sylph-decoder 27f81d6d91 re: the guest presents at 30 fps -- 60 units/s, and the port was right
Answered against the pre-registration committed before the capture.

Units per second was the last open number on the PRESS (A) plate, and both
prior measurements of it were wall-clock readings off an emulator that runs
the guest slow by an unknown factor. They disagreed by 2.9x, because a 30 Hz
guest at full speed and a 60 Hz guest at half speed look identical on a wall
clock.

The ruler here is not a clock. ADV.wmv declares 30.0000 fps in its own ASF
header, so a decoded movie frame is a tick the emulator's speed cannot
stretch. Presented frames per decoded movie frame is guest_fps/30 with no
wall clock in the chain.

  predicted  H_A 30 fps ->  60 units/s -> 1.0
             H_B 60 fps -> 120 units/s -> 2.0
  measured                                1.0000

Both pre-registered guards pass. Guard 2: a perfect repeating 3-buffer
cycle, 52 uses each (exactly 156/3), 2 chroma planes per luma on 156 of 156.
Guard 1: run lengths are 156 runs ALL of length 1 -- no smear, so the
dropped-movie-frame bias that would have pushed the answer toward 120 is
measurably absent rather than argued away.

So H_A. The port keeps its 60 and changes nothing.

REFUTES the live H3 hypothesis that 120 units/s explains the play-test's
late plate. That hypothesis was well-formed and attractive precisely because
it would have explained the complaint, which is why it needed a ruler that
is not a clock.

Which means finding 3 still has no cause. The strongest remaining candidate
is decoded rather than speculative: the plate's declared onset is t=214, not
t=236 -- a 22-unit fade, matching the T=22 the oracle confirmed by measuring
+23 alpha per presented frame on that element.

The pre-registered control could NOT be run: this logger build emits vb=
addresses, not vertex contents, so there was no alpha to check +34 against.
A weaker control is substituted and labelled -- the splash shader/blend
census, which validates the log's structure (what this measurement uses) and
not alpha extraction (which it does not).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
2026-09-01 18:49:40 +00:00

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-cli and 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

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.

Description
No description provided
Readme MIT 820 MiB
Languages
Rust 57.6%
Python 27.7%
Shell 10.6%
GDScript 3.5%
Dockerfile 0.4%
Other 0.1%