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start modularization

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This commit is contained in:
KubaPro010
2025-06-21 15:06:27 +02:00
parent 33ffcd9682
commit 16f0a53c05
18 changed files with 79 additions and 43 deletions
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15
modulation/fm_modulator.c Normal file
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#include "fm_modulator.h"
void init_fm_modulator(FMModulator *fm, float frequency, float deviation, float sample_rate) {
fm->frequency = frequency;
fm->deviation = deviation;
fm->sample_rate = sample_rate;
fm->osc_phase = 0.0f;
}
float modulate_fm(FMModulator *fm, float sample) {
float inst_freq = fm->frequency+(sample*fm->deviation);
fm->osc_phase += (M_2PI * inst_freq) / fm->sample_rate;
fm->osc_phase -= (fm->osc_phase >= M_2PI) ? M_2PI : 0.0f;
return sinf(fm->osc_phase);
}

14
modulation/fm_modulator.h Normal file
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#pragma once
#include "../dsp/oscillator.h"
typedef struct
{
float frequency;
float deviation;
float osc_phase;
float sample_rate;
} FMModulator;
void init_fm_modulator(FMModulator *fm, float frequency, float deviation, float sample_rate);
float modulate_fm(FMModulator *fm, float sample);

26
modulation/stereo_encoder.c Normal file
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#include "stereo_encoder.h"
// Multiplier is the multiplier to get to 19 khz, or 31.25 if polar
void init_stereo_encoder(StereoEncoder* st, uint8_t multiplier, Oscillator* osc, uint8_t polar, float mono_volume, float pilot_volume, float stereo_volume) {
st->multiplier = multiplier;
st->osc = osc;
st->polar = polar;
st->mono_volume = mono_volume;
st->pilot_volume = pilot_volume;
st->stereo_volume = stereo_volume;
}
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right) {
float mid = (left+right) * 0.5f;
if(!enabled) return mid * st->mono_volume;
float side = (left-right) * 0.5f;
if(!st->polar) {
float pilot = get_oscillator_sin_multiplier_ni(st->osc, st->multiplier);
float carrier = get_oscillator_sin_multiplier_ni(st->osc, st->multiplier * 2.0f);
return (mid*st->mono_volume) + (pilot*st->pilot_volume) + ((side*carrier) * st->stereo_volume);
} else {
float carrier = get_oscillator_sin_multiplier_ni(st->osc, st->multiplier);
return (mid*st->mono_volume) + (((side+0.2f)*carrier) * st->stereo_volume); // Polar stereo does not contain a pilot, but it contains a -14 db carrier wave on the stereo subcarrier
}
}

18
modulation/stereo_encoder.h Normal file
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#pragma once
#include <stdint.h>
#include "../dsp/oscillator.h"
typedef struct
{
uint8_t multiplier;
Oscillator* osc;
uint8_t polar;
float mono_volume;
float pilot_volume;
float stereo_volume;
} StereoEncoder;
void init_stereo_encoder(StereoEncoder *st, uint8_t multiplier, Oscillator *osc, uint8_t polar, float mono_volume, float pilot_volume, float stereo_volume);
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right);