{Minutes} TTWG Meeting 2019-12-19

Thanks all for attending today's TTWG meeting. Minutes can be found in HTML format at https://www.w3.org/2019/12/19-tt-minutes.html


We resolved to publish 4 errata. The review period under our Decision Policy is 10 working days, which I will extend beyond the normal 2 calendar weeks in light of the seasonal holidays, so that it expires on Monday 6th January 2020. Nevertheless I expect that the automated errata publication system will publish the errata sooner; this does not prevent us from removing those errata later should there be any objections.

Those minute in text format:

   [1]W3C

      [1] https://www.w3.org/


                Timed Text Working Group Teleconference

19 December 2019

   [2]Previous meeting. [3]Agenda. [4]IRC log.

      [2] https://www.w3.org/2019/12/12-tt-minutes.html

      [3] https://github.com/w3c/ttwg/issues/83

      [4] https://www.w3.org/2019/12/19-tt-irc


Attendees

   Present
          Atsushi, Cyril, Glenn, Nigel, Pierre

   Regrets
          Andreas, Gary

   Chair
          Nigel

   Scribe
          nigel

Contents

     * [5]Meeting minutes
         1. [6]This meeting
         2. [7]IMSC 1.2 FPWD Next Steps
         3. [8]Potential semantic conflict between ttp:profile and
            ttp:contentProfiles. imsc#506
         4. [9]IMSC 1.1 Errata
         5. [10]#extent-root implies support for #extent-auto
            imsc#489
         6. [11]Errata to correct disposition of #bidi in IMSC 1.1
            imsc#498
         7. [12]Errata on non-prohibition of partially supported
            features imsc#500
         8. [13]Incompatible SMPTE ST 2052-1:2013 extension
            namespace name imsc#512
         9. [14]Errata publishing
        10. [15]AOB: (Re-)join to timed text WG after charter
            renewal
        11. [16]Next meeting 2020-01-09
     * [17]Summary of resolutions

Meeting minutes

   Log: [18]https://www.w3.org/2019/12/19-tt-irc


     [18] https://www.w3.org/2019/12/19-tt-irc


  This meeting

   Nigel: Today we have some IMSC 1.2 FPWD Next steps, IMSC 1.1
   Errata.
   … AOB includes the rejoining, if there are any questions about
   that,
   … and next meeting on Jan 9th.
   … Any other agenda points?

   group: [no other agenda points]

  IMSC 1.2 FPWD Next Steps

   [19]Request WR for IMSC 1.2 ttwg#87

     [19] https://github.com/w3c/ttwg/issues/87


   Nigel: I'm behind on this. I had hoped to get it done earlier
   today, but haven't managed to.
   … Practically speaking the difference between sending tomorrow
   or at beginning of Jan is minor, but I will do it as soon
   … as I can make the time. Apologies for the delay.
   … Moving towards IMSC 1.2 issues.
   … Last week we made some resolutions to issues Glenn raised, in
   his absence. Any points to raise there?

   Glenn: No, no input.

   Nigel: Thanks

  Potential semantic conflict between ttp:profile and
  ttp:contentProfiles. imsc#506

   github: [20]https://github.com/w3c/imsc/issues/506


     [20] https://github.com/w3c/imsc/issues/506


   Nigel: The proposal from last week was:
   … Add a normative SHOULD statement to TTML2: The set of
   features that may be present in the document should all be in
   the set of features supported by the processor, or generate a
   warning.
   … This is a proposed requirement for a validator, based on
   mismatches between the effective content profile and the
   … effective processor profile.
   … If we agree to this proposal then we will move the issue to
   the TTML2 repo.

   Glenn: It's semantically inconsistent with the definition of
   processor profiles because only features that the processor
   … profile designates to be required elicits an abort...
   [thinking out loud]
   … It might never produce a warning. I need to think about it a
   little more.
   … Offhand that doesn't sound semantically consistent with the
   current semantics but I'll give it a once-over offline.

   Nigel: Thank you

   SUMMARY: @skynavga to consider the proposal further

  IMSC 1.1 Errata

   Nigel: We have 4 errata proposed, to iterate through.
   … Has everyone followed that there is a new errata publication
   process.

   Pierre: I've looked into it a little bit.

   [21]IMSC 1.1 Errata

     [21] https://www.w3.org/2018/11/ttml-imsc1.1-errata.html


   Nigel: The document describes the process at the top.
   … Essentially we label errata issues with Errata on GitHub, and
   Editorial if it is editorial, and the document version, and
   … the errata page will be updated automatically.

   Glenn: Will it harvest PR data or issue data?

   Nigel: I think it is the text of the issue itself.

   Glenn: Sounds like magic!

  #extent-root implies support for #extent-auto imsc#489

   github: [22]https://github.com/w3c/imsc/issues/489


     [22] https://github.com/w3c/imsc/issues/489


   Pierre: I copied the text from IMSC 1.2 which we had agreed to.

   Cyril: I'm trying to understand what it means - is it
   specifying format if a value is specified or is it requiring a
   value?

   Pierre: "specified value" has a defined meaning in TTML

   Cyril: I understand, I'm asking if the attribute is required on
   the element or not?

   Pierre: The only way to have a specified value is if it is
   specified.

   Cyril: Sure, but this text doesn't say what happens if it is
   not specified.

   Pierre: If the author does not specify a value then the
   specified value is undefined, so it cannot be.

   Cyril: It does not exist...

   Pierre: Exactly, so it cannot be a length expression, therefore
   it implies it is required.
   … The implication is the only way to satisfy the constraint is
   to include the attribute.
   … We should fix this in IMSC 1.2 and then port it back.

   Nigel: We can agree the words here and do it here and in IMSC
   1.2.

   Pierre: Absolutely. We can hold off making this change now and
   come back to it next meeting in case there is a better idea.

   Nigel: Simple wording change - add "is required to be present"

   Pierre: Folk weren't happy with that previously on the thread.

   Nigel: I don't see that here - Glenn's comment on 10th Oct
   included it for example.

   Pierre: I'll point to the IMSC 1.2 issue that was closed on
   this.
   … It is #475
   … It's a long thread. Suggest Cyril reopens the issue and adds
   the suggestion.

   Cyril: Ok will do.

   SUMMARY: Reconsider the wording for this in conjunction with
   IMSC 1.2 #475 and come up with something all are happy with.

   Pierre: Remember we have to be careful about `<set>`, initial
   value etc.
   … Specify does not necessarily mean it is on the element
   itself, which is why "is present" is not awesome.

   Cyril: Being consistent with oneself is difficult!

   Pierre: Thankfully we have GitHub to remind ourselves.

   Nigel: We've toyed with trying to work "computed" in here in
   the past too.

   Pierre: Yes, and the reason it was open is that style
   properties can be specified using child style elements, which
   is
   … the equivalent of specifying the style property on the
   element itself.
   … There are many ways for something to be considered specified.

   Nigel: I think we're talking about the value of the attribute
   in the specified style set for the region element, following
   … the style resolution process.

   Pierre: That term in TTML2 is "specified style"
   … What I'm saying is "shall be present" is not right because it
   excludes the example that Cyril raised in #475.

   Nigel: In TTML2 terminology section "specified style set" is
   defined but not "specified style". It may be elsewhere.

   <cyril> [23]https://developer.mozilla.org/en-US/docs/Web/CSS/

   specified_value

     [23] https://developer.mozilla.org/en-US/docs/Web/CSS/specified_value


   Cyril: It's an XML term?

   Glenn: I would avoid using CSS terminology.

   Pierre: 10.4.3.1 in TTML2

   [24]TTML2 10.4.3.1 Specified Values

     [24] https://www.w3.org/TR/ttml2/#semantics-style-resolved-value-category-specified


   Cyril: Ok can we link to that?
   … I will change my comment.

   Pierre: It is actually already there in IMSC 1.2 - specified
   value already says that under #extent-region.
   … Your wish has already come through.

   Cyril: Apologies, I'll delete my comment and close the issue.

   Pierre: Going back to IMSC 1.1 do we have to add this link?

   Nigel: I think we should

   Pierre: I will modify that then.
   … [adds extra text to signify the meaning of "specified value"]
   … done

   Nigel: I see that "specified value" is now a link.

   Pierre: Shall we approve this erratum?

   Nigel: Any objections to approving this erratum?

   group: [no objections]

   Resolution: Approve this erratum as summarised at [25]https://
   github.com/w3c/imsc/issues/489#issuecomment-562895235

     [25] https://github.com/w3c/imsc/issues/489#issuecomment-562895235


   Pierre: The text will be taken from the summary, I understand.

  Errata to correct disposition of #bidi in IMSC 1.1 imsc#498

   github: [26]https://github.com/w3c/imsc/issues/498


     [26] https://github.com/w3c/imsc/issues/498


   Nigel: This is one where we're simply applying the disposition
   already agreed in #491 for IMSC 1.2
   … Any objections to publishing this erratum?

   group: [no objections]

   Resolution: Publish this erratum as at [27]https://github.com/

   w3c/imsc/issues/498#issuecomment-562895537

     [27] https://github.com/w3c/imsc/issues/498#issuecomment-562895537


  Errata on non-prohibition of partially supported features imsc#500

   github: [28]https://github.com/w3c/imsc/issues/500


     [28] https://github.com/w3c/imsc/issues/500


   Nigel: This is one we already added to IMSC 1.2, defining
   partial support for a feature.
   … Any objections to proceeding with this erratum?

   group: [no objections]

   Resolution: Publish this erratum as at [29]https://github.com/

   w3c/imsc/issues/500#issuecomment-562895784

     [29] https://github.com/w3c/imsc/issues/500#issuecomment-562895784


   Glenn: I would not say this helps readers but it does somewhat
   resolve the ambiguity.

  Incompatible SMPTE ST 2052-1:2013 extension namespace name imsc#512

   github: [30]https://github.com/w3c/imsc/issues/512


     [30] https://github.com/w3c/imsc/issues/512


   Nigel: I did try to ping Mike Dolan about this but he did not
   respond (on this issue).
   … I think this is super tricky to know what to do without input
   from SMPTE.

   Pierre: The long term decision is tricky. IMSC has used the
   2010 version from the beginning. In the short term the
   … right thing to do for internal consistency in IMSC is to
   update the reference to 2010.
   … For dealing with this in the longer term we need input from
   SMPTE.

   Glenn: TTV did implement it as specified so we would have to go
   back and retrofit this change.

   Pierre: I looked at TTV. For IMSC I think it still uses 2010.
   It does have a profile for SMPTE-TT 2013 but my reading of
   … the code...

   Glenn: Okay I did not go back to verify if the IMSC part uses
   the SMPTE-TT 2013 part for that namespace.
   … You may be right.

   Pierre: I didn't spend hours but my take is TTV supports 2010
   and 2013 but IMSC uses 2010.

   Glenn: I support the suggested change.
   … I don't remember if this group ever consciously made the
   decision to use the 2013 namespace. Do you?

   Pierre: We never discussed it. When we started IMSC SMPTE-TT
   was at 2010 so we used it.
   … When we moved to IMSC 1.1 we tried to date all references but
   in our excitement we didn't check if 2013 was
   … backward compatible with 2010, and it looks like it is not.
   … We need SMPTE to tell us if that was intended or an error
   within SMPTE.

   Glenn: I suspect it was something that wasn't checked.

   Pierre: That's why I suggest we revert the reference to the
   dated 2010 version.

   Glenn: I agree.

   Resolution: Publish this erratum as at [31]https://github.com/
   w3c/imsc/issues/512#issuecomment-562895873

     [31] https://github.com/w3c/imsc/issues/512#issuecomment-562895873


   Nigel: Just double checking there are no objections before
   closing this agenda topic?

   group: [no objections]

  Errata publishing

   Nigel: We have 4 recorded errata showing up but none of them is
   actually listed.

   Pierre: I will follow this up with Atsushi and Philippe.

   Atsushi: Thank you, let me follow up on this.

   Nigel: Thank you.

  AOB: (Re-)join to timed text WG after charter renewal

   Nigel: I've seen several members rejoining, so that seems to be
   working okay.
   … Any other issues?

   group: [none for now, amongst those present]

   Nigel: If you have any difficulties please contact Atsushi or
   Philippe.

   <atsushi> let me write one email to Glenn

   Nigel: Also make sure your AC rep has nominated you to TTWG.

  Next meeting 2020-01-09

   Nigel: We will not have our regular call next week or the
   following week after that, so our next call
   … will be on 9th January 2020.
   … I want to take this moment to say thank you to everyone for
   all the work you've put in over the year,
   … a lot has happened this year. For those having a break, enjoy
   it, and for those for whom it is new year, happy new year.
   … See you all in January. [adjourns meeting]

Summary of resolutions

    1. [32]Approve this erratum as summarised at https://
       github.com/w3c/imsc/issues/489#issuecomment-562895235
    2. [33]Publish this erratum as at https://github.com/w3c/imsc/

       issues/498#issuecomment-562895537
    3. [34]Publish this erratum as at https://github.com/w3c/imsc/

       issues/500#issuecomment-562895784
    4. [35]Publish this erratum as at https://github.com/w3c/imsc/

       issues/512#issuecomment-562895873


    Minutes manually created (not a transcript), formatted by
    [36]scribe.perl version 104 (Sat Dec 7 01:59:30 2019 UTC).

     [36] https://w3c.github.io/scribe2/scribedoc.html

Received on Thursday, 19 December 2019 17:18:57 UTC