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add peak power limit to bs412

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KubaPro010
2025-05-31 11:18:12 +02:00
parent 5fd2383b03
commit b301577227
1 changed files with 5 additions and 0 deletions
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5
src/fm95.c
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@@ -569,6 +569,8 @@ int main(int argc, char **argv) {
float mpx_only = measure_mpx(&mpx_only_power, mpx * mpx_deviation);
float mpower = measure_mpx(&power, (audio+mpx) * mpx_deviation); // Standard requires that the output is measured specifically
float peak_mpx_only = deviation_to_dbr(mpx * mpx_deviation);
float peak_mpower = deviation_to_dbr((audio+mpx) * mpx_deviation);
if (mpower > mpx_power) {
float excess_power = mpower - mpx_power;
excess_power = deviation_to_dbr(dbr_to_deviation(excess_power) - dbr_to_deviation(mpx_only)); // make sure mpx is not included in the power to attenuate, because we'd be attuating the mpx signal for audio
@@ -576,6 +578,9 @@ int main(int argc, char **argv) {
float target_gain = dbr_to_deviation(-excess_power)/mpx_deviation;
bs412_audio_gain = 0.9f * bs412_audio_gain + 0.1f * target_gain;
audio *= bs412_audio_gain;
} else if (peak_mpower > (mpx_power + 0.1f)) {
float target_gain = dbr_to_deviation(mpx_power - mpower)/mpx_deviation;
bs412_audio_gain = 0.8f * bs412_audio_gain + 0.2f * target_gain;
}
iirfilt_rrrf_execute(mpx_lpf, audio, &audio); // Should have no effect, as audio should be 0-15, and 23-53, this is a filter for 53, assuming the filter is good, this is precaution and recomendation