From 5ab604ddbacb4ff2d26bd4cc6bdcad3b0f4bd688 Mon Sep 17 00:00:00 2001
From: KubaPro010 <kuba.pro010@gmail.com>
Date: Sun, 15 Feb 2026 16:01:55 +0100
Subject: [PATCH] precompute part of dev to dbr

---
 filter/bs412.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/filter/bs412.c b/filter/bs412.c
index a612772..ae434f4 100644
--- a/filter/bs412.c
+++ b/filter/bs412.c
@@ -2,13 +2,15 @@
 
 #define BS412_TIME 60
 
+#define SQRT19000 180499999.99999997f // (19000 / sqrt(2)) * 19000 / sqrt(2)
+
 // inline float dbr_to_deviation(float dbr) {
 // 	return 19000.0f * sqrtf(pow(10.0, dbr / 10.0));
 // }
 
 inline float deviation_to_dbr(float deviation) {
 	if (deviation < 1e-6f) return -100.0f;
-	return 10*log10f((deviation*deviation)/((19000.0f / sqrtf(2.0f)) * (19000.0f / sqrtf(2.0f))));
+	return 10*log10f((deviation*deviation)/(SQRT19000 * SQRT19000));
 }
 
 void init_bs412(BS412Compressor* mpx, uint32_t mpx_deviation, float target_power, float attack, float release, uint32_t sample_rate) {