radio95/fm95
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Code Issues Activity

nug fixes and small tweaks

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This commit is contained in:
KubaPro010
2025-01-29 14:49:12 +01:00
parent 76580ac4d7
commit 09b30852ab
8 changed files with 53 additions and 55 deletions
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65
src/fm95.c
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@@ -4,7 +4,7 @@
#define buffer_maxlength 12288
#define buffer_tlength_fragsize 12288
#define buffer_prebuf 16
#define buffer_prebuf 32
#define DEFAULT_STEREO 1
#define DEFAULT_STEREO_POLAR 0
@@ -14,8 +14,8 @@
#define DEFAULT_ALSA_OUTPUT 1
#define DEFAULT_SCA_FREQUENCY 67000.0f
#define DEFAULT_SCA_DEVIATION 7000.0f
#define DEFAULT_SCA_CLIPPER_THRESHOLD 1.0f // Full deviation
#define DEFAULT_PREEMPHASIS_TAU 50e-6 // Europe
#define DEFAULT_SCA_CLIPPER_THRESHOLD 1.0f // Full deviation, if you set this to 0.5 then you may as well set the deviation to 3.5k
#define DEFAULT_PREEMPHASIS_TAU 50e-6 // Europe, the freedomers use 75µs
//#define USB
@@ -25,7 +25,7 @@
#include "../lib/hilbert.h"
#include "../lib/fm_modulator.h"
#define SAMPLE_RATE 192000 // Don't go lower than 108 KHz, becuase it (53000*2) and (38000+15000)
#define SAMPLE_RATE 192000
#define INPUT_DEVICE "FM_Audio.monitor"
#define OUTPUT_DEVICE "plughw:1,0"
@@ -46,6 +46,7 @@
#define LPF_CUTOFF 15000 // Should't need to be changed
#define HPF_CUTOFF 30 // Unless you wanna have SOME bass then leave this alone
#define CENTER_BASS 50 // Bass upto this will be mono
volatile sig_atomic_t to_run = 1;
@@ -398,7 +399,7 @@ int main(int argc, char **argv) {
// #endregion
// #region Setup Filters/Modulaltors/Oscillators
Oscillator osc;
if(polar_stereo == 1) {
if(polar_stereo) {
init_oscillator(&osc, 31250.0, SAMPLE_RATE); // The stereo carrier itself, the stereo carrier in polar is modulated directly on 31.25 khz with a bit of a carrier
} else {
init_oscillator(&osc, 19000.0, SAMPLE_RATE); // Pilot, it's there to indicate stereo and as a refrence signal with the stereo carrier
@@ -423,6 +424,9 @@ int main(int argc, char **argv) {
FrequencyFilter hpf_l, hpf_r;
init_hpf(&hpf_l, HPF_CUTOFF, SAMPLE_RATE);
init_hpf(&hpf_r, HPF_CUTOFF, SAMPLE_RATE);
FrequencyFilter bass_hpf;
init_hpf(&bass_hpf, CENTER_BASS, SAMPLE_RATE);
// #endregion
signal(SIGINT, stop);
@@ -477,54 +481,47 @@ int main(int argc, char **argv) {
float mono = (ready_l + ready_r) / 2.0f; // Stereo to Mono
if(stereo == 1) {
float stereo = (ready_l - ready_r) / 2.0f; // Also Stereo to Mono but a bit diffrent
if(polar_stereo == 1) {
if(ssb) {
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc, 1); // Get stereo carrier via multiplication
float stereo_carrier_cos = get_oscillator_cos_sample(&osc); // Get Carrier Q of I/Q
if(CENTER_BASS != 0) stereo = apply_frequency_filter(&bass_hpf, stereo);
float stereo_i, stereo_q;
stereo += 0.2;
apply_hilbert(&hilbert, stereo, &stereo_i, &stereo_q); // Compute I/Q
output[i] = delay_line(&monoDelay, mono)*MONO_VOLUME +
(stereo_i*stereo_carrier_cos+stereo_q*(stereo_carrier))*STEREO_VOLUME;
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
float stereo_i, stereo_q;
if(ssb) {
// Compute hilbert here
apply_hilbert(&hilbert, stereo, &stereo_i, &stereo_q);
mono = delay_line(&monoDelay, mono); // Delay Mono
}
if(polar_stereo) {
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc, 1);
if(ssb) {
float stereo_carrier_cos = get_oscillator_cos_multiplier_ni(&osc, 1); // Get Carrier Q of I/Q
output[i] = mono*MONO_VOLUME +
((stereo_i+0.2)*stereo_carrier_cos+(stereo_q+0.2)*stereo_carrier)*STEREO_VOLUME;
} else {
float stereo_carrier = get_oscillator_sin_sample(&osc);
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc, 1);
output[i] = mono*MONO_VOLUME +
((stereo+0.2)*stereo_carrier)*STEREO_VOLUME;
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
}
} else {
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc, 2); // Get stereo carrier via multiplication
float pilot = get_oscillator_sin_multiplier_ni(&osc, 1);
if(ssb) {
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc, 2); // Get stereo carrier via multiplication
float stereo_carrier_cos = get_oscillator_cos_multiplier_ni(&osc, 2); // Get Carrier Q of I/Q
float pilot = get_oscillator_sin_sample(&osc);
float stereo_i, stereo_q;
apply_hilbert(&hilbert, stereo, &stereo_i, &stereo_q); // Compute I/Q
output[i] = delay_line(&monoDelay, mono)*MONO_VOLUME +
output[i] = mono*MONO_VOLUME +
pilot*PILOT_VOLUME +
(stereo_i*stereo_carrier_cos+stereo_q*stereo_carrier)*STEREO_VOLUME;
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
} else {
float stereo_carrier = get_oscillator_sin_multiplier_ni(&osc,2);
float pilot = get_oscillator_sin_sample(&osc);
output[i] = mono*MONO_VOLUME +
pilot*PILOT_VOLUME +
(stereo*stereo_carrier)*STEREO_VOLUME;
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
}
}
advance_oscillator(&osc);
} else {
output[i] = mono*MONO_VOLUME; // Only Mono
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
}
if(strlen(audio_mpx_device) != 0) output[i] += current_mpx_in*MPX_VOLUME;
if(strlen(audio_sca_device) != 0) output[i] += modulate_fm(&sca_mod, hard_clip(current_sca_in, sca_clipper_threshold))*SCA_VOLUME;
}
if(alsa_output == 0) {