The Decoder made this the gate on S00A and that was the right order: ADV plays
itself on boot and can be captured with --gpu=null at 0.96x real time, but S00A
starts ~4.5 s after (A) on a save slot, which needs a driven run, which needs
screens, which rules out --gpu=null. So S00A is necessarily the 0.70x rendered
route with ~10% additive padding, and is only worth a boot if stripping is exact.
It is. A real music+SFX bed -- 137.37 s, carrying 454 genuine zero runs of its
own -- had 1149 holes inserted at 8.37/s to +9.9% length, matching the observed
ALSA profile, then was stripped and correlated in the low band:
original vs itself r 1.000 lag 0.0 s margin +0.141 ceiling
PADDED vs original r 0.436 lag -12.2 s margin +0.006 destroyed
STRIPPED vs original r 1.000 lag 0.0 s margin +0.142 recovered
stripped vs orig-also-stripped r 1.000 margin +0.143
Two things worth reading off that. Padding at that profile destroys correlation
completely -- r 0.436 in the known-absent regime -- which independently confirms
on a file whose contents I control that the earlier captures were unusable for
the reason claimed and not for some other one. And recovery does NOT require
stripping both sides: the stripped capture matches the UNSTRIPPED source at the
ceiling, so the port's reference assets never need touching.
`tools/port/strip-padding` implements it, and its header leads with when the
operation is vandalism rather than with what it does: PulseAudio's monitor
SUBSTITUTES silence and deleting those holes repairs nothing, while Xenia's ALSA
writer PADS and removing that is exact. Running it on the wrong artefact would
look like it worked.
Its output is byte-identical to the control's own stripping, so the tool and the
experiment are one operation rather than two implementations that agree.
Not licensed by this: stripping removes genuine silence too and cannot tell them
apart. Here the genuine runs total 0.71 s in 137 s and cost nothing measurable;
on material that is mostly silence they would.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
b8f939cc4c