JPEG XL decoding support

[BlueSwordM]

Describe the solution you'd like
Now that Action!(screen recording software) and xnView MP have JPEG XL decoding, it would be very nice if nomacs got JPEG XL decoding support, as it seems JPEG XL decoding support is ramping up.

I don't know how long it would take to have decoding support integrated, but it would be great to have it in nomacs, especially since it now supports AVIF.

[Hrxn]

Action!

Is that a new image viewer? Or do you mean the screen recording software?

And by the way, only XnView MP, not the "old" XnView (Classic). Which is Windows only and 32-bit anyway.

[BlueSwordM]

Action! is the screen recording software. It can simultaneously take JPEG XL screenshots and view those screenshots natively in the app.

And yeah, I meant XNView MP, not XNView.

[novomesk]

nomacs is a Qt application and it can potentially load any image format when corresponding Qt Image Plugin is available. That's the way how support for HEIC and AVIF was added.

I asked if someone is making such plug-in: https://gitlab.com/wg1/jpeg-xl/-/issues/46

[BlueSwordM]

Oh yeah, I always forget about it.

Thanks for the response.

[novomesk]

I have a working prototype of Qt plug-in which is able to load some JXL files. I did not publish the code yet (it is in experimental form).

I have impression that JPEG-XL is not yet final and I guess there could be some incompatible changes. Who knows if files saved by older implementation could be opened by future-standard compliant applications.

JPEG-XL has interesting features, I am curious about progress of the format.

[BlueSwordM]

The API is still not final yet, but it should be coming relatively soon(at the end of the year or next year).

[BlueSwordM]

Great news.

The JPEGXL 0.2 RC version has come, which means the format itself has been frozen.
Bitstream is stable now, so what we encode now will stay decodable.

[C0rn3j]

What's the status of this?

@novomesk seems to maintain qt-jpegxl-image-plugin, there's also kimageformats with its own plugin, with which I've took the following screenshot:

I am not sure how this translates to supporting JXL on Windows however

[novomesk]

The plugin works also on Windows.
For example here is development build for Windows where it is bundled: https://ci.appveyor.com/project/diemmarkus/nomacs/build/artifacts

[C0rn3j]

I'd like to add that even with kimageformats installed, JXL is not currently present as a possible export option when saving edited files.

[novomesk]

JXL export is not possible in released nomacs versions, but in git master it should work.

[G2G2G2G]

that installer works fine on several versions of windows I tested, why is it not just released? last nomacs release is years old

[novomesk]

why is it not just released?

I cannot release. There are parts of the project I don't have under control (for example translations and website). @diemmarkus , can we do something about it?

[G2G2G2G]

looking at this and that discussion thread where the website was down and enoms parked it (which is normal, but people thought they bought it lmao) I would say this project is worth forking if the creators aren't going to give anyone control and are going to be AFK / MIA

[leejuyuu]

Closing as completed by #585.