IRC log of tt on 2026-05-07

Timestamps are in UTC.

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logging to https://www.w3.org/2026/05/07-tt-irc
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RRSAgent, make logs Public
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Meeting: Timed Text Working Group Teleconference
14:58:01 [nigel]
Agenda: https://github.com/w3c/ttwg/issues/333
14:58:08 [nigel]
scribe: nigel
14:58:33 [nigel]
Previous meeting: https://www.w3.org/2026/04/23-tt-minutes.html
14:58:40 [nigel]
rrsagent, make minutes
14:58:41 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html nigel
14:59:48 [nigel]
Present: Nigel
15:00:19 [nigel]
Regrets: none
15:02:48 [nigel]
Present+ Chris_Needham, Pierre, Andreas
15:03:06 [cpn]
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Topic: This meeting
15:03:42 [cpn]
scribe+ cpn
15:03:44 [atai1]
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15:03:58 [nigel]
Present+ Gary
15:04:03 [nigel]
Chair: Nigel, Gary
15:05:50 [cpn]
Nigel: (reviews the agenda). Anything else to add, or make sure we cover?
15:06:08 [cpn]
Andreas: Start discussion about TPAC meeting this year
15:06:18 [cpn]
present+ Atsushi
15:06:30 [nigel]
Present+ Atsushi
15:07:27 [nigel]
Topic: DAPT
15:08:23 [nigel]
Subtopic: Profile identifier and TTML registry 23c/dapt#248
15:08:31 [nigel]
github: https://github.com/w3c/dapt/issues/248
15:08:36 [atsushi]
s/sorry, back. BT earphone was on and heard voice, but baby cried in bed...//
15:08:44 [cpn]
s/23c/w3c/
15:09:16 [cpn]
Nigel: In preparing a PR for the TTML profile registry for DAPT, I noticed we have two profile designators, for the content profile and the processor profile
15:10:01 [cpn]
... I don't recall why, though. And I notice we don't do this in TTML or IMSC, where we have a single profile designator that can be used for either
15:10:27 [cpn]
... Does anyone have any views? If we want to change to be a single profile designator, it would be a substantive change, requiring a new CRD
15:10:59 [cpn]
... But from the point of view of the profile registry, we'd have processor profiles with a different value than would appear in the DAPT documents. It's formally correct, but weird
15:12:19 [cpn]
.... The media type and profile registry contains profile identifiers as short codes, then a URN as designator and a specification
15:12:41 [atai1]
+1
15:12:46 [cpn]
... For DAPT we'd have a processor profile identifier and content profile identifier that are kind of for the same thing, but kind of not. Does that help us in general?
15:12:47 [nigel]
ack at
15:13:24 [cpn]
Andreas: How do we expect people to use the designators?
15:13:59 [cpn]
Nigel: In the TTML profile registry and the codecs parameter, it's less clear what they should do. They could put in a processor profile
15:14:36 [cpn]
... But they could specify a codecs value set to the content profile, even though the intent of that is to specify the kind of processor that can process the document, in which case you should use the processor profile
15:15:12 [cpn]
Andreas: Formally it's correct to handle DAPT in the same way
15:15:30 [cpn]
... No strong view, but it would be easier to follow a certain pattern
15:15:51 [cpn]
Nigel: It can be done either way. So you suggest easier to have a single designator that can be used as either?
15:16:04 [cpn]
Andreas: Yes, just follow what we did before and have one designator
15:16:23 [cpn]
... But i wouldn't oppose having two, if there are good arguments for that
15:16:46 [cpn]
Nigel: PRs 103 and 104 relate to this
15:17:35 [cpn]
... 103 moreso than 104
15:17:40 [cpn]
... I need to look more into the history of how we got here, but that's useful input, Andreas
15:17:43 [cpn]
... Any other views?
15:17:48 [cpn]
(nothing)
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15:18:31 [cpn]
rrsagent, draft minutes
15:18:33 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html cpn
15:18:43 [cpn]
rrsagent, make log public
15:19:38 [nigel]
SUMMARY: @nigelmegitt to look again at #104, input from @cconcolato welcome, could be the best option is to use a single designator
15:20:01 [nigel]
Topic: IMSC 1.3
15:21:52 [cpn]
Nigel: The poll ends in 8 hours. Please vote if you haven't already
15:23:03 [nigel]
Topic: TTML Media Type Definition and Profile Registry
15:23:33 [cpn]
Nigel: There are 6 open issues and 5 PRs to address them. Please review those.
15:23:42 [nigel]
-> https://github.com/w3c/tt-profile-registry/pulls Pull Requests
15:24:40 [cpn]
Nigel: There was a question about an IRT document that I think is now owned by ARD. We should update the contact information, any update Andreas?
15:24:49 [cpn]
Andreas: What's the timeline for doing it?
15:25:15 [cpn]
Nigel: It's only a note, so can be whenever
15:25:41 [cpn]
... I might create a separate issue for the contact info so we can merge the URL change
15:26:55 [cpn]
... (Reviews the PRs)
15:28:02 [nigel]
Topic: WebVTT
15:28:59 [cpn]
Gary: There's a call for consensus which passed. Next steps? Atsushi has a couple of PRs, but is anything else needed?
15:29:38 [cpn]
Atsushi: I updated a PR with the boilerplate. Once that's merged we can run streamlined publication of the CRD
15:29:44 [nigel]
-> https://github.com/speced/bikeshed-boilerplate/pull/197 Bikeshed WebVTT boilerplate change PR
15:29:58 [nigel]
q+
15:30:12 [cpn]
Gary: Once the bikeshed PR goes through, we can update the WebVTT PR to use that, which will unblock everything?
15:30:48 [cpn]
Atsushi: Yes, or we can merge the WebVTT one first
15:31:59 [cpn]
Nigel: The text that appears in CR for WebVTT, including the exit criteria, which is different to what we've had before. I think it's fine. It has more specific CR exit criteria in the charter
15:32:44 [cpn]
... Is anything more specific for what that means for WebVTT? I welcome views on whether it should say more about what it means in the context of WebVTT
15:33:02 [cpn]
Gary: It's generic text for the WG
15:33:38 [cpn]
Atsushi: We could remove this from the boilerplace and put the exit criteria in the spec itself
15:34:09 [cpn]
... I believe there's no strict requirement to say anything specific about the exit criteria in the boilerplate
15:34:22 [cpn]
Gary: Pointing to the charter sounds reasonable, rather than duplicating the text
15:35:20 [cpn]
Nigel: It's simpler to do that, which is good. Does any other CR do this? Will it cause any friction for other groups?
15:35:58 [cpn]
... Such as horizontal review groups, or AC reviewers, I mean
15:37:06 [cpn]
Atsushi: The AC reviews the charter itself, so following the charter should be fine. The standard checklist is quite welcome for browser specs
15:37:37 [cpn]
Nigel: We forgot to put exit criteria in IMSC, so we put them in the implementation report, and there weren't any issues
15:37:53 [cpn]
Atsushi: The implementation report will be reviewed when we go to AC review
15:38:40 [cpn]
Gary: To summarise, we need to review the bikeshed boilerplate PR. Once merged, that'll unblock the WebVTT spec changes
15:38:56 [cpn]
... Any other WebVTT topics to discuss?
15:39:09 [cpn]
(nothing)
15:39:44 [cpn]
Gary: One thing to mention, when James was summarising the attributes block discussion last time, he realised there are some edge cases we didn't address.
15:40:11 [cpn]
... For example, custom attribute names, and we decided to require a hyphen in them, but we didn't address whether we want to disallow names that start with a hyphen.
15:40:43 [cpn]
... There's a couple more, not major issues. But if anyone has time to review, or if you have thoughts now?
15:41:15 [cpn]
Nigel: It's a common pattern to prefix with a hypen, e.g., CSS property names, so it seems there's precedent for it
15:41:26 [cpn]
... Any lessons from that experience?
15:42:13 [cpn]
Gary: I don't see downsides. The only reason not to allow it is if we wanted a get attributes method to camel-case the attribute name
15:42:31 [cpn]
... But I don't think that's a strong case
15:42:57 [cpn]
Nigel: The expectation should be that the attribute keys should be portable into an HTML attribute
15:43:35 [cpn]
... What should the behaviour be if the WebVTT attribute has a syntax you can't use in an HTML attribute?
15:44:02 [cpn]
Gary: Use the JavaScript API. We've discussed a getAttributes() API
15:45:07 [cpn]
Nigel: Now I'm in two minds whether it's a good or a bad thing.
15:45:44 [cpn]
... There must be constraints on the JavaScript properties to avoid name conflicts
15:46:29 [cpn]
Gary: We could return a map object instead of a plain JS object. Good to look at how CSS handles properties starting with a hyphen
15:46:53 [cpn]
... But I'm inclined to allow such properties at the moment
15:47:22 [cpn]
... Or be more strict initially, and relax later
15:47:46 [cpn]
Nigel: In the absence of other guidance, it seems that's the WebVTT way
15:47:50 [cpn]
Gary: Sounds good.
15:48:16 [nigel]
s/other guidance/specific use cases
15:48:28 [cpn]
Gary: To summarise, look at how CSS handles camel casing of properties and whether it makes sense to use the same mechanism. Otherwise, start stricter and relax later
15:48:54 [nigel]
Topic: Impact of AI technologies on Timed Text Working Group's mission
15:49:25 [nigel]
-> https://github.com/w3c/webai-roadmap/issues/37 Team request for input
15:49:59 [cpn]
Atsushi: W3C is gathering information on the impact of AI on WGs. Any comment, please add to the issue
15:51:07 [cpn]
Nigel: I'm a bit puzzled. (Reads the group's mission in the charter.)
15:51:40 [cpn]
... We're defining interchange formats, and we don't say anything about how they're produced or consumed. Nobody has asked for AI specific changes so far
15:52:04 [cpn]
... So from that point of view, there's no obvious change needed to our mission
15:52:13 [atai1]
q+
15:52:14 [cpn]
... Interested to hear other views
15:52:25 [cpn]
ack n
15:52:33 [nigel]
ack at
15:53:19 [cpn]
Andreas: No particular proposal, but there have been discussion about metadata that should be carried with timed text, verify how timed text can be used in this context.
15:54:04 [cpn]
... One thing that's related, use timed text formats to transport timed metadata instead of timed text
15:54:18 [cpn]
... Not sure if we want to cover that use case, but people do use the formats in that way
15:54:38 [gkatsev_cloud]
q+
15:55:15 [cpn]
Nigel: If something additional is needed related to AI, people would be asking for it. We haven't heard so far
15:55:40 [cpn]
Andreas: There may be requirements from people not in the group, though
15:56:42 [cpn]
... There was the question of interoperable metadata, e.g., the quality of generated text based on the AI engine. How TTML is used in this context could be improved, but not necesasrily something the group needs to work on. Would be good to verify that
15:57:39 [cpn]
Nigel: A question I'd have for Dom, who raised the issue, is how tightly scoped to the mission in the charter is the question? Or is he more interested in other things that may be relevant?
15:58:43 [cpn]
Atsushi: I believe the intent is to gather any related impact, so AI related metadata could be an impact. If it's not in the scope of the charter, we could list them as potential impacts
16:01:41 [cpn]
Chris: It may be broader, relating to production and consumption of timed text in general
16:02:30 [cpn]
Gary: One thing that could be helpful, is having mixed timed text and metadata content in the same file, which is doable in TTML now, but not in WebVTT
16:02:55 [cpn]
...We're adding attributes for file-level metadata, which could be used to note the content is AI generated
16:03:07 [cpn]
... But it doesn't change the group's mission
16:03:12 [cpn]
Nigel: I agree
16:03:43 [nigel]
Topic: Meeting close
16:03:52 [nigel]
Nigel: Thank you everyone, we're at time.
16:04:35 [nigel]
.. Next meeting is in 2 weeks, 2026-05-21, agenda is w3c/ttwg#339
16:04:39 [nigel]
.. [adjourns meeting]
16:04:46 [nigel]
rrsagent, make minutes
16:04:48 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html nigel
16:20:54 [nigel]
s/WebVTT boilerplate/TTWG boilerplate
16:22:29 [nigel]
rrsagent, make minutes
16:22:30 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html nigel
16:23:19 [nigel]
s/sorry, back. BT earphone was on and heard voice, but baby cried in bed...//
16:23:22 [nigel]
rrsagent, make minutes
16:23:23 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html nigel
16:24:00 [nigel]
scribeOptions: -final -noEmbedDiagnostics
16:24:07 [nigel]
zakim, end meeting
16:24:07 [Zakim]
As of this point the attendees have been Nigel, Chris_Needham, Pierre, Andreas, Gary, Atsushi
16:24:09 [Zakim]
RRSAgent, please draft minutes v2
16:24:10 [RRSAgent]
I have made the request to generate https://www.w3.org/2026/05/07-tt-minutes.html Zakim
16:24:16 [Zakim]
I am happy to have been of service, nigel; please remember to excuse RRSAgent. Goodbye
16:24:17 [Zakim]
Zakim has left #tt
16:24:21 [nigel]
rrsagent, excuse us
16:24:21 [RRSAgent]
I see no action items