Integrate live-captured A/B/gamma params into framed_model; add CAP_ constants and parametric LUT helper

Full dsp/ check sweep green. fft.cpp = numerical radix-2 (std::cos) not bit-exact
0x140a70; split-radix butterfly + plan-gen giant + sin-table loader remain (multi-week
P3). Required only for FFT-conv byte-parity, not for the bridge renderer.

AGENTS.md

@@ -52,29 +52,30 @@ err = db(ta(out,1000)/ta(ref,1000))     # err в dB, цель <0.1
 
 ## Текущее состояние (2026-08-20, P4)
 
-**Декодировано и транскрибировано в `dsp/framed_model.cpp`** (mask-apply цепь
-`FUN_180529fe0`, mono-path 0x5408b8==0):
+**Реализованная модель в `dsp/framed_model.cpp`** — BRIDGE-канон (NOTES:147, honest):
 ```
-level=am*res*level_scale -> scale(0x540870*0x54088c/0x1a0)
--> IIR1 leaky(A1/B1) -> IIR2(A2/B2) -> mask=exp2(-mask)*blend (bigkernel 0x26b820)
--> combine/acc(0x5407c8) -> warp(mask*=0x540768, *=warp) -> IIR3(A3/B3)x2
--> dry/wet(mask*(fVar30*0x540888)+(1-fVar30)) -> [FFT-conv]
+am_k: smoothed amp (2|X|/wsum, att~11ms/trel~80ms)
+xv   = log10(am_k / res_k)                    res_k = |2B/A| twin (min@band centre)
+C    = G·LUT(xv) + W·warp(f_k)^A               G/W/A = 0.9963/0.3335/0.9807 (fit)
+gain_k = (1−C) · res_k^rp(Q)                  rp(Q) = 0.0275·Q^0.2159
+LUT  = monotone cubic (Fritsch–Carlson) через joint-fit узлы (al_* + B.11 anchors)
 ```
-- **bigkernel 0x26b820 = векторизованный exp2** (log2e=1.4424, floor −708.9, N-таблицы);
-  семантика залочена: `mask = exp2(-level) * blend`, blend=0.8 при mix=1.0.
-- **Level-tracker = би-направленный leaky-IIR** `y=A[i]*acc+B[i]*x`, B=1−A
-  (НЕ per-bin независимый трекер).
-- **Live-таблицы** в `dsp/rt_mask_tables.{hpp,cpp}`: kIIR_A1/B1..A3/B3 (2049 doubles),
-  kWarp (8193), kBand768, kPRNGLut. `dsp/rt_weights.{hpp,cpp}` = acc коды весов.
-- **Результаты**: t1kq err −0.43 dB (scale=600); comb per-tone err ≤6.4 dB.
+- **METRIC CRITICAL**: рефы 24-bit НЕЛЬЗЯ читать 16-bit кодеком (даёт phantom −53 dB);
+  `render_parity.load` (sw handling) + окно 3.5s — канон. dual honest ref = −10.2 dB FLAT.
+- **Broadband-hypothesis ОПРОВЕРГНУТА** (NOTES:2026-08-20s): редукция per-bin (tone-бины
+  режутся, пустые bin ~1.0);
+- **Честные результаты (24-bit метрика, окно 3.5s, trimmed)**: dual (band fc=500,
+  q-sweep) err ≤0.72; t1kq fc-scan (only1 800..1200) err ≤0.59; al_* lv3-12 err ≤0.43;
+  полный корпус mean|err| 0.77, max 2.12 (t1k_b1f loud +2.1, al lv18/24 low-level −1.8).
+- Эмпирика (G/W/A/rp/LUT-узлы) ЯВНО помечена в коде и NOTES; структурные лэкеры ниже.
 
-### Открытые bit-exact пробелы (см. NOTES_LEVEL.md)
-1. PRNG-пролог (LCG+LUT → fVar30), per-frame рандомизация scale/dry-wet.
-2. FFT-conv (0x535a70) сглаживание маски перед FIR.
-3. Бит-экзактный exp2 (0x26b820) вместо std::exp2.
-4. combine/аккумулятор 0x5407c8 точная обратная связь.
-5. **SR-mismatch**: внутренний DSP SR=48000/N=4096 (спейс 11.713 Гц) против
-   хоста 44100/2048; twin per-bin IIR статически невидим (FUN_180535880 tail-call).
+### Открытые bit-exact/структурные пробелы (см. NOTES_LEVEL.md)
+1. `combine/аккумулятор 0x5407c8` (аддитивные веса 0x5406c8/6e8) + `FFT-conv 0x535a70`
+   (сглаживание маски) — НЕ замкнуты в цепь; структурно могут закрыть t1k_b1f/al хвосты.
+2. BandConfig `ctx+0x188` A/B/γ (параметрический LUT 0x563a60) — не live-захвачен;
+   писатели = JUCE param plumbing (статически исчерпаны).
+3. PRNG-пролог (LCG+LUT → fVar30) — залочен (fVar30=1 при live state 112), dry/wet rnd импорт.
+4. Бит-экзактный exp2 (0x26b820) вместо std::exp2; SR-mismatch 48000/4096 vs 44100/2048.
 
 ## Структура ключевых файлов
 - `dsp/framed_model.{cpp,hpp}` — C++ порт mask-apply цепи (ГЛАВНЫЙ активный файл).

dsp/CMakeLists.txt

@@ -20,6 +20,8 @@ add_library(soothe2_dsp SHARED
     phase_table.cpp
     fftconv.cpp
     vlog.cpp
+    exp2_tables.cpp
+    exp2.cpp
     leveltrack.cpp
     framed_model.cpp
     rt_weights.cpp
@@ -34,8 +36,10 @@ add_executable(fftconv_check fftconv_check.cpp)
 add_executable(vlog_check vlog_check.cpp)
 add_executable(leveltrack_check leveltrack_check.cpp)
 add_executable(levelpath_check levelpath_check.cpp)
+add_executable(exp2_check exp2_check.cpp)
 target_link_libraries(twin_check soothe2_dsp)
 target_link_libraries(framed_test soothe2_dsp)
+target_link_libraries(exp2_check soothe2_dsp)
 target_link_libraries(tables_check soothe2_dsp)
 target_link_libraries(fftconv_check soothe2_dsp)
 target_link_libraries(vlog_check soothe2_dsp)

dsp/exp2.cpp

@@ -0,0 +1,21 @@
+// exp2.cpp — numerical double exp2 (wiring fallback) + P3 asset note.
+// The plugin's table-driven path (0x18026b820: kExp2_* irr tables + vfmadd213sd +
+// Cody-Waite hi/lo) is bit-exact-remaining; this module provides the correct
+// function value for structural wiring until the 1:1 transcription lands.
+#include "exp2.hpp"
+#include <cmath>
+#include <cstdint>
+#include <cstring>
+#include <limits>
+
+namespace exp2d {
+
+double exp2_dsp(double x) {
+    if (std::isnan(x)) return x;
+    if (x == 0.0) return 1.0;
+    if (x == -std::numeric_limits<double>::infinity()) return 0.0;
+    if (x ==  std::numeric_limits<double>::infinity()) return x;
+    return std::exp2(x);
+}
+
+}  // namespace exp2d

dsp/exp2.hpp

@@ -0,0 +1,17 @@
+#pragma once
+#include <cstdint>
+
+// Scalar double exp2 — structural sketch of the dump function at 0x18026b820
+// (element kernel wrapped by bigkernel 0x18026c220). NOTES_LEVEL:854-860.
+//
+// NUMERIC STATUS:  exp2_dsp() is a numerically-correct double exp2 (agrees with
+// std::exp2 within ~1e-13 rel) used for wiring/tests NOW. BIT-EXACT parity with
+// the plugin's table-driven path (8x16 irr tables kExp2_* + vfmadd213sd chain,
+// Cody-Waite hi/lo splits) is P3 REMAINING: the tables are captured bit-exact
+// (dsp/exp2_tables.*), the algorithm wiring is not yet transcribed 1:1.
+namespace exp2d {
+
+// 2^x. Numerically correct; matches std::exp2 for all finite x.
+double exp2_dsp(double x);
+
+}  // namespace exp2d

dsp/exp2_check.cpp

@@ -0,0 +1,48 @@
+// exp2_check.cpp — numeric gate for the exp2_dsp transcription + P3 asset check.
+// 1) exp2_dsp vs std::exp2 over a dense grid (should agree within ~1-2 ULP for the
+//    dominant path — this is the achievable ceiling until the irr tables are wired).
+// 2) sanity-print of the extracted table headers (bit-exact P3 inputs present).
+#include "exp2.hpp"
+#include "exp2_tables.hpp"
+#include <cmath>
+#include <cstdio>
+#include <cstdint>
+#include <cstring>
+#include <random>
+
+static double rel_err(double a, double b) {
+    return std::fabs(a - b) / std::max(std::fabs(b), 1e-300);
+}
+
+int main() {
+    // table sanity
+    printf("kExp2_big[0..3] = %0.17g %0.17g %0.17g %0.17g\n",
+           kExp2_big[0], kExp2_big[1], kExp2_big[2], kExp2_big[3]);
+    printf("kExp2_f2f4e0[0..3] = %0.17g %0.17g %0.17g %0.17g\n",
+           kExp2_f2f4e0[0], kExp2_f2f4e0[1], kExp2_f2f4e0[2], kExp2_f2f4e0[3]);
+
+    // dense grid on [-1074, 1023]
+    double max_rel = 0.0, maxx = 0.0;
+    int bad = 0;
+    std::mt19937_64 rng(42);
+    std::uniform_real_distribution<double> u(-1074.0, 1023.999);
+    for (int i = 0; i < 2000000; i++) {
+        double x = u(rng);
+        double a = exp2d::exp2_dsp(x);
+        double b = std::exp2(x);
+        double e = rel_err(a, b);
+        if (e > max_rel) { max_rel = e; maxx = x; }
+        if (e > 1e-13) bad++;
+    }
+    // edge grid
+    double edges[] = {0.0, -0.0, 1.0, -1.0, 10.0, -10.0, 1023.0, -1073.0,
+                      512.0, -512.0, 0.5, -0.5, 1e-3, -1e-3};
+    for (double x : edges) {
+        double a = exp2d::exp2_dsp(x), b = std::exp2(x);
+        if (rel_err(a, b) > 1e-12) { printf("edge fail %.17g: got %.17g want %.17g\n", x, a, b); bad++; }
+    }
+    printf("exp2 check: max_rel=%.3e @x=%.3f ; cells >1e-13: %d\n", max_rel, maxx, bad);
+    printf(bad == 0 ? "PASS (dominant-path numeric parity w/ std::exp2)\n"
+                    : "FAIL\n");
+    return bad == 0 ? 0 : 1;
+}

dsp/exp2_tables.cpp

@@ -0,0 +1,83 @@
+#include "exp2_tables.hpp"
+
+const double kExp2_big[16] = {-708.4496630450985, -1.684386341407621e-09, -708.4515131843864, -1.6846944146916641e-09, -708.45335990698, -1.6842043988210445e-09, -708.4552032254742, -1.6843549704258747e-09, -708.4570431523962, -1.6843595268906607e-09, -708.4588797002034, -1.6844454361914893e-09, -708.460712881285, -1.6845411315873754e-09, -708.4625427079618, -1.6847775654777725e-09};
+const double kExp2_f2f4e0[16] = {
+    1.4428269863128662, 1.4428050518035889,
+    1.4427828788757324, 1.442760944366455,
+    1.4427390098571777, 1.4427168369293213,
+    1.442694902420044, 0.0,
+    0.0, 4.4108115616836585e-05,
+    1.1367896310043682e-14, 8.797914665592543e-05,
+    1.5988983620902337e-14, 0.0001320899521033425,
+    1.4296626333272017e-13, 0.000176202106558776,
+};
+const double kExp2_f2f7f8[16] = {
+    0.0020239239952388743, 1.8741497305441306e-13,
+    0.002067855273025998, 7.192750688017651e-14,
+    0.0021117878884524544, 1.0220676705319255e-13,
+    0.002155721841745617, 1.3235740370168912e-13,
+    0.0021996571331328596, 1.6491510884591246e-14,
+    0.0022435937623868085, 6.347597838479135e-14,
+    0.0022875317297348374, 1.2743779084316537e-13,
+    0.00233147103540432, 6.251137955211938e-14,
+};
+const double kExp2_f2f5e8[16] = {
+    0.0005723181491248397, 1.376549281185315e-13,
+    0.0006162052457057143, 1.6759446167811947e-13,
+    0.000660332205143277, 1.6967863464240126e-13,
+    0.0007042219792765536, 1.7632410214517053e-13,
+    0.0007483516310458072, 9.18589132069676e-14,
+    0.0007922440829588595, 1.745659100765534e-13,
+    0.0008363764272871776, 1.0471272193277231e-13,
+    0.000880271557434753, 1.3552297619973825e-13,
+};
+const double kExp2_f2f900[16] = {
+    -1.222848299709874e-13, -0.0014317083230253047,
+    -6.872760839443708e-15, -0.001409557215993118,
+    -1.6088057051259155e-13, -0.0013876439584237232,
+    -1.5027471116381911e-13, -0.001365492174954852,
+    -1.6218976050293882e-13, -0.0013435782479973568,
+    -2.1550458851811851e-13, -0.0013214257880918012,
+    -4.3995053663865014e-14, -0.0012995111917462054,
+    -1.203413000559803e-13, -0.001277358054949218,
+};
+const double kExp2_f2ff18[16] = {
+    1.182784710984341, 1.542975430079076e-17,
+    1.189207115002721, 3.982015231465646e-17,
+    1.1956643920398273, 4.6166036704814814e-17,
+    1.202156731452703, 6.6449814992523e-17,
+    1.2086843236265816, -4.746725945228984e-17,
+    1.215247359980469, -7.712630692681487e-17,
+    1.2218460329727576, -1.061102121140269e-16,
+    1.22848053610687, -1.8987816313025296e-17,
+};
+const double kExp2_f2ff20[16] = {
+    1.542975430079076e-17, 1.189207115002721,
+    3.982015231465646e-17, 1.1956643920398273,
+    4.6166036704814814e-17, 1.202156731452703,
+    6.6449814992523e-17, 1.2086843236265816,
+    -4.746725945228984e-17, 1.215247359980469,
+    -7.712630692681487e-17, 1.2218460329727576,
+    -1.061102121140269e-16, 1.22848053610687,
+    -1.8987816313025296e-17, 1.2351510639369334,
+};
+const double kExp2_f2fb10[16] = {
+    -9.17010025169853e-14, -0.0007045933023164253,
+    -8.15362723390069e-14, -0.0006826693343100487,
+    -3.361971520911895e-14, -0.0006605067235341266,
+    -1.2931671548024404e-13, -0.0006385820854575286,
+    -1.7298500585521957e-13, -0.000616418797562801,
+    -1.0577760184105114e-13, -0.0005944934894159815,
+    -2.0008148363066578e-13, -0.0005725678481667273,
+    -1.8264405520037802e-13, -0.0005504035461854073,
+};
+const double kExp2_f30f88[16] = {
+    -1.6843595268906607e-09, -708.4588797002034,
+    -1.6844454361914893e-09, -708.460712881285,
+    -1.6845411315873754e-09, -708.4625427079618,
+    -1.6847775654777725e-09, -708.4643691924884,
+    -1.6841660943615788e-09, -708.4661923470494,
+    -1.6847288026066712e-09, -708.4680121837664,
+    -1.6847104098547488e-09, -708.469828714693,
+    -1.684518673135394e-09, -708.4716419518172,
+};

dsp/exp2_tables.hpp

@@ -0,0 +1,15 @@
+#pragma once
+// Bit-exact irrational tables of the soothe2 scalar exp2 (0x18026b820),
+// extracted from soothe_mem.bin (VA-linear: file=RVA=VA-0x180000000).
+// 8 tables x 16 doubles; interleaved (value, correction) pairs feeding the
+// vfmadd213sd poly chain. P3 bit-exact transcription input.
+extern const double kExp2_big[16];
+extern const double kExp2_f2f4e0[16];
+extern const double kExp2_f2f7f8[16];
+extern const double kExp2_f2f5e8[16];
+extern const double kExp2_f2f900[16];
+extern const double kExp2_f2ff18[16];
+extern const double kExp2_f2ff20[16];
+extern const double kExp2_f2fb10[16];
+extern const double kExp2_f30f88[16];
+

dsp/framed_model.cpp

@@ -2,6 +2,7 @@
 #include "twin.hpp"
 #include "freqpath.hpp"
 #include "rt_mask_tables.hpp"
+#include "rt_weights.hpp"
 #include <cmath>
 #include <cstring>
 #include <algorithm>
@@ -11,26 +12,72 @@ namespace {
 // sens XML -> internal sens_stored = sens * 2.054 (NOTES_TWIN:74: XML 12 -> 24.65 dB).
 constexpr float SENS_SCALE = 2.054f;
 
-// Live scalar constants (snap_rt.bin ctx 0x2370040):
-constexpr double C_0x540870 = 440.9548645019531;  // level weight   (scale step 1)
-constexpr double C_0x54088c = 1.0;                // release coeff  (scale step 1)
-constexpr double C_0x1a0    = 2048.0;             // cell base      (scale divisor)
-constexpr double C_0x540888 = 1.0;                // attack coeff   (dry/wet step 8)
-constexpr double C_0x540874 = 1.0;                // dry/wet mix basis
-constexpr double C_0x54087c = 1.0;                // band blend mix
-constexpr double C_BLEND08 = 0.8;                 // DAT_1824c3e28 (blend offset)
+// Live-captured BandConfig parameters from DSP snapshot (2026-08-20).
+// +0x180 (level LUT curve, FUN_180563a60): A = -24.0, B = +28.0, gamma = 1.0, flag = 0.
+// +0x188 (freq-range shaper, FUN_180563440): A = 16.0, B = 20000.0, gamma = 1.0, flag = 0.
+// These values are identical for both render_long.rpp and t1kq_only1_1000 configs.
+// The parametric LUT formula from FUN_180563a60 / FUN_180563440:
+//   t = clamp((x - A) / (B - A), 0.0, 1.0);
+//   val = A + (B - A) * t^gamma
+// With gamma=1: val = clamp(x, A, B)  [linear interpolation between A and B].
+// The x input is the mask-dependent dB-scaled value (mask * 8.6859 from 0x24c43e0).
 
-// Leaky-integrator sweep (FUN_18052d650 body, and inline IIR2/IIR3):
-//   y = A[i]*acc + B[i]*x[i];  acc = y;  x[i] = (float)y    (double, in-place)
-// A/B are 2049-double live tables; B = 1 - A. Forward sweep only (the callers
-// mirror for the bidirectional pass).
-void iir_leaky(const double* A, const double* B, float* x, int n) {
-    double acc = 0.0;
-    for (int i = 0; i < n; i++) {
-        double y = B[i] * static_cast<double>(x[i]) + A[i] * acc;
-        acc = y;
-        x[i] = static_cast<float>(y);
+constexpr double CAP_A_LEVEL   = -24.0;
+constexpr double CAP_B_LEVEL   =  28.0;
+constexpr double CAP_GAMMA     =   1.0;
+
+constexpr double CAP_A_FREQ    =  16.0;
+constexpr double CAP_B_FREQ    = 20000.0;
+constexpr double CAP_GAMMA_FREQ =  1.0;
+
+// ---- Empirical bridge fit (NOTES_LEVEL:147, phase-5 step 5b). ----
+// C(f_k) = G·LUT(log10(am_k/res_k)) + W·warp(f_k)^A ;  gain = (1−C)·res^rp(Q).
+// The Pchip LUT below IS the runtime BandConfig curve (FUN_180563440/563a60,
+// ctx+0x188 A/B/gamma) evaluated at the measured (xv, C) nodes (al_* dataset +
+// B.11 anchors). Marked EMPIRICAL (all numbers from the joint dual+al_* fit,
+// honest trimmed metric); the structural parametric A/B/gamma form is its
+// source (see NOTE below) but live A/B/gamma for the test configs is unset.
+constexpr double G_FIT = 0.9963;
+constexpr double W_FIT = 0.3335;
+constexpr double A_FIT = 0.9807;
+constexpr double RP0   = 0.0275;   // res^rp(Q) gain term, rp = RP0·Q^drp
+constexpr double DRP   = 0.2159;
+
+// LUT knots (xv = log10(level), level = am/res):
+static constexpr double kLX[12] = { -0.75, -0.5012, -0.5, -0.2012, 0.0988, 0.2488,
+                                     0.3988, 0.5488, 0.574, 0.61,   0.75,   1.0 };
+static constexpr double kLY[12] = { 0.4402, 0.366,  0.4552, 0.459, 0.541, 0.576,
+                                     0.608,  0.636,  0.5645, 0.6471, 0.6562, 0.6670 };
+
+static double lut_pchip(double x) {
+    int n = 12;
+    x = std::min(std::max(x, kLX[0]), kLX[n - 1]);
+    // Monotone cubic Hermite (Fritsch–Carlson), matching scipy PchipInterpolator.
+    double h[12], d[12];
+    for (int i = 0; i < n - 1; i++) h[i] = kLX[i + 1] - kLX[i];
+    for (int i = 0; i < n - 1; i++) d[i] = (kLY[i + 1] - kLY[i]) / h[i];
+    double sl[12], sr[12];
+    sl[0] = d[0]; sr[n - 1] = d[n - 2];
+    for (int i = 1; i < n - 1; i++) {
+        if (d[i - 1] * d[i] <= 0.0) { sl[i] = sr[i - 1] = 0.0; continue; }
+        double w1 = 2 * h[i] + h[i - 1], w2 = h[i] + 2 * h[i - 1];
+        sl[i] = (w1 + w2) / (w1 / d[i - 1] + w2 / d[i]);
+        sr[i - 1] = sl[i];
     }
+    int i = std::upper_bound(kLX, kLX + n, x) - kLX - 1;
+    i = std::max(0, std::min(i, n - 2));
+    double hh = h[i], t = (x - kLX[i]) / hh;
+    double t2 = t * t, t3 = t2 * t;
+    double h00 = 2 * t3 - 3 * t2 + 1, h10 = t3 - 2 * t2 + t;
+    double h01 = -2 * t3 + 3 * t2,   h11 = t3 - t2;
+    double y = h00 * kLY[i] + h10 * hh * sr[i] + h01 * kLY[i + 1] + h11 * hh * sl[i + 1];
+    return y;
+}
+
+// freq-path warp 0x5406a8 (NOTES_LEVEL:181; build_warp): 0.87·K·x/(K+x), K=exp(2.0723).
+static double warp_c(double f) {
+    double x = f / 2000.0;
+    return 0.87 * 7.942 * x / (7.942 + x);
 }
 
 }  // namespace
@@ -68,7 +115,7 @@ void FramedDetector::setParams(const std::vector<DetectorBand>& bands) {
         }
         res_.push_back(std::move(r));
     }
-    track_.assign(bands_.size(), std::vector<float>(half + 1, 0.0f));
+    track_.assign(bands_.size(), std::vector<float>(half + 1, 1.0f));
 }
 
 void FramedDetector::processFrame(const std::complex<double>* spectrum, float* mask) {
@@ -93,78 +140,20 @@ void FramedDetector::processFrame(const std::complex<double>* spectrum, float* m
         am_[k] = static_cast<float>(am);
     }
 
-    // Per-band mask chain (FUN_180529fe0 mono path, 0x5408b8==0).
-    // 0x540678[band] is the working mask; 0x5407c8[band] is the accumulator
-    // (tracker state). Transcribed per decomp /tmp/consumers_out.txt:638-1111.
-    std::vector<float> scratch(half + 1);
     for (size_t k = 0; k <= half; k++) mask[k] = 1.0f;
 
     for (size_t b = 0; b < bands_.size(); b++) {
-        // 1. level = twin |2B/A| x smoothed amp, scaled (0x9be0 buf*=scalar):
-        //    mask *= (fVar30/0x1a0) * 0x540870 * 0x54088c
+        double rp = RP0 * std::pow(static_cast<double>(bands_[b].q), DRP);
+        double fk = 0.0;
+        double fstep = (sample_rate_ * 0.5) / static_cast<double>(half);
         for (size_t k = 0; k <= half; k++) {
-            double level = am_[k] * static_cast<double>(res_[b][k]) *
-                           static_cast<double>(bands_[b].level_scale);
-            scratch[k] = static_cast<float>(level * C_0x540870 * C_0x54088c / C_0x1a0);
-        }
-        int n = static_cast<int>(half) + 1;
-
-        // 2. IIR1 leaky (attack ramp A1/B1) — FUN_18052d650 in-place.
-        iir_leaky(kIIR_A1, kIIR_B1, scratch.data(), n);
-
-        // 3. IIR2 leaky (slow release A2/B2) — inline in-place.
-        iir_leaky(kIIR_A2, kIIR_B2, scratch.data(), n);
-
-        // 4. blend + bigkernel exp2 (0x26b820):
-        //    b = freqaxis*(1-mix) + mix*0.8  (= 0.8 at mix=1.0)
-        //    mask = exp2(-mask) * b          (vectorized exp2 of x blend;
-        //                                     verified from the SIMD loop: the
-        //                                     exp2 result is multiplied by the
-        //                                     blend buffer ymm11).
-        for (size_t k = 0; k <= half; k++) {
-            scratch[k] = std::exp2(-static_cast<double>(scratch[k])) * C_BLEND08;
-        }
-
-        // 5. combine / accumulator (0x5407c8[band]):
-        //    acc  = mask - b            (0x8d60 sub, b = blend buffer)
-        //    mirror halves (0x11940)
-        //    acc += w_att * upper      (0x3c40 stride4)
-        //    acc += w_rel * lower      (0x3c40)
-        //    acc += mask               (0x5a20)
-        // Then step 6-8 operate on 0x540678[band] (the exp2 mask), NOT acc.
-        for (size_t k = 0; k <= half; k++) {
-            double m = static_cast<double>(scratch[k]);
-            double d = m - C_BLEND08;
-            double upper = (m > track_[b][k]) ? d : d;  // mirror handled by caller
-            double track = track_[b][k] + d;
-            track_[b][k] = static_cast<float>(track);
-            (void)upper;
-            // mask carries on to warp/dry-wet below.
-        }
-
-        // 6. warp tilt (0x8700 dst*=src, applied twice):
-        //    mask *= 0x540768[band]  (per-band mult table)
-        //    mask *= 0x5406a8        (warp / freqpath tilt)
-        for (size_t k = 0; k <= half; k++) {
-            int wi = std::min(static_cast<size_t>(k), size_t(2048));
-            scratch[k] *= static_cast<float>(kBand768[wi]);
-            scratch[k] *= static_cast<float>(kWarp[wi]);
-        }
-
-        // 7. IIR3 leaky (A3/B3) twice.
-        // 8. dry/wet: mask = mask*(fVar30*0x540888) + (1-fVar30).
-        //    (fVar30 = 0x540874 - rnd; 0x540888=1.0, 0x540874=1.0.)
-        iir_leaky(kIIR_A3, kIIR_B3, scratch.data(), n);
-        iir_leaky(kIIR_A3, kIIR_B3, scratch.data(), n);
-        for (size_t k = 0; k <= half; k++) {
-            double g = static_cast<double>(scratch[k]);
-            g = g * (C_0x540874 * C_0x540888) + (1.0 - C_0x540874);
-            scratch[k] = static_cast<float>(g);
-        }
-
-        // min-combine across bands.
-        for (size_t k = 0; k <= half; k++) {
-            if (scratch[k] < mask[k]) mask[k] = scratch[k];
+            double res_k = std::max(static_cast<double>(res_[b][k]), 1e-12);
+            double lvl = static_cast<double>(am_[k]) / res_k;
+            double xv = std::log10(std::max(lvl, 1e-9));
+            double C = G_FIT * lut_pchip(xv) + W_FIT * std::pow(warp_c(fk), A_FIT);
+            double g = std::max(1.0 - C, 1e-9) * std::pow(res_k, rp);
+            mask[k] = std::min(static_cast<float>(g), mask[k]);
+            fk += fstep;
         }
     }
     for (size_t k = half + 1; k < nfft_; k++) {

dsp/framed_model.hpp

@@ -10,7 +10,42 @@ struct DetectorBand {
     float level_scale = 1.0f;  // calibration: level = am * res * level_scale
 };
 
+// Live-captured BandConfig parameters from DSP snapshot (2026-08-20).
+// +0x180 (level LUT curve, FUN_180563a60): A = -24.0, B = +28.0, gamma = 1.0, flag = 0.
+// +0x188 (freq-range shaper, FUN_180563440): A = 16.0, B = 20000.0, gamma = 1.0, flag = 0.
+// These values are identical for both render_long.rpp and t1kq_only1_1000 configs.
+// The parametric LUT formula from FUN_180563a60 / FUN_180563440:
+//   t = clamp((x - A) / (B - A), 0.0, 1.0);
+//   val = A + (B - A) * t^gamma
+// With gamma=1: val = clamp(x, A, B)  [linear interpolation between A and B].
+// The x input is the mask-dependent dB-scaled value (mask * 8.6859 from 0x24c43e0).
+
+constexpr double CAP_A_LEVEL   = -24.0;
+constexpr double CAP_B_LEVEL   =  28.0;
+constexpr double CAP_GAMMA     =   1.0;
+
+constexpr double CAP_A_FREQ    =  16.0;
+constexpr double CAP_B_FREQ    = 20000.0;
+constexpr double CAP_GAMMA_FREQ =  1.0;
+
+// Helper: parametric LUT evaluation (gamma=1 path, linear interpolation)
+inline double lut_parametric(double x, double A, double B, double gamma) {
+    double t = (x - A) / (B - A);
+    if (t < 0.0) t = 0.0;
+    if (t > 1.0) t = 1.0;
+    if (gamma == 1.0) {
+        // linear: val = A + (B - A) * t = clamp(x, A, B)
+        return A + (B - A) * t;
+    }
+    // power-law path (gamma != 1)
+    double abs_t = std::abs(t);
+    double sign_t = (t >= 0.0) ? 1.0 : -1.0;
+    double pow_val = std::pow(std::max(abs_t, 1e-12), gamma);
+    return A + (B - A) * 0.5 * (1.0 + sign_t * pow_val);
+}
+
 // FramedDetector — C++ transcription of the real soothe2 mask-apply chain
+
 // (FUN_180529fe0 mono path, 0x5408b8==0), bit-exact structure.
 //
 // Per band, per bin (exact decomp /tmp/consumers_out.txt:638-1111):
@@ -23,6 +58,10 @@ struct DetectorBand {
 //   7. IIR3 leaky: twice with A3/B3
 //   8. dry/wet:    mask = mask*(fVar30*0x540888) + (1-fVar30)
 // final = min over bands.
+// PRNG (FUN_180529fe0 prologue :515-583): LCG state 0x2404e0 advances by round
+// offsets; fVar30 (scale coeff) = (int)(LUT[s+1]*LUT[s]+0.001), DAT_18262b5c8/
+// b704/b700 == 1 (VA-linear dump; earlier 0.4552/0.6089/0.6070 was a bad offset).
+// At live state 112 this yields fVar30 == 1.0 deterministically over many frames.
 class FramedDetector {
 public:
     FramedDetector(size_t nfft, float sample_rate);
@@ -36,9 +75,11 @@ private:
     size_t nfft_;
     float sample_rate_;
     double wsum_;
+    int prng_state_ = 112;  // 0x2404e0 (live snapshot value; advances per frame)
 
     std::vector<DetectorBand> bands_;
     std::vector<std::vector<float>> res_;   // per band, per bin |2B/A|
     std::vector<float> am_;                 // smoothed per-bin amplitude
+    std::vector<float> f6f8_;               // shared 0x5406f8 blend buffer (IIR1 out)
     std::vector<std::vector<float>> track_; // per band, per bin accumulator 0x5407c8
 };

handoff/NOTES_CAPTURE.md

@@ -95,7 +95,40 @@
 - => P1.5 "live capture" is a dead end; scalars must be derived statically or the two missing
   constants recovered from the original soothing_mem.bin (not currently present in workspace).
 
-## 2026-08-20b (P1.5 SOLVED: live ctx + level-tracker A[] captured via realtime playback)
+## 2026-08-20c (BREAKTHROUGH: LEVEL-PATH OBJECT captured live in /tmp/snap_rt.bin)
+
+The BandConfig A/B/gamma (roadmap gap 2, block of F2/F3) is now LIVE-CAPTURED.
+Read-only scan of the existing realtime snapshot `/tmp/snap_rt.bin` (ctx 0x2370040,
+render_long.rpp) — no new capture needed.
+
+### Method (repro, ~2s)
+1. Level-path fingerprint = per-band **level_gain pair buffer**: 0x400 f32 pairs
+   (`[level, gain]`), with `level[j] == j/1024` exactly (level[0]==0.0, step 1/1024).
+   Vectorized scan (2nd derivative of level slots == 0 + level[0]==0.0) finds them.
+2. Six such buffers at stride  0x2020..0x2040  (band0: 0x4083020, b1: 0x4085040,
+   b2: 0x4087080, b3: 0x40890a0, b4: 0x408b0e0, b5: 0x408d100).
+3. Find u64 refs to the six → consecutive slots stride 0x18 at **+0xe0+band*0x18**
+   → object base = **0x3975460** (level-path object).
+
+### Level-path object (base 0x3975460, region unknown / heap)
+- `+0x178` = band-list ptr → 0x32c0c60
+- `+0x180` → BandConfig 0x32c0aa0: **A=-24.0, B=+28.0, gamma@0xc=1.0, byte flag@0x10=0** → linear, no callback@0x90
+- `+0x188` → BandConfig 0x32c09c8: A=16.0, B=20000.0, gamma@0xc=1.0, flag=0 (freq-range shaped cfg; +0x18.. floats 0.55,7.13,2.77,2.718 = nonlinear shaper consts)
+- `+0x4198 + band*0x2000` = **band mask doubles**, 512 usable per band:
+  band0 ~1.0 const; band1 1.001→1.216 (rising); band2 0.999→0.579 (falling);
+  band3 1.291→1.002 (falling); band4/5 1.0→~0.983
+- `+0xe0+band*0x18` → per-band level_gain pair buffers (live LUT output already has
+  gains: b0 0.53123 const, b1 0.5314→0.535, b2 const, b3 0.598→, b4 const, ...; many
+  bands `~0.531` because mask≈1.0 & render_long default cfg)
+
+### Interpretation / next
+- The captured A/B/gamma are the **default render_long config** (A/B semantics =
+  level-scaler LUT min/max; rendering default band). To get the A/B/gamma of a SPECIFIC
+  band shape (t1kq_only1_1000 etc.) re-run rtctx_rt.py with that test RPP and re-scan
+  the same fingerprint (base offset shifts). Method is now automated.
+- This UNBLOCKS the parametric band-LUT 0x563440/0x563a60 as a structural source
+  (t=(x−A)/(B−A), clamped, ^gamma, ×norm) instead of fitted Pchip.
+- Dump helper: /tmp/dump_levelpath.py, /tmp/probe_base.py.
 The dead end above was wrong — the missing piece was REALTIME audio playback, not more scanning.
 `-renderproject` uses the OFFLINE audio engine (fields live "only during audio", per earlier note);
 the ctx object only materializes during a realtime transport play.

handoff/NOTES_LEVEL.md

@@ -884,3 +884,233 @@ exact LCG sequence per frame. scale already calibrated (t1kq -0.43 dB).
 4. combine/accumulator (0x5407c8) exact feedback (1500Hz comb err +6.4 dB)
 5. internal SR=48000/N=4096 vs host 44100/N=2048 and twin per-bin IIR (statically
    invisible, FUN_180535880 tail-calls)
+
+## ============ UPDATE 2026-08-20n: PRNG fVar30 LOCKED + CONSTANT FIX ============
+### CRITICAL CORRECTION: DAT_18262b5c8/b704/b700 == 1 (NOT 0.4552/0.6089/0.6070)
+soothe_mem.bin is a VA-linear dump: file offset = RVA = VA - 0x180000000.
+Earlier 0.4552/0.6089/0.6070 came from adding a spurious (+0x1e00-ish) section
+adjustment that is NOT applicable. Verified at raw=RVA=0x262b5c8/b704/b700:
+bytes 01 00 00 00 => int 1. Code does cvtdq2ps => (float)1 = 1.0. All three = 1.
+Verified constants at raw=RVA: 0x24c3c58=0.001, 0x24c3e28=0.8, 0x24c4674=-0.7,
+0x24c4670=-0.5 (match NOTES).
+
+### PRNG prologue (FUN_180529fe0 :515-583) TRANSCRIBED to C++ (prng_fvar30):
+  LCG state 0x2404e0 (live=112), round offsets: +0x3cdca,+0x140236,+0x10d56,+0xdf6b6
+  fVar30(line554) = (int)(f32(LUT[s+1])*f32(LUT[s]) + 0.001f)   [b5c8=b704=1]
+  => at live state 112, fVar30 == 1.0 deterministically over 300 frames.
+  => scale step: level *= (fVar30/0x1a0)*0x540870*0x54088c = /2048*440.95*1.0.
+     scale is NOT effectively randomized for this LUT/state.
+  dry/wet fVar30 (line1163) = 0x540874 - rnd, rnd from IAT stub 0x181a14cac
+  (jmp *0x181bab330, CRT import) - random dither, not statically lockable.
+
+### framed_model.cpp: scale coeff now computed via prng_fvar30() (prng_state_=112),
+   not a hardcoded constant. t1kq still -0.43 dB at level_scale=600 (unchanged).
+
+## ============ UPDATE 2026-08-20o: CRITICAL — level = am / res (not am * res) ============
+Found + fixed a sign/direction bug in framed_model.cpp level computation.
+
+res = |2B/A| (twin) is MINIMAL at band centre (0.117), NOT maximal. The model uses
+xv = log10(A_k / res_k), i.e. LEVEL = am / res. My code had level = am * res which
+inverted the fc-resonance: it cut MORE off-center and LESS at fc, producing a flat
+inverted fc-response.
+
+Fix: level = am_ / res_[b][k] (with 1e-12 floor). Now the fc-scan (tone1kq, band fc
+swept 800..1200, refs t1kq_only1_<fc> = true single-band) tracks the reference shape
+(deepest at fc==tone):
+  scale=42: fc900 +0.3, fc950 +1.3, fc1000 +0.9, fc1100 +0.2; mean|err| 2.46 dB,
+  max 5.3 dB (worst at edges fc800 +3.9, fc1200 +5.3 - ref cuts broader than model,
+  likely needs FFT-conv mask smoothing / wider effective notch).
+Remaining under-cut off-center: real soothe reduces ~16-22 dB broadly across
+800-1200 while model narrows; candidate = FFT-conv smoothing + warp + q shape.
+DEFAULT level_scale for am/res path ~= 35-45 (was 600 for the wrong am*res path).
+
+## ============ UPDATE 2026-08-20p: Phase B — framed_model RE-TRANSCRIBED ============
+Re-transcribed dsp/framed_model.cpp per confirmed chain (NOTES:199-226, source
+/tmp/consumers_out.txt:638-1111). Structural divergences from the old approximation:
+- IIR1 (FUN_18052d650, state 0x440518) writes into the SHARED 0x5406f8 buffer,
+  then bridges into the band's 0x540678 (:731 0x5160); IIR2 (0x3404f8/0x2c04f8 on
+  the band mask) kept separate.
+- mirror 0x11940: upper half = reversed lower (Hermitian), full-nfft scratch.
+- blend step: f6f8 = 0x540698·(1−mix) + mix·0.8; mask = exp2(−mask)·f6f8. C_AXIS=1.3
+  placeholder (offline 0x540698 = per-band scalar, NOT the exp-formula; NOTES:354).
+- combine (0x8d60/0x3c40/0x5a20): track = (mask−blend) + kRTAtt·blend +
+  kRTRel·blend + mask, using live weight tables kRTAtt/kRTRel (0x5406c8/6e8).
+- warp (0x540768·0x5406a8), IIR3 (A3/B3)x2, dry/wet identity.
+
+VALIDATION (scale sweep):
+- DUAL (band fc=500, tones 500+2000 at −7.23 dBFS): ref @500 −53.7/@2000 −29.6.
+  model @500 matches over scale (s30 −51.5, s42 −58.1); @2000 stuck ~−4..−13 (way
+  short). The DAZING far-field reduction (reduce 2000 by −29.6 when band is at 500)
+  does NOT come from the exp2(−linear·level) chain — exp2(am/res) collapses to ~0
+  once res@2000 (1.344) ≫ res@500 (0.1175).
+- T1KQ only1 fc1000: −21.1 vs ref −22.1 (OK). fc-scan shape intact.
+=> Phase B confirms structurally: the missing stage for dual-far-field is the
+   dB-domain LUT FIX_180563a60 (level_dB = 20·log10(mask) → t=(dB−A)/(B−A) clamp →
+   t^γ), which COMPRESSES the exp2 collapse into a smooth log curve. NEXT = decode
+   BandConfig ctx+0x188 writers (A/B/gamma) + 0x540698 -> then wire into the chain.
+
+## ============ UPDATE 2026-08-20q: METRIC FIX + LOG-DOMAIN LUT PORTED (honest baseline) ============
+### CRITICAL METRIC BUG FOUND: 24-bit refs mis-decoded as 16-bit
+Earlier dual
+
+## ============ UPDATE 2026-08-20r: FULL-CORPUS HONEST ASSESSMENT (committed baseline) ============
+Honest 24-bit metric across ALL datasets (input=3.5s window, correct sw decoding):
+  dual (band fc=500, q-sweep 11): mean|err| 0.41-0.61, max 0.72     ✓
+  al_* (fc=1000==tone, level sweep): lv3-12 err 0.05-0.43; lv18 -1.12, lv24 -1.80  (LOW-level over-cut)
+  res_only1 (resonant.wav, fc 300..700): -1.71..+0.81               (under-cut off-center, shape)
+  t1k_b1f (tone1k 0dBFS loud, fc sweep): +1.6..+2.12                (LOUD under-cut: LUT cap 0.667 too low)
+  t1kq_only1 (tone1kq, fc 800..1200): -0.59..+0.01                  ✓
+  OVERALL mean|err|=0.77, max 2.12.
+Systematics: Pchip LUT frozen (floor 0.366/cap 0.667 from al_* mid-level) under-predicts
+BOTH the loud tail (t1k_b1f xv>0.8 needs LUT~0.70) and over-predicts low tail (al lv24
+xv<-0.4 needs LUT~0.35). Real LUT extracted from refs: 0.351@-0.5, 0.60@0.07, 0.70@0.85.
+Parametric FUN_180563a60 fit to extracted points: A=-13.78dB B=68.29dB gamma=0.344
+(mean|err| 0.017 over extraction pts) but full-render VALIDATION regressed dual (real
+multiband interplay absent) -> keep Pchip baseline committed; A/B/gamma = runtime
+BandConfig ctx+0x188, NOT live-captured (SET TO: static path uses preset curve).
+Structural next: decode BandConfig ctx+0x188 writers (FUN_1804835d0/487200 at
+decomp_funs2.txt:21937/21962), wire combine 0x5407c8 + FFT-conv 0x535a70.
+
+## ============ UPDATE 2026-08-20s: BROADBAND HYPOTHESIS TESTED (NEGATIVE) + LUT re-cut attempt ============
+Tested the mask
+
+## ============ UPDATE 2026-08-20s: BROADBAND HYPOTHESIS TESTED (NEGATIVE) + LUT re-cut attempt ============
+Tested the "mask uses scalar broadband level" hypothesis (NOTES:637) directly: windowed
+FFT of dual_b1q_1.0 ref vs dual.wav input (2.5-3.5s steady):
+  gain@500 = 0.309 (-10.2dB), gain@2000 = 0.292 (-10.7dB), gain@1000 (NO tone) = 0.995 (-0.05dB),
+  gain@1500/3000/5000 = 0.85/1.00/1.00.
+=> REDUCTION IS PER-BIN: only bins *with a tone* are cut, empty bins pass through (~1.0).
+   So the level path is am_k/res_k (per-bin), NOT a scalar broadband level. Model structure correct.
+LUT re-cut attempt (floor 0.35/cap 0.70 from t1k_b1f+al_ extraction, monotone 16 knots):
+  REGRESSED whole corpus (mean|err| 0.77 -> 1.09, dual/t1kq/local worse). Reverted to the
+  joint-fit 12-knot Pchip (dual<=0.72, fc-scan<=0.59, corpus mean 0.77, max 2.12) = KEEP.
+Root cause of t1k_b1f residual (+2.1 loud) and al low-level (-1.8): NOT LUT cap shape alone;
+  al/t1k use DIFFERENT input (0dBFS vs -18dBFS) and the am normalization (pipeline am vs
+  tone_amp metric) differs; the joint-fit nodes were fit AT the al_* pipeline xv, so they
+  don't extrapolate cleanly to t1k_b1f's xv~0.85. Structural A/B/gamma (BandConfig ctx+0x188)
+  would give the *curve*, but writers are JUCE param plumbing (FUN_1804835d0/487200 = UI curve
+  setters, not DSP scalar setters) - static decode exhausted for now.
+NEXT: wire combine/accumulator 0x5407c8 + FFT-conv 0x535a70 into the chain (structural, may
+  close the t1k_b1f/al tail by smoothing the mask) - todo #3.
+
+## ============ UPDATE 2026-08-20t: FIT EXPLORATION (todo #3 diagnostics) ============
+Tracked what DOESN'T move the needle (all reverted, committed 12-knot Pchip + G/W/A/rp
+= 0.9963/0.3335/0.9807/0.0275/0.2159 remains optimal, corpus mean|err| 0.774 max 2.12):
+1. sqrt-Hann STFT analysis window (matching framed_render canon) REGRESSED to 0.788 max
+   2.91 -> kept Hann-Hann (the C++ full-render metric is authoritative, not the python
+   mask-level canon).
+2. Runtime (env) full-corpus fit of G/W/A/rp via framed_test renderer - mask-level
+   optimizer said G=0.877/W=0.402/A=0.673/rp0=0.0041/drp=0.28 (mean 0.66 mask-level) but
+   FULL RENDER regressed to 0.812 max 2.37 -> reverted. Mask-level objectives do NOT
+   transfer to the OLA render (mask applied per-bin interacts with window vs tone_amp
+   metric); the render metric is the ONLY honest one.
+3. Residuals are level-dependent (t1k_b1f loud +0.8..2.9, al low -1.1..-1.8, everything
+   else <=0.9): the empirical LUT is optimal AT the fit levels; structural A/B/gamma
+   (FUN_180563a60 band curve) is the missing level-dependence.
+TODO todo#3 remains: structural combine/acc 0x5407c8 + FFT-conv 0x535a70 wiring (NOTES:
+   FFT-conv window ~flat, likely marginal; combine adds band-weight interplay).
+
+### TWIN RES vs PY CANON (todo#3 check)
+C++ twin |2B/A| (fs=44100,N=2048, sens_stored=24.65, built via build_twin_coeff/twin_apply)
+vs Python bandres (GAIN=4.132=10^(24.65/40), render_parity): match within ~1.5% at fc
+300..2000 (fc300: 1.1798 vs 1.1887; fc1000: 0.11746 vs 0.11714; fc2000: 0.7057 vs 0.6963).
+=> res shape is NOT the source of the res_only1 fc=300 residual (-1.71 over-cut); that
+   residual is level-LUT related (input resonant.wav level differs from fit levels).
+
+## ============ UPDATE 2026-08-20u: F0 GATE — DETERMINISM VERIFIED (bit-exact REACHABLE) ============
+Re-rendered test RPPs twice each (reaper -nosplash -renderproject on /tmp copies with
+RENDER_FILE -> /tmp), then byte-compared data chunks:
+
+1. res_only1_500.rpp (4s):
+   - a vs b (two fresh renders): data chunk IDENTICAL (max|dx|=0 over 352800 samples).
+   - a vs committed res_only1_500.wav: data chunk IDENTICAL.
+2. t1kq_only1_1000.rpp (6s, 1587600 data bytes):
+   - a vs b: IDENTICAL.  a vs committed t1kq_only1_1000.wav: IDENTICAL.
+
+Whole-file cmp differs ONLY in the bext chunk timestamp (offset ~381: "02-08-2020")
+= Reaper render-metadata, NOT audio. Dither/PRNG does not corrupt the rendered signal
+(dry/wet rnd in FUN_180529fe0:1163 evidently locked/stabilized in offline render).
+
+CONCLUSION: soothe2 output is byte-deterministic and our Reaper/yabridge CLI re-renders
+reproduce the committed references EXACTLY. => Bit-exact (bytes) is REACHABLE; the gate
+that could have made it impossible (per-run randomization) is closed. The remaining work
+to bytes-parity is purely: exact structural chain + exact kernels + internal 48000/4096
+geometry + live A/B/gamma, NOT fighting host nondeterminism.
+
+## ============ UPDATE 2026-08-20v: EXISTING PARAMETRIC LUT SETS BENCHED (F1 closure) ============
+All previously-derived parametric-LUT sets (from repo scripts + NOTES) tested on the
+FULL honest 24-bit corpus (59 cases) inside ONE fixed bridge pipeline
+(C = G*LUT(xv)+W*warp^A, gain=(1-C)*res^rp, committed G/W/A/rp). Result:
+
+  LUT form            mean|err|  max
+  ------------------  --------  -----
+  pchip   (committed)   0.773   3.426   <-- BEST (unchanged)
+  linear  (0.483/0.717) 1.017   3.116
+  realpts (lutpts.npy)  1.134   3.192
+  u563a60 (A=-13.78/B=68.29/g=0.344) 1.669 6.004
+  lut5    (0.4356/0.5914/1.999/0.9364) 1.785 3.951
+  lut4    (fit_lut)     1.785   3.951
+  powerlaw(C=8)         6.809  11.880
+
+=> The empirical Pchip curve remains the best form-factor; NO existing parametric set
+   beats it at fixed bridge params. Realistic conclusion: the recovered runtime curve
+   (NOTES:967) was fit to extracted (xv,C) points, but those points themselves came from
+   the SAME bridge-shaped model (LUT=xv->C), so parameteric fits overfit their source
+   and lose on the honest render metric. Pchip baseline (0.773) stays canonical.
+   F1 (params of the LUT curve) is hereby CLOSED as "already produced, none accepted";
+   the structural A/B/gamma from ctx+0x188 remains the only path to bytes (blocked:
+   level-path object not live-captured; see F2/F5.)
+
+## ============ UPDATE 2026-08-20w: F2 STRUCTURAL WIRING TESTS — BOTH REGRESS (documented) ============
+Tested wiring the two remaining structural chain pieces onto the committed bridge
+(quick python precompute+OLA on a representative subset; honest 24-bit tone metric):
+  base    : mean|err| 0.75-0.80, max 2.1
+  FFT-conv step5 (mask *= win8193 0.5->1.0) : mean 5.22 (worse)  — masking the gain by
+     the freq window is WRONG direction; the 0x540658 window enters the FIR step, not a
+     simple gain multiply (confirms NOTES "window ~flat, adds almost nothing").
+  combine 0x5407c8 accumulator (acc += att*df+rel*df+g, df=g-acc, per-bin kRTAtt/kRTRel):
+     mean 4.68 (worse) — naive acc toward 2.36*g overd red by ~6x; the decomp combine
+     operates in the REDUCTION/exp2 domain (blend 0.8 pedestal + bigkernel exp2), NOT on
+     the fitted bridge final-gain. Mismatched domain => not a valid wiring test.
+CONCLUSION: F2 "wire combine+FFT-conv into the bridge" is rejected in naive form. The
+structural pieces belong to the exp2(mask) chain which regressed (Phase B, da63adc
+replaced it with the log-domain LUT bridge). The bridge (Pchip, 0.773) remains canonical.
+Path to bytes stays: exact A/B/gamma (blocked live), SR geom 48000/4096, bit-exact
+exp2/FFT. No code change made this session; NOTE-only.
+
+## ============ UPDATE 2026-08-20x: F2/F4 structural geometry test — NOT the gap ============
+Tested internal-geometry hypothesis (internal DSP SR=48000/N=4096 vs host 44100/2048):
+render the bridge at 48000/4096 with scipy resample_poly in/out to 44100:
+  host44100/2048  : mean|err| 0.683 (subset)
+  internal48000/4096: mean|err| 1.004 (worse)
+=> geometry/SR-mismatch is NOT the source of the level-dependent residuals.
+ALL structural adaptations tried and rejected (doc'd): parametric LUT sets (6), FFT-conv
+window (step5), combine 0x5407c8 accumulator, internal 48000/4096 geometry. The bridge
+(Pchip, full-corpus mean 0.774) remains canonical; empirical ceiling.
+Remaining real paths to bytes: (F1) live capture of level-path object (A/B/gamma) OR
+(F5) bit-exact exp2/FFT kernels — neither changes the mean but both are required for
+byte parity. No code change; NOTE-only.
+
+## ============ UPDATE 2026-08-20y: F5b — exp2 0x26b820 (assets + numeric fallback) ============
+- 0x26b820 = SCALAR double exp2 (vmulsd/vaddsd family; vmovups wrapper 0x26c220 =
+  32-at-a-time bigkernel with MXCSR/fnstcw control). Table-driven fdlibm-style,
+  Cody-Waite hi/lo: 8x16 irr tables + 0x181f31940.. series (-708.449.. step, companion
+  -1.684e-9) + kExp2_f2f4e0.. (log2e~1.4428 head) + vfmadd213sd poly chain.
+- EXTRACTED bit-exact P3 assets: dsp/exp2_tables.{hpp,cpp} (8x16 doubles straight from
+  soothe_mem.bin file=RVA; lead-in series kExp2_big). NOT yet wired 1:1 (algorithm body
+  has many special branches: subnormal/overflow/precision split).
+- exp2_dsp() (dsp/exp2.cpp): numerically correct double exp2 (=std::exp2) for wiring;
+  RELIABLY NOT bit-exact to plugin (documented). exp2_check: 2e6 dense grid + edges,
+  PASS vs std::exp2 (0 cells >1e-13) -> ensures fallback correctness only.
+Bit-exact exp2 transcription stays P3 (same bucket as DSP-FFT butterfly wiring).
+
+## ============ UPDATE 2026-08-20z: F5c — DSP-FFT 0x140a70 status (P3 confirmed) ============
+Full dsp/ check run (twin/tables/fftconv/vlog/leveltrack/levelpath/exp2): ALL PASS.
+FFT status: dsp/fft.cpp = numerical radix-2 (std::cos twiddle) used by the STFT
+framework — produces correct transform, but NOT bit-exact to the plugin DSP-FFT
+0x140a70. P3 bit-exact DSP-FFT plan: twiddle source (DAT_182616800 sin-table, sin(k*2pi/
+1024), loader FUN_180039b00 stride 2^(10-m)) + split-radix 2/4/8 in-place butterflies
+(FUN_18000bfc0/18000c5e0 with 0x8440 elementwise mul + FUN_1800437c0 acc) + plan-gen
+giant (FUN_18002f980 recursion + per-log2 factor tables) remain unwired. This is the
+multi-week gap (roadmap P3), required only for byte-parity of the FFT-conv path; the
+bridge renderer does not depend on it.