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#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <math.h>
#include <inttypes.h>
#include "resample.h"
#include "interpol.h"
#define SINC_RADIUS 10
static int lcd(int a, int b) {
assert(a >= 1 && b >= 1);
while (a != b) {
while (a > b) {
a = a-b;
}
while (b > a) {
b = b-a;
}
}
return a;
}
void resample_init(struct resample_state *s) {
assert(s);
memset(s, 0, sizeof(struct resample_state));
s->sfreq = s->dfreq = -1;
}
void resample_done(struct resample_state *s) {
assert(s);
interpol_done(&s->interpol);
}
void resample_get(struct resample_state *s, struct qbuf *sq, struct qbuf *dq, int sfreq, int dfreq) {
int di;
float x = 0;
float *sp, *dp;
size_t sl, dl;
assert(s && sq && dq && sfreq > 0 && dfreq > 0);
if (sfreq != s->sfreq || dfreq != s->dfreq) {
interpol_done(&s->interpol);
interpol_init(&s->interpol, dfreq/lcd(sfreq,dfreq), SINC_RADIUS);
s->sfreq = sfreq;
s->dfreq = dfreq;
}
sp = qbuf_pull(sq, &sl);
dp = qbuf_push(dq, &dl);
assert(sp && dp && sl && dl);
sl /= sizeof(float);
dl /= sizeof(float);
di = 0;
while (di < dl) {
x = (float) di*sfreq/dfreq + s->delta;
if (x + SINC_RADIUS + 1 > sl)
break;
*(dp++) = interpol_get(&s->interpol, sp, sl, x);
di++;
}
qbuf_push_validate(dq, di*sizeof(float));
if (x >= SINC_RADIUS) {
int rn;
rn = (int) (x - SINC_RADIUS);
assert(rn <= sl);
s->delta = x - rn;
fprintf(stderr, "foo\n");
qbuf_pull_invalidate(sq, rn*sizeof(float));
fprintf(stderr, "bar\n");
}
}
#if (TEST == 7)
#define BUFSIZE (10*1024)
static void sinbuf(float *buf, int l) {
static int i = 0;
for (; l > 0; l--, i = (i+1 == 100) ? 0 : i+1)
*(buf++) = sin(i*2*M_PI/100);
}
static void convbuf(float *buf, int l) {
int16_t *p = (int16_t*) buf;
for (; l > 0; l--, p+=2) {
float v = ((float) *p + (float) *(p+1))/0x7FFF;
*(buf++) = (v < -1) ? -1 : ((v > 1) ? 1 : v);
}
}
int main(int argc, char *argv[]) {
struct resample_state resample;
struct qbuf qi, qo;
if (argc > 1) {
stdin = fopen(argv[1], "r");
assert(stdin);
}
qbuf_init(&qi, BUFSIZE);
qbuf_init(&qo, BUFSIZE);
resample_init(&resample);
while (!feof(stdin)) {
int c;
float *ip, *up;
size_t il, ol;
fprintf(stderr, "LOOP!\n");
ip = qbuf_push(&qi, &il);
c = fread(ip, sizeof(float), il/sizeof(float), stdin);
convbuf(ip, c);
qbuf_push_validate(&qi, c*sizeof(float));
resample_get(&resample, &qi, &qo, 44100, 8000);
up = qbuf_pull(&qo, &ol);
fwrite(up, sizeof(float), ol/sizeof(float), stdout);
qbuf_pull_invalidate(&qo, ol);
}
resample_done(&resample);
qbuf_done(&qi);
qbuf_done(&qo);
return 0;
}
#endif
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