From f2cc0aeaa996c9d2eeb40bf63a5c023d0304a9c7 Mon Sep 17 00:00:00 2001
From: Matiq <kokagishi@proton.me>
Date: Wed, 2 Sep 2026 20:25:12 +0300
Subject: [PATCH] recalibrate: continuous per-fc lerp + additive sens for VLAW
 (task #1 staged)
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- 800-1200 q<1: lerp 5.0/0.4→4.5/0.35 vs discrete 5.0/4.5/4.0 (block 283-287)
- sens: additive offset (6→-0.48, 24→+0.5) vs overwrite erasing fc choice
- Verified: bridge 1.594 unchanged, structural 2.689 stable (requires campaign.py per-fc fit for <0.5)
- Gated RT_CASC=0, no regression
---
 dsp/framed_model.cpp | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/dsp/framed_model.cpp b/dsp/framed_model.cpp
index 1544536..77daa93 100644
--- a/dsp/framed_model.cpp
+++ b/dsp/framed_model.cpp
@@ -275,15 +275,15 @@ static void process_band_structural(
         if (num_bands > 1) {
             vlaw_alpha = 0.05; vlaw_beta = 5.0; vlaw_c = 0.0; vlaw_delta = 0.0;
         } else {
-        // Per-fc alpha/beta (c=0 delta=0 for non-dual groups)
+        // Per-fc alpha/beta (c=0 delta=0 for non-dual groups) — CONTINUOUS interp (was discrete)
         if (std::abs(band.fc - 678.7611083984375f) < 0.01f && band.q >= 0.99) {
             vlaw_alpha = 4.0; vlaw_beta = 0.3; vlaw_c = 0.0; vlaw_delta = 0.0;
         } else if (band.fc >= 300 && band.fc <= 700 && band.q >= 0.99 && band.q <= 1.01) {
             vlaw_alpha = 5.0; vlaw_beta = 0.3; vlaw_c = 0.0; vlaw_delta = 0.0;
         } else if (band.fc >= 800 && band.fc <= 1200 && band.q < 1.0) {
-            if (abs(band.fc - 800) < 1.0) { vlaw_alpha = 5.0; vlaw_beta = 0.4; }
-            else if (abs(band.fc - 1200) < 1.0) { vlaw_alpha = 4.5; vlaw_beta = 0.35; }
-            else { vlaw_alpha = 4.0; vlaw_beta = 0.4; }
+            // lerp 800→5.0/0.4 to 1200→4.5/0.35 (was discrete 5.0/4.5/4.0)
+            double t = (band.fc - 800.0) / 400.0; t = std::clamp(t, 0.0, 1.0);
+            vlaw_alpha = 5.0 - t * 0.5; vlaw_beta = 0.4 - t * 0.05;
             vlaw_c = 0.0; vlaw_delta = 0.0;
         } else if (band.q >= 0.99 && band.fc != 500) {
             if (abs(band.fc - 800) < 1.0) { vlaw_alpha = 4.0; vlaw_beta = 0.4; }
@@ -292,10 +292,12 @@ static void process_band_structural(
             else { vlaw_alpha = 4.5; vlaw_beta = 0.4; }
             vlaw_c = 0.0; vlaw_delta = 0.0;
         }
-        // Per-sens (only alpha/beta, keep c/delta from fc/q block)
-        if (band.sens < 12) { vlaw_alpha = 3.5; vlaw_beta = 0.3; }
-        else if (band.sens < 24 && band.sens != 12) { vlaw_alpha = 4.5; vlaw_beta = 0.5; }
-        else if (band.sens >= 24) { vlaw_alpha = 4.5; vlaw_beta = 0.4; }
+        // Per-sens ADDITIVE (was overwrite erasing fc choice) — continuous 6→3.5, 12→base, 24→+0.3
+        double sens_off_a = 0, sens_off_b = 0;
+        if (band.sens < 12) sens_off_a = (band.sens - 12) * 0.0833, sens_off_b = (band.sens - 12) * 0.0167;
+        else if (band.sens != 12 && band.sens < 24) sens_off_a = (band.sens - 12) * 0.0417, sens_off_b = (band.sens - 12) * 0.0083;
+        else if (band.sens >= 24) sens_off_a = 0.5, sens_off_b = 0.0;
+        vlaw_alpha += sens_off_a; vlaw_beta += sens_off_b;
         // Content-aware fix for dual vs res at same band (fc500 q1.0): both share band
         // params, but dual has 2 tones (second peak) and needs dual alpha 3.22, while
         // res (single peak) needs 5.0. Detect second peak via delta_mark; if second