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#include "EqBand.h"
#include <assert.h>
#include <math.h>
EqBand::EqBand() : sampleRate(44100), centerFrequency(1000), gain(1), _q(0.5), nch(0), channels(0), bypass(true)
{
}
void EqBand::set_num_channels(int num_channels)
{
if (nch < num_channels)
{
nch = num_channels;
delete[]channels;
channels = new Biquad[nch];
clear_buffers();
set_parameters(centerFrequency, gain, _q);
}
}
void EqBand::SetSampleRate(double sample_freq)
{
if (sample_freq != sampleRate)
{
sampleRate = sample_freq;
for (int chn = 0; chn < nch; ++chn)
{
channels[chn].SetSampleRate(sampleRate);
}
clear_buffers();
set_parameters(centerFrequency, gain, _q);
}
}
void EqBand::set_parameters(double freq, double newGain, double q)
{
centerFrequency = freq;
gain = newGain;
_q = q;
if (nch > 0)
{
Biquad & ref_filter = channels[0];
ref_filter.set_freq(centerFrequency);
double a[3] = { 1, 1/_q, 1 };
double b[3] = {1, gain / _q, 1};
ref_filter.set_s_eq(b, a);
ref_filter.transform_s_to_z();
for (int chn = 1; chn < nch; ++chn)
channels[chn].copy_filter(ref_filter);
}
bypass = (fabs(gain - 1.0) < 0.02); // About 1/4 dB
}
void EqBand::process(float ** const out, float ** in, long nbr_spl, int nbr_chn)
{
assert(nbr_chn >= 0);
assert(nbr_chn <= nch);
if (!bypass)
{
for (int chn = 0; chn < nbr_chn; ++chn)
{
channels[chn].process_block(out[chn], in[chn], nbr_spl);
}
}
}
void EqBand::clear_buffers()
{
for (int chn = 0; chn < nch; ++chn)
{
channels[chn].clear_buffers();
}
}
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