TWO THINGS, and the first is that nothing needed changing. The Decoder withdrew one of the two legs under its settle-time run: the plate pulse period it had offered as proof the run was not slowed rests on one interval at a 125 ms sample rate, and re-picking the troughs gives 2.628 s rather than 2.369 -- an adjacent local minimum counted as a separate trough. It cannot resolve a real-time factor below ~7%. Nothing in the port moves, because the numbers that correction touches were already unauthored. Checked rather than remembered: grep over authored/ and port/scripts/ finds no 0.531 and no 0.482. The only build-in reference in the tree is the plate arithmetic t=118 -> t=238, 120 units, which is the anchored leg -- it agrees with three prior readings and with the disc's own declaration. I had declined those two as one-run figures the Decoder itself flagged, with the port already within ~0.1 s from the disc's keyframes. That reasoning now has a second, independent justification I did not have at the time: a few per cent of slowdown sits inside them undetected. SECOND: `tools/port/verify-dwell`. Last iteration's hand comparison refuted a red flag I had filed myself -- `rest.t` is the wrong settle landmark, but "everything the sequencer paces off it is therefore late" was false and I nearly re-paced screens that already matched the game to 0.05 s. That check existed once, in a transcript. Now it runs. Its header carries the trap it exists to prevent, because that is the whole point: a port's TRANSITION TIMESTAMPS and the oracle's VISIBLE SPANS are not the same quantity, and differ by the exit ramp plus the black hold -- about 0.6 s, the entire discrepancy. The same confusion cost this corpus 0.48 s on the plate delay. The bar is the oracle's own run-to-run spread plus one film interval. Three cold boots of the real game differ by 0.3 s, so agreeing more tightly than the oracle agrees with itself would mean nothing. The developer-logo span reads 3.50 s on the hand-run and 3.75 s here, one interval apart and both inside the bar -- the tool reporting its resolution rather than hiding it. The oracle's numbers are in the script as a labelled test fixture citing their RE document; nothing in the port derives them. 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.