Re: Call for informal discussion: APNG

Chris Lilley <[email protected]> Thu, 14 Sep 2017 20:52:28 -0400
Newsgroups gmane.comp.graphics.png.general
Message-ID <[email protected]>
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On 14-Sep-17 19:51, Glenn Randers-Pehrson wrote:
> It really only needs two things to get my vote.  That is to recommend
> the extension .apng instead of .png
> in the filenames, and to define a different MIME type.  In fact,
> mozilla has pursued the separation of apng
> from png to the extent of recommending a different internet mime type.
> They registered image/vnd.mozilla.apng
> (see http://www.iana.org/assignments/media-types/image/vnd.mozilla.apng) in 2015
> but then decided they didn't like that, and put in the APNG spec:
> "APNG can be identified using
> the image/apng MIME type." without anyone's approval, with someone
> stating in the
> bugzilla report words to the effect, "we'll deal with IANA later".
Interesting. I see image/apg listed on

https://wiki.mozilla.org/APNG_Specification

but not on

https://developer.mozilla.org/en-US/docs/Mozilla/Tech/APNG

I see a related chrome bug musing on the Internet Media Type here; 
Chrome sends an accept header for image/apng while Firefox and Safari do 
not.

https://bugs.chromium.org/p/chromium/issues/detail?id=706679

If APNG succeeds, I can register image/apng with IANA.


>
>
> On Thu, Sep 14, 2017 at 7:09 PM, Chris Lilley <[email protected]> wrote:
>> This is a call for informal discussion on APNG - specifically, the three
>> chunks acTL, fcTL, and fdAT.
>>
>> These chunks have been discussed before, and voted on before. Per the rules
>> for registration:
>>
>>   The same chunk cannot be brought up again for another discussion
>>   period and vote either until a 180-day waiting period has elapsed, to
>>   allow for implementation and testing, or until a substantial change
>>   to the specification is made.
>>
>> APNG failed voting on 20 April 2007, which is more than 180 days ago:
>>
>> FAILED
>> APNG 20070405a
>> ftp://ftp.simplesystems.org/pub/png-group/documents/
>> png-apng-proposal-20070405a.txt
>>
>> Voting has closed on the APNG proposal.  There were 8 YES
>> votes, 10 NO votes, no abstentions, and no ineligble votes
>> cast.  The proposal has failed and the APNG chunks are not
>> registered.
>>
>> My reason for re-opening discussion is the "implementation and testing"
>> part. APNG has since become widespread. Compared to animated GIF, it offers
>> 24bit (and 48bit!) colors rather than 256, and full transparency rather than
>> binary opacity.
>>
>> Regardless of what we may think about the reduced capabilities relative to
>> MNG, or the advisability of re-using an image type for animations, this is
>> the current state of the world and it seems sub-optimal to me that the PNG
>> specification and extensions documents continue to not reflect this. I would
>> like therefore to kick off informal discussion, then a formal discussion
>> period and (re)vote.
>>
>> APNG continues to be supported in Mozilla Firefox (and other apps using the
>> Gecko rendering engine), starting from version 3, June 2008.
>>
>> APNG is supported by Safari (and other apps using the WebKit rendering
>> engine) since version 8, October 2014.
>>
>> In addition, native apps on MacOS X and iOS use native support for APNG,
>> since iOS 10 and OS X Yosemite, October 2014.
>>
>> APNG is now supported by Google Chrome (and other apps using the Blink
>> rendering engine, such as Opera and Samsung Internet), starting from version
>> 59, June 2017.
>>
>> Microsoft Edge does not support APNG, but MS Edge Devs stated that this is
>> "under review". Meanwhile, APNG displays in Edge as the first frame, which
>> is the expected fallback behavior.
>>
>> A starter document is attached to facilitate discussion.
>>
>> --
>> Chris Lilley
>> @svgeesus
>> Technical Director @ W3C
>> W3C Strategy Team, Core Web Design
>> W3C Architecture & Technology Team, Core Web & Media
>>
>>
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> _______________________________________________
>> png-mng-misc mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/png-mng-misc
>>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> png-mng-misc mailing list
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> https://lists.sourceforge.net/lists/listinfo/png-mng-misc

-- 
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture & Technology Team, Core Web & Media


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    <div class="moz-cite-prefix">On 14-Sep-17 19:51, Glenn
      Randers-Pehrson wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CA+PdXctb=xWQ6hV=FCAsXuMbG5Ht47Zs=bVD70UFmT9diTW_+g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org">
      <pre wrap="">It really only needs two things to get my vote.  That is to recommend
the extension .apng instead of .png
in the filenames, and to define a different MIME type.  In fact,
mozilla has pursued the separation of apng
from png to the extent of recommending a different internet mime type.
They registered image/vnd.mozilla.apng
(see <a class="moz-txt-link-freetext" href="http://www.iana.org/assignments/media-types/image/vnd.mozilla.apng">http://www.iana.org/assignments/media-types/image/vnd.mozilla.apng</a>) in 2015
but then decided they didn't like that, and put in the APNG spec:
"APNG can be identified using
the image/apng MIME type." without anyone's approval, with someone
stating in the
bugzilla report words to the effect, "we'll deal with IANA later".</pre>
    </blockquote>
    Interesting. I see image/apg listed on<br>
    <p><a class="moz-txt-link-freetext" href="https://wiki.mozilla.org/APNG_Specification">https://wiki.mozilla.org/APNG_Specification</a></p>
    <p>but not on</p>
    <p><a class="moz-txt-link-freetext" href="https://developer.mozilla.org/en-US/docs/Mozilla/Tech/APNG">https://developer.mozilla.org/en-US/docs/Mozilla/Tech/APNG</a></p>
    <p>I see a related chrome bug musing on the Internet Media Type
      here; Chrome sends an accept header for image/apng while Firefox
      and Safari do not.<br>
    </p>
    <p><a class="moz-txt-link-freetext" href="https://bugs.chromium.org/p/chromium/issues/detail?id=706679">https://bugs.chromium.org/p/chromium/issues/detail?id=706679</a></p>
    <p>If APNG succeeds, I can register image/apng with IANA.<br>
    </p>
    <p><br>
    </p>
    <blockquote type="cite"
cite="mid:CA+PdXctb=xWQ6hV=FCAsXuMbG5Ht47Zs=bVD70UFmT9diTW_+g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org">
      <pre wrap="">


On Thu, Sep 14, 2017 at 7:09 PM, Chris Lilley <a class="moz-txt-link-rfc2396E" href="mailto:[email protected]">&lt;[email protected]&gt;</a> wrote:
</pre>
      <blockquote type="cite">
        <pre wrap="">This is a call for informal discussion on APNG - specifically, the three
chunks acTL, fcTL, and fdAT.

These chunks have been discussed before, and voted on before. Per the rules
for registration:

 The same chunk cannot be brought up again for another discussion
 period and vote either until a 180-day waiting period has elapsed, to
 allow for implementation and testing, or until a substantial change
 to the specification is made.

APNG failed voting on 20 April 2007, which is more than 180 days ago:

FAILED
APNG 20070405a
<a class="moz-txt-link-freetext" href="ftp://ftp.simplesystems.org/pub/png-group/documents/">ftp://ftp.simplesystems.org/pub/png-group/documents/</a>
png-apng-proposal-20070405a.txt

Voting has closed on the APNG proposal.  There were 8 YES
votes, 10 NO votes, no abstentions, and no ineligble votes
cast.  The proposal has failed and the APNG chunks are not
registered.

My reason for re-opening discussion is the "implementation and testing"
part. APNG has since become widespread. Compared to animated GIF, it offers
24bit (and 48bit!) colors rather than 256, and full transparency rather than
binary opacity.

Regardless of what we may think about the reduced capabilities relative to
MNG, or the advisability of re-using an image type for animations, this is
the current state of the world and it seems sub-optimal to me that the PNG
specification and extensions documents continue to not reflect this. I would
like therefore to kick off informal discussion, then a formal discussion
period and (re)vote.

APNG continues to be supported in Mozilla Firefox (and other apps using the
Gecko rendering engine), starting from version 3, June 2008.

APNG is supported by Safari (and other apps using the WebKit rendering
engine) since version 8, October 2014.

In addition, native apps on MacOS X and iOS use native support for APNG,
since iOS 10 and OS X Yosemite, October 2014.

APNG is now supported by Google Chrome (and other apps using the Blink
rendering engine, such as Opera and Samsung Internet), starting from version
59, June 2017.

Microsoft Edge does not support APNG, but MS Edge Devs stated that this is
"under review". Meanwhile, APNG displays in Edge as the first frame, which
is the expected fallback behavior.

A starter document is attached to facilitate discussion.

--
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture &amp; Technology Team, Core Web &amp; Media


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</pre>
      </blockquote>
      <pre wrap="">
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</pre>
    </blockquote>
    <pre class="moz-signature" cols="72">-- 
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture &amp; Technology Team, Core Web &amp; Media</pre>
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