Re: Call for informal discussion: APNG

"Soni L." <[email protected]> Wed, 20 Sep 2017 16:57:40 -0300
Newsgroups gmane.comp.graphics.png.general
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FLIF has it, so I think it's a good idea for us to have it too.

Due to the way normal APNG chunks work, it's *arguably* already 
supported - just deliberately use the "wrong" sequence numbers ;).

https://wiki.mozilla.org/APNG_Specification#Chunk_Sequence_Numbers

On 2017-09-20 04:15 PM, Pavel Zlatovratskii wrote:
>
> If we do new APNG we could do anything we want, but I don't think 
> global interlacing is good idea.
>
> It break too much compatibility and significantly increase difference 
> with current APNG (and so complexity of decoder).
>
> I think best way for "new APNG" (which definitely should get new name) 
> is be superset of current APNG (with different chunk names), so at 
> least some subset of NewAPNG could be converted to APNG files without 
> decoding image data, but just with chunk repacking.
>
>
> 20.09.2017 20:18, Soni L. пишет:
>> If we do get a new APNG, can we get full image interlacing?
>>
>> As you know, in APNG, you can do interlacing to make each frame 
>> visible faster at a lower resolution, but EACH FRAME ONLY. The idea 
>> with full interlacing is that you'd interlace IDAT and fdAT, such 
>> that you can quickly load the whole APNG animation (at a lower 
>> resolution), and slowly get it up to high-res by loading the 
>> following chunks.
>>
>> On 2017-09-20 12:30 PM, Pavel Zlatovratskii wrote:
>>>
>>> I don't think approval of APNG could be any use for now. It was 
>>> important in 2007 to motivate browsers (and other software) support 
>>> it. But today it is already have pretty wide support as you 
>>> describe, so I see no reason to not left it as Mozilla's 
>>> "side-standard".
>>>
>>> May be it's possible to design some new animation PNG based on APNG 
>>> and make it standard. Like SPDY and HTTP/2: Google design and spread 
>>> SPDY, but SDPY is now left as SPDY, not became HTTP2.0 nor was 
>>> approved by IETF HTTP WG.
>>>
>>> There is also a little problem with official APNG same as Mozilla 
>>> APNG: current decoders may not able to handle approved aCTL chunk as 
>>> it is supposed to handle private acTL chunk. So without any benefit 
>>> for aCTL it may be never spread.
>>>
>>> 15.09.2017 2:09, Chris Lilley пишет:
>>>> 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
>>>
>>> -- 
>>> Have a nice DOS.
>>>
>>> Pavel Zlatovratskiiscondo-JGs/[email protected];[email protected]
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> 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
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>>
>>
>> _______________________________________________
>> png-mng-misc mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/png-mng-misc
>
> -- 
> Have a nice DOS.
>
> Pavel Zlatovratskiiscondo-JGs/[email protected];[email protected]
>
>
> ------------------------------------------------------------------------------
> 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


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    <tt>FLIF has it, so I think it's a good idea for us to have it too.<br>
      <br>
    </tt><tt>Due to the way normal APNG chunks work, it's *arguably*
      already supported - just deliberately use the "wrong" sequence
      numbers ;).<br>
      <br>
      <a class="moz-txt-link-freetext" href="https://wiki.mozilla.org/APNG_Specification#Chunk_Sequence_Numbers">https://wiki.mozilla.org/APNG_Specification#Chunk_Sequence_Numbers</a><br>
    </tt><br>
    <div class="moz-cite-prefix">On 2017-09-20 04:15 PM, Pavel
      Zlatovratskii wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:b633f591-4d17-1ece-9811-821d7007b796-o+MxOtu4lMCHXe+LvDLADg@public.gmane.org">
      <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
      <p>If we do new APNG we could do anything we want, but I don't
        think global interlacing is good idea.</p>
      <p>It break too much compatibility and significantly increase
        difference with current APNG (and so complexity of decoder).</p>
      <p>I think best way for "new APNG" (which definitely should get
        new name) is be superset of current APNG (with different chunk
        names), so at least some subset of NewAPNG could be converted to
        APNG files without decoding image data, but just with chunk
        repacking.<br>
      </p>
       <br>
      <div class="moz-cite-prefix">20.09.2017 20:18, Soni L. пишет:<br>
      </div>
      <blockquote
        cite="mid:d5597239-0e12-d71e-a6c1-d311caf70b11-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org"
        type="cite">
        <meta http-equiv="Content-Type" content="text/html;
          charset=utf-8">
        If we do get a new APNG, can we get full image interlacing?<br>
        <br>
        As you know, in APNG, you can do interlacing to make each frame
        visible faster at a lower resolution, but EACH FRAME ONLY. The
        idea with full interlacing is that you'd interlace IDAT and
        fdAT, such that you can quickly load the whole APNG animation
        (at a lower resolution), and slowly get it up to high-res by
        loading the following chunks.<br>
        <br>
        <div class="moz-cite-prefix">On 2017-09-20 12:30 PM, Pavel
          Zlatovratskii wrote:<br>
        </div>
        <blockquote type="cite"
          cite="mid:ab199da1-004a-5f1c-843a-4f3dda06b755-o+MxOtu4lMCHXe+LvDLADg@public.gmane.org">
          <meta content="text/html; charset=utf-8"
            http-equiv="Content-Type">
          <p>I don't think approval of APNG could be any use for now. It
            was important in 2007 to motivate browsers (and other
            software) support it. But today it is already have pretty
            wide support as you describe, so I see no reason to not left
            it as Mozilla's "side-standard". <br>
          </p>
          <p>May be it's possible to design some new animation PNG based
            on APNG and make it standard. Like SPDY and HTTP/2: Google
            design and spread SPDY, but SDPY is now left as SPDY, not
            became HTTP2.0 nor was approved by IETF HTTP WG.<br>
          </p>
          <p>There is also a little problem with official APNG same as
            Mozilla APNG: current decoders may not able to handle
            approved aCTL chunk as it is supposed to handle private acTL
            chunk. So without any benefit for aCTL it may be never
            spread.<br>
          </p>
          <div class="moz-cite-prefix">15.09.2017 2:09, Chris Lilley
            пишет:<br>
          </div>
          <blockquote
            cite="mid:fa3adedb-5d2c-c892-4ae4-ef928270e542-Pl0VvzL1eo4@public.gmane.org"
            type="cite">
            <meta http-equiv="content-type" content="text/html;
              charset=utf-8">
            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.<br>
            <p>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.<br>
            </p>
            <p>APNG continues to be supported in Mozilla Firefox (and
              other apps using the Gecko rendering engine), starting
              from version 3, June 2008.</p>
            <p>APNG is supported by Safari (and other apps using the
              WebKit rendering engine) since version 8, October 2014.<br>
            </p>
            <p>In addition, native apps on MacOS X and iOS use native
              support for APNG, since iOS 10 and OS X Yosemite, October
              2014.</p>
            <p>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.</p>
            <p>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.</p>
            <p>A starter document is attached to facilitate discussion.<br>
            </p>
            <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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          <pre class="moz-signature" cols="72">-- 
Have a nice DOS.

Pavel Zlatovratskii <a class="moz-txt-link-abbreviated" href="mailto:scondo-JGs/[email protected]" moz-do-not-send="true">scondo-JGs/[email protected]</a>; <a class="moz-txt-link-abbreviated" href="mailto:[email protected]" moz-do-not-send="true">[email protected]</a>
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      <pre class="moz-signature" cols="72">-- 
Have a nice DOS.

Pavel Zlatovratskii <a class="moz-txt-link-abbreviated" href="mailto:scondo-JGs/[email protected]" moz-do-not-send="true">scondo-JGs/[email protected]</a>; <a class="moz-txt-link-abbreviated" href="mailto:[email protected]" moz-do-not-send="true">[email protected]</a>
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