forked from unom/punktfunk
enricobuehler
48565c4e9e
Two host-side halves of the same sweep. **The cadence latch.** `cadence_degraded` — which makes the control task refuse bitrate CLIMBS — was latched true for as long as the session was escalated (adaptive capture depth or pipelined retrieve), independently of whether encode was still missing deadlines. The client cannot tell that refusal apart from an encoder's real ceiling: both arrive as a short `BitrateChanged`, and two identical ones latch a cap. Escalation needs ~20 net behind-frames, which a startup hitch supplies while the ABR is still in slow start at the 20 Mbps default — so one transient pinned the whole session there, long after the escalation had bought back the headroom it was for, and escaping cost +12.5 % per 60 s. An escalated session is still judged strictly (ANY net behind-frame keeps it flagged, where an unescalated one gets the full bucket), but being escalated no longer flags it by itself: escalating exists so cadence CAN be held, and once it is, refusing climbs refuses the thing that worked. The rule moves into `encode_behind_cadence` so it is stateable and testable. **The silent re-target.** `adopt_built_bitrate` publishes the rate a rebuilt pipeline actually opened at — `build_pipeline` re-resolves an Automatic rate whenever the source delivers a size the session did not negotiate, the mirrored-panel case — and the encoder's own clamp can land below what the control task already acked. Neither reached the client, whose controller keeps its own copy of that number as its climb base. A 1080p client mirroring a 4K panel therefore believed 20 Mbps while the host encoded 60, and its first climb computed from the stale base asked for 40: a re-target DOWNWARD, paying an encoder rebuild to get there. Both paths now push the applied rate to the control task, which sends `BitrateChanged` — the existing 9-byte message, which already means precisely this and which clients already handle arriving unprompted. No wire-format change, no capability negotiation, old clients unaffected. 2 host tests added.