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