Latency between speakers grew to multiple seconds and only reset on
rejoining voice. Root cause was the receiver playout logic, not the
codec settings: the playout clock free-ran in real time while the
sender omitted silence from its timestamps (and set no header flags),
and the only correction snapped the clock to the *oldest* buffered
frame — which could only ever add standing latency. target_depth_ms_
was computed but never enforced, so latency could only grow or reset.
Fix: bound playout against the stream's leading edge (newest frame).
(Re)seed to the leading edge on start/marker/starve (no prebuffer, so
latency stays low), and frame-skip catch-up trims any backlog beyond
target+hysteresis — the missing downward force.
Hardening: sender now stamps kFlagMarker (talkspurt start) and kFlagDtx,
consumed on recv for clean resync; adaptive late-drop window; EWMA
outlier rejection so silence gaps/stragglers don't poison the estimate;
duplicate counting and ring-underrun diagnostics.
New test_jitter_depth asserts depth stays bounded (<200ms) while
arrivals outrun playback. ctest --preset dev green (27/27).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
