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agc?

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This commit is contained in:
KubaPro010
2025-04-19 13:04:07 +02:00
parent 702ee8922b
commit 4564bbf737
8 changed files with 107 additions and 45 deletions
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6
lib/bs412.h
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@@ -3,9 +3,9 @@
typedef struct
{
int i;
int sample_rate;
double sample;
int i;
int sample_rate;
double sample;
} MPXPowerMeasurement;
float dbr_to_deviation(float dbr);

2
lib/debug.h
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@@ -1,4 +1,4 @@
#pragma once
#include <stdio.h>
#define debug_printf(fmt, ...) \
printf("[%s:%d in %s] " fmt, __FILE__, __LINE__, __func__, ##__VA_ARGS__)
printf("[%s:%d in %s] " fmt, __FILE__, __LINE__, __func__, ##__VA_ARGS__)

6
lib/filters.h
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@@ -7,12 +7,6 @@
#include "optimization.h"
#include "oscillator.h"
#if USE_NEON
#define LPF_ORDER 20 // neon has to have divisable by 4
#else
#define LPF_ORDER 10
#endif
typedef struct
{
float alpha;

40
lib/gain_control.c Normal file
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@@ -0,0 +1,40 @@
#include "gain_control.h"
void initAGC(AGC* agc, int sampleRate, float targetLevel, float minGain, float maxGain, float attackTime, float releaseTime) {
agc->sampleRate = sampleRate;
agc->targetLevel = targetLevel;
agc->minGain = minGain;
agc->maxGain = maxGain;
agc->attackTime = attackTime;
agc->releaseTime = releaseTime;
agc->attackCoef = expf(-1.0f / (sampleRate * attackTime));
agc->releaseCoef = expf(-1.0f / (sampleRate * releaseTime));
agc->currentGain = 1.0f;
agc->currentLevel = 0.0f;
agc->rms_buffer = 0.0f;
}
float process_agc_stereo(AGC* agc, float left, float right, float *right_out) {
float sample = (left+right)/2;
float x2 = sample * sample;
float rmsAlpha = expf(-1.0f / (agc->sampleRate * 0.04));
agc->rms_buffer = rmsAlpha * agc->rms_buffer + (1.0f - rmsAlpha) * x2;
float instantLevel = sqrtf(agc->rms_buffer);
float alpha = (instantLevel > agc->currentLevel) ? agc->attackCoef : agc->releaseCoef;
agc->currentLevel = alpha * agc->currentLevel + (1.0f - alpha) * instantLevel;
float desiredGain = agc->targetLevel / fmaxf(agc->currentLevel, 1e-10f);
desiredGain = fminf(fmaxf(desiredGain, agc->minGain), agc->maxGain);
float gainAlpha = (desiredGain > agc->currentGain) ? agc->attackCoef : agc->releaseCoef;
agc->currentGain = gainAlpha * agc->currentGain + (1.0f - gainAlpha) * desiredGain;
*right_out = right * agc->currentGain;
return left * agc->currentGain;
}

22
lib/gain_control.h Normal file
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@@ -0,0 +1,22 @@
#pragma once
#include <math.h>
typedef struct {
float targetLevel;
float maxGain;
float minGain;
float attackTime;
float releaseTime;
float currentGain;
float currentLevel;
int sampleRate;
float attackCoef;
float releaseCoef;
float rms_buffer;
} AGC;
void initAGC(AGC* agc, int sampleRate, float targetLevel, float minGain, float maxGain, float attackTime, float releaseTime);
float process_agc_stereo(AGC* agc, float left, float right, float *right_out);

10
lib/oscillator.c
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@@ -23,15 +23,15 @@ float get_oscillator_cos_sample(Oscillator *osc) {
}
float get_oscillator_sin_multiplier_ni(Oscillator *osc, float multiplier) {
float new_phase = osc->phase * multiplier;
new_phase -= (new_phase >= M_2PI) ? M_2PI : 0.0f;
return sinf(new_phase);
float new_phase = osc->phase * multiplier;
new_phase -= (new_phase >= M_2PI) ? M_2PI : 0.0f;
return sinf(new_phase);
}
float get_oscillator_cos_multiplier_ni(Oscillator *osc, float multiplier) {
float new_phase = osc->phase * multiplier;
new_phase -= (new_phase >= M_2PI) ? M_2PI : 0.0f;
return cosf(new_phase);
new_phase -= (new_phase >= M_2PI) ? M_2PI : 0.0f;
return cosf(new_phase);
}
void advance_oscillator(Oscillator *osc) {

60
src/dcf95.c
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@@ -133,41 +133,41 @@ void calculate_dcf77_bits(time_t now, int *bits) {
bits[20] = 1;
int minutes = t->tm_min;
for (int i = 0; i < 4; i++) {
bits[21 + i] = (minutes % 10 >> i) & 1;
}
for (int i = 0; i < 3; i++) {
bits[25 + i] = (minutes / 10 >> i) & 1;
}
for (int i = 0; i < 4; i++) {
bits[21 + i] = (minutes % 10 >> i) & 1;
}
for (int i = 0; i < 3; i++) {
bits[25 + i] = (minutes / 10 >> i) & 1;
}
int minute_parity = 0;
for (int i = 21; i <= 27; i++) {
minute_parity ^= bits[i];
}
bits[28] = minute_parity;
int minute_parity = 0;
for (int i = 21; i <= 27; i++) {
minute_parity ^= bits[i];
}
bits[28] = minute_parity;
int hours = t->tm_hour;
if(cest) hours += 1;
for (int i = 0; i < 4; i++) {
bits[29 + i] = (hours % 10 >> i) & 1;
}
for (int i = 0; i < 2; i++) {
bits[33 + i] = (hours / 10 >> i) & 1;
}
bits[29 + i] = (hours % 10 >> i) & 1;
}
for (int i = 0; i < 2; i++) {
bits[33 + i] = (hours / 10 >> i) & 1;
}
int hour_parity = 0;
for (int i = 29; i <= 34; i++) {
hour_parity ^= bits[i];
}
bits[35] = hour_parity;
for (int i = 29; i <= 34; i++) {
hour_parity ^= bits[i];
}
bits[35] = hour_parity;
int day = t->tm_mday;
for (int i = 0; i < 4; i++) {
bits[36 + i] = (day % 10 >> i) & 1;
}
for (int i = 0; i < 2; i++) {
bits[40 + i] = (day / 10 >> i) & 1;
}
bits[36 + i] = (day % 10 >> i) & 1;
}
for (int i = 0; i < 2; i++) {
bits[40 + i] = (day / 10 >> i) & 1;
}
int dow = t->tm_wday == 0 ? 7 : t->tm_wday;
bits[42] = dow & 0x01;
@@ -176,17 +176,17 @@ void calculate_dcf77_bits(time_t now, int *bits) {
int month = t->tm_mon + 1;
for (int i = 0; i < 4; i++) {
bits[45 + i] = (month % 10 >> i) & 1;
}
bits[45 + i] = (month % 10 >> i) & 1;
}
bits[49] = (month / 10) & 0x01;
int year = t->tm_year % 100;
for (int i = 0; i < 4; i++) {
bits[50 + i] = (year % 10 >> i) & 1;
bits[50 + i] = (year % 10 >> i) & 1;
}
for (int i = 0; i < 4; i++) {
bits[54 + i] = (year / 10 >> i) & 1;
}
bits[54 + i] = (year / 10 >> i) & 1;
}
int year_parity = 0;
for (int i = 36; i <= 57; i++) {

6
src/fm95.c
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@@ -21,6 +21,7 @@
#include "../lib/fm_modulator.h"
#include "../lib/optimization.h"
#include "../lib/bs412.h"
#include "../lib/gain_control.h"
#define DEFAULT_SAMPLE_RATE 192000
@@ -453,6 +454,10 @@ int main(int argc, char **argv) {
MPXPowerMeasurement mpx_only_power;
init_modulation_power_measure(&mpx_only_power, sample_rate);
AGC agc;
void initAGC(AGC* agc, int sampleRate, float targetLevel, float minGain, float maxGain, float attackTime, float releaseTime);
initAGC(&agc, sample_rate, 0.707f, 0.25f, 2.5f, 0.01f, 0.4f);
signal(SIGINT, stop);
signal(SIGTERM, stop);
@@ -512,6 +517,7 @@ int main(int argc, char **argv) {
float ready_l = apply_preemphasis(&preemp_l, l_in);
float ready_r = apply_preemphasis(&preemp_r, r_in);
ready_l = process_agc_stereo(&agc, ready_l, ready_r, &ready_r);
ready_l = hard_clip(ready_l*audio_volume, clipper_threshold);
ready_r = hard_clip(ready_r*audio_volume, clipper_threshold);