forked from unom/punktfunk
PyroWave never checked frame dimensions against the session, and it applies no alignment — `width`/`height` are the negotiated mode verbatim — so a mismatched frame was encoded edge-smeared or cropped, silently, forever. Every other Linux backend already refuses exactly this, with this shape, in `submit`: libav-NVENC (`linux/mod.rs`), VAAPI (`vaapi.rs`) and openh264 (`sw.rs`) all carry the same `ensure!`. PyroWave was the only one that didn't. That is the justification; an earlier draft cited `vulkan_video.rs` instead, which is the weaker precedent — it bails in its Dmabuf arms only, and its CSC path and CPU arm have no dimension guard at all. Mostly this is a wrong-picture bug and not a memory-safety one: `rgb2yuv.comp` clamps every fetch with `min(p, textureSize - 1)` and the CPU arm uploads `min(len, need)` into a session-sized image. But it also closes a narrow real hazard that was not in the filing: `import_cached` keys on `(st_dev, st_ino)` and returns the cached `VkImage` on a hit WITHOUT rechecking the extent, and unlike the capture side it is never cleared on a renegotiation — so a dmabuf inode recycled across a shrinking renegotiation would hand the encoder an image sized for the old, larger allocation. This check closes that route. ⚠ Recorded at the code because it changes the failure mode, not just the detection: a mismatch is NOT always transient. A compositor-initiated PipeWire renegotiation updates the capturer's size in place and signals nothing the encode loop reads, so it can be a permanent new steady state — and `reset()` reopens at the same dimensions by construction, so the host's five-reset budget cannot recover (~3.1 s of frozen stream, then the session ends) where before it would have streamed on with a wrong picture. For a real mode change that trade is clearly right; for a 16-row KWin mismatch it is not, and the proper fix is for the host to classify this error as a PIPELINE rebuild rather than an encoder reset. Filed, not done here. The device-selection half of WP4.5 was written, reviewed and WITHDRAWN — see the handoff doc. Matching the selected render GPU regresses the hybrid Intel-compositor + NVIDIA-present topology this project has a live field report for, because `selected_gpu()` answers NVIDIA whenever `/dev/nvidiactl` exists regardless of where capture actually runs. WP4.5 (dimension half). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>