35bf469172
Audited my own docs for the Decoder's method-versus-subject error -- a negative
about the instrument written as a negative about the subject. Clean: every
impossibility claim in DECISIONS is already method-scoped ('undecodable WITH
REACH', 'cannot be answered BY LISTENING'), and both live open rows in BLOCKED
read 'not observed' and 'deliberately not inferred'. Nothing to fix, recorded as a
negative.
Then three cheap measurements located the fidelity fault exactly. Identity --
source against a second decode of itself at lag 0 -- subtracts to -inf, so
decode-and-subtract is exact and the pipeline was never the problem. A LOSSLESS
flac of the identical fold reaches only 14.2 dB down, searched exhaustively at
stride 1 over 300 lags, where it must reach about 90. The shipped transcode's 8.73
dB is therefore meaningless.
So the difference path is disqualified rather than inconclusive, and every number
it produced in this thread -- including the 'difference louder than source'
readings I reported twice -- was an artefact of the lag search, not evidence about
a transcode. The tool now refuses on that path and carries its acceptance test in
the code: make lossless-vs-source return >= 60 dB down before believing anything
it says.
The identity test costs one decode and no encoder, and it should have been the
first thing run three iterations ago. Before asking whether an instrument can
measure a difference, ask whether it returns zero for no difference.
Hypotheses ruled out and recorded so nobody re-runs them: drift (offset stable at
about -2465 samples across t=2, 10 and 20 s), container start time (start_time is
exactly 0), the codec being perceptual (the lossless control fails the same way),
and level or content mismatch (bands agree to 0.66 dB).
P4's waveform question is now open with a disqualified instrument -- worse than it
looked yesterday, and better than believing 8.73 dB meant something. The band
check is unaffected and still asserts.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
Sylpheed
A clean-room reverse engineering and port project for Project Sylpheed: Arc of Deception (Xbox 360, 2007).
Three things live here, in one repository so that a change spanning them lands as one commit:
| The decoders | crates/sylpheed-formats — the disc's formats, read and verified disc-wide |
| The port | port/ — a Godot 4 project, plus crates/sylpheed-export which converts a disc into the open asset tree it reads |
| The corpus | docs/re/ — what has been reverse engineered, with its evidence, its retractions and its dead ends |
You need your own copy of the game. No game content is in this repository and none ever will be. The exporter reads the disc you supply.
The oracle is the real game
sylpheed-cliand the Explorer are tools for verifying our decoding. They are hypotheses under test and they have been wrong. When something must be checked against the truth, the truth is the game running in Xenia Canary, captured — not any renderer of ours.
This is stated first because getting it backwards is the most expensive mistake this project has made.
Layout
crates/
sylpheed-formats/ the decoders. Disc-wide verified; the corpus is its spec
sylpheed-cli/ headless tools -- render a screen, dump a table, probe audio
sylpheed-viewer/ the Explorer: a human's window onto the disc. STATIC data only
sylpheed-export/ disc -> the open, moddable asset tree
port/ the Godot 4 project. Reads open formats ONLY
authored/ decisions that are NOT on the disc, each with its reason
data/
base/ generated by the exporter. Gitignored, never hand-edited
mods/ drop-in overrides. Yours
docs/
re/ the corpus: findings, refutations, method traps
game/ how the game is navigated -- menus, modals, flight
port/ the port's mission, its handoff contract, modding rules
agents/ how the agent team works together
tools/ capture harnesses, probes, the share tool
exchange/ transient inter-agent files. NOT in git
docker/ the agent containers
Where to start
docs/re/INDEX.md— what is decodeddocs/re/REFUTED.md— what has been tested and dieddocs/re/METHOD.md— traps this project has already paid fordocs/game/navigation.md— how the game is navigateddocs/port/MODDING.md— why the asset tree looks the way it does
Xenia Canary is a separate repository: it is a fork tracking upstream, and it carries our instrumentation.
Conventions
Confidence is per claim, never per document: ✅ CONFIRMED · 🟡 PROBABLE ·
❔ HYPOTHESIS · ❌ REFUTED. A withdrawn result is kept with its reasoning
rather than deleted — that is why the numbers here can be trusted.