From 096837306496d53201b52e8b2d81713b51a956df Mon Sep 17 00:00:00 2001
From: KubaPro010 <kuba.pro010@gmail.com>
Date: Wed, 31 Dec 2025 12:12:37 +0100
Subject: [PATCH] remove bs412 max

---
 filter/bs412.c | 9 ++++-----
 filter/bs412.h | 3 +--
 src/fm95.c     | 6 +-----
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/filter/bs412.c b/filter/bs412.c
index eef8952..2ca1f0b 100644
--- a/filter/bs412.c
+++ b/filter/bs412.c
@@ -9,7 +9,7 @@ inline float deviation_to_dbr(float deviation) {
 	return 10*log10f((deviation*deviation)/((19000.0f / sqrtf(2.0f)) * (19000.0f / sqrtf(2.0f))));
 }
 
-void init_bs412(BS412Compressor* mpx, uint32_t mpx_deviation, float target_power, float attack, float release, float max, uint32_t sample_rate) {
+void init_bs412(BS412Compressor* mpx, uint32_t mpx_deviation, float target_power, float attack, float release, uint32_t sample_rate) {
 	mpx->mpx_deviation = mpx_deviation;
 	mpx->avg_power = 0.0f;
     mpx->alpha = 1.0f / (60.0f * sample_rate);
@@ -18,7 +18,6 @@ void init_bs412(BS412Compressor* mpx, uint32_t mpx_deviation, float target_power
 	mpx->release = expf(-1.0f / (release * sample_rate));
 	mpx->target = deviation_to_dbr(19000.0f * pow(10.0, target_power / 10.0)); // target is expected to not be our rms format
 	mpx->gain = 0.0f;
-	mpx->max = max;
 	mpx->can_compress = 0;
 	mpx->second_counter = 0;
 	#ifdef BS412_DEBUG
@@ -71,15 +70,15 @@ float bs412_compress(BS412Compressor* mpx, float sample) {
 		mpx->gain = mpx->release * mpx->gain + (1.0f - mpx->release) * target_gain;
 	}
 	
-	mpx->gain = fmaxf(0.0f, fminf(mpx->max, mpx->gain));
+	mpx->gain = fmaxf(0.0f, fminf(sqrtf(2), mpx->gain));
 
-	float output_sample = sample * mpx->gain * sqrtf(2);
+	float output_sample = sample * mpx->gain;
 	if(deviation_to_dbr(avg_deviation * mpx->gain) > mpx->target && deviation_to_dbr(avg_deviation) < mpx->target) {
 		// Gain is too much, reduce
 		float overshoot_dbr = deviation_to_dbr(avg_deviation * mpx->gain) - mpx->target;
 		float reduction_factor = powf(10.0f, -overshoot_dbr / 10.0f);
 		mpx->gain *= reduction_factor;
-		mpx->gain = fmaxf(0.0f, fminf(mpx->max, mpx->gain));
+		mpx->gain = fmaxf(0.0f, fminf(sqrtf(2), mpx->gain));
 	}
 
 	mpx->sample_counter++;
diff --git a/filter/bs412.h b/filter/bs412.h
index 4f87695..a66d4cc 100644
--- a/filter/bs412.h
+++ b/filter/bs412.h
@@ -19,7 +19,6 @@ typedef struct
 	float target;
 	float attack;
 	float release;
-	float max;
 	float gain;
 	double avg_power;
 	double alpha;
@@ -30,5 +29,5 @@ typedef struct
 float dbr_to_deviation(float dbr);
 float deviation_to_dbr(float deviation);
 
-void init_bs412(BS412Compressor *mpx, uint32_t mpx_deviation, float target_power, float attack, float release, float max, uint32_t sample_rate);
+void init_bs412(BS412Compressor *mpx, uint32_t mpx_deviation, float target_power, float attack, float release, uint32_t sample_rate);
 float bs412_compress(BS412Compressor *mpx, float average);
\ No newline at end of file
diff --git a/src/fm95.c b/src/fm95.c
index d8b07ed..1adac22 100644
--- a/src/fm95.c
+++ b/src/fm95.c
@@ -73,7 +73,6 @@ typedef struct
 	float agc_min;
 	float bs412_attack;
 	float bs412_release;
-	float bs412_max;
 	float lpf_cutoff;
 } FM95_Config;
 
@@ -345,8 +344,6 @@ static int config_handler(void* user, const char* section, const char* name, con
         pconfig->audio_preamp = strtof(value, NULL);
     } else if (MATCH("fm95", "deviation")) {
         pconfig->audio_deviation = strtof(value, NULL);
-	} else if(MATCH("fm95", "bs412_max")) {
-		pconfig->bs412_max = strtof(value, NULL);
 	} else if(MATCH("fm95", "agc_target")) {
 		pconfig->agc_target = strtof(value, NULL);
 	} else if(MATCH("fm95", "agc_attack")) {
@@ -501,7 +498,7 @@ void init_runtime(FM95_Runtime* runtime, const FM95_Config config) {
 		last_sample_counter = runtime->bs412.sample_counter;
 		last_second_counter = runtime->bs412.second_counter;
 	}
-	init_bs412(&runtime->bs412, config.mpx_deviation, config.mpx_power, config.bs412_attack, config.bs412_release, config.bs412_max, config.sample_rate);
+	init_bs412(&runtime->bs412, config.mpx_deviation, config.mpx_power, config.bs412_attack, config.bs412_release, config.sample_rate);
 	runtime->bs412.gain = last_gain;
 	runtime->bs412.avg_power = last_power;
 	runtime->bs412.can_compress = last_compress;
@@ -557,7 +554,6 @@ int main(int argc, char **argv) {
 		.agc_max = 1.5f,
 		.bs412_attack = 0.05f,
 		.bs412_release = 0.025,
-		.bs412_max = 1.0f,
 		.lpf_cutoff = 15000,
 	};