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30 lines
857 B
C
30 lines
857 B
C
#pragma once
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#define FILTER_TAPS 256
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#include <math.h>
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#include <string.h>
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#include <stdlib.h>
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#include "constants.h"
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typedef struct
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{
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float alpha;
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float prev_sample;
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} ResistorCapacitor;
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void init_preemphasis(ResistorCapacitor *filter, float tau, float sample_rate);
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float apply_preemphasis(ResistorCapacitor *filter, float sample);
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typedef struct {
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// https://www.earlevel.com/main/2012/11/26/biquad-c-source-code/
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float a0, a1, a2;
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float b1, b2;
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float z1, z2;
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} BiquadFilter;
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void init_lpf(BiquadFilter* filter, float cutoffFreq, float qFactor, float sampleRate);
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float apply_biquad(BiquadFilter* filter, float input);
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float hard_clip(float sample, float threshold);
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float voltage_db_to_voltage(float db);
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float power_db_to_voltage(float db);
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float voltage_to_voltage_db(float linear);
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float voltage_to_power_db(float linear); |