Bind the session's IO streams to the encode thread's high-priority copy
stream: in sync-retrieve depth-1 use the per-frame input copy and cursor
blend now enqueue with NO cuStreamSynchronize and encode_picture orders
after them on the stream. Same stream both directions, so the encode's
completion is inserted into the stream and later work (the next frame's
copy into a reused ring slot) waits for it.
Soundness gate: the fast path engages only when pending is empty (true
depth-1 usage) — every prior encode was drained by a blocking poll, and
the caller holds the frame payload across the matching poll (contract now
documented on Encoder::submit; both host loops already comply). Pipelined
callers and PUNKTFUNK_NVENC_ASYNC mode keep the blocking copies.
True zero-copy input registration (registering the worker-owned IPC
buffer directly) stays the LN2 v2 follow-up — it needs a contiguous
worker-pool NV12 layout and a registration<->IPC-mapping lifetime tie.
PUNKTFUNK_NVENC_STREAM_ORDERED=0 restores the old blocking behavior.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehler
cd36c46388