7465e49c8e
The Decoder asked me to decode a voice region's leading chunk -- it has no XMA1
decoder in its container -- and the decoder run refuted a claim of mine that it
had already adopted into `docs/re/structures/voice-region-leading-chunk.md`.
I wrote that a region's two equal-length chunks are HANDOFF Q10's decoded
two-stem shape. Equal duration was a SHAPE match and I carried the music census
across on the strength of it. The content does not support it:
S00A chunk 2 is DIGITAL SILENCE -- 4497300 samples, peak -inf.
ADV chunk 2 is 0.60x chunk 1, best-fit scalar, residual 26.8 dB below the
target: about 95% of its energy is a -4.4 dB copy of the first chunk.
That cost real level. Summing chunk 1 with silence at 1/n put S00A's dialogue
6.02 dB down for nothing -- the exported file peaked at -16.2 dBFS against a
source chunk peaking at -4.2. `export_voice` now drops a digitally silent chunk
before the sum, which is arithmetic and not a judgement about content.
WHAT ADV'S NEAR-DUPLICATE SECOND CHUNK IS REMAINS OPEN AND IT IS STILL SUMMED.
Whether the game plays both is a decoding question, 26.8 dB of residual is not
nothing, and dropping a chunk because it correlates with another would be
answering it.
The leading chunk, answered as far as a measurement goes: ADV region + 1392, 394
packets, 84.553 s, stereo 48 kHz, peak -2.48 dBFS, 6 silent gaps over 0.4 s
totalling 45.3 s -- 54% silence, the same duty cycle as the full-length chunks.
Speech-structured, so not a header and not padding. "Cutscene or mission" is an
identification and this agent has no ears and no oracle; envelope correlation
peaks at 0.768 at the last lag in the search range, which is where a statistic
lands when it has found nothing, and it is not an answer.
Not taken yet, and said so in BLOCKED: the discriminator should be
`bank_header_len`, not a duration tie. This exporter never used `riffs.len()`, so
it already handles both of the Decoder's cases, but a tie is an observation and
`bank_header_len` is decoded. It switches when `c1f3608` reaches `main`;
`sylpheed-formats` is a path dependency and merging another agent's topic branch
is not the port's to do.
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.