{Minutes} TTWG Teleconference 2023-12-07

Thanks all for attending today’s TTWG meeting. Minutes can be found in HTML format at https://www.w3.org/2023/12/07-tt-minutes.html


In text format:

   [1]W3C

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


                Timed Text Working Group Teleconference

07 December 2023

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

      [2] https://www.w3.org/2023/11/23-tt-minutes.html

      [3] https://github.com/w3c/ttwg/issues/270

      [4] https://www.w3.org/2023/12/07-tt-irc


Attendees

   Present
          Andreas, Atsushi, Cyril, Nigel, Pierre

   Regrets
          Gary

   Chair
          Nigel

   Scribe
          nigel

Contents

    1. [5]This meeting
    2. [6]IMSC-HRM
         1. [7]Add note on conversion from CTA 608 signals
            w3c/imsc-hrm#72
         2. [8]IMSC-HRM Tests and call for implementations
    3. [9]DAPT
         1. [10]Rework audio description original and translation
            languages w3c/dapt#179
         2. [11]Next steps and Wide Reviews
    4. [12]Meeting close

Meeting minutes

  This meeting

   Nigel: Today we have IMSC-HRM and DAPT on the agenda.
   … Specifically with IMSC-HRM, some test suite changes and
   implementation work
   … And for DAPT the main thing to cover is the languages PR
   … Any other business, or points to make sure we cover within
   those agenda topics?

   no other business

  IMSC-HRM

    Add note on conversion from CTA 608 signals [13]w3c/imsc-hrm#72

     [13] https://github.com/w3c/imsc-hrm/issues/72


   github: [14]w3c/imsc-hrm#72

     [14] https://github.com/w3c/imsc-hrm/pull/72


   Nigel: There's been some debate on the wording for this
   editorial note, would
   … be good to complete it today if we can.
   … Pierre, any specific questions to be able to resolve this?

   Pierre: The general disagreement is if we should make a more
   general statement and
   … I'm not excited by that for 2 reasons.
   … 1 is, there's a case I'm comfortable talking about, which is
   the 608 line 21 example at 59.94fps
   … I've seen a lot of streams like that.
   … 2nd is, this is just a note and we should try to avoid
   designing a system in the note.
   … The general question of conversion to IMSC is worth its own
   document.
   … I'd like to keep it to just a specific example highlighting
   the challenges.
   … That's my preference.
   … I'm happy with the group decision ultimately.
   … I can try to make another pass explaining that more clearly.

   Nigel: Worth noting that this note is right after an "e.g."
   pointing to 608 in the text immediately above it.
   … Can we just remove the phrase about 59.94 Hz? The issue would
   remain at other frame rates
   … such as 29.97.

   Pierre: If that resolves both your and Cyril's concerns I'm
   happy to do it.

   Cyril: I don't think adding the sample rate helps, and I don't
   want to add a note that is not totally accurate.

   Nigel: Maybe say "at the video field rate" to clarify that this
   isn't happening once every few seconds,
   … but many many times per second.

   Pierre: There's a general misunderstanding - 608 is sampled at
   a field rate, but sometimes the packets
   … are combined for other transport mechanisms. But 608 has no
   option other than sampling at the field rate,
   … at least classic 608, like line 21.

   Nigel: Is this the change that we can accept then?

   Pierre: I'll put this on screen. [shares screen]
   … Now says "... for every CEA-608 packet, which are sampled at
   the video field rate. ..."

   Cyril: I like that we removed the 59.94. Field rate is related
   to interlace. Should we say field or frame?
   … I'm fine with this. A field is a frame when there's no
   interlace.
   … And maybe we will have to change it again if we have Teletext
   issues.

   Nigel: Teletext doesn't have this "build up a buffer character
   by character" approach, so it doesn't arise.

   Pierre: That's modified, I'll ask for a re-review.

   SUMMARY: Live edits made, needs re-review

    IMSC-HRM Tests and call for implementations

   Nigel: Exciting news: I completed a second validation
   implementation of IMSC HRM,
   … based on the EBU-TT Live Interoperability Toolkit, as a
   starting model.
   … That means it can process all the files in the test suite
   that can conform to EBU-TT-D as well as IMSC Text.
   … As part of this exercise I updated, and Pierre reviewed, the
   tests to be EBU-TT-D conformant.
   … We had some other fun along the way, identifying some tests
   that weren't quite right,
   … and found bugs.

   Pierre: The bugs we found were in the implementations and we
   are fixing them right now.

   Nigel: We are also in the process of adding tests for region
   presentation.
   … That came out of a fun discussion about the handling of
   tts:showBackground on region elements
   … that set a backgroundColor that is not entirely transparent.
   … There's also an issue about one of the test pairs, dur005,
   which we're in the process of resolving.
   … So it's been a useful exercise.
   … Next steps: finish sorting out the tests, and update the
   implementation report to add the additional implementation.

   Pierre: Have you checked the implementation report?

   Nigel: Not yet.

   Atsushi: I have not either.
   … The main question is we may need to list the mapping between
   HRM features and the test suite.

   Pierre: In each of the test files there is a description.

   Atsushi: In any case we may need a script to list those things
   easily.

   Pierre: Why?

   Atsushi: There are a bunch of test files.

   Pierre: They're organised into two directories, which are
   sufficient for automatic testing.

   Atsushi: In any case I need to set some time aside to check it.

   Pierre: Ok.

   Nigel: Edits needed at the moment are: adding the new tests,
   and the 2nd validating implementation

   [15]Implementation Report

     [15] https://www.w3.org/wiki/TimedText/IMSC-HRM-1ED-Implementation-Report


   Nigel: If at some stage we need to demonstrate the truth of the
   emails to the Chair listed under
   … Content producing implementations, I'm sure we can find a way
   to do that.
   … Anything else on IMSC-HRM?

   Pierre: Not for me, thanks for everyone's help and input on
   this. We're getting super close
   … and hopefully can close this very early next year if not this
   year.

  DAPT

    Rework audio description original and translation languages
    [16]w3c/dapt#179

     [16] https://github.com/w3c/dapt/issues/179


   github: [17]w3c/dapt#179

     [17] https://github.com/w3c/dapt/pull/179


   Nigel: This has been open since July 31 and has been through an
   amazing number of iterations,
   … each one making it better than before.
   … I think we're probably about done with it, and would like to
   know if we can merge it today
   … or if anyone wants more review time.
   … Since the last review the main change is to model the
   daptm:langSrc attribute better and to
   … define the semantics and constraints better.
   … Those changes are in line with the issue and pull request
   discussion, I think,
   … but I am aware that Andreas had some reservations.
   … I did try to address those.

   Andreas: Thanks first for all your work on that pull request.
   It was an amazing amount of editing
   … work to resolve the different comments. I think it gets
   better and better.
   … As I signalled, maybe offline, I'm happy with the way forward
   as described in the comments.
   … It's not just one line, you have to check the whole document.
   … I can review it in the next couple of weeks but if you want
   to merge it now that's okay.

   Nigel: I could merge it and then if you find issues with it
   then open new issues.

   Andreas: That would be okay.

   Cyril: I concur with Andreas. I would also like to give it
   another review, and I can do it tomorrow.

   Nigel: OK then I will leave it open and then react based on the
   result of your review.

   Cyril: After my review I will try to implement the solution in
   my prototype tool to see if there is any
   … problem in our source content. I can do the review first. If
   I see any problem I will open a new issue.

   Nigel: Great, thank you.

   SUMMARY: @cconcolato to review, @nigelmegitt to respond
   accordingly. @andreastai to read through when time allows.

    Next steps and Wide Reviews

   Cyril: Do we have all the responses?

   Nigel: Not quite.

   Cyril: We have TAG and i18n.

   Nigel: We haven't had the formal response from APA yet.
   … We've been told not to expect a response on Security unless
   they identified a problem.

   Atsushi: If we can resolve all of the issues raised against
   DAPT then we can state that
   … all HR is finished.

   Nigel: Please could you check on the status of those, Atsushi?

   Atsushi: Of course, I will do it during winter holiday season.

   Nigel: My other question is about the feedback from DVW - do we
   have a way to complete
   … the conversation with them after the detailed discussion
   responses?

   Cyril: I'm hoping to get a response from them, yes.

   Nigel: In terms of tasks, we have some issues that need
   decisions to be made,
   … at some point we need test suites (not formally until after
   CR),
   … and there are a couple of PRs open from June that need
   something doing with them.

   Cyril: Those PRs are still on my list!

  Meeting close

   Nigel: We have one more meeting this year, on 21st December.
   … We've completed our agenda today. Thank you everyone.
   [adjourns meeting]


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