PNG maintenance and development #58
Comments
|
The original PNG group has become active again recently and is discussing adding EXIF to PNG. Will see how that discussion and eventual vote goes. |
|
http://caniuse.com/#feat=apng |
and another version, same authors,
|
|
Those are both the same version, 0.10. |
|
Several mentions of APNG at the W3C Workshop on Digital Publication Layout and Presentation (from Manga to Magazines) |
|
A reasonably complete testsuite |
|
Chrome shipped APNG support, not behind a flag, on by default, with Chrome 59 so it is just Edge holding out now. |
|
Safari preview has APNG support now https://webkit.org/blog/9621/release-notes-for-safari-technology-preview-95/ |
|
Also using the [ I think its time to start a PNG CG to maintain this spec and to roll in APNG into the main spec. |
|
This came up again recently, the ColorWeb CG wants a new PNG chunk for CICP |
|
The original PNG Group mailing list is now moribund. |
|
A major issue for any new work is getting support into libpng which is a very mature library, but one which has not had updates in terms of new features for some time. Mainly bugfixes, security fixes. |
svgeesus
moved this from Exploration
to Investigation
in Strategy Team's Incubation Pipeline (Funnel)
|
Libpng has an issue about adding APNG support, which comes down to waiting for a specification update. |
|
An Editors Draft for PNG is now being maintained, rolling in all errata. |
|
An updated REC could be published (CR -> PR -> Rec) for just the errata, including substantive change. New features would need a W3C Working Group. ISO/IEC JTC1 SC24 should be notified when the errata-ed spec goes to CR so they can apply the same changes to
Question is whether to combine the two steps or do them sequentially. The value of a new PNG Rec with very minor errata fixes, updated references etc seems minimal if it doesn't also document the widely-supported APNG extensions. Such a specification would also allow libpng to add official APNG support rather than each browser, linux distro etc all supporting their own patched versions. |
|
WPT has just three tests for APNG as of Mar 2021. wpt.fyi results and wpt canvas APNG results. This should be substantially expanded. There is also another APNG test suite which is used by WebKit. It should be added to WPT as well. That site serves the APNG and |
|
Browsers are using |
|
Draft charter, Advance notice sent 18 May 2021 |
|
Funnel issue on chartering: #268 |
|
given the separate issue on the draft charter, I propose closing this and moving to strategy work concluded |
dontcallmedom
moved this from Investigation
to Strategy Work Concluded
in Strategy Team's Incubation Pipeline (Funnel)
The first version of PNG was done on a mailing list, and independent of W3C. It was then published a Proposed Rec.
The original group of people that wrote PNG still functions to discuss PNG and to consider updates to the specification (via an extension registry not by changes to the main spec). It has occasional bursts of activity. It has it's own, lightweight, process involving a minimum duration of involvement before getting to vote.
You can see that not much happens by looking at the revision history section in
http://www.libpng.org/pub/png/spec/register/pngreg-1.4.6-pdg.html
and
http://www.libpng.org/pub/png/spec/register/pngext-1.4.0-pdg.html
The second edition was done jointly with ISO. It included errata from the first edition, but the majority of the work was to comply with ISO requirements on wording and document structure, and to then ensure the resulting spec was technically identical to the original wording. Having gone through that process, it was a lot of effort for little gain.
The ISO and W3C versions of PNG second edition are precisely identical, except for the cover pages. The W3C one is free and the ISO one is on paper and costs money. Copyright is joint; W3C copyright on ours, ISO copyright on theirs.
The APNG proposal was voted on but rejected (I voted in favour). Since then it had a little implementation (in Mozilla and in the old, Presto-based Opera). In 2016 Apple also added support (at the OS level, for the iOS iMessage app).
http://caniuse.com/#search=apng
Google was always opposed because they wanted to promote WebP instead, although that continues to be discussed and experimental (non-shipping) support is going in as of July 2016:
https://bugs.chromium.org/p/chromium/issues/detail?id=1171
and now seesm to be ready to ship
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/KcMjmFOgG2w
Microsoft was neither for or against. There is a uservoice for it
https://wpdev.uservoice.com/forums/257854-microsoft-edge-developer/suggestions/6513393-apng-animated-png-images-support-firefox-and-sa
It would be valuable to get the APNG spec rolled back into the PNG spec (MNG is a separate, and largely failed, specification). However, from a W3C perspective, that was only worth doing if at least one of Google or Microsoft planned to ship APNG support in their browser. Getting support into the main libpng software library would also be a benefit.
That work would also roll in the extensions:
http://www.libpng.org/pub/png/spec/register/pngreg-1.4.6-pdg.html
http://www.libpng.org/pub/png/spec/register/pngext-1.4.0-pdg.html
The text was updated successfully, but these errors were encountered: