Corrected diagnosis (Ed: the machine's OWN speakers audibly play the Windows tune
and NVDA at the boot lock screen — the endpoint is NOT silent): a loopback capture
attached in the first seconds of boot can land on an audio-engine mix the
logon-session audio path was never wired into. Callbacks flow (fed by our own
silence keepalive) but carry none of the audio that is audibly playing, and Windows
fires no device event about it — the previously-shipped device-change reopen never
triggers. Signing in re-plumbs the session audio into the graph, which is why sound
starts instantly with zero change on our side; a capture opened after sign-out
(graph fully live) works at the lock screen, matching Jonathan's reports exactly.
Fix: while sending, the 15s capture pulse now drives a self-heal — if the capture
has heard only silence since it opened (pre-encode peak < 0.001 on every pulse), or
its callbacks freeze, tear down and re-open the capture so it re-attaches to the
live graph. Capped at 3 attempts per sending stint; the first real audio ends the
ladder so a quiet-but-healthy capture is never churned. Ladder refills on Resume()
and on power resume (wake re-plumbs the graph like boot). Every re-open is logged
with the attempt count, so Jonathan's next log shows either "re-open recovered
audio" (fixed) or three silent re-opens (deeper Windows routing issue, and we know
exactly where we stand).
Decision core (ShouldReopenSilentCapture) is pure and pinned by a new self-test.
Gate: 39/39.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
EdnunpandClaude Opus 4.8
c72169c7f5