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/*
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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