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{minutes} TTWG Meeting 2015-03-19

From: Nigel Megitt <nigel.megitt@bbc.co.uk>
Date: Thu, 19 Mar 2015 15:10:00 +0000
To: "public-tt@w3.org" <public-tt@w3.org>
Message-ID: <D13096FE.1D00A%nigel.megitt@bbc.co.uk>
Thanks all for attending today's TTWG meeting. Minutes are available in HTML format at http://www.w3.org/2015/03/19-tt-minutes.html

In text format:


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

                Timed Text Working Group Teleconference

19 Mar 2015

   See also: [2]IRC log

      [2] http://www.w3.org/2015/03/19-tt-irc


          pal, glenn, nigel, tmichel

          Frans, mike, jdsmith, atai2




     * [3]Topics
         1. [4]this meeting
         2. [5]Action Items
         3. [6]F2F
         4. [7]IMSC Test Suite and Implementation Report
         5. [8]Issues
     * [9]Summary of Action Items

   <trackbot> Date: 19 March 2015

this meeting

   group: no AOB

Action Items


   <trackbot> action-364 -- Glenn Adams to Add paragraph in intro
   that summarizes changes from ttml1 (comment from tm) -- due
   2015-03-17 -- OPEN


     [10] http://www.w3.org/AudioVideo/TT/tracker/actions/364

   glenn: No progress on this one. This needs to be done for the
   WD for wide review.
   ... This can be pushed back more.

   nigel: I've added a comment and pushed it back to 17th April to
   be more in keeping with the updated
   ... timeline for TTML2.


   <trackbot> action-378 -- Pierre-Anthony Lemieux to Draft smpte
   request including dispositions from action-369 and
   backgroundcolor initial value question -- due 2015-03-05 --


     [11] http://www.w3.org/AudioVideo/TT/tracker/actions/378

   nigel: Mike sent an email to the reflector shortly before this
   meeting suggesting that removing
   ... the initial value constraints from IMSC 1 would be a
   reasonable idea, which would mean we
   ... don't need to make any requests from SMPTE about that part
   of the action.

   pal: I've done some informal polling. There's the initial value
   issue and also ttp:frameRate and ttp:frameRateMultiplier
   ... being tied to the related video object, and also rounding
   rules that were left from CFF.
   ... Everything I've heard is consistent with Mike's view that
   CFF's intention was not to reference
   ... all of SMPTE-TT but just the backgroundImage part.
   ... On the frame rate issue the trend these days is to make
   frame rate and resolution independent
   ... TTML files, and the frame rate constraint isn't consistent
   with that. I haven't heard a clear reason
   ... why that's required in IMSC 1.

   nigel: On the rounding, we should maybe have one consistent set
   of rounding rules between IMSC1 and TTML1SE

   pal: My proposal is to 1) remove the SMPTE default values, 2)
   remove the constraint on frame rate
   ... being the same as the related video object and 3) to remove
   the rounding constraint difference
   ... to make it the same in IMSC 1 as in TTML1SE.

   glenn: On the frame rate and frame rate multiplier, that was
   there to facilitate conversion from
   ... frame values to second values in SMPTE continuous mode, or
   media mode.

   pal: My suggestion is to make those changes, and issue a new

   tmichel: It depends how substantial the changes are - if
   they're just editorial then we can issue
   ... a new CR. Since we're not on the old process we don't have
   to go back to LC.

   nigel: There's a query here on how substantive the changes are
   - I support them, but wonder
   ... what the criteria are.

   tmichel: That's not well defined and is in the end down to the

   pal: The IMSC timeline allows for another CR. What would the
   process be for this second CR.

   tmichel: We issue a transition request, and if the Director
   approves then we move to the second CR.
   ... Then once we have enough implementations to meet the exit
   criteria then we can do so. We can
   ... proceed to PR if there are no features that have not been
   implemented. If there are at risk
   ... features that have not been implemented they may get

   pal: If the changes don't affect the test suite...

   tmichel: That's a good definition for 'not substantial'

   glenn: I would not consider these changes to be substantial. I
   view clarification of semantics to
   ... be editorial - for me the definition is that there is a
   change to syntax or normative conformance
   ... requirements.

   tmichel: I would agree with that. Or if it impacts

   nigel: My understanding is that we do not need a further wide
   review to go CR->CR.

   pal: Is there a minimum period between CR and PR?

   tmichel: To exit CR you do have to put an earliest possible
   date, but you can also remain in CR for
   ... years if you'd rather wait for implementations.

   pal: I propose to make those changes, and other changes, and
   prepare a list of the delta since the
   ... current CR.
   ... How does that sound?

   nigel: Sounds good to me.

   tmichel: +1.
   ... If you do label those changes, mention them as substantive
   or editorial.

   pal: For now I will just list them without labelling them.

   <scribe> ACTION: pal Create IMSC 1 issues for removing initial
   value constraints, rounding definitions different to TTML1 and
   frame rate relationship to video [recorded in

   <trackbot> Created ACTION-380 - Create imsc 1 issues for
   removing initial value constraints, rounding definitions
   different to ttml1 and frame rate relationship to video [on
   Pierre-Anthony Lemieux - due 2015-03-26].

   pal: I think we no longer need a communication to SMPTE on
   initial value history

   <scribe> ACTION: pal Prepare new list of changes to IMSC 1
   since CR1. [recorded in

   <trackbot> Created ACTION-381 - Prepare new list of changes to
   imsc 1 since cr1. [on Pierre-Anthony Lemieux - due 2015-03-26].

   pal: I haven't created the draft wording for the SMPTE liaison
   yet - I need to unfold all the comments

   nigel: Probably best if I can pull that all together.

   glenn: I don't have any further comments on the Action-369

   <scribe> ACTION: nigel Summarise Action-369 end point [recorded
   in [14]http://www.w3.org/2015/03/19-tt-minutes.html#action03]

   <trackbot> Created ACTION-382 - Summarise action-369 end point
   [on Nigel Megitt - due 2015-03-26].


   <trackbot> Action-379 -- Nigel Megitt to Obtain png images for
   #linepadding and #multirowalign test cases. -- due 2015-03-19
   -- OPEN


     [15] http://www.w3.org/AudioVideo/TT/tracker/actions/379

   nigel: I've been in touch with Andreas about this, and also
   verified that we do need separate images
   ... for this because the test cases aren't in the referenced
   EBU document. This is ongoing.


   nigel: I think more people have joined now.


     [16] https://www.w3.org/wiki/TimedText/F2F-april-2015

   nigel: We now have 7 attendees.
   ... I suspect the first item on the agenda will be to work out
   the agenda scheduling!
   ... We have the opportunity to discuss both TTML and also
   WebVTT issues over the 2 days,
   ... and Dave Singer has invited the CG to attend in person or
   maybe by dialling in.

IMSC Test Suite and Implementation Report

   pal: I have received some feedback and committed some minor
   ... Glenn, apparently one of the TTML XSDs is missing the XML
   declaration line at the beginning.

   glenn: That's possible - let me take a quick look.

   pal: This is the ttm1-styling.xsd file

   glenn: Yes, it's missing, but it's still valid XML.

   pal: Apparently Xerces complains about it.

   glenn: since the other files all have it then it should
   probably have it.
   ... Looks like an editorial oversight.

   pal: I will file an issue for this.

   glenn: That will also prompt me to check the TTML2 schema too.

   <inserted> Issue-376 captures this.



   <trackbot> issue-289 -- For TTML created for overlay on top of
   video, signal the aspect ratio of the video the TTML was
   created for -- pending review


     [17] http://www.w3.org/AudioVideo/TT/tracker/issues/289

   nigel: This was implemented in ยง14.3.2 <named-item>

   glenn: Yes, all of the EBU proposed metadata are defined there.
   They're still subject to
   ... refinement and syntax. There's an editorial note to format
   the syntax rather than making it
   ... an open string. That's a tbd for me to go back to the
   ... We may want to cover document aspect ratio separately
   because there will be extra verbiage.
   ... Including parameters.

   nigel: I want to verify that the EBU is happy with this general
   approach as well.
   ... In the meantime it's hard to complete the review without
   the syntax being complete by
   ... definition or reference.

   glenn: We did close off a load of SMPTE issues that had a
   similar objection on the basis that we
   ... can review the editorial fixes later and raise any issues.

   nigel: This applies to issue-289, issue-290, issue-291 and
   issue-292 which are all implemented
   ... the same way.

   close issue-289

   <trackbot> Closed issue-289.


   <trackbot> issue-290 -- For TTML created for overlaying on
   video, add ebuttm:documentTargetActiveFormatDescriptor --
   pending review


     [18] http://www.w3.org/AudioVideo/TT/tracker/issues/290

   close issue-290

   <trackbot> Closed issue-290.


   <trackbot> issue-291 -- Document Intended Target Bar Data --
   pending review


     [19] http://www.w3.org/AudioVideo/TT/tracker/issues/291

   close issue-291

   <trackbot> Closed issue-291.


   <trackbot> issue-292 -- Specify target formats for which the
   TTML has been authored for easy conversion -- pending review


     [20] http://www.w3.org/AudioVideo/TT/tracker/issues/292

   close issue-292

   <trackbot> Closed issue-292.


   <trackbot> issue-353 -- Normatively define short code
   processorProfiles parameter -- pending review


     [21] http://www.w3.org/AudioVideo/TT/tracker/issues/353

   glenn: I marked this as a duplicate of issue-351

   nigel: I don't agree - it's a pre-requisite for issue-351

   reopen issue-353

   <trackbot> Re-opened issue-353.

   issue-353: This is not a duplicate of issue-351 but is a
   pre-requisite for it.

   <trackbot> Notes added to issue-353 Normatively define short
   code processorProfiles parameter.


   <trackbot> issue-359 -- Add support for font kerning
   enable/disable -- pending review


     [22] http://www.w3.org/AudioVideo/TT/tracker/issues/359

   glenn: This is similar to other properties that are on p and
   span like fontStyle. It comes from a
   ... usage in the LambdaCap system in Japan that allows kerning
   to be switched on or off. I have no
   ... data on how often it is used. Kerning is the other side of
   the coin from letter spacing so they go together.
   ... In Japan it would only be used for roman characters
   ... There is a CSS property in the fonts module of the same
   name, with the same semantics.

   close issue-359

   <trackbot> Closed issue-359.


   <trackbot> issue-364 -- Relax constraint between the extents of
   the root container and the dimensions of the related video
   object frame -- pending review


     [23] http://www.w3.org/AudioVideo/TT/tracker/issues/364

   pal: This has been done for a while - it was done after the CR
   but is already in the test suite.
   ... It was the response to Simon Hailes' comment.
   ... The general idea is to make it possible for authors to be
   able to create resolution independent files.

   close issue-364

   <trackbot> Closed issue-364.

   pal: This is one of the changes I'll be listing prior to
   publishing a new CR.

   nigel: We've just closed all the pending review issues! And
   we're out of time, this is a good point to end on.
   ... Thanks everyone, see you at the same time next week.
   [adjourns meeting]

Summary of Action Items

   [NEW] ACTION: nigel Summarise Action-369 end point [recorded in
   [NEW] ACTION: pal Create IMSC 1 issues for removing initial
   value constraints, rounding definitions different to TTML1 and
   frame rate relationship to video [recorded in
   [NEW] ACTION: pal Prepare new list of changes to IMSC 1 since
   CR1. [recorded in

   [End of minutes]

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Received on Thursday, 19 March 2015 15:10:32 UTC

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