CR3 files imported as preview-only with the 1620x1080 PRVW JPEG and no metadata
(no camera, capture time, exposure, lens or GPS): nothing read the container.
- crates/meta/src/cr3.rs: bounded ISO base media box parser for CR3 (Canon uuid
box with CMT1-4 and THMB, tracks with their sample entries, CMP1 coding header
and sample location, XMP uuid box). Every size/offset checked; depth and box
count bounded.
- Metadata: CMT1 (IFD0), CMT2 (Exif) and CMT4 (GPS) merged into one TIFF Exif
block, so CR3 reads like any TIFF-based raw; XMP from its uuid box.
- Preview: the full-size JPEG track (6960x4640 on an EOS R6 Mark III) before
PRVW/THMB; imports report the full image size.
- Tests: synthetic CR3 (boxes, tracks, merged Exif), truncation/corruption sweep,
JPEG track preferred over PRVW with fallback.
Raw (CRX) data is still not decoded; CR3 stays preview-only.
RAF header/record parsing, raw IFD (0xf000) with 16-bit, 12-bit LSB and
32-bit-word MSB packings found by black-box analysis of CC0 samples,
X-Trans layout (reversed record, anchored at 0,0), crop, black levels,
WB_GRB levels, metadata and preview from the embedded JPEG. Compressed
RAF reports Unsupported. Colour uses the documented neutral fallback.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Maurice Rogers