enricobuehlerandClaude Fable 5 1bc156aab0 perf(latency): T2.2 Linux NVENC two-thread retrieve + T2.3 REALTIME auto-gate ...

design/latency-reduction-2026-07.md tier 2, the two code-side halves:

- T2.2: the Linux direct-NVENC backend gains the two-thread retrieve
  (PUNKTFUNK_NVENC_ASYNC, the same opt-in knob as Windows): the session stays
  sync-mode (async events are Windows-only) but the blocking lock_bitstream
  moves to a dedicated pf-nvenc-out thread — the NVENC guide's sanctioned
  submit-thread/output-thread split. poll() drains completions non-blocking,
  submit() backpressures at PUNKTFUNK_NVENC_ASYNC_DEPTH (default 4) in-flight;
  map/unmap and every other session call stay on the encode thread; teardown
  joins the thread before destroying the session. Under a GPU-saturating game
  completed frames queue instead of serializing capture on the encode wait.
- T2.3: PUNKTFUNK_GPU_PRIORITY_CLASS gains 'auto' AND IT IS THE NEW DEFAULT
  (gpu-contention §5.C): HIGH immediately, then REALTIME where the documented
  NVIDIA+HAGS+near-full-VRAM NVENC hang cannot bite — HAGS probed once via
  D3DKMT WDDM_2_7_CAPS (off => REALTIME outright); HAGS on => a pf-gpu-prio
  monitor flips REALTIME<->HIGH on LOCAL-segment VRAM headroom (downgrade
  >92% of budget, restore <=85% for 3x2s polls). 'high' restores the old
  static default; 'realtime' pins it (operator owns the hazard).

Validated: .21 clippy -D warnings (punktfunk-host --features nvenc) against
the QSV-merged main; .133 Windows cargo check of pf-frame + punktfunk-host.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

2026-07-17 19:57:38 +02:00

..

src

perf(latency): T2.2 Linux NVENC two-thread retrieve + T2.3 REALTIME auto-gate

2026-07-17 19:57:38 +02:00

Cargo.toml

feat(encode): native QSV backend — libvpl-sys + qsv.rs (Phases 0-3 of design/native-qsv-encoder.md)

2026-07-17 19:34:18 +02:00