The T.800 spec says there should only be one 'colr' box, but the
extended jpx file format spec in T.801 annex M allows having multiple.
Method 2 is a basic ICC profile, while method 3 (jpx-only) allows full
ICC profiles. Support that.
For the test, I opened buggie.png in Photoshop, converted it to
grayscale, and saved it as a JPEG2000, with "JP2 Compatible" checked
and "Include Transparency" unchecked. I also unchecked "Include
Metadata", and "Lossless". I left "Fast Mode" checked and the quality
at the default 50.
.jpf (JPEG2000) files written by Photoshop contain a whole bunch of
these boxes.
fileformats.archiveteam.org/wiki/Boxes/atoms_format lists a few
UUID types. Of those 3, these are in Photoshop-written .jpf files:
* 0537cdab-9d0c-4431-a72a-fa561f2a113e Exif
* 2c4c0100-8504-40b9-a03e-562148d6dfeb Photoshop Image Resource
* be7acfcb-97a9-42e8-9c71-999491e3afac XMP
This doesn't have to be a virtual method: it's called from
various create_from_stream() methods that have a static type
that's created. There's no point in the virtual call here,
and it makes it harder to add additional parameters to
read_from_stream() in some subclasses.
Previously, ChunkID's from_big_endian_number() and
as_big_endian_number() weren't inverses of each other.
ChunkID::from_big_endian_number() used to take an u32 that contained
`('f' << 24) | ('t' << 16) | ('y' << 8) | 'p'`, that is
'f', 't', 'y', 'p' in memory on big-endian and 'p', 'y', 't', 'f'
on little-endian, and return a ChunkID for 'f', 't', 'y', 'p'.
ChunkID::as_big_endian_number() used to return an u32 that for a
ChunkID storing 'f', 't', 'y', 'p' was always 'f', 't', 'y', 'p'
in memory on both little-endian and big-endian, that is it stored
`('f' << 24) | ('t' << 16) | ('y' << 8) | 'p'` on big-endian and
`('p' << 24) | ('y' << 16) | ('t' << 8) | 'f'` on little-endian.
`ChunkID::from_big_endian_number(0x11223344).as_big_endian_number()`
returned 0x44332211.
This change makes the two methods self-consistent: they now take
and return a u32 that always has the first ChunkID part in the
highest bits of the u32 (`'f' << 24`), and so on. That also means
they return a u32 that in-memory looks differently on big-endian
and little-endian. Since that's normal for numbers, this also
renames the two methods to just `from_number()` and `to_number()`.
With the semantics cleared up, change the one use in ISOBMFF to read a
BigEndian for chunk headers and brand codes. This has the effect of
tags now being printed in the right order.
Before:
```sh
% Build/lagom/bin/isobmff ~/Downloads/sample1.jp2
Unknown Box (' Pj')
[ 4 bytes ]
('pytf') (version = 0, flags = 0x0)
- major_brand = ' 2pj'
- minor_version = 0
- compatible_brands = { ' 2pj' }
Unknown Box ('h2pj')
[ 37 bytes ]
Unknown Box ('fniu')
[ 92 bytes ]
Unknown Box (' lmx')
[ 2736 bytes ]
Unknown Box ('c2pj')
[ 667336 bytes ]
```
After:
```sh
% Build/lagom/bin/isobmff ~/Downloads/sample1.jp2
hmm 0x11223344 0x11223344
Unknown Box ('jP ')
[ 4 bytes ]
('ftyp' ) (version = 0, flags = 0x0)
- major_brand = 'jp2 '
- minor_version = 0
- compatible_brands = { 'jp2 ' }
Unknown Box ('jp2h')
[ 37 bytes ]
Unknown Box ('uinf')
[ 92 bytes ]
Unknown Box ('xml ')
[ 2736 bytes ]
Unknown Box ('jp2c')
[ 667336 bytes ]
```
The former automatically adapts the prefix to binary and octal
output, and is what we already use in the majority of cases.
Patch generated by:
rg -l '0x\{' | xargs sed -i '' -e 's/0x{:/{:#/'
I ran it 4 times (until it stopped changing things) since each
invocation only converted one instance per line.
No behavior change.
Currently, the `isobmff` utility will only print the media file type
info from the FileTypeBox (major brand and compatible brands), as well
as the names and sizes of top-level boxes.
