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/*
t48_8.c
David Rowe
May 10 2012
Unit test for 48 to 8 kHz sample rate conversion functions. I
evaluated output by plotting using Octave and looking for jaggies:
pl("../unittest/out48.raw",1,3000)
pl("../unittest/out8.raw",1,3000)
Listening to it also shows up anything nasty:
$ play -s -2 -r 48000 out48.raw
$ play -s -2 -r 8000 out8.raw
*/
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "codec2_fdmdv.h"
#define N8 180 /* processing buffer size at 8 kHz */
#define N48 (N8 * FDMDV_OS_48)
#define MEM8 FDMDV_OS_TAPS_48_8K
#define FRAMES 50
#define TWO_PI 6.283185307
#define FS 48000
#define SINE
int main() {
float in8k[MEM8 + N8];
short in8k_short[N8];
float out48k[N48];
short out48k_short[N48];
FILE *f48;
float in48k[FDMDV_OS_TAPS_48K + N48];
float out8k[N48];
short out8k_short[N8];
FILE *f8, *f8in;
int i, f, t, t1;
float freq = 800.0;
f48 = fopen("out48.raw", "wb");
assert(f48 != NULL);
f8 = fopen("out8.raw", "wb");
assert(f8 != NULL);
f8in = fopen("in8.raw", "wb");
assert(f8in != NULL);
/* clear filter memories */
for (i = 0; i < MEM8; i++) in8k[i] = 0.0;
for (i = 0; i < FDMDV_OS_TAPS_48K; i++) in48k[i] = 0.0;
t = t1 = 0;
for (f = 0; f < FRAMES; f++) {
#ifdef DC
for (i = 0; i < N8; i++) in8k[MEM8 + i] = 16000.0;
#endif
#ifdef SINE
for (i = 0; i < N8; i++, t++)
in8k[MEM8 + i] = 16000.0 * cos(TWO_PI * t * freq / (FS / FDMDV_OS_48));
#endif
for (i = 0; i < N8; i++) in8k_short[i] = (short)in8k[i];
fwrite(in8k_short, sizeof(short), N8, f8in);
/* upsample */
fdmdv_8_to_48(out48k, &in8k[MEM8], N8);
/* save 48k to disk for plotting and check out */
for (i = 0; i < N48; i++) out48k_short[i] = (short)out48k[i];
fwrite(out48k_short, sizeof(short), N48, f48);
/* add a 10 kHz spurious signal for fun, we want down sampler to
knock this out */
for (i = 0; i < N48; i++, t1++)
in48k[i + FDMDV_OS_TAPS_48K] =
out48k[i] + 16000.0 * cos(TWO_PI * t1 * 1E4 / FS);
/* downsample */
fdmdv_48_to_8(out8k, &in48k[FDMDV_OS_TAPS_48K], N8);
/* save 8k to disk for plotting and check out */
for (i = 0; i < N8; i++) out8k_short[i] = (short)out8k[i];
fwrite(out8k_short, sizeof(short), N8, f8);
}
fclose(f48);
fclose(f8);
fclose(f8in);
return 0;
}
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