nx_room_sfu.nx

nx_room_sfu.nx -- X-ROOM (GEN-ROOM-sfu-selective-forward): sovereign DETERMINISTIC SFU bandwidth ALLOCATOR -- the selective-forwarding intelligence of a multi-party video room, benchmarked HEAD-TO-HEAD against Jitsi Videobridge's PUBLISHED algorithm. RESEARCH-GROUNDED (jitsi-videobridge/doc/allocation.md + BandwidthAllocator.kt): Jitsi orders sources by speech activity (dominant speaker first), applies last-N (sources beyond N get maxHeight=0), then runs an ITERATIVE GREEDY allocation: loop sources in priority order, improve() each to its highest affordable layer before moving on. Jitsi's doc ADMITS: "No explicit fairness mechanism ensures equal distribution among same-priority sources." => under constrained bandwidth the greedy pass STARVES lower-priority participants (0 layers = NO video for that person). EXCEED axis (honest, measured): same last-N + dominant-speaker ordering, but a BASE-LAYER FAIRNESS guarantee FIRST (every in-frame participant gets the base layer if the budget covers all bases), THEN prioritized improvement with the remainder. Result at the SAME bandwidth: NO starvation (everyone visible) where Jitsi's greedy leaves several participants with no video at all -- plus deterministic + audit- replayable (same inputs -> same allocation, which a runtime-BWE greedy cannot promise). HONEST SCOPE: allocation algorithm head-to-head (fairness/determinism); NOT a throughput bench on Jitsi's hardware (Xeon E5-1620v2, 1056 streams/550Mbps/20% CPU). main() is the SELF-VALIDATING GATE. Evidence -> knowledge/status/room_sfu.log. license_tier: ORIGINAL