Feature request: APNG support

[AsukaLangleyfag]

Currently nomacs shows APNG as a static image.

[diemmarkus]

I will have a look at it

[Sukid]

I know this is old but just in case, there is a qt5 apng plugin now. Would a patched libpng still be necessary with that? Would still love to see this happen.

[diemmarkus]

if there is a qt5 plugin, you can just install that on your machine & nomacs will be able to load APNG (on windows you need to copy the dll into nomacs/imageformats)

[Sukid]

I've tried it. I'm on arch so I installed both the qt5 plugin and libpng-apng and apngs still remain static when I load them.

[PinkSerenity]

I can confirm that the libraries don't work with nomacs, at least when moving the DLL files into the .\bin folder.

[novomesk]

Now it works when I add qapng.dll from qtapng-msvc2017_64-5.14.1.zip (downloaded from https://github.com/Skycoder42/QtApng/releases/tag/1.1.4 )

But animation plays only when file has .apng extension, .png files are loaded via official Qt plug-in.

[C0rn3j]

APNG is being enshrined in core PNG standard in the Third Edition.

https://github.com/w3c/PNG-spec/blob/main/Third_Edition_Explainer.md

It does not seem even current Qt 6.6 has any support for APNG, just PNG and always refers to it as an image format, no mention of animations - if someone knows a place to report a bug report at for Qt, it's probably the way to go.