The Canon maker note's AspectInfo (tag 0x009a: aspect code, cropped width,
height, left, top) holds the rectangle of the shot, measured from the
recommended image crop. Use it as the CR3 default crop, so 3:2, 4:3, 16:9 and
1:1 shots develop in the shape the photographer chose. The tag is ignored when
it is missing, does not fit, or the recommended crop itself is inconsistent.
RENDER_CACHE_VERSION 15 -> 16. The M50 C-RAW corpus sample (raw.pixls.us 2663)
was shot at 1:1 and now develops at 4000 x 4000.