void fm_demod(struct fm_state *fm)
{
int i, pcm;
pcm = polar_discriminant(fm->signal[0], fm->signal[1],
fm->pre_r, fm->pre_j);
fm->signal2[0] = (int16_t)pcm;
for (i = 2; i < (fm->signal_len); i += 2) {
switch (fm->custom_atan) {
case 0:
pcm = polar_discriminant(fm->signal[i], fm->signal[i+1],
fm->signal[i-2], fm->signal[i-1]);
break;
case 1:
pcm = polar_disc_fast(fm->signal[i], fm->signal[i+1],
fm->signal[i-2], fm->signal[i-1]);
break;
case 2:
pcm = polar_disc_lut(fm->signal[i], fm->signal[i+1],
fm->signal[i-2], fm->signal[i-1]);
break;
}
fm->signal2[i/2] = (int16_t)pcm;
}
fm->pre_r = fm->signal[fm->signal_len - 2];
fm->pre_j = fm->signal[fm->signal_len - 1];
fm->signal2_len = fm->signal_len/2;
}
void fm_demod(struct demod_state *fm)
{
int i, pcm = 0;
int16_t *lp = fm->lowpassed;
int16_t pr = fm->pre_r;
int16_t pj = fm->pre_j;
for (i = 0; i < (fm->lp_len-1); i += 2) {
switch (fm->custom_atan) {
case 0:
pcm = polar_discriminant(lp[i], lp[i+1], pr, pj);
break;
case 1:
pcm = polar_disc_fast(lp[i], lp[i+1], pr, pj);
break;
case 2:
pcm = polar_disc_lut(lp[i], lp[i+1], pr, pj);
break;
case 3:
pcm = esbensen(lp[i], lp[i+1], pr, pj);
break;
}
pr = lp[i];
pj = lp[i+1];
fm->lowpassed[i/2] = (int16_t)pcm;
}
fm->pre_r = pr;
fm->pre_j = pj;
fm->lp_len = fm->lp_len / 2;
}
void fm_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
pcm = polar_discriminant(lp[0], lp[1],
fm->pre_r, fm->pre_j);
fm->result[0] = (int16_t)pcm;
for (i = 2; i < (fm->lp_len-1); i += 2) {
switch (fm->custom_atan) {
case 0:
pcm = polar_discriminant(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
case 1:
pcm = polar_disc_fast(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
case 2:
pcm = polar_disc_lut(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
}
fm->result[i/2] = (int16_t)pcm;
}
fm->pre_r = lp[fm->lp_len - 2];
fm->pre_j = lp[fm->lp_len - 1];
fm->result_len = fm->lp_len/2;
}
void demodulate(struct demod_state *d)
{
int i, pcm;
int16_t *buf = d->buf;
int16_t *result = d->result;
pcm = polar_disc_fast(buf[0], buf[1],
d->pre_r, d->pre_j);
result[0] = (int16_t)pcm;
for (i = 2; i < (d->buf_len-1); i += 2) {
// add the other atan types?
pcm = polar_disc_fast(buf[i], buf[i+1],
buf[i-2], buf[i-1]);
result[i/2] = (int16_t)pcm;
}
d->pre_r = buf[d->buf_len - 2];
d->pre_j = buf[d->buf_len - 1];
}
void fm_demod(struct fm_state *fm)
{
int i, pcm;
pcm = polar_discriminant(fm->signal[0], fm->signal[1],
fm->pre_r, fm->pre_j);
fm->signal2[0] = (int16_t)pcm;
for (i = 2; i < (fm->signal_len); i += 2) {
if (fm->custom_atan) {
pcm = polar_disc_fast(fm->signal[i], fm->signal[i+1],
fm->signal[i-2], fm->signal[i-1]);
} else {
pcm = polar_discriminant(fm->signal[i], fm->signal[i+1],
fm->signal[i-2], fm->signal[i-1]);
}
fm->signal2[i/2] = (int16_t)pcm;
}
fm->pre_r = fm->signal[fm->signal_len - 2];
fm->pre_j = fm->signal[fm->signal_len - 1];
}