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{minutes} TTWG Meeting 2016-08-18

From: Nigel Megitt <nigel.megitt@bbc.co.uk>
Date: Thu, 18 Aug 2016 15:22:44 +0000
To: Timed Text Working Group <public-tt@w3.org>
Message-ID: <D3DB9129.291CE%nigel.megitt@bbc.co.uk>
Thanks all for attending today's TTWG meeting. Minutes can be found in HTML format at https://www.w3.org/2016/08/18-tt-minutes.html

In text format:


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

                Timed Text Working Group Teleconference

18 Aug 2016

   See also: [2]IRC log

      [2] http://www.w3.org/2016/08/18-tt-irc


          Nigel, Glenn, Pierre, Mike

          Andreas, Frans




     * [3]Topics
         1. [4]This Meeting
         2. [5]TPAC 2016
         3. [6]TTML1 & TTML2 issues, actions, PRs, editorial
            actions etc
     * [7]Summary of Action Items
     * [8]Summary of Resolutions

This Meeting

   nigel: Today I had planned for an extra 30 minutes for Dave
   Singer to chair the agenda item
   ... on WebVTT but he tells me the preparation isn't ready yet
   for that. So we can get the 30 minutes back or use it.

   group: Need to finish after 60 minutes

   <scribe> scribe: nigel

   nigel: Agenda for today is TPAC, TTML. AOB?

   group: No AOB.

   tmichel: I sent a list today about a request from Amazon for
   TTML2 tests, so if we do have
   ... up to date tests a pointer would be useful.

   gadams: I followed up on that out of band and sent them a
   pointer to the TTT github repo
   ... where there is some TTML2 test material, not W3C sanctioned
   at this point.

   tmichel: Thank you Glenn!

   <gadams> I received the following from Mr Michel. The TTML2
   test suite which will be created by the W3C for the purpose of
   validating the TTML2 specification is not yet available as a
   whole. However, there are some initial tests found under [1],
   primarily at [2] and [3]. This project TTT [1] is a work in
   progress, and support for TTML2 is currently being added, with
   scheduled completion of March 2017. Note that this project is
   not originated by W3C itself, but from a 3rd par

      [1] http://www.w3.org/
      [2] http://www.w3.org/2016/08/18-tt-irc
      [1] http://www.w3.org/

   <gadams> party, namely my company. [1]
   [9]https://github.com/skynav/ttt [2]
   resources/com/skynav/ttv/ttml2 [3]

      [1] http://www.w3.org/
      [9] https://github.com/skynav/ttt
      [2] http://www.w3.org/2016/08/18-tt-irc
     [10] https://github.com/skynav/ttt/tree/master/ttt-ttv/src/test/resources/com/skynav/ttv/ttml2
     [11] https://github.com/skynav/ttt/tree/master/ttt-ttpe/src/test/resources/com/skynav/ttpe/ttml2

   <tmichel> Glenn maybe you could copy me your email response
   would be helpfull for a response from me.

   <tmichel> thanks Glenn

   nigel: I will also respond CC Thierry to explain the status of
   the TTML2 work and when we will move to implementation/test

   mike: They may or may not mean TTML2. They may have grabbed the
   latest spec but actually
   ... be interested in deployment of TTML1, specifically EBU-TT-D
   and IMSC1 so it would be
   ... helpful to educate them on the status of those specs too,
   and their test materials.

   nigel: +1

   gadams: I don't know for a fact but it's possible that they've
   been talking to Netflix about TTML2 also.

   nigel: There's no harm educating, so I'll do that.

TPAC 2016

   nigel: Registration closes on Sep 2!

   <tmichel> FYI Amazon is NOT a W3C Member. We tryed to have them
   in for Digital publishing but they use their own KINDLE format
   and not EPUB.


   <trackbot> action-475 -- Nigel Megitt to Contact the chair of
   the web & tv ig to ask about schedule and joint meeting time.
   -- due 2016-07-28 -- OPEN


     [12] http://www.w3.org/AudioVideo/TT/tracker/actions/475

   tmichel: I will meet Yosuke next Tuesday so I'll ping him
   directly by voice then.

   nigel: Okay, thanks.

   tmichel: I will tell him it is a priority because TPAC is
   getting closer now.

   nigel: True. On that topic I will give myself an action to put
   together a straw man agenda
   ... that we can look at, adjust as needed before the meeting.

   <scribe> ACTION: nigel Put together a TPAC straw man agenda
   [recorded in

     [13] http://www.w3.org/2016/08/18-tt-minutes.html#action01]

   <trackbot> Created ACTION-476 - Put together a tpac straw man
   agenda [on Nigel Megitt - due 2016-08-25].

   nigel: Next week I'm on vacation so if someone wants to step in
   and chair this meeting please
   ... volunteer, otherwise we have 3 meetings before the face to
   face at TPAC.
   ... Please let me know any agenda items especially if they may
   be unexpected.

   glenn: We should probably coordinate on getting together on
   Sunday evening if we want to.

   nigel: I'd be happy to meet up at say 2000 based on my arrival

   glenn: Maybe those who are going to be there could let you know
   their locations and we
   ... could triangulate.

   nigel: Yes, sure, okay, also we usually put hotels etc on the
   wiki meeting page, so I'll set that
   ... up as part of action-475

   pal: I'll be there.

TTML1 & TTML2 issues, actions, PRs, editorial actions etc


   <trackbot> action-462 -- Glenn Adams to Create issue on ttml2
   to add "mapping from other versions and profiles of ttml" --
   due 2016-04-28 -- OPEN


     [14] http://www.w3.org/AudioVideo/TT/tracker/actions/462

   glenn: No progress on that yet.

   nigel: [diverts topic to IMSC temporarily] Pierre do we need to
   talk about the IMSC roadmap PR?

   pal: Not really, but I have been asked to update the wiki with
   the latest IMSC implementations
   ... and plan to do that in the next week or so.

   nigel: Is that also for test resources?

   pal: For IMSC 1 we duplicated the implementation report so that
   we can add new results,
   ... test vectors etc so that we could update this new page, so
   that may be the right place to
   ... list IMSC 1 implementations, because they will also have
   tests, test reports etc. Then I would
   ... add a link from the TTML and WebVTT implementations page to
   the new IMSC implementations page.
   ... While I'm doing that I will also apply the PR.

   nigel: [Back on TTML2 topic] There have been some new issues
   also. What's best to discuss first?
   ... Let's cover position syntax first:

     [15] https://github.com/w3c/ttml2/issues/174

   gadams: I was creating some test content for position and
   backgroundPosition style attributes
   ... that are new to TTML2 and I discovered that there was a
   missing rule in the grammar for
   ... position that effectively made it different than what CSS3
   uses for position. CSS3 Background
   ... and Borders defines the CSS3 property position allows you
   to reverse the horizontal and
   ... vertical components of the position specification, but they
   allow vertical first and horizontal second.
   ... That was apparently an oversight when I transcribed the

   nigel: How do you know which way round the values are, if
   that's not a stupid question?

   gadams: That's a good question, particularly because the
   keyword "center" can apply to both.
   ... If you use top or bottom first then it's clear that you
   mean a vertical offset.

   <gadams> <style tts:backgroundPosition="center left"/> <!-- NG
   --> <!-- TTML does not support this valid CSS3 expression -->
   <style tts:backgroundPosition="center right"/> <!-- NG --> <!--
   TTML does not support this valid CSS3 expression --> <style
   tts:backgroundPosition="top center"/> <!-- NG --> <!-- TTML
   does not support this valid CSS3 expression --> <style

   gadams: I've pasted above the four test cases (not well
   formatted) that did not quite work.

   nigel: In the issue you use offset-position-h and
   offset-position-v but in CSS the interchangeable
   ... terms are keyword-position-h and keyword-position-v.

   <gadams> [16]https://www.w3.org/TR/ttml2/#style-value-position

     [16] https://www.w3.org/TR/ttml2/#style-value-position

   gadams: For the 2 component value it was missing the reverse
   version. This is expanded
   ... out as opposed to abbreviated compared to the CSS3 spec.

   nigel: At least one of the position keywords must be present to
   resolve reversed values.

   gadams: That's right, and they have to be something other than
   ... It is probably worth noting under the grammar that two
   linked or center values should
   ... be mapped to offset horizontal followed by vertical.

   nigel: Okay, let's move on to
   ... The background here is that it was unclear if implied
   anonymous regions should be
   ... implemented as new regions or modifications to current
   regions. Since then Glenn has
   ... added a note to the issue to suggest that we add a
   parameter attribute to direct the
   ... behaviour, which sounds like a good idea to me.

     [17] https://github.com/w3c/ttml2/issues/168

   gadams: I hadn't thought about the modification option before
   you raised it Nigel but I'm
   ... willing to give it a try both in the specification and the

   pal: What's the advantage of having both methods?

   gadams: The modification approach allows region styling to be
   maintained while applying an
   ... anonymous set of the region origin and extent, for border,
   backroundColor etc.

   pal: What's important to understand is whether the adopters of
   this syntax also intended to
   ... apply region styling with their method. For example if I
   use tts:extent and tts:position on a
   ... p then I cannot apply backgroundColor on that and hope that
   it applies. It would be good to know
   ... what they intended, and to dig deeper before concluding
   that we need to support both methods.

   gadams: I'm assuming based on experience and having talked to
   people that their understanding
   ... was based on creating a new region.

   nigel: I suspect that the users of this syntax never added the
   complexity of region styling
   ... or even had temporally overlapping content. For those
   documents then it won't make
   ... any difference which approach is used. For more complex
   uses then it would be helpful to have the choice.

   gadams: One of the best arguments against the modification
   approach is the use of two
   ... temporally overlapping content elements in the same region.
   I also know Netflix has a
   ... definite requirement for the flavour of creating a new

   pal: There are tons of tools that put extent and origin on
   elements other than region. We're
   ... trying to reverse engineer that into TTML2. The other
   option that we should consider is
   ... simply allowing all the region styling on p and just apply
   to the anonymous region.

   gadams: That doesn't work because we have a growing number of
   properties that apply to
   ... both content and region, like padding, border, bpd and ipd,
   and more. They apply
   ... independently to both content elements and regions. It
   would make the spec much more
   ... complicated if I have to try to explain how to handle those
   dual use properties.

   nigel: I'm sympathetic to keeping things simple, and adding a
   new parameter is adding
   ... complexity, but in this case I think there's utility in
   both approaches so I would propose
   ... we add it in and then if necessary later put it in the at
   risk list for CR.

   pal: Another approach is to say that if a region is not
   specified then it would mean 'new' or
   ... if a region is also specified then it would mean
   'modified'. That would prevent the addition
   ... of features.

   nigel: Ok, we're out of time so let's adjourn for today.

   mike: By the way, I've just submitted
   ... Do we want to review and merge it now?

     [18] https://github.com/w3c/tt-profile-registry/pull/25

   nigel: Let's not rush for the sake of the meeting, and look at
   it offline - if we can add our
   ... "LGTM"s etc then we can merge on that basis.

   mike: OK, thanks.

   nigel: Shall we go ahead with a volunteer chair for next week?

   group: Skip next week.

   nigel: Okay, see you in 2 weeks then. Thanks all!
   ... [adjourns meeting]

Summary of Action Items

   [NEW] ACTION: nigel Put together a TPAC straw man agenda
   [recorded in

     [19] http://www.w3.org/2016/08/18-tt-minutes.html#action01

Summary of Resolutions

   [End of minutes]

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Received on Thursday, 18 August 2016 15:23:11 UTC

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