TWO DEFECTS AND ONE MEASUREMENT, all from verifying the previous commit rather
than from reading it.
Channel 2 of both voice streams is DIGITALLY SILENT -- peak -inf over the whole
file. The voice is a mono recording carried in a nominally stereo stream, and
averaging it with silence cost 5.94 dB. The doc comment directly above the code
that did it warned that "a stereo matrix applied to a mono voice track is not an
error, it is a -6 dB attenuation that nothing reports", and then the code checked
the DECLARED channel count instead of the content. `live_channels` now measures
which channels carry signal and averages only those.
Three defects this iteration were the same shape: a silent chunk in a sum, a
silent channel in a fold, and a pan matrix naming channels that do not exist.
Each is an input contributing nothing while still counting in a divisor, and none
is visible in anything but a level.
THE LEADING CHUNK IS THE TAIL OF THE FULL-LENGTH ONE. The Decoder settled by
byte-span analysis that it is the movie's own dialogue, 17 of 17 -- killing its
own hypothesis that it was an in-mission line -- and asked whether dropping it is
a truncation, having no XMA1 decoder. Sliding envelope correlation with overhang
allowed and normalised over the overlap: ADV r=0.998 at +52.8 s, S00A r=0.932 at
+25.6 s, against controls of 1.000 (self) and 0.289 (a different movie). Both
lags put chunk 0 flush against the END of chunk 1. Sample domain, lag refined to
one sample then a scalar best-fit: residuals 16.70 dB and 23.15 dB below target.
So dropping it removes a DUPLICATE and the exporter was right for a worse reason
than it gave. The manifest note is NOT rewritten to claim that -- the structural
conclusion belongs on the Decoder's page, not in my manifest -- but it no longer
equates the chunk with BGM_103's third sub-wave, which a disc-wide census showed
is a different structure, and it now says in words that the omission must not be
read as junk removal.
Not converted, deliberately: the Decoder's 504464 B anchor constant. Bytes per
second is not constant even inside one region -- chunk 1 is 1118268 B and chunk 2
is 1171516 B for the SAME 137.324 s -- so any figure in seconds off it would be
invented.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
0e7fcc2dda