;
+    float A = 100.0;
+    
+    /* optionally filter with 2nd order system */
+    float alpha = 0.25*M_PI, gamma=0.99;
+    float a[2] = {-2.0*gamma*cos(alpha), gamma*gamma};
+    float mem[2] = {0};
+    
+    for (int j=0; j<Nsecs; j++) {
+	if (rande) {
+	    float AdB_min = 20.0*log10(100.0);
+	    float AdB_step = 6.0;
+	    float num_values = rande;
+
+	    // discrete RV between 0..1
+	    float r = (float)rand()/RAND_MAX;
+	    r = floor(r*num_values);
+	    
+	    float AdB = AdB_min + r*AdB_step;
+	    A = pow(10.0,AdB/20.0);
+	    fprintf(stderr, "r: %f AdB: %f A: %f\n", r, AdB, A);
+	}
+	if (randf0) {
+	    float pitch_period = FS/400.0 + (FS/80.0 - FS/400.0)*rand()/RAND_MAX;
+	    f0 = (float)FS/pitch_period;
+	    //fprintf(stderr, "P: %f f0: %f\n", pitch_period, f0);
+	}
+	float Wo = 2.0*M_PI*f0/FS;
+	int L = M_PI/Wo;
+	float e = 0.0;
+	for(int i=0; i<FS; i++) {
+	    buf[i] = 0;
+	    // 1/sqrt(L) term makes power constant across Wo
+	    for(int m=1; m<L; m++)
+		buf[i] += (A/sqrt(L))*cos(m*Wo*(t + n0));
+	    e += pow(buf[i], 2.0);
+	    t++;
+	}
+	//fprintf(stderr, "e (dB): %f\n", 10*log10(e));
+	if (filter) {
+	    for(int i=0; i<FS; i++) {
+		float x = (float)buf[i];
+		float y = (x - mem[0]*a[0] - mem[1]*a[1]);
+		mem[1] = mem[0]; mem[0] = y;
+		buf[i] = (short)y;
+	    }
+	}
+    
+	fwrite(buf, sizeof(short), FS, stdout);
+    }
+    
+    return 0;
+}
-- 
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