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
