photocraft/crates/heif

photocraft-heif

The optional HEIF/HEIC decoder of PhotoCraft: iPhone and Mac photos. A thin, panic-guarded wrapper around heic-rs, a pure-Rust HEVC still-picture decoder (no unsafe, MIT OR Apache-2.0): single pictures and grid-tiled photos, 8- and 10-bit (10-bit decodes to 16-bit), alpha auxiliary images, the container's rotation/mirror/crop, ICC, EXIF and XMP. Read-only: writing would need an HEVC encoder.

let info = photocraft_heif::probe(&bytes)?;             // size, depth, alpha: check limits first
let img = photocraft_heif::decode(&bytes, &photocraft_heif::Options::default())?;
// img.width, img.height, img.has_alpha, img.sixteen_bit, img.data (RGB/RGBA), img.icc, img.exif, img.xmp

Errors are Error::Unsupported (image sequences, overlays, …), Error::Limit or Error::Malformed. It never panics: every call into heic-rs runs under catch_unwind, and a panic inside it (fuzzing found two in 0.1.1) becomes Error::Malformed.

Why it is a separate, optional crate

• A young decoder. heic-rs is new and has a single maintainer. It is pinned exactly (=0.1.1); moving the pin is a reviewed change (re-run cargo fuzz run decode_heif in crates/codecs and cargo xtask test-corpus).
• HEVC patents are a distributor's call. HEVC is patent-encumbered in some jurisdictions, so whether a build includes an HEVC decoder is a build-time choice. photocraft-codecs uses this crate only behind its non-default heif feature; the apps forward it (cargo build -p photocraft --features heif). Official PhotoCraft builds and CI enable it. Without it, HEIC files are still recognised and opening one is a clear "HEIC/HEIF support isn't included in this build" error.

The crate depends on no other PhotoCraft crate and knows nothing of photocraft-codecs' types; codecs → heif is the one allowed dependency between standalone crates (cargo xtask layers). Tests on real files live in photocraft-codecs (tests/heif.rs, features corpus,heif, files fetched by cargo xtask corpus --heif).