Files
punktfunk/crates/pf-encode
enricobuehlerandClaude Opus 5 310b85f155 fix(encode): a forced-Vulkan pref must not advertise codecs that arm will refuse
With `PUNKTFUNK_ENCODER=vulkan`, `open_video_backend`'s vulkan arm bails outright for
anything that is not HEVC/AV1 ("the Vulkan Video encoder supports HEVC + AV1; the
session negotiated {codec:?}"). But `host_wire_caps` for that same pref fell through
to the VAAPI probe / static superset, which includes H.264 — so the host advertised
H.264, a client could negotiate it, and the session died at encoder open.

The pref now contributes a CEILING that is intersected with the device probe, never a
replacement for it. That distinction is the whole fix: pinning a static HEVC|AV1
would have ADDED AV1 on the AMD/Intel hosts whose probe currently withholds it
(pre-RDNA3, pre-Arc), re-creating this very bug for a different codec. Intersecting
can only ever narrow.

Without the `vulkan-encode` feature the pref cannot open anything at all — that arm
bails with "requires a build with --features vulkan-encode" — so the ceiling is
empty there rather than optimistic.

Costs nothing on the handshake path: a `&str` match plus a const-folded `cfg!`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-25 03:17:45 +02:00
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