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mirror of https://github.com/radio95-rnt/fm95.git synced 2026-02-26 11:22:00 +01:00

clean up ssb stuff a little

This commit is contained in:
2026-02-15 13:27:53 +01:00
parent 6ff653f5d4
commit 36b861b7e5
6 changed files with 46 additions and 45 deletions

21
dsp/delay.c Normal file
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@@ -0,0 +1,21 @@
#include "delay.h"
void init_delay_line(delay_line_t *delay_line, uint32_t sample_rate) {
delay_line->buffer = malloc(sample_rate * sizeof(float));
memset(delay_line->buffer, 0, sample_rate * sizeof(float));
}
void set_delay_line(delay_line_t *delay_line, uint32_t new_delay) {
delay_line->delay = new_delay;
}
float delay_line(delay_line_t *delay_line, float in) {
delay_line->buffer[delay_line->idx++] = in;
if (delay_line->idx >= delay_line->delay) delay_line->idx = 0;
return delay_line->buffer[delay_line->idx];
}
void exit_delay_line(delay_line_t *delay_line) {
if(delay_line->buffer != NULL) free(delay_line->buffer);
delay_line->buffer = NULL;
}

12
dsp/delay.h Normal file
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@@ -0,0 +1,12 @@
#include <string.h>
typedef struct delay_line_t {
float *buffer;
uint32_t delay;
uint32_t idx;
} delay_line_t;
void init_delay_line(delay_line_t *delay_line, uint32_t sample_rate);
void set_delay_line(delay_line_t *delay_line, uint32_t new_delay);
float delay_line(delay_line_t *delay_line, float in);
void exit_delay_line(delay_line_t *delay_line);

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@@ -1,45 +1,23 @@
#include "stereo_encoder.h" #include "stereo_encoder.h"
#ifdef STEREO_SSB
static void init_delay_line(struct delay_line_t *delay_line, uint32_t sample_rate) {
delay_line->buffer = malloc(sample_rate * sizeof(float));
memset(delay_line->buffer, 0, sample_rate * sizeof(float));
}
static void set_delay_line(struct delay_line_t *delay_line, uint32_t new_delay) {
delay_line->delay = new_delay;
}
static inline float delay_line(struct delay_line_t *delay_line, float in) {
delay_line->buffer[delay_line->idx++] = in;
if (delay_line->idx >= delay_line->delay) delay_line->idx = 0;
return delay_line->buffer[delay_line->idx];
}
static void exit_delay_line(struct delay_line_t *delay_line) {
free(delay_line->buffer);
}
#endif
// Multiplier is the multiplier to get to 19 khz // Multiplier is the multiplier to get to 19 khz
void init_stereo_encoder(StereoEncoder* st, uint8_t multiplier, Oscillator* osc, float audio_volume, float pilot_volume) { void init_stereo_encoder(StereoEncoder* st, uint8_t multiplier, Oscillator* osc, float audio_volume, float pilot_volume) {
st->multiplier = multiplier; st->multiplier = multiplier;
st->osc = osc; st->osc = osc;
st->pilot_volume = pilot_volume; st->pilot_volume = pilot_volume;
st->audio_volume = audio_volume; st->audio_volume = audio_volume;
#ifdef STEREO_SSB #ifdef STEREO_SSB
init_delay_line(&st->delay, STEREO_SSB*2+1); init_delay_line(&st->delay, osc->sample_rate);
#endif set_delay_line(&st->delay, STEREO_SSB*2+1);
#endif
} }
#ifdef STEREO_SSB
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right, firhilbf *hilbert) { float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right, firhilbf *hilbert) {
#else
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right) {
#endif
float mid = (left+right) * 0.5f; float mid = (left+right) * 0.5f;
if(!enabled) return mid * st->audio_volume; if(!enabled) return mid * st->audio_volume;
#ifdef STEREO_SSB
mid = delay_line(&st->delay, mid); mid = delay_line(&st->delay, mid);
#endif
float half_audio = st->audio_volume * 0.5f; float half_audio = st->audio_volume * 0.5f;
@@ -60,4 +38,8 @@ float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right)
#else #else
return (mid*half_audio) + (signalx1*st->pilot_volume) + ((side*signalx2) * half_audio); return (mid*half_audio) + (signalx1*st->pilot_volume) + ((side*signalx2) * half_audio);
#endif #endif
}
void exit_stereo_encoder(StereoEncoder* st) {
exit_delay_line(&st->delay);
} }

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@@ -4,17 +4,9 @@
#include <stdint.h> #include <stdint.h>
#include "../dsp/oscillator.h" #include "../dsp/oscillator.h"
#ifdef STEREO_SSB
#include <liquid/liquid.h> #include <liquid/liquid.h>
#include <complex.h> #include <complex.h>
#include <string.h> #include "../dsp/delay.h"
typedef struct delay_line_t {
float *buffer;
uint32_t delay;
uint32_t idx;
} delay_line_t;
#endif
typedef struct typedef struct
{ {
@@ -22,15 +14,9 @@ typedef struct
Oscillator* osc; Oscillator* osc;
float audio_volume; float audio_volume;
float pilot_volume; float pilot_volume;
#ifdef STEREO_SSB
struct delay_line_t delay; struct delay_line_t delay;
#endif
} StereoEncoder; } StereoEncoder;
void init_stereo_encoder(StereoEncoder *st, uint8_t multiplier, Oscillator *osc, float audio_volume, float pilot_volume); void init_stereo_encoder(StereoEncoder *st, uint8_t multiplier, Oscillator *osc, float audio_volume, float pilot_volume);
#ifdef STEREO_SSB
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right, firhilbf *hilbert); float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right, firhilbf *hilbert);
#else void exit_stereo_encoder(StereoEncoder* st);
float stereo_encode(StereoEncoder* st, uint8_t enabled, float left, float right);
#endif

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@@ -145,7 +145,7 @@ void cleanup_runtime(FM95_Runtime* runtime, const FM95_Config config) {
} }
#ifdef STEREO_SSB #ifdef STEREO_SSB
firhilbf_destroy(runtime->stereo_hilbert); firhilbf_destroy(runtime->stereo_hilbert);
free(runtime->stencode.delay.buffer); exit_stereo_encoder(runtime->stencode);
#endif #endif
} }

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