The pre-decode FrameChannel is strictly FIFO because H.26x reference
chains forbid mid-stream drops — falling behind is only recoverable via
the coarse jump-to-live thresholds (depth ≥6 sustained, or 400 ms behind
the capture clock) at the cost of a keyframe round-trip.
PyroWave has no reference chains: every AU decodes independently, so a
slow consumer can skip straight to the newest queued AU with zero
recovery cost. The pump now flags the channel all-intra for PyroWave
sessions and pop() drains to the newest, which caps any standing
pre-decode queue at ~1 frame structurally — the 2026-07 field report's
780M client could otherwise ratchet a real multi-frame backlog (and with
it the OSD latency) between those coarse thresholds.
Skips are counted separately from losses (they were delivered, just
superseded) and surfaced at debug on the report tick — the OSD 'lost'
line keeps meaning wire loss.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehlerandClaude Fable 5
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