f91ac9aad3
f3-title-plays-bgm-102-and-103.md's BGM census resolved a literal
`addi r5,r0,<imm>` before every call to the play primitive, which is blind by
construction to a cue id supplied any other way. Two of the primitive's 34
callers ARE supplied another way -- one is a register passthrough inside a
generic 6-caller wrapper `sub_821CCCB0(obj, cueId)` with a -1 "don't play"
sentinel. One of its six callers chains back to slot 1 of GamePart_Title's
OWN dispatch table at 0x820a3dec, identified by its adjacent
RegisterToFactory<0, class silph::GamePart_Title> string -- the same
convention already used disc-wide for the other 28 GameParts, not a
neighbourhood guess this time.
Traced as far as static analysis goes: the field that would carry the cue id
traces to a 19-caller shared helper's return value, too common to be
title-specific -- reads as "allocate a sound-emitter handle", not "here is
the cue". The value most likely gets set at whatever runtime moment the game
wants this emitter to speak, which a disassembly listing does not contain.
Classified undecodable-with-reach, not a fourth thing -- narrower and
better-aimed than the prior reach ("SE goes through a different call").
Every address cited was independently re-decoded from the raw .pe bytes
(file offset = VA - 0x82000000), not taken from the database's own
mnemonic/operands columns, and all agree.
Refutation attempt this iteration: checked whether the "6 callers is
exhaustive" claim for sub_821CCCB0 survives indirect dispatch (a plain
kind='call' xref scan is blind to a vtable/function-pointer-array entry).
Checked function_pointer_array_entries and kind='ind_call' xrefs for all
four functions in the chain -- none found. The claim survives.
What would close it: --xma_param_probe=true during a title boot's build-in,
watching for a newly-decoded stream when the plate reaches full alpha with
no input -- the same technique menu-audio-cues.md used for the menu's SE
census. Not run this iteration; this is the static half only.
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
-- and RUNNING.md, which is how you actually start it
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.