55 lines
1023 B
C
55 lines
1023 B
C
/*
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mksine.c
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David Rowe
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10 Nov 2010
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Creates a file of sine wave samples.
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*/
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#include <assert.h>
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#include <errno.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define TWO_PI 6.283185307
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#define FS 8000.0
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int main(int argc, char *argv[]) {
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FILE *f;
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int i, n;
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float freq, length;
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short *buf;
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float amp = 1E4;
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if (argc < 4) {
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printf("usage: %s outputFile frequencyHz lengthSecs [PeakAmp]\n", argv[0]);
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exit(1);
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}
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if (strcmp(argv[1], "-") == 0) {
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f = stdout;
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} else if ((f = fopen(argv[1], "wb")) == NULL) {
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fprintf(stderr, "Error opening output file: %s: %s.\n", argv[3],
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strerror(errno));
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exit(1);
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}
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freq = atof(argv[2]);
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length = atof(argv[3]);
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if (argc == 5) amp = atof(argv[4]);
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n = length * FS;
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buf = (short *)malloc(sizeof(short) * n);
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assert(buf != NULL);
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for (i = 0; i < n; i++) buf[i] = amp * cos(freq * i * (TWO_PI / FS));
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fwrite(buf, sizeof(short), n, f);
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fclose(f);
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free(buf);
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return 0;
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}
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