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/*
mksine.c
David Rowe
10 Nov 2010
Creates a file of sine wave samples.
*/
#include <assert.h>
#include <errno.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define TWO_PI 6.283185307
#define FS 8000.0
int main(int argc, char *argv[]) {
FILE *f;
int i, n;
float freq, length;
short *buf;
float amp = 1E4;
if (argc < 4) {
printf("usage: %s outputFile frequencyHz lengthSecs [PeakAmp]\n", argv[0]);
exit(1);
}
if (strcmp(argv[1], "-") == 0) {
f = stdout;
} else if ((f = fopen(argv[1], "wb")) == NULL) {
fprintf(stderr, "Error opening output file: %s: %s.\n", argv[3],
strerror(errno));
exit(1);
}
freq = atof(argv[2]);
length = atof(argv[3]);
if (argc == 5) amp = atof(argv[4]);
n = length * FS;
buf = (short *)malloc(sizeof(short) * n);
assert(buf != NULL);
for (i = 0; i < n; i++) buf[i] = amp * cos(freq * i * (TWO_PI / FS));
fwrite(buf, sizeof(short), n, f);
fclose(f);
free(buf);
return 0;
}
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