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 w3c/dapt#216
github: https://
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 w3c/ttml2#1247
github: https://
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 w3c/ttml2#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 w3c/ttml2#1271
github: https://
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> https://
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> https://
Andreas: We could discuss another time, and about a follow up meeting in Berlin on June 10
<atai> https://
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]