54fa940591
Found because the port refused to apply my stream assignment and did the arithmetic instead: the running decoder's three ADV contexts sum to 3 584 000 B against a resolved region of 3 114 352 -- 15 % too small to hold them. Two spans, one wrong, and it was the disc side. The gap is 238 packets exactly (487 424 B), which is what a start offset looks like; ctx0 declares 632 packets and the resolver's leading chunk has 394. Verified against the decoder's own byte_sizes, which cannot be fitted to: at -238 packets to_xma_riffs yields [1294336, 1118208, 1171456], all three exactly. It is a real boundary and not the end of a sweep -- at -300 the previous asset's chunks appear while the three ADV sizes stay stable. Disc-wide: 24 of 24 single-chunk regions start at a boundary; 8 of 10 three-chunk regions start mid-stream. The defect is specific to the multichannel case. The audit's per-movie number is an UPPER BOUND, not the clip -- its stopping rule is the chunk count changing, and to_xma_riffs absorbs a few packets of the previous asset first (243 reported for ADV against a true 238). Only ADV has external ground truth. Consequence: in those 8 movies the leading chunk is a truncated first stream, not a spurious artefact, and anything measured on it was measured on a fragment -- including this corpus's own chunk-0 level, though the assignment survives because its ratio test was chosen to be immune to the clipping. The resolver is NOT patched. Why the predecessor cue's trailer lands 238 packets into the next asset is unanswered, and a fix guessed from one movie would be worse than a documented defect. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v
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.