APNG playback limitation?

[fire-eggs]

APNG files are repeating only a limited number of times. The count matches the number of "fcTL" segments in the file.

For example, the attached animated PNG file "plays" only 6 times. It contains 5 "fcTL" segments [as identified by pngcheck].

This seems "wrong" to me: shouldn't animation "keep going"? Or is this a need for a "loop animation" option?

852009.png.zip

[rageworx]

I've been tested on other viewer—Honeyview, very famous image viewer of South Korea.
It also displays strange animation time period, there's total 5 frames, but shortly return to first frame.
User can see each frames manually by clicking frame count control pannel on the left bottom, but this PNG file looks something bad.

You can try Windows version here, all free for all.
https://en.bandisoft.com/honeyview/

[fire-eggs]

Thanks for the data point.

In a browser (firefox, etc) the animation is a slow blink for each sprite; pause between blinks; and continuous loop.

YAIV is five very fast blinks; no pause; and no looping.

XnviewMP (cross platform viewer/organizer) displays as a medium-fast blinks;slight pause; and looping.

I think bug #1 is that the animation should loop. Bug #2 would be the playback speed seems too fast; this may be a problem in my conversion of APNG animation rules to animated-gif.