> There was talk about upgrading PNG to support the equivalent of animated GIFs but it never really happened because of complexity
This was mostly due to overengineering on the part of the PNG committee. Why stop at animated PNGs, when we could support sound and interactivity! MNG is not a simple format, and the spec has MNG-LC ("low complexity") and MNG-VLC ("very low complexity") subsets, because the whole thing is too complex. Did you know you can embed JPEGs in MNGs? That it has synchronization points for sound, even though sound is still "coming at a later date"? That it allows pasting other images into the movie at arbitrary 2D transforms?
MNG's complexity is self-inflicted, because they second-system effect'd their way into features nobody wanted.
APNG, by contrast, is a series of PNG chunks with a couple extra fields on top for timing and control information.
This was mostly due to overengineering on the part of the PNG committee. Why stop at animated PNGs, when we could support sound and interactivity! MNG is not a simple format, and the spec has MNG-LC ("low complexity") and MNG-VLC ("very low complexity") subsets, because the whole thing is too complex. Did you know you can embed JPEGs in MNGs? That it has synchronization points for sound, even though sound is still "coming at a later date"? That it allows pasting other images into the movie at arbitrary 2D transforms?
MNG's complexity is self-inflicted, because they second-system effect'd their way into features nobody wanted.
APNG, by contrast, is a series of PNG chunks with a couple extra fields on top for timing and control information.