Bug overview description.
APNG files currently aren't being labeled as animated. Similarly to how GIF files aren't always necessary animated, it would be crusial to know if PNG file is.

What part(s) of the site page(s) are affected?
Post search pages.

What is the expected behavior?
Thumbnail states either ANIM or APNG.

What actual behavior is given instead?
Thumbnails show up similarly to static image posts.

Time of incident (if applicable).
-

Can you reproduce the bug every time?
Yes.

What steps did you take to replicate this bug?
- Upload APNG file.
- Make sure it has both animated and animated_png tags applied.
- Check the post by searching for animated.

Errors or other messages returned (if any).
Nope.

Animated pngs are pngs with additional data to be parsed as animated, if the browser does not support apngs it will display the first frame anyways.

I've made apng avatars on forums with the first frame stating the browser they are using does not support animated pngs.

Edit: This isn't a bug per-se just apngs are not a unique file type from pngs, and all apngs are pngs primarily with some additional data that without proper tools is not utilized.

Easy way to demonstrate this is to open an apng in something like IE or old edge. They do not support animations, so only the first frame is displayed.

deadoon said:
Animated pngs are pngs with additional data to be parsed as animated, if the browser does not support apngs it will display the first frame anyways.

I've made apng avatars on forums with the first frame stating the browser they are using does not support animated pngs.

Edit: This isn't a bug per-se just apngs are not a unique file type from pngs, and all apngs are pngs primarily with some additional data that without proper tools is not utilized.

Easy way to demonstrate this is to open an apng in something like IE or old edge. They do not support animations, so only the first frame is displayed.

You completely and utterly failed to read my whole thing apparently.

These here, are animated GIFs:
post #1945161 post #1944584 post #1940573
Notice the nice little ANIM in the thumbnails? Good.

Here's some GIFs which are not animated:
post #1944302 post #1865425 post #1854159
Now, notice how the thumbnails do not have ANIM lable?

All of the files above are .gif but site will label them animated, when they are animated from what I assume is from the tags. So this is simply oversight where this has not been extended to .png files.

So meanwhile animated PNG:
post #1578197
not animated PNG:
post #1945629

Not very realted to the topic, but I wonder if there is an easy way to make a APNG file o:

blitzdrachin said:
Not very realted to the topic, but I wonder if there is an easy way to make a APNG file o:

defines how many times it will loop, default is 1, infinite is 0.
If you need transparency, make sure the input format is lossless AVI with alpha channel or PNG image sequence.

I'm pretty sure I have seen some plugins to something like GIMP and some standalone software with drag-and-drop interface, but cannot recall the names or useability of any of those. APNG is still kinda toddler when it comes to compatibility and support especially with creation tools.

After that, rename .apng into .png (this is safe as it's acceptable file extension in this case) and run the file trough either Pingo (there's GUI for windows) with lossless (web) option or APNG Optimizer with default settings. This sometimes halves the filesize, so it's highly recommended.

I would love to recommend Pingo (GUI called Pinga) more as it can also do stuff like losslessly rotate JPG files and scrub EXIF data from them so there's no stuff like GPS location data attached to it when uploading online, increasing compatibility and security with no quality loss. It also makes PNG files much smaller in seconds. Just make sure that either of lossless option is enabled and make backups when necessary.

Mairo said:
You completely and utterly failed to read my whole thing apparently.

I kind of misunderstood what you were meaning to a degree, I was seeing it as an automated way to differentiate them(which would be much more difficult). Also, The anim thing on the posts is part of the overlay, not the thumbnail, when you said thumbnail I thought you were meaning how flash files display, or something baked in.

Apngs are a very weird thing compared to animated gifs, animated gifs are a distinct part of the file structure and format, apngs are not. Apngs are just some extra data stuffed into a standard non-animated png, the extra data will be passed off as junk data by a strict interpretation of the standard.

deadoon said:
I kind of misunderstood what you were meaning to a degree, I was seeing it as an automated way to differentiate them(which would be much more difficult). Also, The anim thing on the posts is part of the overlay, not the thumbnail, when you said thumbnail I thought you were meaning how flash files display, or something baked in.

Apngs are a very weird thing compared to animated gifs, animated gifs are a distinct part of the file structure and format, apngs are not. Apngs are just some extra data stuffed into a standard non-animated png, the extra data will be passed off as junk data by a strict interpretation of the standard.

Oh yeah, I was talking of this website specifically and the label is still practically part of the thumbnail, even if technically it's overlayd on top of it. Because I'm pretty sure that GIF labeling is according to tags rather than from file itself.

APNG is extremely weird format and the way that it's being handled on unsupported software is what makes it extremely icky. If I see static PNG file my first idea is that it's static, not that it's supposed to be animated. Then software like PNGGauntlet will actually destroy the animation frames as it thinks they are garbage metadata after the actual image.

However the format is still I'd say one of the only ways to share lossless full color animations online, because WebP support is still a joke, VP9 will most likely die for majority if you use anything other than yuv420p and even with limited color palettes it's still lower filesizes from GIFs.