I carried this as "0.03 s outside a composite bound, probably a property of the bound rather than the game", and the Decoder agreed. Both wrong, and the way it was settled is the point: I stopped reasoning about the bound and filmed the transition. At 0.05 s the port fell straight out of the publisher's fade into the developer logos -- mean 5.06 -> 0.32 at t=4.20, then 5.65 at t=4.25. NO BLACK FRAME AT ALL, where the oracle measures a 0.17-0.23 s pure-black plateau (HANDOFF Q7). The bound was fine; the port was missing a fifth of a second of black, and had been since P3. Authored at 12 units because the boot path has nothing to read it from: publisher_logo and developer_logos each carry a single palogo_eff0, a 1280x720 primitive with ONE keyframe at t=0 -- static, not a transition ramp. The menus' quad declares black for 12 units and 12/60 = 0.200 s sits mid-range, so the number is the disc's where a screen has one. Filmed after: t=4.25, 4.30, 4.35, 4.40 all at mean 0, then the developer logos at 4.45. publisher interval 4.26 DIFFERS -> 4.47 agrees; developer 3.62 -> 3.73, still agrees. Settled-frame comparisons untouched, as they should be. THE LESSON IS THE SHAPE OF THE DISMISSAL, NOT THE NUMBER. "A 0.03 s miss against a bound composed from two measured ranges plus jitter slack is more likely a property of the bound" is plausible, was accepted by both of us, and was wrong. The composite bound is why the miss looked small -- the underlying gap was 0.2 s -- and a plausible explanation for a small number is how a real defect stays hidden. The film cost one command. Also recorded: the Decoder has reproduced across two build-ins that the console NEVER draws ptlogo_back2eff3 (0 draws against ~5 expected), with sampling phase, invisible draws and position error all ruled out -- but WHY is not established, and nothing in eff3's record differs from its neighbours. The port keeps drawing it, deliberately: dropping an element the disc declares on a measurement with no mechanism is authoring a behaviour neither agent can derive, and nothing this port gates on would notice, since the flashes live only in the build-in and verify-capture compares the settled frame. 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.