PyroWave's wavelet encode runs on the GPU's compute/shader cores, so a GPU-bound
game starves it: submit spikes from ~2 ms to ~15 ms under a 95%+ game load and
the stream fps collapses. NVENC is immune (separate encoder ASIC). Two levers to
let the encode get scheduled ahead of the game's rendering:
- Windows process GPU scheduling: D3DKMTSetProcessSchedulingPriorityClass, env
PUNKTFUNK_GPU_PRIORITY = off|above-normal|high (default)|realtime. Best-effort,
once per process, non-fatal on refusal (enc/windows/pyrowave.rs).
- Global-priority Vulkan encode queue (Granite patch 0005): request a
VK_KHR_global_priority queue (PYROWAVE_QUEUE_PRIORITY = off|high|realtime,
default realtime), downgrading REALTIME→HIGH→none on NOT_PERMITTED so a refused
class never regresses the encoder to HEVC.
HONEST STATUS: on an RTX 4090 / Windows / WDDM neither moved the ~15 ms spikes —
the graphics-vs-compute preemption granularity is the wall, not the priority
level. Kept because both are correct, harmless (graceful fallback), and may help
other GPUs/drivers. For a GPU-saturated game the working levers are reducing the
encode's GPU cost (4:2:0/8-bit) or H.265; PyroWave holds full rate on the desktop
and in games that leave the GPU headroom.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Phase 0 of design/pyrowave-codec-plan.md — the opt-in wired-LAN ultra-low-
latency codec. Vendored at upstream 509e4f88 (API 0.4.0, Granite 44362775,
volk + vulkan-headers pins in PUNKTFUNK-VENDOR.txt), pruned to the 6.6 MB
the standalone no-renderer build needs; scripts/vendor-pyrowave.sh
reproduces the tree (a pin bump is protocol-affecting, plan §4.2).
build.rs drives the wrapper CMakeLists (static archives incl. a static
C-API lib upstream only ships shared) + bindgen over pyrowave.h; Linux and
Windows only, empty stub elsewhere (Apple gets a native Metal port, §4.7).
Offline-safe by construction: no network, no system lib, vendored Vulkan
headers — same model as the opus dep (flatpak builder has no network).
Phase-0 validation on .21 (RTX 5070 Ti, driver 610.43.03):
- upstream pyrowave-c-test + interop test (incl. dmabuf/DRM-modifier
Vulkan<->Vulkan) pass, from the pristine AND the pruned tree
- GPU kernel times at ~1.6 bpp noise: encode/decode 0.090/0.042 ms @800p,
0.146/0.067 @1080p, 0.226/0.103 @1440p, 0.477/0.201 @4K — order of
magnitude under NVENC's 1-2 ms retrieve, CBR lands within ~100 B of
target
- cargo test -p pyrowave-sys green (static link + API-version pin check)
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehlerandClaude Fable 5