Please remove this last part of the sentence, as it could be misleading - I don't believe it's true, ICC has be around for ages, JXL native color encoding is new and less likely to be widely supported.

I'd revert back to setting and testing `bool write_icc` for exclusive `JxlEncoderSetColorEncoding` or `JxlEncoderSetICCProfile`, `goto`s are not that easy to follow (ok only for the drop out case on some failure...)

remove the CUSTOM related stuff

not in CICP/H.273, use ICC

ditto

set `color_encoding.primaries` instead (for primaries, 709 = sRGB)

This one doesn't exist in CICP/H.273, so just fall back to ICC

No need to set these at all - we never want to use CUSTOM values: either standard ones, or go the ICC way

malloc check?

Not really an error, ok to print as a warning on stdout

For the same reasons as above, the standard output color spaces should use existing CICP/H.273 enums like JXL_PRIMARIES_SRGB etc. Please leave the custom values just for ones that cannot be covered. Also, please move this section to be exclusive w/ the `if(write_icc)` block below as it expresses the intent better. [The exclusivity is mandated by the spec.](https://github.com/libjxl/libjxl/blob/0f387788921c76e9e3490c5aba3fd80cf2fb3cfe/lib/include/jxl/encode.h#L253-L282)

These two are for proofing on display only, not used for export AFAIK

Ditto, I'd stick to the really usable ones (see avif.c again)

Don't think we want to cover this one as channels/primaries are switched?

Section might be more readable with switch/case? (see avif.c)

I don't think this is ideal: you want to store JXL_WHITEPOINT_D65, JXL_WHITEPOINT_DCI, etc. when known, as I envisage any JXL readers will leverage those known values to figure out the reverse process... The custom white point setting should only happen if you don't hit any of the "standard" `over_type`s below, and the cases below should include the white point as well.

error check?

```suggestion option(USE_JXL "Enable JPEG XL export support" ON) ```

can probably be a const (likewise just below).

const

const

const

please use calloc() here to ensure all is initialized to 0.

const

const

const

const

const

const

Is that some remaining debug code ?

Remove this option from default config, we always use BMFF container anyway?

Should be JXL_TRUE?

This deleted macro is still found a in a few places

remove dead code related to this macro if unused

File not changed, please remove from commit

Consider requiring min 0.5 version and removing support for anything below, as it seems those were not mature/stable anyway?

2021 only here :)