The port caught this with arithmetic off the disc, and it was right: build 2 has a keyframe group of its own, so "when build 4 has settled, wait 2.13 s, then composite build 2" puts the plate at settle + 2.13 + 3.97 s. Confirmed build 2's group here independently of their message: `ptbtn00.t32` reaches a=255 at t=238. The reconciliation needs no free parameter. Both builds run on ONE clock, started together, and the premise that fails is `rest.t`: rest.t is NOT when a screen settles. It is the last HOLD keyframe before the exit. ptlogo1 rests at t=251 and stops moving at t=42. The title's visible build-in ends at t=118, where pteff01, pteff02.prm and ptlogoall_eff end their ramps together. 238 - 118 = 120 units = 2.000 s, against a measured 2.138 and 2.132. So the interval the two runs agreed on to 6 ms was a DECLARED one and I handed over a wall-clock reading of it. That reading is 6.7% long, and the corpus already knew why: 120 units in 2.135 s is the game presenting at 28.06 / 28.14 fps against a nominal 30, and the idle title was independently measured at 28.5 fps before these runs. Corroborated from inside the same two runs -- first pixels -> settle is 1.643 s and 2.131 s, a 30% spread, while settle -> plate is 2.138 and 2.132. Frames are dropped during the build-in, not during the hold, which a change in the game's own timing could not do. So the port authors nothing here. What is unchanged: ScreenView still has to draw two builds at once and the boot's end state is still not plate-free. Not settled, and said so on the page: which reading of the keyframe times is right (it moves the plate by 2 units and I cannot separate them from these traces), and my settle landmark to better than +/-5 units. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014voBspJ6kFncNErZJuZcLw
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.