f3f31d4923
The Decoder found it in the format: a nested record is itself a RATC bundle and its header's +0x08 is the LOOP LENGTH. A record's keyframes need not fill it and the slack is a hold at the final pose, so ptbtn00f is 105 units of ramp inside a 120-unit cycle -- the glow rests dark for 15 units. The five ptbtn0Nf records fill their 120 exactly, which shows the slack belongs to that record and not to the format. Disc-wide over 1781 timed nested records: 92.3% declare exactly their last keyframe time, 7.7% more, 0 LESS -- the falsifier never fires. THE DECISIVE TEST USED THIS PORT'S NUMBER. Both candidates need the same emulator pacing factor, and the ring measures it independently: declared 120 -> 2.177 s -> 1.0885. 105 units needs 1.211-1.337 to reach the measured 2.12-2.34 s, which EXCLUDES it; 120 units needs 1.060-1.170, which CONTAINS it. Two different elements in different bundles, separate runs, tied only by both declaring 120. My three readings in order are the useful record: 129 (105 + the since-deleted exit_ramp_units) fitted the measurement for a reason that evaporated; 105 (the group length) I shipped knowing it was 17% short; 120 is decoded. And the 123-vs-129 pair I once called unseparable STRADDLED the right answer without containing it -- the sharpest argument I have seen against treating "two candidates, nothing separates them" as if the truth must be one of the two. Verified bit-identical 120 units apart (mean 0), 0.061 at a quarter, 0.888 at half. Still authored because the pinned tag does not expose +0x08; delete the entry the day a tag does. THEIR rest() FLAG, CHECKED RATHER THAN ASSUMED: they warned a focus record is the kind of element rest() mishandles. Censused -- 34 focus-record elements, only 2 with a varying alpha, both ptbtn00f, whose rest.alpha of 80 IS their peak, exactly the pathology described. The port does not hit it because the plate draws through the loop path, and the other 32 are constant-alpha so rest() is safe. 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.