- From: Nigel Megitt <nigel.megitt@bbc.co.uk>
- Date: Thu, 9 May 2024 16:52:16 +0000
- To: "public-tt@w3.org" <public-tt@w3.org>
- Message-ID: <14685F25-DA44-4712-B242-18A735569F88@bbc.co.uk>
Thanks all for attending today’s TTWG meeting. Minutes can be found in HTML format at https://www.w3.org/2024/05/09-tt-minutes.html
In plain text:
[1]W3C
[1] https://www.w3.org/
Timed Text Working Group Teleconference
09 May 2024
[2]Previous meeting. [3]Agenda. [4]IRC log.
[2] https://www.w3.org/2024/04/25-tt-minutes.html
[3] https://github.com/w3c/ttwg/issues/281
[4] https://www.w3.org/2024/05/09-tt-irc
Attendees
Present
Andreas, Chris_Needham, Cyril, Gary, Matt, Nigel, Pierre
Regrets
-
Chair
Gary, Nigel
Scribe
cpn, nigel
Contents
1. [5]This meeting
2. [6]DAPT
1. [7]Add informative section about mapping from TTML to
the DAPT data model w3c/dapt#216
3. [8]TTML2 ttm:role issues
1. [9]Permit ttm:role attribute in ttm:desc elements
w3c/ttml2#1247
2. [10]Inheritance model of ttm:role attribute is unclear
w3c/ttml2#1271
4. [11]TPAC 2024
5. [12]CCSubs report
6. [13]Meeting close
Meeting minutes
This meeting
Nigel: DAPT, some TTML issues on ttm:role, also relevant to
DAPT. TPAC planning, there's a deadline.
Andreas: Also briefly mention CCSUBs
Nigel: Anything else to cover today?
(nothing)
DAPT
Add informative section about mapping from TTML to the DAPT data
model [14]w3c/dapt#216
[14] https://github.com/w3c/dapt/issues/216
github: [15]w3c/dapt#216
[15] https://github.com/w3c/dapt/pull/216
Nigel: One of the points we got exercised about was the
forwards and backwards comaptibility model
… After last meeting, I've done some editing work. You may not
have had time to review
… PR preview is failing. So you'd need to clone the repo
locally to view the branch
… We already agreed to restrict the ttp:content profile
attribute values to be ones the processor writing the document
knows it can support
… I moved that to the ttp:content profiles section
… I decided the term "foreign vocabulary" was useful, so added
that
… Added advice on retaining unsupported foreign vocabulary if a
child of a metadata element, but require pruning outside that
space
… So there's a place people can put stuff where it's not
pruned. I documented the way foreign vocabulary is supported -
create a document profile and include the profile designator in
the content or processor profiles
… So a conformant processor will know what to do
… Andreas commented, if you're trying to keep the foreign
vocabulary, the document might be restructured such that the
home of the vocabulary might not exist, so I added a note on
that
… Please have a look. Any immediate reaction?
Andreas: Thanks for addressing it, I'll review
Cyril: I'll also review. We talked about grouping of script
events, nested divs, where did we end up?
Nigel: We specified rules and they have normative keywords on
them. The rules haven't changed
… (reads the current rules in the pull request)
Cyril: Ok, will have to read again.
… A side note, I commented that identifying a script event just
by fragment ID seems fragile.
Nigel: Yes. We don't have other rules in place. I think
ttm:role isn't a good mechanism for that
Cyril: If a document goes through multiple tools or workflows
they might add IDs, seems fragile
Nigel: Not sure if a real world problem, but could be. Could
end up with empty script events
… More likely, the opposite will occur, things that should
qualify as script events don't have the xml id and are ignored
Cyril: What do you define as foreign vocabulary, is it anything
outside the ttml and dapt namespaces?
Nigel: (reads current definition)
Foreign vocabulary consists of the set of elements and
attributes whose namespace is not one of the namespaces listed
in 5.3 Namespaces and the set of attributes in the global
namespace that are not otherwise defined in DAPT or in [TTML2].
Cyril: OK, I'll read again
Nigel: Two potentially overlapping sets of foreign and
unrecognised vocabulary
… Might relate to a feature the processor doesn't support. I
tried to address both of those
Cyril: I'll read and let you know
Nigel: This is one of the last CR blocking issues. We should
try to get it merged.
… Anything else on this topic or DAPT things?
(nothing)
SUMMARY: Recent commit described, awaiting reviews
TTML2 ttm:role issues
Permit ttm:role attribute in ttm:desc elements [16]w3c/ttml2#1247
[16] https://github.com/w3c/ttml2/issues/1247
github: [17]w3c/ttml2#1247
[17] https://github.com/w3c/ttml2/issues/1247
Nigel: I opened this to suggest we allow the ttm:role attribute
in ttm:desc attributes. I've seen real world use of this
… We resolved in September 2022 to allow metadata attributes on
metadata elements
… I noticed recently that ttm:role doesn't behave as I'd
thought. Spec says it's a set of role values that apply to
content elements, and it applies to that element and all its
descendents.
… So there's no way to invert the application of the role, it's
an additive approach rather than an inheritance model that you
might have e.g., color or language where what you set locally
overrides what's set above.
… Don't think the model is wrong, but it seems bizarre to have
role applied to elements in the metadata space
Cyril: Why would putting things on the metadata element on a
div apply to the div
Nigel: That's how it's defined
… (talks through the spec detail)
… "applies semantically to the div element and its descendants
as a whole"
… If we say, the child elements of metadata, e.g., ttm:desc,
that doesn't permit a ttm:role attribute. If it should have one
we'd have to work out the inheritance model
… There's discussion in the issue. I checked DAPT, it defines a
different attribute for the same thing
Cyril: So we should restrict the use of ttm:role?
Nigel: I think it's fine, but for DAPT we should explain the
model
… It's not obvious, which we discovered trying to implement it
… Suggest closing this TTML2 issue with no change.
Cyril: What about [18]w3c/ttml2#1271?
[18] https://github.com/w3c/ttml2/issues/1271
Nigel: It doesn't say what happens in this context. My
expectation is they're additive, so in both cases you are
specifying roles that apply semantically to the metadata and
content elements
Andreas: You'd need to define precedence if there are
conflicting values
Nigel: They're additive rather than conflicting
… It's clear ttm:role on the metadata child does apply to the
div element and descendants.
… But not clear that the ttm:role attribute applied on the div
also does so.
… Precedence would suggest it could be one or other, but here I
think you can both
Andreas: Could use exclusive values, just need to be clear how
it's managed
Nigel: Doesn't have to be mutually exclusive, it could be both
values
… Should we allow role on ttm:desc? Options are to keep
discussing and come back to it, or decide immediately
Cyril: It seems so complex, I'd steer away from ttm:role
Nigel: It's actually surprisingly simple, but I understand the
reaction
… What to with this issue? I've proposed closing it without
change
… Suggest we allow more time for consideration
SUMMARY: Allow more time for consideration
Inheritance model of ttm:role attribute is unclear
[19]w3c/ttml2#1271
[19] https://github.com/w3c/ttml2/issues/1271
github: [20]w3c/ttml2#1271
[20] https://github.com/w3c/ttml2/issues/1271
Nigel: role attributes on content elements also apply to
descendants
… Glenn agreed on this
… Do we also need more time for this? It might be wording
that's obviously missing, that includes attributes in the
metadata attributes group
… Proposal is to add attributes to the current definition
Cyril: I don't have a strong opinion, so would follow your
suggestion. Would it need a new edition of TTML2
Nigel: We're in CR for a new update of TTML2 anyway, would like
to do a new snapshot at some stage
Nigel: Any objections to me proposing that additional wording?
SUMMARY: @nigelmegitt to propose a pull request for this change
Nigel: I'll create a pull request
TPAC 2024
Nigel: Chris reminded me that the deadline for requesting
meeting time is 20 May. We don't have a meeting before then
Atsushi: There's a WBS form to fill in before the deadline
Nigel: I'll assume we'll have a meeting. Gary and I will think
about joint meetings
… In the past we've met with CSS, but nothing has advanced, so
may not need to
… APA and MEIG, which was useful. Also MEIG is useful
… I'd hope to be in an advanced stage with DAPT, so would be
keen to do that
Cyril: What about the group that does SSML
Atsushi: There may be a CG, don't think there's a WG
<atsushi> [21]https://www.w3.org/Voice/
[21] https://www.w3.org/Voice/
Nigel: Worth discussing overlap with DAPT
Cyril: Yes, but generally speech and voice mixing
Nigel: When we met with APA WG they were thinking about
embedding speech directives in to HTML, they had a couple of
different models
… So would be worth talking with them
… Do we need anything from Media WG
… Timed Text in MSE always comes up
Andreas: The last MEIG meeting briefly discussed requirements
for subtitles in immersive environments. We could see if
there's a need to discuss between the groups on that
Chris: That came from Jer at Apple.
… There's not really a MediaWG item on that.
… It was more a gap analysis that Apple had done.
… It's not something MediaWG has taken on.
… It would be exploratory. There's no home for it yet as far as
I know.
… It may not be a joint meeting with the WG as the most
appropriate mechanism.
… It might be better in a TTWG meeting, or a breakout.
… I'm happy to help and contact Jer about what he'd want to do
with that.
… At the time we discussed it in the WG we didn't really
determine the next steps.
… It was more being raised for awareness.
… We could pull it into an MEIG joint meeting type of thing
Nigel: Any Community Groups to reach out to, probably the AD
group
group: discussion of the WBS poll and how to arrange joint
meetings
Gary: I can fill in the WBS poll and ping you with any
questions Nigel
Nigel: Thank you
Chris: You can specify timeslots and flexibility re meeting
times for joint meetings.
… That means that one of the groups in the joint meeting needs
to request a timeslot,
… or we need to point out the timeslot for the joint meeting.
Nigel: TPAC is 23-27 September
… Not aware that it's adjacent to other events
Pierre: Don't see anything major in my calendar
Nigel: So we probably can be flexible
CCSubs report
<atai> [22]https://ccsubs.org/nab-2024-meetup/
[22] https://ccsubs.org/nab-2024-meetup/
Andreas: We could discuss another time, and about a follow up
meeting in Berlin on June 10
<atai> [23]https://ccsubs.org/mws-2024-meetup-registration/
[23] https://ccsubs.org/mws-2024-meetup-registration/
Nigel: I'd encourage everyone to think about getting more
interoperability in the market
Chris: and to read the report - it's concise, and tells you the
key points.
Meeting close
Nigel: Thanks everyone, we've hit time. Let's adjourn [adjourns
meeting]
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Received on Thursday, 9 May 2024 16:52:30 UTC