AVIF support

Enable avif deliberately. It selects the in-tree safe Rust AVIF/AV1 implementation. There is no native codec fallback, FFI bridge, or runtime download.

Application scope

The high-depth, HDR and animation additions below are on main, awaiting the next release. The published 0.1.3 crate retains its earlier partial scope.

The maintained matrix contains 343 active AVIF decode/inspect/verify rows. All 32 encoder rows remain planned. These counts describe selected files and operations, not all legal AVIF streams.

Selected still images, grids, high-depth images and animations have exact Pillow output checks. The tested animations include frame pixels, timing, loop metadata, auxiliary alpha, hidden references and show-existing frames. The HDR witness preserves encoded values in Pillow-compatible RGB output; it does not add tone mapping or general color management.

Check your own files before adopting these paths. Untested syntax, geometry and color declarations can still return an unsupported error.

Unsupported behavior and errors

Unsupported syntax, transforms, auxiliary relationships, sequence states, and encoding remain explicit failures or planned capabilities. Inspect the generated capability page and open roadmap for the exact tracked scope. Do not route these files through a native decoder and label the result Rust parity.

Reproduce evidence

The fixture provenance guide records the actual assets and pinned oracle tooling. The reconstruction index and sidecars are regenerated together from reviewed inputs and the pinned dav1d/Pillow oracles. Keep them available to clean source checkouts.

Add a complete public input and exact oracle comparison for a new state. A traced entropy sentence or bounded leaf proof alone cannot establish whole- frame pixel parity. The final caller-visible frame must be compared before promoting the corresponding capability.