8d7373b16c
A real defect in the P4 output, found by the human on ADV.wmv and widened by the RE agent to the whole disc: the disc ships 28 movies in 5.1 WMA Pro (every cutscene, INCLUDING both movies this port needs) and 69 already in stereo. A bare `-ac 2` therefore does two different things and records neither -- stereo passes through, and 5.1 is folded by ffmpeg's DEFAULT matrix. How loudly centre-channel dialogue sits against the music is a content decision, and it was being made by accident and could move under an ffmpeg upgrade. Now stated: ITU-R BS.775, LFE dropped, normalised by 1/(1+2*sqrt(1/2)) = 0.4142. It appears in the recorded command, so the manifest determines the output. MEASURED rather than chosen by taste, and the measurement is the interesting part: the explicit matrix and ffmpeg's inherited default differ by a residual of -91 dB -- about one LSB at 16-bit -- with peak and mean agreeing to 0.1 dB. So ffmpeg's default IS this matrix, and the audio does not change; what changes is that the manifest now says which matrix. The UNnormalised textbook form was measured too and clips at 0.0 dBFS, which is why the scaling is there. The filter is applied only to 6-channel sources, probed per file with ffprobe, so a stereo source is never run through a matrix referencing channels it lacks. Also: encode to a temp name and rename on success. ffprobe read a mid-write .ogv as 33 s against a 137 s source -- no error, no warning, the exact shape of catastrophic truncation. The filesystem is shared with the RE agent, so that is a race, not an edge case, and a half-written file must never be visible under its final name. tools/verify-video-audio answers the second of the three questions docs/AUDIO-VERIFICATION.md separates: does GODOT route the audio. An AudioEffectRecord on the Master bus writes Godot's own mixed output to a WAV from a headless run, so "no sound card" was never the obstacle I claimed. It deliberately checks non-silence and level only -- a difference-signal RMS against the source is inconclusive without cross-correlation alignment and an agreed downmix, and would produce a confident wrong number.
Sylpheed Godot
A clean-room Godot 4 port of Project Sylpheed: Arc of Deception, starting with the menu shell: developer splash → intro video → title → main menu → submenus.
You need your own copy of the game. Nothing in this repository is game content. An offline exporter reads the disc you supply and writes an open, moddable asset tree; the Godot project reads only that tree and never touches a disc format.
your disc ──▶ crates/sylpheed-export ──▶ export/ ──▶ port/ (Godot 4)
(Rust; decoders come from JSON + PNG reads ONLY
sylpheed-formats) + OGG + OGV open formats
Why the wall
Two reasons, and the second is the interesting one:
- Godot cannot read IPFB archives, RATC bundles, T8aD textures, XMA banks or WMV video, and it should not learn to.
- Modding is a goal of this port. If the runtime reads the original formats, modding means reverse engineering. If it reads JSON and PNG, modding means opening a file.
Where the knowledge comes from
The decoders live in sylpheed-formats, pinned by revision — a
separate project, where the reverse engineering happens. Its
docs/port/HANDOFF.md is the contract: what has been decoded, what was measured
off the running game, and what is known to be undecodable. Read it before
assuming a value is on the disc.
Layout
crates/sylpheed-export/ |
disc → open formats. Regenerates export/ wholesale |
port/ |
the Godot 4 project |
authored/ |
decisions that are not on the disc, each with its reason |
export/ |
generated, gitignored, never hand-edited |
tools/ |
verification harnesses that hold the port to the reference renderer |
docs/ |
the mission, the format spec, the agent's loop prompt |
Verifying
The oracle is the Xenia Canary capture and the game, not either renderer.
sylpheed-cli screen render is an explorer and extraction CLI for verifying
decodes, and it can be wrong -- three times both it and the port agreed and both
were wrong, each caught only by a capture.
So tools/verify-screen is a consistency check and a regression detector,
not a grade. It draws every exported screen both ways -- built from the same
sylpheed-formats revision the exporter is pinned to -- and reports the largest
per-channel difference in the frame:
tools/verify-screen # every screen in the manifest
tools/verify-screen main_menu # one of them
A difference means the two moved apart; docs/DECISIONS.md says which one moved
and why, rather than tuning the port until the number goes down. Correctness is
checked against the captures indexed at docs/re/captures/ORACLE-CAPTURES.md --
mind that they are not gamma-neutral, so RMSE against them has a floor.
Status
P1. The exporter writes GP_TITLE's twelve screen builds and their sprites,
and the Godot project draws any of them statically at 1280x720 from that tree
alone. main_menu matches the reference renderer to within 3/255 on every
channel of every pixel. Next: P2, keyframe animation.