From 4e9c1b1ed74713772b7b76b059281f193b190031 Mon Sep 17 00:00:00 2001 From: Matiq Date: Thu, 20 Aug 2026 20:54:05 +0300 Subject: [PATCH] =?UTF-8?q?P4:=20F4=20geometry=20test=20=E2=80=94=20intern?= =?UTF-8?q?al=2048000/4096=20does=20NOT=20close=20residual=20(0.68=20vs=20?= =?UTF-8?q?1.00);=20all=20structural=20adaptations=20rejected?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Tested internal-geometry (48000/4096 + resample) — worse. Combined with earlier negative results (parametric LUT x6, FFT-conv window, combine acc), every structural adaptation is rejected. Bridge (Pchip 0.774) = empirical ceiling. Bytes require live A/B/gamma capture or bit-exact exp2/FFT kernels. --- handoff/NOTES_LEVEL.md | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/handoff/NOTES_LEVEL.md b/handoff/NOTES_LEVEL.md index 366e00a..b179b35 100644 --- a/handoff/NOTES_LEVEL.md +++ b/handoff/NOTES_LEVEL.md @@ -1077,3 +1077,16 @@ structural pieces belong to the exp2(mask) chain which regressed (Phase B, da63a 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.