From 4dd6a3f325b5c79dbb9f3bdfcb475fd777905ce1 Mon Sep 17 00:00:00 2001 From: sylph-decoder Date: Sun, 30 Aug 2026 20:17:23 +0000 Subject: [PATCH] re: a bank's wave 1 is not a filtered copy of wave 0 -- and my own discriminator cannot finish the job MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Coherence on BGM_103, the menu's bank, with controls run first: a real linear filter of wave 0 reads 0.93-0.94 in every band, a different bank reads 0.001, and wave 0 misaligned by 1 s reads 0.004-0.057. The measurement reads 0.027 at 1-4 kHz, so the 'wave 1 is wave 0 filtered' model is refuted. The frequency structure is inverted relative to any mic-pair or reverb model: coherence rises with frequency (0.169 -> 0.827) while energy falls (71 % -> 0.2 %), and a rear pair decorrelates fastest at HF. In the midrange the two waves are 13x further apart than the two channels of one wave. But the L-R control is what limits the tool and it is recorded as such: within one wave, genuinely one performance in two channels, coherence is only 0.221-0.497. So 'same performance' does not imply high coherence here, my positive control was the wrong model of the rear-pair reading, and the šŸŸ” is NOT settled. The tool tests for linear filtering and neither surviving reading requires it. Also corrects MISSION's Q10 row, which still carried the refuted three-sub-wave premise and had directed work at a dead question for days. Its gate is in fact met. Co-Authored-By: Claude Opus 5 (1M context) Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v --- docs/port/MISSION.md | 33 +++++++++++- docs/re/REFUTED.md | 28 ++++++++++ docs/re/data/bgm-stem-coherence.txt | 71 ++++++++++++++++++++++++++ docs/re/structures/bgm-two-stems.md | 41 +++++++++++++++ tools/re-capture/bgm_stem_coherence.py | 71 ++++++++++++++++++++++++++ 5 files changed, 243 insertions(+), 1 deletion(-) create mode 100644 docs/re/data/bgm-stem-coherence.txt create mode 100644 tools/re-capture/bgm_stem_coherence.py diff --git a/docs/port/MISSION.md b/docs/port/MISSION.md index 15be5c45..c3a8f9f4 100644 --- a/docs/port/MISSION.md +++ b/docs/port/MISSION.md @@ -74,7 +74,7 @@ alongside it. | **Q7** | **Transitions.** What happens visually between screens ā€” the `pteff00.prm` quads, a fade, a cut ā€” and its timing | Described and timed against a capture | | **Q8** | **Menu audio.** Which BGM per screen; which cue on move / confirm / back / error. The cue table is complete; the event binding is not | Cue names bound to events, with how you established each | | **Q9** | **Video binding.** Which movie is the boot intro vs the new-game intro; whether playback is skippable and what ends it | Named movies plus the playback rules | -| **Q10** | **What are a music bank's sub-waves?** `BGM_001.slb` is three sub-waves ā€” 10 KB, 4.47 MB, 4.67 MB ā€” and we currently **concatenate them blindly** into one 347 s track. Two near-equal halves could be intro + loop, or two variations, or two halves of one piece. A menu that loops its music needs to know which | The role of each sub-wave, established for at least the menu BGM. "Concatenate" is a decision, not a default ā€” right now it is a default nobody chose | +| **Q10** | ~~**What are a music bank's sub-waves?**~~ āœ… **ANSWERED ā€” see below.** Every factual premise in the original row is refuted: a bank is **two** waves, not three (the 10 KB was the bank *header*, emitted by our own reader), and the three candidate roles it listed ā€” intro + loop, two variations, two halves ā€” are all dead. | āœ… **Gate met.** Role established on the menu's own bank: [`bgm-two-stems.md`](../re/structures/bgm-two-stems.md). šŸŸ” One sub-question survives ā€” *which kind* of second stem ā€” and it is šŸŸ” by measurement, not by neglect | | **S1** | ~~**Ready Room probe.**~~ **DONE 2026-08-28 ā€” [no-go](../re/ready-room-probe.md).** It is 2D and enumerates fine, but the pak is briefing/tactical-map content, not the Ready Room menu | āœ… go/no-go written | ## āœ… Emulator-side questions are NOT blocked ā€” corrected 2026-08-30 @@ -290,6 +290,37 @@ What needs a decision is which way the divergence gets closed: Recorded rather than chosen, per "do not improvise around a blocker". +## āœ… Q10 is answered ā€” corrected 2026-08-30 + +The Q10 row above was written on a premise that has since been **refuted in every +part**, and it survived as a live question for days after the refutation landed. +Recording the correction here rather than silently editing the row: + +* āŒ *"`BGM_001.slb` is three sub-waves (10 KB, 4.47 MB, 4.67 MB)"* ā€” the 10 KB is + the **bank header**. Our reader emitted it, from a modulus valid only for a + header shorter than one XMA packet. A bank is **two** waves, **28/28** disc-wide. +* āŒ *"we currently concatenate them blindly"* ā€” and concatenating is **wrong**, + now measured: the two waves are **sample-synchronous** and the running game + decodes **both at once** (the XMA probe at the main menu saw two stereo streams + whose byte sizes are `BGM_103`'s two declared waves, exactly). +* āŒ *"could be intro + loop, or two variations, or two halves of one piece"* ā€” all + three predict unequal durations; **32 banks give equal ones**. +* āœ… **The gate ā€” "the role of each sub-wave, established for at least the menu + BGM" ā€” is met**, and on the menu's own bank: `BGM_103`, named from the + executable, confirmed against the disc and against the running game. + +šŸŸ” **What is still open is narrower than the row**: *which kind* of second stem ā€” +the rear pair of a 4-channel mix, or a second intensity layer. Both predict +simultaneity, so runtime observation cannot separate them, and a coherence +discriminator run 2026-08-30 **refuted the "filtered copy" model but could not +separate the two** ā€” its own control showed that in this material even L vs R of +one performance reads only 0.22ā€“0.50, so the test's premise does not hold. +[`../re/data/bgm-stem-coherence.txt`](../re/data/bgm-stem-coherence.txt) + +āš ļø **This distinction does not block the port.** Both readings give the same +instruction: play both waves, aligned at sample 0, together. It changes only how +they would be *mixed* if the port ever does surround. + ## Known unknowns ā€” say so, do not fill them in Some of these may turn out to be undecodable. That is a valid, useful answer, and diff --git a/docs/re/REFUTED.md b/docs/re/REFUTED.md index ea7f6412..2b3d82c1 100644 --- a/docs/re/REFUTED.md +++ b/docs/re/REFUTED.md @@ -761,3 +761,31 @@ sweep phases ā€” and the 350Ɨ396 logo ROI is **byte-identical across all of the (0 / 138 600 px differing, max |d| 0), reproduced in two independent sessions**, while 5ā€“8 % of the whole frame moves as a contrast control. The sweep ink does not land on the logos. The Ā±1ā€“2 residual is not sweep. + +### Music-bank stems (2026-08-30) + +* ~~"wave 1 is wave 0 put through a filter"~~ ā€” āŒ **refuted** on `BGM_103` by + magnitude-squared coherence. A real linear filter of wave 0 reads **0.93ā€“0.94** + in every band (positive control); the measurement reads **0.027** at 1ā€“4 kHz. + No linear filter does that in a band where both waves carry energy. + [data](data/bgm-stem-coherence.txt) +* ~~"the rear-pair reading can be tested by coherence"~~ ā€” āŒ **refuted, and it was + my own test's premise.** The control that matters ā€” L vs R *within* one wave, + genuinely one performance in two channels ā€” reads only **0.221ā€“0.497**, so in + this material "same performance" does not imply high coherence. A 4-channel + mix's rear pair is not a linear filter of its front pair, so the discriminator + never had the power to separate the two readings. The šŸŸ” stands. + +### Refutation attempt on the corpus's "two stems of ONE PERFORMANCE" ā€” šŸŸ” SURVIVED, WEAKENED (2026-08-30) + +**Target:** `structures/bgm-two-stems.md` (the `BGM_103` section is another +agent's), which reads the two waves as two stems *of one performance*. + +**My attempt:** if they are one performance, they should share signal structure; +coherence should be well above the independent floor across the bands carrying +the music. + +**Result: the claim survives, but one of its supporting readings is dead and the +bands carrying 96 % of the energy read 0.169 and 0.184** ā€” far above the 0.001 +independent floor, so *not* independent, and far below a filtered copy. "One +performance" stands; "rear pair, i.e. a filtered view of the same mix" does not. diff --git a/docs/re/data/bgm-stem-coherence.txt b/docs/re/data/bgm-stem-coherence.txt new file mode 100644 index 00000000..5e529f9f --- /dev/null +++ b/docs/re/data/bgm-stem-coherence.txt @@ -0,0 +1,71 @@ +# Is a music bank's wave 1 the SAME instruments filtered, or DIFFERENT parts? +# BGM_103 (the menu's music) -- 2026-08-30 +# +# structures/bgm-two-stems.md leaves two readings alive for wave 1: the rear +# pair of a 4-channel mix, or a second intensity layer -- and correctly notes +# that runtime simultaneity cannot separate them, because both predict it. +# This is a static attempt at a discriminator. +# +# METHOD: magnitude-squared coherence, Welch, NFFT 8192 @ 48 kHz, 60 s window +# (702 segments, so the bias floor is ~1/702 = 0.0014). Coherence is ~1 wherever +# one signal is a LINEAR FILTER of the other and ~0 for independent signals. +# tools/re-capture/bgm_stem_coherence.py +# +# WAVES: slb_extract_wave.py BGM_103.slb 14336 1893 2 48000 (wave 0) +# slb_extract_wave.py BGM_103.slb 3903488 1919 2 48000 (wave 1) +# then ffmpeg -i x.riff x.wav. Both decode to 87.744 s, 4 211 729 frames. +# CONTROL BANK: BGM_104.slb 14336 1305 (a different piece, same codec). +# +CONTROLS + POS w0 vs linear-filter(w0) 0-0.2k 0.929 0.2-1k 0.938 1-4k 0.936 4-12k 0.938 12-16k 0.938 16-24k 0.937 + NEG w0 vs a different bank 0-0.2k 0.001 0.2-1k 0.001 1-4k 0.001 4-12k 0.001 12-16k 0.001 16-24k 0.002 + NEG w0 vs w0 shifted 1 s 0-0.2k 0.057 0.2-1k 0.048 1-4k 0.007 4-12k 0.019 12-16k 0.015 16-24k 0.004 + REF w0 L vs R (one perf.) 0-0.2k 0.321 0.2-1k 0.221 1-4k 0.363 4-12k 0.445 12-16k 0.497 16-24k 0.450 + REF w1 L vs R (one perf.) 0-0.2k 0.078 0.2-1k 0.051 1-4k 0.089 4-12k 0.411 12-16k 0.453 16-24k 0.455 + +MEASUREMENT + w0 vs w1 0-0.2k 0.169 0.2-1k 0.184 1-4k 0.027 4-12k 0.635 12-16k 0.768 16-24k 0.827 + +ENERGY SHARE + w0 0-0.2k 71.4% 0.2-1k 24.8% 1-4k 2.4% 4-12k 1.0% 12-16k 0.1% 16-24k 0.2% + w1 0-0.2k 53.8% 0.2-1k 40.9% 1-4k 2.3% 4-12k 2.1% 12-16k 0.3% 16-24k 0.6% + +# ------------------------------------------------------------------------------ +# READING IT +# +# āœ… THE INSTRUMENT IS CALIBRATED. A real linear filter of w0 reads 0.93-0.94 in +# every band; a different bank reads 0.001-0.002; w0 against itself misaligned by +# 1 s reads 0.004-0.057. So the estimator detects filtering and is not fooled by +# two pieces of music in the same codec. +# +# āŒ REFUTED: "wave 1 is wave 0 put through a filter." The positive control says +# a filter reads 0.936 at 1-4 kHz. The measurement reads 0.027 there. No linear +# filter produces that in a band where both waves carry energy. +# +# šŸ“Œ THE FREQUENCY STRUCTURE IS INVERTED relative to any mic-pair or reverb +# model. Coherence RISES with frequency -- 0.169, 0.184, 0.027, 0.635, 0.768, +# 0.827 -- while energy FALLS -- 71.4 %, 24.8 %, 2.4 %, 1.0 %, 0.1 %, 0.2 %. +# A rear pair or a reverb return decorrelates FASTEST at high frequency, which +# is the opposite. What is coherent lives in bands holding ~1.3 % of the energy; +# the bands holding 96 % of it read 0.169 and 0.184. +# +# šŸ“Œ AND IN THE MUSICAL MIDRANGE THE TWO WAVES ARE FURTHER APART THAN THE TWO +# CHANNELS OF ONE WAVE: 1-4 kHz gives 0.027 between waves against 0.363 for w0's +# own L vs R -- a factor of 13. Two channels of one performance agree far more +# than the two waves do. +# +# šŸ”“ BUT THE L-R CONTROL IS ALSO WHAT LIMITS THIS TOOL, AND IT KILLS THE CLEAN +# ANSWER. L vs R within a single wave is genuinely "one performance, two +# channels", and it reads only 0.221-0.497 -- nowhere near the 0.94 a filter +# gives. So in THIS material "same performance" does not imply high coherence, +# which means my positive control was the wrong model of the rear-pair reading: +# a real 4-channel mix's rear pair is not a linear filter of its front pair. +# +# => The filter model is dead. The two named readings are NOT separated. This +# tool cannot separate them, and the reason is stated rather than discovered +# later: it tests for linear filtering, and neither reading requires it. +# +# āš ļø REACH: one bank (BGM_103), one 60 s window, mono-summed for the coherence +# rows. Not run over the other 31 banks. The 16-24 kHz reading of 0.827 sits in +# 0.2-0.6 % of the energy and is unexplained -- it is NOT generic codec +# behaviour, since the different-bank control reads 0.002 in the same band. diff --git a/docs/re/structures/bgm-two-stems.md b/docs/re/structures/bgm-two-stems.md index 47ea5066..ceb207dd 100644 --- a/docs/re/structures/bgm-two-stems.md +++ b/docs/re/structures/bgm-two-stems.md @@ -92,6 +92,47 @@ twice, the second time as a bass-less secondary stem. decorrelated between L and R, and with the bass managed away to the front pair. * **A second intensity layer** to be mixed in or crossfaded. +### āŒ One of the two is now narrowed: wave 1 is NOT a filtered copy of wave 0 + +**measured 2026-08-30** ā€” [`../data/bgm-stem-coherence.txt`](../data/bgm-stem-coherence.txt), +`tools/re-capture/bgm_stem_coherence.py`, on **`BGM_103`**, the menu's bank. + +Magnitude-squared coherence is ~1 wherever one signal is a **linear filter** of +the other. Controlled first: a real filter of wave 0 reads **0.93ā€“0.94** in every +band, a different bank reads **0.001**, and wave 0 against itself misaligned by +1 s reads **0.004ā€“0.057**. + +| band | w0 vs w1 | w0's own L vs R | energy in w0 | +|---|---|---|---| +| 0ā€“200 Hz | 0.169 | 0.321 | 71.4 % | +| 200 Hzā€“1 kHz | 0.184 | 0.221 | 24.8 % | +| **1ā€“4 kHz** | **0.027** | **0.363** | 2.4 % | +| 4ā€“12 kHz | 0.635 | 0.445 | 1.0 % | +| 16ā€“24 kHz | 0.827 | 0.450 | 0.2 % | + +āŒ **"Wave 1 is wave 0 filtered" is dead.** A filter reads 0.936 at 1ā€“4 kHz; the +measurement reads **0.027**. + +šŸ“Œ **The frequency structure is inverted** relative to any mic-pair or reverb +model: coherence *rises* with frequency while energy *falls*. A rear pair or a +reverb return decorrelates fastest at HF. Whatever is coherent lives in bands +holding ~1.3 % of the energy; the bands holding 96 % of it read 0.169 and 0.184. + +šŸ“Œ **In the midrange the two waves are 13Ɨ further apart than the two channels of +one wave** ā€” 0.027 against 0.363. + +šŸ”“ **But the same control kills the clean answer, so this does NOT settle the +šŸŸ”.** L vs R *within* one wave is genuinely one performance in two channels, and +it reads only **0.221ā€“0.497** ā€” nowhere near 0.94. So in this material "same +performance" does not imply high coherence, and my positive control was the wrong +model of the rear-pair reading: a real 4-channel mix's rear pair is not a linear +filter of its front pair. **The tool tests for linear filtering, and neither +surviving reading requires it.** Stated here rather than discovered later. + +āš ļø Reach: one bank, one 60 s window, mono-summed. The 16ā€“24 kHz reading of 0.827 +is unexplained and is *not* generic codec behaviour ā€” the different-bank control +reads 0.002 in that same band. + **Not settled, and the obvious field does not settle it.** `ChannelMask` is `0x0002` on *both* waves, and [`sound-slb.md`](sound-slb.md) already records that this game writes meaningless channel metadata (movie voices declare 2 channels diff --git a/tools/re-capture/bgm_stem_coherence.py b/tools/re-capture/bgm_stem_coherence.py new file mode 100644 index 00000000..f50ae715 --- /dev/null +++ b/tools/re-capture/bgm_stem_coherence.py @@ -0,0 +1,71 @@ +#!/usr/bin/env python3 +"""Are a music bank's two waves the SAME instruments filtered, or DIFFERENT parts? + +`structures/bgm-two-stems.md` leaves two readings alive for wave 1 -- the rear +pair of a 4-channel mix, or a second intensity layer -- and notes that runtime +simultaneity cannot separate them, since both predict it. + +This tries a static discriminator. Magnitude-squared coherence is ~1 wherever +one signal is a LINEAR FILTER of the other, and ~0 for independent signals, so +a rear pair modelled as "front pair, filtered" should read high and a different +arrangement layer should read low. + +āš ļø READ THE CONTROLS BEFORE THE MEASUREMENT. The L-vs-R control below is the +one that matters and it is the one that limits this tool: see the docs page. + + bgm_stem_coherence.py + +Waves come from slb_extract_wave.py + ffmpeg; see the docs page for the exact +offsets and packet counts. +""" +import sys, wave, numpy as np + +NFFT, HOP, FS = 8192, 4096, 48000 +BANDS = [(0,200),(200,1000),(1000,4000),(4000,12000),(12000,16000),(16000,24000)] + +def load(p, nmax, stereo=False): + w = wave.open(p); n = min(nmax, w.getnframes()) + a = np.frombuffer(w.readframes(n), dtype="=lo)&(f=lo)&(f