Chromium Adds Support For Animated PNGs

[phoronix]

Phoronix: Chromium Adds Support For Animated PNGs

Google's Chrome/Chromium web-browser is introducing support for animated PNGs (APNG)...

http://www.phoronix.com/scan.php?page=news_item&px=Chromium-APNG-Support

[FireBurn]

Now all we need to go is argue over how APNG is pronounced ah-ping, app-en-gee, ahh-pee-en-gee, ahh-pee-en-jay

[eigenlambda]

why? webm has already replaced gif in most places

[ldo17]

One thing for sure “PNG” should not be pronounced “ping”, because “ping” already means something

I think it should be pronounced “pinge”, to rhyme with “housinge”.

[ssokolow]

Well, I'll continue to sanitize uploaded files according to the PNG spec, which says that a valid PNG header must guarantee that the file contains only a single frame.

(And if anyone complains, I'll add a FAQ entry which says just that... that APNG is a violation of the PNG spec and additional frames are stripped by the untrusted input sanitizer.)

That rule has been in the PNG spec since the beginning and Mozilla knew what they were doing when they decided to start relying on their own built-in copy of libpng because upstream insisted that multi-frame files must have a different header before patches would be accepted.

[calc]

Well, I'll continue to sanitize uploaded files according to the PNG spec, which says that a valid PNG header must guarantee that the file contains only a single frame.

(And if anyone complains, I'll add a FAQ entry which says just that... that APNG is a violation of the PNG spec and additional frames are stripped by the untrusted input sanitizer.)

That rule has been in the PNG spec since the beginning and Mozilla knew what they were doing when they decided to start relying on their own built-in copy of libpng because upstream insisted that multi-frame files must have a different header before patches would be accepted.

It would seem the actual spec states otherwise:

https://www.w3.org/TR/PNG/

Introduction
k. Flexibility: future extensions and private additions should be allowed for without compromising the interchangeability of standard PNG datastreams.

5 Datastream Structure

https://www.w3.org/TR/PNG/#5DataRep

11 Chunk Specifications

https://www.w3.org/TR/PNG/#11Chunks

APNG details:

https://en.wikipedia.org/wiki/APNG

https://wiki.mozilla.org/APNG_Specification

[Gusar]

why? webm has already replaced gif in most places

webm is an audio/video format and quite a complex one at that, it requires a lot of code to parse properly. APNG is *much* simpler in this regard and serves a different purpose. For short, few-second long looping animations, webm is total overkill.

Also, what's replaced gif is "gifv", which is basically h264 video in mp4, so an actual video with a wrong file extension. *Not* a good replacement and definitely not what one can possibly describe as an "animated image format". It's maybe because websites have resorted to such hacks like gifv that more browsers are opening themselves up to APNG.

APNG is something that's simply *needed*, so the PNG folks should show some flexibility here . Especially now that real-life usage is against them - when it was just Mozilla, that was one thing, but now with other browsers getting on board, the situation is quite a bit different.

[maxst]

Well, I'll continue to sanitize uploaded files according to the PNG spec, which says that a valid PNG header must guarantee that the file contains only a single frame.

PNG Group is currently debating adding EXIF support, like register official chunk name for it, and everything.

That will inevitably lead to PNGs with thumbnails inside.

[smitty3268]

Well, I'll continue to sanitize uploaded files according to the PNG spec, which says that a valid PNG header must guarantee that the file contains only a single frame.

(And if anyone complains, I'll add a FAQ entry which says just that... that APNG is a violation of the PNG spec and additional frames are stripped by the untrusted input sanitizer.)

That rule has been in the PNG spec since the beginning and Mozilla knew what they were doing when they decided to start relying on their own built-in copy of libpng because upstream insisted that multi-frame files must have a different header before patches would be accepted.

Nobody cares.

[kersurk]

I remember also the original Opera adding support a long time ago.