I read the seek chunk's packet count big-endian; it is little-endian at seek+12,
with size == 8 + 4*count. And a seek sits immediately AFTER its own data, so an
entry's first seek usually belongs to the PREVIOUS bank (implied start -25232
for D_452, -145988 for TCAF_608). I was comparing an entry's first seek against
its first data -- different waves by construction, which is why no reading lined
up.
With that fixed, the declared sizes are honest: every RIFF-bearing entry on the
disc has seek magic at exactly data_at + declared_size with count*2048 ==
declared. 7620/7620, zero failures.
VOICE_TCAF_608 is not truncated. Its Channels is 2 and I decoded it as mono;
read as stereo it gives 6520176 bytes = 33.96 s, agreeing with both length
signals in the bank (33.88 s from cumulative samples, 33.97 s from
PsuedoBytesPerSec). 170 of 8021 banks (2.12%) are stereo -- exactly the rate of
my 1-in-60 outlier.
This is the mono/stereo trap already documented on this very page, met from the
other direction: I had written 'at two channels every bank yields one frame' and
then spent several passes blaming missing data for a one-frame decode.
Code fix: to_xma_riffs built the leading segment with a hard-wired mono fmt. It
now reads Channels from the bank's first RIFF. 7 disc tests pass.
The ties needed a different signal, not a longer scan. Banks carry one: a seek
chunk sitting on a packet boundary, so seek_pos % 2048 IS the data offset. On
the 6033 labelled banks with a seek before their first RIFF, 6031 agree
(99.97%) -- better than the packet scan and structural rather than statistical,
so scan_data_offset now tries it first.
On the scan's 28 ties it resolves 26 correctly and 0 wrongly (2 have no usable
seek). Combined rule scores 7354/7358 = 99.95%, up from 99.62%. 762 of the 1495
RIFF-less banks carry a seek, so the signal exists where it is needed.
Also ruled out, since a wrong offset was this page's whole subject: the header
is not audio being discarded. Adding 0 to the candidate set, it wins 6 of 7358.
7 disc tests pass.
Two comments claimed it is 'honest per sub-wave'. Measured: 5296 of 7586 banks
declare more than the entry holds and none declares exactly what it holds, so
the existing .min(slb.len()) clamp is load-bearing rather than defensive.
Comment-only change; 7 disc tests still pass.
1495 banks carry no RIFF and take a separate path that hardcoded both the
offset and stereo. Across a random 48-bank sample there was NOT ONE where the
old stereo-at-1392 pair beat the best mono offset; median gain 184x, individual
banks going from 0-4816 decoded bytes to 180000-380000. Stereo shows the same
stop-after-one-frame signature already recorded for the leading segment.
With no RIFF the offset cannot be derived, so scan_data_offset picks among the
four disc offsets by XMA1 packet-header plausibility. Validated on the LABELLED
set -- all 7358 banks that do have a RIFF, where the answer is forced: 7330
correct (99.62%), and all 28 misses are ties on the top score, never a wrong
unique winner. Ties fall back to 1392.
The winning offsets also reproduce, by directory, the distribution measured
independently from the RIFF-bearing banks. jpn\etc splits 1468/1600, so path
alone is not sufficient -- which is why this is a scan and not a lookup table.
7 disc tests pass (build-reborn test -p sylpheed-formats --test
slb_leading_segment_disc, SYLPHEED_DISC wired up).
HEADERLESS_DATA_OFFSET is the value the offset takes in <lang>\etc\, not a
property of the format. The leading stream is a whole number of 2048-byte XMA1
packets ending at the first RIFF, so its start is first_riff % XMA1_PACKET.
Disc-wide that takes four values -- 1392, 1468, 1600, 1728 -- varying by
language and subdirectory.
Verified by decoding, not by arithmetic: on a random 140-bank sample with a
non-empty leading region, the derived offset yields more audio in 85, identical
in 54 (the eng\etc controls, where it must and does reproduce the old
behaviour) and less in 1. Median gain among the improved is 70x --
eng\Voice\VOICE_TCAF_592 goes 1506 -> 97152 bytes, jpn 2910 -> 127178.
This withdraws my own claim from earlier today that the Japanese banks were a
different undecoded layout. They are the same format with a different offset;
I had treated a constant derived from one subdirectory as a property of the
format. The same error was hiding the identical defect in 1873 eng\Voice banks.
to_xma_riffs now emits the leading headerless segment when it sits at a whole
number of XMA1 packets and carries a non-zero byte. VOICE_D_453 goes from a
0.14 s trailing fragment to a 45116-byte leading sub-wave that dominates it.
I withdrew this exact change earlier for two reasons. Both are now answered
rather than argued away:
* "It recovers no audio" -- it used the STEREO format. At two channels every
bank yields exactly 1792 bytes, one frame, whatever its size. Mono yields up
to 113x more.
* "It matches 1524 of 8021 RIFF-bearing entries" -- the byte-level reach is
still 1524, but the audible reach is not. Across the 84 movie-bound banks
the segment adds >1 s to exactly 7, the hokyu_*_H tankers on D_453/D_454 --
precisely the broken ones -- and <=0.25 s to 66 of the rest. The largest
non-resupply addition is S04A at +0.66 s on a 256 s movie.
The safety oracle is recorded with its limits: 8 of the 84 banks ALREADY
exceed their movie's duration before the change, by hundredths of a second,
so it cannot resolve differences at that scale. It establishes scoping, not
correctness. Callers clamp to the movie length regardless.
VOICE_D_451's all-zero leading region is skipped by the non-zero guard, so
the rule cannot prepend silence to a bank that does not need it. Pinned, as
is the packet arithmetic (n = 8, 1, 7, 22, 29) which has no tunable.
slb_disc, movie_subtitle_disc and movie_manifest_disc all still pass.
NOT verified by ear -- that needs a human.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
The structure is exact. In all five resupply banks the first RIFF sits at
HEADERLESS_DATA_OFFSET + n*2048, where 1392 is a constant this crate already
had and 2048 is the XMA1 packet size: n = 8, 1, 7, 22, 29. No free parameter
to tune, and the raw bytes agree -- high entropy from offset 0, then a zero
run immediately before the RIFF. VOICE_D_451 is the control, its single
packet being all zeros.
So I made the obvious fix, emitting that region as a sub-wave, and then
withdrew it on two measurements:
* It does not recover audio. Coverage went 5.4% -> 89.9% for VOICE_D_453, but
the emitted stream decodes through FFmpeg to 1792 PCM bytes -- silence --
while the RIFF sub-waves from the same banks decode to 150-270 KB. Byte
coverage was the wrong success metric and it looked like progress.
* It is not narrow. The rule matches 1524 of the 8021 RIFF-bearing entries in
sound.pak, including RT* movie banks that decode correctly today. Landing
it would have risked a wide regression in order to not-fix five banks.
to_xma_riffs is back to its previous behaviour, verified by re-measuring:
coverage is 5.4% / 9.7% again. The refuted attempt is recorded in the code
beside the branch it would have changed, so the next person does not
re-derive the arithmetic and re-make the change.
XMA1_PACKET is kept as a named constant because the blast-radius scan uses
it. Artifacts: examples/voice_bank_shape.rs (structure), voice_bank_dump.rs
(sub-waves for decoding), slb_hybrid_scan.rs (the 1524 count).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
Cracked how the game maps a movie to its voice track and reimplemented it,
fixing wrong/short voices for RT and hokyu cutscenes.
## Mechanism (RE'd from a Canary file-I/O trace, user-confirmed by ear)
The movie voices are ONE continuous XMA stream, physically chunked into
`<lang>\Movie\VOICE_*.slb` (and `\etc\VOICE_D_*.slb`) sound.pak TOC entries
whose boundaries do NOT align with the cutscene cues. A single cue routinely
spans two `.slb` chunks, so a `.slb` does not necessarily hold the track its
name claims (they are off-by-one vs the cues). Each cue ends at an inline
trailer descriptor `(sound_id:u32be, 0x11, …)` whose id repeats at +0x800.
Resolution chain (all derivable on-disc, no guest-code RE):
1. movie -> cue token (ADVERTISE_MOVIE manifest VOICETRACK)
2. cue token -> sound-id (master sound registry, tables.pak
a2c8c185=eng / b04238e0=jpn, schema 0x13cb84ba)
3. sound-id -> [start,end) scan the stream for trailer(id) and its
predecessor; cue audio = the bytes between,
read continuously across chunk boundaries.
Validated: decoded voice length matches each movie within ~0.4s, including
cross-boundary cues (ADV/RT01A/RT01B/RT01C/S00A/S01A + the 5 bound hokyu).
## Changes
- sylpheed-formats/src/movie_voice.rs (new): registry_voice_ids(),
find_descriptor(), find_descriptor_before() (gap-tolerant predecessor).
Unit-tested.
- viewer iso_loader.rs: resolve_movie_voice_region() + decode_voice_region()
(continuous read via existing read_segment_range + to_xma_riffs). Voice/
audio requests now region-first; a `\Movie\` token that fails region stays
SILENT (never plays the wrong off-by-one chunk). Removed the old
movie_is_demo_based suppress hack.
- Anchor tries subdirs Movie/etc/Voice so hokyu `\etc\VOICE_D_*` resolve too.
- Examples resolve_all/validate_cues/hokyu_final document + validate the pipeline.
## Status
- RT / S / ADV cutscene voices: CORRECT (user-confirmed).
- 5 manifest-bound hokyu (VOICE_D_450-454): CORRECT (user-confirmed).
## OPEN (handoff)
13 of 18 hokyu movies have NO manifest VOICETRACK; the game reuses the 5
recordings across stages via a code rule. `hokyu_fallback_token()` currently
guesses by category (ship LS/DS x source carrier-A/tanker-H: LS/A->450,
LS/H->453, DS/A->452, DS/H->454). USER REPORTS THIS IS SOMETIMES WRONG.
- LS/carrier has two takes (450 from s02A, 451 from s09A); the early-vs-late
split is unknown — unbound LS/A currently all default to 450.
- Definitive fix = Canary `--phase_a_fileio_only` file.read trace of an unbound
hokyu (e.g. hokyu_LS_s03A) to see which VOICE_D the game actually streams,
then encode the real rule. Same method that cracked the RT mapping.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
list_voice_clips now enumerates every spoken-line category so the standalone audio player covers them all — bound movie voices (\Movie\), in-mission radio (\Voice\, \etc\), and mission briefings (\Briefing\, whose BR<NN>_<MM> names lack "VOICE"); music (BGM_*) stays excluded.
Viewer voice-library fixes: invalidate the library when a new game source loads, and don't latch an empty result as "loaded" (sounds.tbl always has thousands of clips, so empty = a failed read) so re-opening the menu retries.
Voice decode reverted to the first sub-wave (base behaviour): a naive multi-sub-wave concat produced the wrong track for RT movies. The per-sub-wave splitter (to_xma_riffs) is kept + documented for the eventual real fix, which needs ground-truth playback instrumentation to resolve segments-vs-takes-vs-timecode placement.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The movie cutscene subtitle + voice pipeline, driven by the ADVERTISE_MOVIE
manifest (the authoritative movie -> subtitle -> voice index). Also flushes
several sessions of local WIP (async viewer loading, grouped-pool XBG7/hero-ship
decode, drawlog tooling). See docs/HANDOFF-movie-voice-subtitles-2026-07-19.md.
Subtitles (movie_subtitle.rs):
- Full movie->track->text chain; join multi-line captions sharing one timing
(fixes S13A dropped "Look at it father" line); overlap-safe active_cues();
Latin-1 accents preserved.
Voice (slb.rs): XACT .slb -> XMA1 RIFF; take the FIRST sub-wave bounded by its
declared data size (fixes S10-S16 alternate-take garble); list_voice_clips.
Manifest (movie_manifest.rs): parse ADVERTISE_MOVIE (0x5B983A08) for the real
movie->voice binding (not always VOICE_<movie>; e.g. hokyu -> VOICE_D_* in etc\).
Resolve the token's sound.pak path via sounds.tbl. DIRECT bindings only — the
demo-id shared-clip fallback for unbound hokyu movies was verified WRONG in-game
and reverted (unbound hokyu stay unvoiced; correct join key is an OPEN problem).
Viewer: manifest-driven voice (movie player toggle + solo button), standalone
"Voice Lines" browser, stacked caption overlay.
Tests: 46 formats-lib + 11 viewer-lib + movie_manifest/movie_subtitle/slb disc
tests; full workspace green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
