The 15s silence-pulse trigger was far too slow (Ed: the boot tune would be over
before the first check) and silence alone was always a weak signal — a quiet
machine and a deaf capture look identical from inside the stream.
New detector: read the endpoint's OWN output meter (IAudioMeterInformation
.MasterPeakValue) every watch tick, independently of our capture stream, and
compare it with what the capture is hearing. Device audibly playing (meter >=
0.003) while the capture has heard only silence since it opened = the capture is
provably DEAF -> re-open it immediately so it re-attaches to the live audio graph.
- Service loop tick 1000ms -> 500ms; deafness threshold is TIME-based (450ms of
continuous divergence) so reaction lands ~1s after the first audible sound —
fast enough that the boot tune itself comes through — and a fast test cadence
can't trip it (a healthy capture hears real sound within ~200ms).
- Zero churn risk: a quiet machine reads quiet on BOTH sides, so healthy captures
never re-open (the old design would have re-opened 3x on any quiet stint).
- Frozen callbacks (2s+) still re-open regardless of loudness.
- Ladder: max 3 re-opens per stint, 2s spacing, ends at the first real audio
heard; refilled on Resume and power resume.
- Meter readers swapped per (re)apply, disposed on suspend; per-device catch
absorbs a disposed/invalidated endpoint mid-read.
- 15s pulse is now purely diagnostic and logs capPeak + meterPeak maxima with an
explicit "(DEVICE AUDIBLE BUT CAPTURE SILENT)" flag.
- Decision core (ShouldReopenCapture) pure + pinned by updated self-test.
Gate: 39/39.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
EdnunpandClaude Opus 4.8
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