void run_equalizer(FloatBuffer *fbin, FloatBuffer *fbout, EqualizerData *data)
{
int i, rpos;
float lpf_out[EQUALIZER_BANDS + 1];
float sum = 0.0;
/* Save the input read location; we can reuse the same input data on all
* of the LPFs. */
rpos = fbin->rpos;
/* Run the child filters. */
for (i = 0; i < EQUALIZER_BANDS + 1; i++)
{
fbin->rpos = rpos;
run_lpf(fbin, &data->fb[i], &data->lpf[i]);
lpf_out[i] = data->fb[i].buff[data->fb[i].rpos++];
}
/* Now process the results of the filters. Remember that each band is
* output(hi)-output(lo). */
for (i = 0; i < EQUALIZER_BANDS; i++)
sum += (lpf_out[i+1] - lpf_out[i]) * data->gain[i];
/* Write that result. */
fb_ensure_writable(fbout, 1);
fbout->buff[fbout->rlen++] = sum;
}
void
run_lpf(FloatBuffer *fbin, FloatBuffer *fbout, LPFData *data)
{
float sum = 0.0;
int i = 0;
if (fbin->rpos + data->taps - 1 >= fbin->rlen)
{
print("WARNING: upcoming underflow in run_lpf()\n");
}
for (i = 0; i < data->taps; i++)
{
sum += fbin->buff[fbin->rpos + i] * data->coeff[i];
}
fbin->rpos += data->decimation + 1;
/* */
/* Check that there's room in the output buffer; */
/* move data if necessary. */
/* */
fb_ensure_writable(fbout, 1);
fbout->buff[fbout->rlen++] = sum;
return;
}
void run_demod(FloatBuffer *fbin, FloatBuffer *fbout)
{
float temp, gain;
gain = MAX_AMPLITUDE * SAMPLING_RATE / (BANDWIDTH * M_PI);
temp = fbin->buff[fbin->rpos] * fbin->buff[fbin->rpos + 1];
temp = gain * atan(temp);
fbin->rpos++;
fb_ensure_writable(fbout, 1);
fbout->buff[fbout->rlen++] = temp;
}
