radio95/fm95
0
1
Fork 0
mirror of https://github.com/radio95-rnt/fm95.git synced 2026-07-30 00:09:16 +02:00
Code Issues Activity

proper phase shifts for rds2 - less deviation

Browse Source
This commit is contained in:
kuba
2026-07-12 09:58:46 +02:00
parent f3035091d7
commit 224ad3bc64
4 changed files with 32 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/fm95.c
+12 -15
View File
@@ -31,7 +31,6 @@ typedef struct {
float headroom;
float pilot;
float rds;
float rds_step;
float drive;
float makeup;
} FM95_Volumes;
@@ -111,9 +110,7 @@ static inline bool compare_dvs(const FM95_DeviceNames *a, const FM95_DeviceNames
}
static float calculate_sharedaudio_volume(const FM95_Volumes volumes, const int rds_streams) {
float rds_volume = 0.0f;
for (int i = 0; i < rds_streams; i++) rds_volume += volumes.rds * powf(volumes.rds_step, i);
return 1.0f - rds_volume - volumes.pilot - volumes.headroom;
return 1.0f - (volumes.rds * rds_streams) - volumes.pilot - volumes.headroom;
}
static void stop(int signum) {
@@ -206,7 +203,8 @@ int run_fm95(FM95_Config* config, FM95_Runtime* runtime, FM95_RunResult* result)
}
for(uint16_t i = 0; i < BUFFER_SIZE; i++) {
bool cycle = advance_oscillator(&runtime->osc);
advance_oscillator(&runtime->osc);
bool do_result = (i == BUFFER_SIZE - 1);
float mpx = 0.0f;
@@ -245,25 +243,26 @@ int run_fm95(FM95_Config* config, FM95_Runtime* runtime, FM95_RunResult* result)
mpx = stereo_encode(&runtime->stencode, config->stereo, mod_l, mod_r, &audio);
{
float rds_level = config->volumes.rds;
static const float stream_shift[4] = {0.0f, (float)M_PI, (float)M_PI_2, (float)(3.0 * M_PI_2)};
static float prev_shifted_phase[4] = {0.0f, (float)M_PI, (float)M_PI_2, (float)(3.0 * M_PI_2)};
float clock = get_oscillator_cos_multiplier_ni(&runtime->osc, 1.0f);
for(uint8_t stream = 0; stream < config->rds_streams; stream++) {
if (cycle) {
for (uint8_t stream = 0; stream < config->rds_streams; stream++) {
if (oscillator_did_cycle(&runtime->osc, stream_shift[stream], &prev_shifted_phase[stream])) {
uint8_t bit;
if (bit_ring_read1(&runtime->rds_bitring[stream], &bit)) runtime->rds_last_bit[stream] = bit;
runtime->rds_symbol[stream] = runtime->rds_last_bit[stream] ? 1.0f : -1.0f;
}
uint8_t osc_stream = 12 + stream;
if(osc_stream >= 13) osc_stream++;
if (osc_stream >= 13) osc_stream++;
float shaped = 0.0f;
iirfilt_rrrf_execute(runtime->rds_filter[stream], runtime->rds_symbol[stream], &shaped);
float carrier = get_oscillator_cos_multiplier_ni(&runtime->osc, osc_stream * 4.0f);
if(config->stereo_ssb) carrier = delay_line(&runtime->rds_delays[stream], carrier);
mpx += clock * shaped * carrier * rds_level;
rds_level *= config->volumes.rds_step; // Prepare level for the next stream
if (config->stereo_ssb) carrier = delay_line(&runtime->rds_delays[stream], carrier);
mpx += clock * shaped * carrier * config->volumes.rds;
}
}
@@ -351,7 +350,6 @@ static int config_handler(void* user, const char* section, const char* name, con
else if(MATCH("advanced", "makeup")) pconfig->volumes.makeup = strtof(value, NULL);
else if(MATCH("volumes", "pilot")) pconfig->volumes.pilot = strtof(value, NULL);
else if(MATCH("volumes", "rds")) pconfig->volumes.rds = strtof(value, NULL);
else if(MATCH("volumes", "rds_step")) pconfig->volumes.rds_step = strtof(value, NULL);
return 1;
}
@@ -619,7 +617,6 @@ int main(int argc, char **argv) {
.volumes = {
.pilot = 0.09f,
.rds = 0.045f,
.rds_step = 0.9f,
.headroom = 0.05f,
.drive = 1.0f,
.makeup = 1.0f