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Sylpheed/tools
Sylpheed port agent ff8d608b1e port: check-capture passed a file that was 36% holes -- it now catches starvation
The Decoder diagnosed take 2 as a STARVED capture and I verified it here rather
than take it on trust: 35.6% of frames silent on all six channels, 10482
alternating runs, median burst 13.5 ms and gap 3.9 ms, a 17.4 ms period at 57 Hz.
Their untruncated original reads 39.3% and 10595 runs; the difference is exactly
the truncation and every other number agrees.

So my rebuilt correlator was working correctly on a file that could not carry the
signal. The alarming reading it produced -- that the game may not play the .wmv's
WMA track, so ADV.ogv's audio has been wrong since P4 -- is NOT SUPPORTED by this
capture and is not refuted either. Withdrawn as a concern arising from evidence,
with nothing changed in either direction. It was the most expensive-to-act-on
hypothesis in the port and it came from a file that could not speak to it.

THE REAL DEFECT WAS MINE: `check-capture` tested only for duplicated channels, so
it cleared a recording that was 36% holes. A provenance check that passes the
artefact it was built in response to is not a check.

It now measures starvation, and TWO THRESHOLDS I INVENTED WERE BOTH WRONG:

  counting exact-zero frames -- real audio crosses zero constantly, so a clean
    voice track scored 5947 "gaps" of median 0.0 ms and was called starved. A gap
    is a RUN, not a sample; only runs over 1 ms count.
  gap count and median length -- a genuine music bed shows 454 gaps at a median
    of 1.4 ms, because quiet 16-bit passages really are zero for milliseconds.

What separates them is the RATE: 32.9 gaps/s starved, 3.3 for a real bed, 0.03
for a voice track that is 53% pauses. Bar at 20/s, derived from those controls
rather than chosen and then justified. Controlled both directions: real stereo
bed PASS, six distinct tones PASS, starved capture FAIL. It also reports a `data`
chunk declaring 0 bytes -- what a file copied mid-write looks like, which is what
happened.

VOICE CHANNEL ROLES ARE NOT OBTAINABLE THIS SESSION. Both routes closed: the
monitor sink is starved by construction, and the internal tap at
SDLAudioDriver::SubmitFrame needs a Canary rebuild the Decoder has costed at a
whole session. That is the human's call, not an agent's. The port keeps authoring
with the known recorded.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
2026-08-29 16:25:17 +00:00
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