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{minutes} TTWG Meeting 2015-11-19

From: Nigel Megitt <nigel.megitt@bbc.co.uk>
Date: Thu, 19 Nov 2015 16:22:12 +0000
To: Timed Text Working Group <public-tt@w3.org>
Message-ID: <D273A788.2C5E2%nigel.megitt@bbc.co.uk>
Thanks all for attending today's TTWG meeting. Minutes can be found in HTML format at http://www.w3.org/2015/11/19-tt-minutes.html


In text format:


   [1]W3C

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


                Timed Text Working Group Teleconference

19 Nov 2015

   See also: [2]IRC log

      [2] http://www.w3.org/2015/11/19-tt-irc


Attendees

   Present
          pal, nigel, tmichel, Frans

   Regrets
          dakim, atai

   Chair
          nigel

   Scribe
          nigel

Contents

     * [3]Topics
         1. [4]This meeting
         2. [5]Action Items
         3. [6]IMSC
         4. [7]TTML2
     * [8]Summary of Action Items
     * [9]Summary of Resolutions
     __________________________________________________________

   <scribe> scribe: nigel

This meeting

   nigel: We have a new handy Board:
   [10]http://www.w3.org/AudioVideo/TT/board/

   ... We now have a list of Pull Requests which are a nice thing
   for us to review.
   ... We should think about how long we leave them open for
   review - I think we said 2 weeks.

     [10] http://www.w3.org/AudioVideo/TT/board/


   pal: We also need to consider PRs geting stale and avoid them
   needing to be rebased as
   ... other code changes around them, so leaving them open for a
   long time generates more work.
   ... So we should go through the PRs. Unless someone objects to
   merging the PRs maybe
   ... the editor should automatically merge after 2 weeks. Then
   further discussions can
   ... be handled with new filed issues.

   nigel: I agree with that.
   ... Also you can clearly identify what went into each change in
   case you want to back it out later.
   ... So the proposal for today's meeting is to review the open
   PRs. Any other business?

   group: No AOB.

Action Items

   action-448?

   <trackbot> action-448 -- Nigel Megitt to Put timing diagrams
   somewhere they can be reviews -- due 2015-11-06 --
   PENDINGREVIEW

   <trackbot>
   [11]http://www.w3.org/AudioVideo/TT/tracker/actions/448


     [11] http://www.w3.org/AudioVideo/TT/tracker/actions/448


   nigel: I did this as a PR which we'll be able to look at later
   in this meeting.

   close action-448

   <trackbot> Closed action-448.

   action-449?

   <trackbot> action-449 -- Philippe Le Hégaret to Create board
   for ttwg similar to that for webperf -- due 2015-11-19 --
   PENDINGREVIEW

   <trackbot>
   [12]http://www.w3.org/AudioVideo/TT/tracker/actions/449


     [12] http://www.w3.org/AudioVideo/TT/tracker/actions/449


   nigel: I already mentioned the board, which plh made, so this
   is done.

   close action-449

   <trackbot> Closed action-449.

IMSC

   pal: Let's start with PR #88:
   [13]https://github.com/w3c/imsc/pull/88


     [13] https://github.com/w3c/imsc/pull/88


   nigel: By the way, a quick way to see all the PRs is to look
   at: [14]https://github.com/w3c/imsc/pulse

   ... How can we see the HTML natively, with the changes applied?

     [14] https://github.com/w3c/imsc/pulse


   <pal>
   [15]http://rawgit.com/w3c/imsc/issue-68/spec/ttml-ww-profiles.h

   tml

     [15] http://rawgit.com/w3c/imsc/issue-68/spec/ttml-ww-profiles.html


   pal: The recipe is, when you click "View document" then click
   "Raw" and then replace raw.githubusercontent.com with
   rawgit.com
   ... The changes address the issue on the Note in §9.5. I
   removed the wording around
   ... complex scripts and simple scripts. My research showed that
   it is sometimes seen as
   ... contentious and also incorporates other areas of
   complexity.
   ... I also listed the scripts directly rather than referencing
   the appendix, and removed appendix H.
   ... Appendix H was only going to be referenced once, so there
   was no advantage in doing that.

   nigel: I can't see Appendix 24 at the Unicode link.

   pal: It's Annex 24.

   <pal> [16]http://www.unicode.org/reports/tr24/tr24-24.html


     [16] http://www.unicode.org/reports/tr24/tr24-24.html


   pal: I'll change the wording to point to the right place.

   [17]http://www.unicode.org/Public/UCD/latest/ucd/PropertyValueA

   liases.txt

     [17] http://www.unicode.org/Public/UCD/latest/ucd/PropertyValueAliases.txt


   nigel: Don't you want to include the "common" script in the set
   with GCpy=12?

   pal: I haven't because I haven't gone through everything in
   common to check it yet.
   ... There's another page where you can see the list of scripts
   ... I'm looking at it now and there are a lot of symbols but
   they're not all in the recommended characters
   ... It's hard to tell if some of those would have a one to many
   mapping.
   ... I'd like to take an action item to dig deeper into that.
   Also recall that Glenn still
   ... owes us a list of simple vs complex scripts, so we can deal
   with that together.

   <scribe> ACTION: pal Check character to glyph mappings for
   common script value [recorded in
   [18]http://www.w3.org/2015/11/19-tt-minutes.html#action01]

   <trackbot> Created ACTION-450 - Check character to glyph
   mappings for common script value [on Pierre-Anthony Lemieux -
   due 2015-11-26].

   pal: Based on this, I recommend we merge this and then action
   further changes if we identify them.

   nigel: Seems okay to me. Any other views?

   Frans: okay by me

   pal: I'll make that change right now and see how it works...

   nigel: I can confirm that addresses all my issues in issue #68

   pal: That's merged now.
   ... Next I propose we look at the aspectRatio one.
   ... It's issue #84 and PR #89

   [19]https://github.com/w3c/imsc/issues/84


     [19] https://github.com/w3c/imsc/issues/84


   [20]https://github.com/w3c/imsc/pull/89


     [20] https://github.com/w3c/imsc/pull/89


   pal: I want to make sure that "Related Video Object frame"
   literally means each image frame of the related video object,
   ... regardless of how it is displayed. Because the goal is to
   capture authorial intent with respect to the positioning
   relative to elements on the video frame.

   nigel: So the goal was not to address the case where not all of
   the video is shown?

   pal: Exactly. That's a similar goal as with synchronisation:
   capture authorial intent and then
   ... let applications handle other scenarios as nicely as they
   can.
   ... It's complex as your presentation shows nicely.
   ... I can imagine lots of possibilities, with applications
   generating different versions.
   ... [lists lots of possibilities!]

   nigel: We could signal a safe area within the root container,
   outside of which there's no content.

   pal: You can do that by, say, having aspectRatio="4 3".

   nigel: That doesn't work on 16:9 video when they're displayed
   on a 21:9 display - that can
   ... clip the container.

   group: [discussion about what devices should do if the video
   frame is not fully shown]

   pal: We could add an example for when the display device is not
   showing all of the
   ... related video object frame, to show a reasonable behaviour
   in that case, vs the one specified.

   nigel: Okay

   pal: I'll have a go at drafting one that we can then review.
   ... The drawback is you lose positioning, but that's a choice
   that maybe the system in
   ... conjunction with the user might correctly take.
   ... Issue #81 is more straightforward. Glenn pointed out that
   if somebody uses cellResolution on linePadding,
   ... the author should be encouraged to set ttp:cellResolution
   on tt. I looked at EBU-TT-D
   ... and it says "should" set cellResolution. The proposal here
   is to follow that in IMSC 1.
   ... I had an action item to go through the features in IMSC 1
   and work out feature
   ... dependencies, so I've done that.

   nigel: I saw that and was confused that lots of features were
   being prohibited.

   pal: What I did was, for image profile, where parent features
   were prohibited, I listed the
   ... dependent features as being prohibited also.

   nigel: That sounds great - we'll do the 2 week review, and if
   no adverse comments, the Editor can go ahead and Merge the PR.

   pal: That will get us to Dec 3, so hopefully then we'll be able
   to get another CR published.

   nigel: Yes, that would be good.

   pal: I've started the list of substantive changes and will
   update further based on these closed issues.
   ... There have been a lot of cosmetic changes but I only found
   3 substantive changes.
   ... For example the changes in the Recommended Characters don't
   affect conformance.
   ... Then there's the change to the HRM, and ttp:profile element
   being prohibited, the addition of Liberation font to the
   reference fonts.

   nigel: We're out of time now.

   pal: Shall we do 2 hours next week?

   nigel: Okay, no problem.

TTML2

   nigel: I just wanted quickly to mention the Timing work at
   [21]https://github.com/w3c/ttml2/pull/143


     [21] https://github.com/w3c/ttml2/pull/143


   pal: It looks good - it's a great help.

   nigel: Great. The main thing is that the content is right.

   pal: Yes, I think it matches my intuitive understanding. The
   second diagram is one where
   ... an external context starts some way through the media
   timeline, which shrinks the
   ... Root Temporal Extent. So the Root Temporal Extent is shrunk
   by the external context.

   nigel: Yes, that's right.

   pal: That makes it unambiguous so people have a clear thing to
   disagree with!

   nigel: Great. It would be good for the record if you could add
   your review comment to the PR.

   pal: Done!

   nigel: Thanks everyone, we'll meet for 2 hours next week as
   requested. [adjourns meeting]

Summary of Action Items

   [NEW] ACTION: pal Check character to glyph mappings for common
   script value [recorded in
   [22]http://www.w3.org/2015/11/19-tt-minutes.html#action01]

Summary of Resolutions

   [End of minutes]
     __________________________________________________________


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Received on Thursday, 19 November 2015 16:23:06 UTC

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