Two freeze drivers found live on the RTX box (DDA-only, 5K@240 HDR SudoVDA):
Step 1 — the per-frame format-change check (995db69) mis-fired EVERY frame in HDR
(827+/session): self.hdr_fp16 is derived from the duplication ModeDesc (FP16
scanout mode), but legacy DuplicateOutput always hands back 8-bit BGRA, so the
acquired-texture format never equals hdr_fp16 → a rebuild storm (each rebuild
re-inits device+NVENC → freeze). Make the acquire check SIZE-only; a real
HDR<->SDR toggle still arrives as ACCESS_LOST → recreate_dupl re-detects it.
Step 3 — ACCESS_LOST (0x887A0026) churn: HDR overlay/MPO flips invalidate the
duplication continuously and the recovery loop had no rate limit (the 250ms
throttle guarded only the full rebuild, not the cheap try_reduplicate), so it
spun DuplicateOutput + up-to-16ms Acquire and starved the encode thread. Add a
last_recover throttle capping ALL recovery attempts to ~one per 5ms; between
attempts return None so the caller repeats the last frame, paced at the frame
interval (no busy-spin, encode thread keeps running).
Real FP16 HDR capture (DuplicateOutput1) + per-loss desktop-reisolation cleanup
are the next steps; validate this in SDR first.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
d11f2bf800