radio95/fm95
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Code Issues Activity

get rid of compressor

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This commit is contained in:
KubaPro010
2025-03-02 10:30:07 +01:00
parent 30ddac535d
commit bae5ae5c1b
3 changed files with 5 additions and 48 deletions
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31
lib/filters.c
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@@ -119,33 +119,4 @@ float voltage_to_voltage_db(float linear) {
float voltage_to_power_db(float linear) { float voltage_to_power_db(float linear) {
return 10.0f * log10f(fmaxf(linear, 1e-10f)); // Avoid log(0) return 10.0f * log10f(fmaxf(linear, 1e-10f)); // Avoid log(0)
} }
void init_compressor(Compressor *compressor, float attack, float release) {
compressor->attack = attack;
compressor->release = release;
compressor->max = 0.0f;
}
float peak_compress(Compressor *compressor, float sample) {
float sample_abs = fabsf(sample);
if(sample_abs > compressor->max) {
compressor->max += (sample_abs - compressor->max) * compressor->attack;
} else {
compressor->max *= compressor->release;
}
return sample/(compressor->max+0.01);
}
float peak_compress_stereo(Compressor *compressor, float l, float r, float *output_r) {
float l_abs = fabsf(l);
float r_abs = fabsf(r);
float max = (l_abs > r_abs) ? l_abs : r_abs;
if(max > compressor->max) {
compressor->max += (max - compressor->max) / compressor->attack;
} else {
compressor->max *= compressor->release;
}
*output_r = r/(compressor->max+0.01);
return l/(compressor->max+0.01);
}

11
lib/filters.h
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@@ -29,13 +29,4 @@ float hard_clip(float sample, float threshold);
float voltage_db_to_voltage(float db); float voltage_db_to_voltage(float db);
float power_db_to_voltage(float db); float power_db_to_voltage(float db);
float voltage_to_voltage_db(float linear); float voltage_to_voltage_db(float linear);
float voltage_to_power_db(float linear); float voltage_to_power_db(float linear);
typedef struct {
float attack;
float release;
float max;
} Compressor;
void init_compressor(Compressor *compressor, float attack, float release);
float peak_compress(Compressor *compressor, float sample);
float peak_compress_stereo(Compressor *compressor, float l, float r, float *output_r);

11
src/fm95.c
View File

@@ -34,7 +34,7 @@
#include <pulse/error.h> #include <pulse/error.h>
#define MASTER_VOLUME 1.0f // Volume of everything combined, for calibration #define MASTER_VOLUME 1.0f // Volume of everything combined, for calibration
#define AUDIO_VOLUME 1.0f // Audio volume, before clipper #define AUDIO_VOLUME 1.5f // Audio volume, before clipper
#define MONO_VOLUME 0.45f // L+R Signal #define MONO_VOLUME 0.45f // L+R Signal
#define PILOT_VOLUME 0.09f // 19 KHz Pilot #define PILOT_VOLUME 0.09f // 19 KHz Pilot
#define STEREO_VOLUME 0.45f // L-R signal, should be same as MONO #define STEREO_VOLUME 0.45f // L-R signal, should be same as MONO
@@ -374,9 +374,6 @@ int main(int argc, char **argv) {
BiquadFilter lpf_l, lpf_r; BiquadFilter lpf_l, lpf_r;
init_lpf(&lpf_l, LPF_CUTOFF, 1.25f, SAMPLE_RATE); init_lpf(&lpf_l, LPF_CUTOFF, 1.25f, SAMPLE_RATE);
init_lpf(&lpf_r, LPF_CUTOFF, 1.25f, SAMPLE_RATE); init_lpf(&lpf_r, LPF_CUTOFF, 1.25f, SAMPLE_RATE);
Compressor comp;
init_compressor(&comp, 0.9995f, 0.8f);
// #endregion // #endregion
signal(SIGINT, stop); signal(SIGINT, stop);
@@ -417,10 +414,8 @@ int main(int argc, char **argv) {
float current_mpx_in = mpx_in[i]; float current_mpx_in = mpx_in[i];
float current_sca_in = sca_in[i]; float current_sca_in = sca_in[i];
float ready_r; float ready_l = apply_frequency_filter(&lpf_l, l_in);
float ready_l = peak_compress_stereo(&comp, l_in, r_in, &ready_r); float ready_r = apply_frequency_filter(&lpf_r, r_in);
ready_l = apply_frequency_filter(&lpf_l, l_in);
ready_r = apply_frequency_filter(&lpf_r, r_in);
ready_l = apply_preemphasis(&preemp_l, ready_l)*4; ready_l = apply_preemphasis(&preemp_l, ready_l)*4;
ready_r = apply_preemphasis(&preemp_r, ready_r)*4; ready_r = apply_preemphasis(&preemp_r, ready_r)*4;
ready_l = hard_clip(ready_l*audio_volume, clipper_threshold); ready_l = hard_clip(ready_l*audio_volume, clipper_threshold);