IRC log of tt on 2024-08-29

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logging to https://www.w3.org/2024/08/29-tt-irc
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Meeting: Timed Text Working Group Teleconference
15:00:35 [nigel_]
Agenda: https://github.com/w3c/ttwg/issues/289
15:00:56 [nigel_]
Previous meeting: https://www.w3.org/2024/08/15-tt-minutes.html
15:02:56 [nigel_]
scribe+ nigel_
15:05:27 [nigel_]
Regrets: Gary
15:05:48 [nigel_]
Present: Nigel, Pierre, Matt, Cyril
15:06:15 [nigel]
scribe+ nigel
15:06:19 [nigel]
rrsagent, make minutes
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I have made the request to generate https://www.w3.org/2024/08/29-tt-minutes.html nigel
15:06:29 [cpn]
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present+ Chris_Needham
15:06:48 [nigel]
Topic: This meeting
15:07:25 [cpn]
scribe+ cpn
15:07:44 [cpn]
Nigel: DAPT, IMSC, and TPAC. Anything else?
15:08:00 [cpn]
(nothing)
15:08:23 [cpn]
Topic: DAPT
15:09:01 [nigel]
Subtopic: Add section about mapping from TTML to the DAPT data model w3c/dapt#216
15:09:06 [nigel]
github: https://github.com/w3c/dapt/pull/216
15:09:32 [cpn]
Nigel: Is there anything left?
15:10:06 [cpn]
Cyril: The PR as a whole makes sense, it's good and consistent. We're making it more complicated by allowing flexibility on use of nested divs
15:10:14 [cpn]
.... for a potential future use case
15:10:44 [cpn]
... Pierre suggested making breaking changes for new requirements
15:10:58 [cpn]
... I suggest reflecting on that during the PR phase, and based on feedback
15:11:15 [cpn]
... I'd like the ability to roll back the nested divs if too complicated in implementation
15:11:25 [cpn]
Nigel: I don't mind marking it as at risk
15:11:58 [cpn]
Cyril: Could mark nested divs as being prohibited
15:12:56 [cpn]
Nigel: We could, my only hesitation is that removing it would mean also removing other things, so it would have a bigger editorial impact
15:13:10 [cpn]
... But that's find, and good to get the implementer feedback, and mark it is at risk
15:13:32 [cpn]
... and see how things go
15:13:58 [cpn]
Nigel: I'd prefer to add the at-risk feature separately
15:14:13 [cpn]
s/separately/in a new issue/
15:14:40 [cpn]
... I just created issue #237 for that
15:15:09 [cpn]
... Any other comments on this PR before merging?
15:15:38 [cpn]
Cyril: Thank you for the work on it
15:16:42 [nigel]
SUMMARY: Pull request merged
15:16:47 [nigel]
Subtopic: Issues review
15:17:14 [cpn]
Cyril: We have a few issues that are duplicates, and some at risk, audio resources related
15:17:34 [cpn]
... For example, #113
15:18:29 [cpn]
Nigel: There are question issues, referenced in the spec, then adding at-risk status issues. Those are marked as PR must-have. We'd decide on those at PR time
15:21:12 [cpn]
Cyril: [Reviews CR must-have issues]
15:21:33 [cpn]
Nigel: I'd like us to attempt to raise PRs for those CR must-have issues, so ready to resolve at TPAC
15:23:33 [cpn]
Cyril: Script events, represents attribute or xml id
15:23:57 [cpn]
Nigel: I'm thinking about document verbosity and inheritance of these properties
15:24:36 [cpn]
... There's a combinatorial thing, if represents replaces the script event type. What if they don't agree with each other
15:24:52 [cpn]
... Painful if you have to inspect the entire document
15:25:18 [cpn]
... Should it be reasonable to omit event type or represents? Then you'd need some other way
15:26:06 [cpn]
Cyril: What if any div that's a leaf is a script event? And then you inherit the script type or represents, and change it locally if needed
15:26:14 [cpn]
Nigel: So a leaf doesn't contain any div elements?
15:26:16 [cpn]
Cyril: Yes
15:26:59 [cpn]
Nigel: Another thing about xml id, in operational scenarios, trying to identify to someone where a document change is needed, the xml id makes it unambiguous
15:27:14 [cpn]
... So guiding people to use xml id encourages good practice
15:27:26 [cpn]
Cyril: You may also want to identify groups by xml ids
15:28:16 [cpn]
Nigel: Yes. The other way is to be explicit, e.g., dt, script event or script event group. But then you require it on every div...
15:28:46 [cpn]
Cyril: I'd change the PR to remove the part that requires mandatory properties of a script event. So only leaf divs are script events
15:29:20 [cpn]
... At the same time remote the script event type property and use represents, and explicitly override if you don't want the inherited value
15:30:34 [cpn]
Cyril: The same inheritance rules as xml:lang
15:30:58 [cpn]
Nigel: ttm:role has a different inheritance model
15:31:16 [cpn]
Cyril: We can work on a concrete proposal for the spec text
15:31:31 [cpn]
Nigel: Need to think about making it mandatory
15:32:12 [cpn]
... Good discussion. We have a target to request CR transition at TPAC
15:33:15 [nigel]
... Any other DAPT topics?
15:33:21 [nigel]
no other topics
15:33:26 [nigel]
Topic: IMSC
15:33:44 [nigel]
Subtopic: Superscript/subscript support w3c/imsc#583
15:33:52 [nigel]
github: https://github.com/w3c/imsc/issues/583
15:34:21 [cpn]
Pierre: This was brought to my attention by a platform that has a presence in France
15:34:54 [cpn]
... There's no way to signal superscript or subscript text. It's an issue in French more than in English for ordinal numbers, where it's better to use superscript
15:35:17 [cpn]
... It's in their style guide as something that should be supported
15:35:49 [cpn]
... I looked into it, and there is a TTML2 font-variant attribute that allows super/subscript glyphs to be selected for a particular font
15:36:01 [cpn]
... The spec says it's derived from the equivalent CSS feature
15:36:12 [cpn]
... It's not a layout feature, it's a glyph-selection feature
15:36:25 [cpn]
... I tried it in CSS, but couldn't find a font that supports it
15:36:34 [cpn]
... So I tried to find where the TTML2 feature came from
15:37:04 [cpn]
... An issue raised 10 years ago, based super/subscript support in CEA 708
15:37:32 [cpn]
... I'm not convinced tts:font-variant is the answer, but I'd like input, so we do it right
15:37:55 [cpn]
... Unicode does have super/subscript characters, but not enough coverage for all ordinals, or not meant to be used that way
15:38:35 [cpn]
Nigel: I researched how you'd do this in HTML and CSS. There seem to be two ways:
15:39:08 [cpn]
... The <sup> and <sub> elements, but there's also a CSS vertical-align feature where you can set the baseline of an element
15:39:44 [cpn]
... Parents have a subscript baseline and a superscript baseline and on inline elements you can set to one or other of those
15:40:03 [cpn]
... So there are two ways, I don't know if one is better than the other
15:40:11 [cpn]
Pierre: The HTML elements are widely used
15:40:23 [cpn]
Nigel: Every browser supports vertical-align too
15:41:00 [cpn]
... You can understand tts:vertical-align being a TTML style attribute, whereas introducing new elements isn't very TTML-ish
15:41:45 [cpn]
Pierre: One option, if we decide tts:font-variant isn't great because of it's mapping to CSS font-variant, we could redefine the mapping to something else
15:42:12 [cpn]
... tts:font-variant was introduced to support superscript and subscript
15:42:54 [cpn]
Nigel: The CSS font-variant selects glyphs but doesn't change their position, but if you want to change the alignment then you should use vertical-align
15:43:32 [cpn]
... Sounds not ideal to have a TTML style property that does something different to the CSS style of the same name
15:43:53 [cpn]
Pierre: I agree, but not sure why we went with that at the time
15:44:25 [cpn]
Nigel: A possibility could be to use a font variant
15:45:06 [nigel]
s/font variant/font explicitly defined to include glyphs with super/sub font variant forms
15:45:24 [cpn]
Pierre: Potential next steps: confirm it's a real issue, think about how to fix
15:45:54 [cpn]
Nigel: Yes, and by "real issue" do you mean that there's no workaround
15:46:21 [cpn]
Pierre: Yes, but also if there are subtitle guidelines to discourage use of super/subscript
15:46:38 [cpn]
... The fact it's in CEA708 gives us a good reason to support it
15:46:56 [cpn]
Nigel: Do you have any input on the accessibility of super/subscript text?
15:47:38 [cpn]
Pierre: Yes, the people in France where wondering why they couldn't do it, probably following a guideline for PNG based subtitles
15:48:16 [cpn]
... My sense is they're incentivised to help. Maybe give some time, to after IBC, then think about how to fix?
15:48:41 [cpn]
Nigel: Could be a topic for TPAC as well, need to think about things that affect TTML and IMSC together
15:48:49 [cpn]
Nigel: Any other thoughts on this?
15:49:08 [cpn]
Cyril: I'm enquiring internally on the importance, so will update you
15:49:19 [cpn]
Nigel: I don't expect BBC to have any data points
15:50:06 [cpn]
... I could ask the EBU media access technology group. If you're a member, you could ask on their reflector
15:50:31 [cpn]
... It's a good forum for input on non-English European languages
15:50:55 [cpn]
Pierre: I can ask there, possibly also on social media
15:51:06 [cpn]
Nigel: Thanks
15:51:12 [nigel]
SUMMARY: Investigation into requirements to continue, agenda+ for TPAC
15:51:19 [nigel]
Topic: TPAC 2024
15:51:43 [nigel]
-> https://www.w3.org/wiki/TimedText/tpac2024 TTWG TPAC wiki page
15:51:57 [cpn]
Nigel: I created a wiki page for the TPAC agenda and logistics
15:52:14 [cpn]
... Please add yourself to the table if you'll be participating
15:52:26 [cpn]
... Goals for this year's TPAC:
15:52:36 [cpn]
... Move forward with DAPT, agree to publish CR
15:53:24 [cpn]
... Decide what to do with TTML2. It seems to be static, nobody actively editing. I want to be able to push it on. It could need another editor, to get it to Rec
15:53:36 [cpn]
... Joint meetings with MEIG and APA WG, seems vague
15:53:45 [cpn]
... Future topics
15:54:01 [cpn]
... I have a list of topics, but not mapped to specific timeslots
15:54:56 [cpn]
... Will we really have a MEIG/TTWG joint meeting, then on Friday another one: APA/TTWG/MEIG
15:55:28 [cpn]
... Talking with Chris, that seems to be the intent
15:55:39 [nigel]
cpn: They're different things. The Friday one was at the request of APA.
15:55:53 [nigel]
.. The Monday one was to bring TT and MEIG together as we've done before.
15:56:04 [nigel]
.. It's up to you what you would like the agenda for that session to be.
15:56:30 [nigel]
.. If you don't need all of the time then more time for MEIG specific topics would be helpful.
15:56:34 [nigel]
.. Depends on what you'd like to cover.
15:56:48 [nigel]
.. The Friday session: I haven't had a response from APA about what they'd like to talk about.
15:56:50 [nigel]
.. It's their request.
15:57:12 [nigel]
.. There may be some MediaWG things I could bring, like specs that will need horizontal review, that
15:57:27 [nigel]
.. we could introduce. At this stage I'm unclear as to what we want to use that time for.
15:58:08 [cpn]
Nigel: On the Monday meeting, we'd like to share current TTWG status, show the design and intent for DAPT, to circulate that more widely
15:58:16 [cpn]
... There are likely to be more MEIG people on the Monday than the Friday
15:58:31 [cpn]
... We also talked about raising captions in MSE
15:59:14 [cpn]
... If talked with BBC colleagues, and they see a potential advantage in code simplicity and buffer management, even if the rendering is dealt with separately
15:59:44 [cpn]
... That's enough to justify the meeting on its own
16:00:07 [cpn]
... I'll write it into the agenda
16:00:37 [cpn]
Cyril: So if someone is only interested in TTWG, meetings are on Monday, Thursday, Friday?
16:01:05 [cpn]
Nigel: I'm considering being remote on Monday, then travelling for Friday. I could come on the Thursday if we need an editing session
16:01:15 [cpn]
s/Nigel:/Cyril:/
16:01:21 [cpn]
Nigel: I think that would be helpful
16:01:48 [cpn]
... There's a joint meeting with Audio Description CG on Thursday morning
16:02:22 [cpn]
Nigel: I don't know what input we'll get from the AD CG, so could be an editing session
16:19:21 [nigel]
rrsagent, make minutes
16:19:22 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/08/29-tt-minutes.html nigel
16:20:02 [nigel]
s/But that's find/But that's fine
16:20:59 [nigel]
s/xml id/xml:id/g
16:21:39 [nigel]
s/dt, script event/a dt attribute, with different values for script event
16:21:59 [nigel]
s/remote the script event/remove the script event
16:22:29 [nigel]
s/has a different inheritance model/has a different inheritance model so we do need to be clear about the inheritance model
16:23:54 [nigel]
s/no workaround/no workaround?
16:24:14 [nigel]
s/France where wondering/France were wondering
16:25:41 [nigel]
s/If talked with BBC/I have talked with BBC
16:26:03 [nigel]
Topic: Meeting close
16:26:16 [nigel]
Nigel: Thanks all, we're a couple of minutes over. [adjourns meeting]
16:26:20 [nigel]
rrsagent, make minutes
16:26:21 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/08/29-tt-minutes.html nigel
16:27:12 [nigel]
scribeOptions: -final -noEmbedDiagnostics
16:27:24 [nigel]
Chair: Nigel
16:27:35 [nigel]
zakim, end meeting
16:27:35 [Zakim]
As of this point the attendees have been Nigel, Pierre, Matt, Cyril, Chris_Needham
16:27:37 [Zakim]
RRSAgent, please draft minutes v2
16:27:39 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/08/29-tt-minutes.html Zakim
16:27:45 [Zakim]
I am happy to have been of service, nigel; please remember to excuse RRSAgent. Goodbye
16:27:45 [Zakim]
Zakim has left #tt
16:27:58 [nigel]
rrsagent, excuse us
16:27:58 [RRSAgent]
I see no action items