Clients request a keyframe on every FEC-unrecoverable frame and keep asking
until the IDR actually arrives and decodes — a full round-trip on a link that is
already behind. The host answered every request with a full IDR and only
rate-limited under intra-refresh (opt-in, off by default), so on the default
path a Wi-Fi loss burst produced a 20-40x bitrate spike storm that deepened the
very loss it was recovering from — the second half of the periodic double-jolt.
Coalesce a request storm into at most one forced IDR per cooldown ALWAYS: serve
the first immediately (a genuinely wedged decoder still recovers at once), then
suppress for the window (2 s under intra-refresh's healing wave, 750 ms for a
full-IDR recovery — long enough to swallow one recovery event's round-trip echo,
short enough to re-issue a lost IDR promptly). Seed the cooldown at session open
and stamp it on both rebuild paths so the cold-open / post-rebuild storm
coalesces into the IDR the fresh encoder already emits.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
a1b890ef42