IRC log of tt on 2024-04-11

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Meeting: Timed Text Working Group Teleconference
15:01:33 [nigel]
Agenda: https://github.com/w3c/ttwg/issues/279
15:01:40 [nigel]
Previous meeting: https://www.w3.org/2024/03/28-tt-minutes.html
15:01:43 [nigel]
scribe: nigel
15:01:58 [nigel]
Present: Atsushi, Nigel, Pierre
15:02:38 [nigel]
Present+ Gary
15:02:46 [nigel]
Chair: Gary, Nigel
15:02:54 [nigel]
Present+ Matt
15:03:09 [nigel]
Topic: This meeting
15:03:50 [nigel]
Nigel: Today we have IMSC-HRM and a couple of pull requests on DAPT.
15:04:07 [nigel]
.. Anything else for the agenda, or points to make sure we get to?
15:04:19 [nigel]
Present+ Cyril
15:04:50 [nigel]
Cyril: AOB - NAB is coming and we're organising an event we can mention
15:04:53 [nigel]
Nigel: Thank you
15:05:07 [nigel]
Topic: IMSC-HRM
15:05:36 [nigel]
Nigel: The AC Review poll closed, no objections.
15:05:55 [nigel]
.. I think we need a pull request to address the proposed changes?
15:06:37 [nigel]
Atsushi: Yes. I believe we are waiting. Once the pull request is raised and all comments are satisfied
15:07:00 [nigel]
.. we can go to publication. The changes are just suggestions and are all editorial,
15:07:12 [nigel]
.. so it would be possible to go directly to Rec but it would be better to deal with the suggestions and comments.
15:07:35 [nigel]
Nigel: Pierre, are you okay to open a pull request for those?
15:07:49 [nigel]
-> https://github.com/w3c/imsc-hrm/issues/79 A few minor editorial suggestions w3c/imsc-hrm#79
15:08:03 [nigel]
Pierre: I was just waiting to make sure there were no other comments.
15:08:11 [nigel]
.. I will prepare the pull request straight away.
15:08:15 [nigel]
Nigel: Thank you.
15:08:22 [nigel]
.. Anything else to say about this?
15:08:38 [nigel]
nothing more
15:08:45 [nigel]
Topic: DAPT
15:09:16 [nigel]
-> https://github.com/w3c/dapt/labels/agenda Issues labelled "agenda"
15:10:05 [nigel]
Nigel: We discussed these two last time but there were no concrete actions,
15:10:19 [nigel]
.. and we said we would continue the discussion on the pull requests, but we didn't actually do that,
15:10:26 [nigel]
.. so I put them back on the agenda. Hope that's ok!
15:11:26 [nigel]
Subtopic: Replace workflowType with represents w3c/dapt#217
15:11:36 [nigel]
github: https://github.com/w3c/dapt/pull/217
15:12:07 [nigel]
Matt: Apologies, I didn't notice anything coming through to me for the review request.
15:13:08 [nigel]
Nigel: This is about replacing workflowType with represents as a list of the content types that
15:13:11 [nigel]
.. the document represents.
15:13:30 [nigel]
.. Last time we talked we agreed to make the <content-descriptor> into a Registry Table,
15:13:35 [nigel]
.. and I made that change after the call.
15:14:18 [nigel]
.. We also had it as "alternativeFor" last time and had agreed to change that into "represents" which I also did.
15:15:31 [nigel]
Matt: [recalls the discussion, agrees with the intent]
15:15:49 [nigel]
Nigel: The question for me now is do I go ahead and merge now or wait for a review and
15:15:54 [nigel]
.. take appropriate response on the basis of that.
15:16:01 [nigel]
Matt: I feel I need to read it.
15:16:19 [nigel]
Cyril: I don't have any change to my pull request approval.
15:17:06 [nigel]
.. Just wondering about the granularity of the "represents", could we use represents on Script Events?
15:17:14 [nigel]
Nigel: Further down the tree?
15:17:27 [nigel]
Cyril: Yes, if you want to know which Script Events actually correspond to each type, we already have
15:17:41 [nigel]
.. Script Event Description which is human readable, and we have Script Event Type that has a Registry,
15:17:56 [nigel]
.. but the values don't align - we have dialogue, spoken text, on screen text...
15:19:06 [nigel]
Nigel: Ooh I hadn't thought of that. Looking at it, I agree, it seems like this could be one list.
15:19:51 [nigel]
Matt: I'm happy with the general approach.
15:20:51 [nigel]
Cyril: I'm thinking - if you were to replace the values of represents by the values of Script Event Type...
15:21:08 [nigel]
.. If you made a set of the Script Event Types in the document, would that work?
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15:22:13 [nigel]
Nigel: I see 3 options.
15:22:31 [nigel]
.. 1. What you said Cyril, allow the event type values to be coalesced into represents at the document level.
15:23:22 [nigel]
.. 2. Add a mapping from event type into a simpler smaller set of represents values, e.g. title and OnScreenText in event type
15:23:31 [nigel]
.. both map to visualText in represents.
15:24:06 [nigel]
.. 3. Replace eventType with represents and use the same registry table for both.
15:24:24 [nigel]
.. The nuance is that represents allows a list, whereas eventType maybe should be a single value.
15:25:00 [nigel]
Cyril: Sorry I only noticed this now. Also the registry table for script event type needs some descriptions.
15:25:13 [nigel]
.. I like the idea of the column for mapping to represents.
15:25:41 [nigel]
.. I was wondering what the point of spokenText is?
15:25:56 [nigel]
Nigel: We spent no time looking at the registry table values for event type, they're just example values.
15:26:07 [nigel]
Cyril: I agree those are the three options, I don't have a strong view.
15:26:23 [nigel]
.. You may not want the same granularity of description at the document level as at the script event type.
15:26:34 [nigel]
Nigel: That's why I was thinking of the mapping idea.
15:27:16 [nigel]
.. I think that if we want to do the mapping, that would be a new issue and pull request.
15:27:32 [nigel]
Cyril: A 4th option is to not have the document level summary at all but inspect the document contents
15:27:35 [nigel]
.. to see what it contains.
15:27:47 [nigel]
Nigel: That's true, but...
15:28:03 [nigel]
Cyril: In the workflow you want an early indication of the potential uses of the document.
15:28:14 [nigel]
Nigel: So you're arguing against that previous point?!
15:28:26 [nigel]
Cyril: Yes, I just wanted to note the possibility in case we want to come back to this in the future.
15:28:51 [nigel]
Nigel: What to do?
15:28:53 [nigel]
.. Options:
15:29:15 [nigel]
.. 1. Merge now and open a separate issue and pull request to deal with mapping from script event type to represents
15:29:33 [nigel]
.. 2. Go round the loop one more time and try to fix this up before merging
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.. 3. Merge now and do nothing about script event type for the time being.
15:30:17 [nigel]
.. By the way we will need to come back to all the Registry Tables at some point to make sue
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.. they have the right values. All of the entries are Provisional right now.
15:30:30 [nigel]
s/sue/sure
15:30:45 [nigel]
.. Any preferences?
15:30:54 [nigel]
.. My preference is to merge now and then incrementally improve.
15:31:01 [nigel]
Cyril: We should have an issue that tracks it then.
15:31:28 [nigel]
Nigel: Do you want to open that then?
15:31:35 [nigel]
Cyril: Doing it now.
15:31:56 [nigel]
Matt: Apologies, got to run to another meeting, please prod me if there's any more review needed. Apologies again for not noticing this one.
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Matt leaves
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SUMMARY: Merge pull request, deal with script event type and represents in a separate issue
15:33:16 [nigel]
Subtopic: Add informative section about mapping from TTML to the DAPT data model w3c/dapt#216
15:33:25 [nigel]
github: https://github.com/w3c/dapt/pull/216
15:35:19 [nigel]
Nigel: From last time, I think the determining factor is if we need a class of DAPT implementation
15:35:34 [nigel]
.. that maps from TTML2 into the DAPT data model. If we do, that means we need to make these
15:35:40 [nigel]
.. provisions normative.
15:35:58 [nigel]
Cyril: Taking a step back, we did this pull request to cover the case that there is a document that
15:36:08 [nigel]
.. conforms to the profile but does not map directly to the DAPT data model.
15:36:28 [nigel]
.. In practice if you have an implementation of DAPT that is "just" DAPT, which I think will be the majority case,
15:36:57 [nigel]
.. then this situation should not happen. You shouldn't end up with a document that cannot be easily mapped.
15:37:03 [nigel]
Nigel: Yes, to a point.
15:37:33 [nigel]
.. The exception could be from the compatibility perspective - some future version of DAPT adds in a feature
15:37:42 [nigel]
.. that we want older DAPT processors to handle gracefully.
15:37:53 [nigel]
.. It's not just about TTML2 generically.
15:37:56 [nigel]
Cyril: You're right.
15:38:28 [nigel]
.. Thinking out loud, if we added constraints like feature extensions to restrict a DAPT document
15:38:41 [nigel]
.. to correspond only to the DAPT data model, what would be the problem? Extensibility?
15:38:47 [nigel]
Nigel: Yes, that would be the main one.
15:39:12 [nigel]
.. It's really the structural issue of divs containing other divs or mixed div and p children.
15:39:23 [nigel]
.. Which we agreed there could be a future use for.
15:39:46 [nigel]
.. If we prohibited that then we wouldn't be able to use that capability in the future without making a
15:39:50 [nigel]
.. breaking version change to DAPT.
15:40:34 [nigel]
.. Maybe we could argue that, to make sure that conformant implementations can deal with those changes,
15:40:42 [nigel]
.. that's why we need to make the informative provisions normative.
15:41:01 [nigel]
Cyril: What about text content anywhere other than p and span?
15:41:13 [nigel]
Nigel: It's allowed in p and span but TTML doesn't allow it anywhere else.
15:41:21 [nigel]
.. Except for metadata elements etc, of course.
15:41:25 [nigel]
Cyril: Ok, thank you.
15:42:38 [nigel]
Nigel: Does that argument about future compat seem correct?
15:42:50 [nigel]
Cyril: Yes. In general I prefer something normative otherwise there won't be interoperability.
15:43:08 [nigel]
.. Does this mean we need a DAPT processor type?
15:43:12 [nigel]
Nigel: No I don't think it does.
15:47:39 [nigel]
Cyril: In §7.2 it defines a DAPT Processor in terms of conformance to the profile provisions and to the document.
15:47:50 [nigel]
.. How would we do that?
15:48:04 [nigel]
Nigel: I'd make extension features referencing the new normative provisions, so it all ties together.
15:48:48 [nigel]
Cyril: I would like to take a stab at re-writing §5 or proposing changes.
15:48:55 [nigel]
Nigel: OK, that's fine, otherwise I'd have done it.
15:49:13 [nigel]
Cyril: Not sure when I'll do it.
15:49:26 [nigel]
Nigel: Why don't I do a first pass, and then you can review it?
15:49:47 [nigel]
Cyril: That's fine.
15:50:09 [nigel]
.. I think we should move the new section 5 to after the Constraints section. We're only concerned
15:50:22 [nigel]
.. with valid documents, which are defined in the Constraints section.
15:50:50 [nigel]
.. I would start by saying that the processing behaviour for a processor processing a valid document that
15:50:59 [nigel]
.. contains additional content not in the DAPT model is the following...
15:51:38 [nigel]
.. Say there may be conformant DAPT docs that contain more, e.g. for a new version, or a round trip through
15:51:41 [nigel]
.. a generic TTML tool.
15:51:50 [nigel]
.. That's how I'd start, by explaining that.
15:52:10 [nigel]
.. Once the context is clear I think it's easier to understand.
15:52:56 [nigel]
Nigel: I think it'll be important to say that the graceful handling feature requirements may be replaced
15:53:39 [nigel]
.. in future versions by something that defines some other behaviour.
15:53:45 [nigel]
Cyril: Did you mention parsing, or just mapping?
15:54:01 [nigel]
Nigel: Just mapping. I think parsing is defined by XML, we're talking about building a data model from the parsed entities.
15:54:04 [nigel]
Cyril: OK
15:54:39 [nigel]
Pierre: Are you going to take the TTML approach of pruning?
15:54:39 [nigel]
Nigel: I don't think so, not quite
15:54:41 [nigel]
Cyril: For validation purposes, yes.
15:54:56 [nigel]
.. But a read/write processor should try to retain unrecognised vocab
15:55:11 [nigel]
Pierre: The reason for mentioning: if the processor sees elements or attributes it does not understand then
15:55:23 [nigel]
.. there's no hope it can understand how to deal with those unknown elements.
15:55:42 [nigel]
.. If you merely preserve them, that doesn't take into account the semantics of the unknown elements.
15:55:57 [nigel]
.. Generally it's not possible unless you specify extension rules such as vocabulary in a particular part of the
15:56:10 [nigel]
.. model does not affect e.g. timing etc.
15:56:41 [nigel]
.. Some things can be preserved with minimal risk, but everything else, it's hopeless.
15:57:03 [nigel]
Cyril: You can have multiple values of profiles in the contentProfiles attribute, but if you write back
15:57:17 [nigel]
.. a file then you shouldn't write back values of contentProfiles that you don't understand.
15:57:52 [nigel]
.. You could end up with semantically incorrect content.
15:58:14 [nigel]
Nigel: Example is an attribute for number of words, doc says 3, editor adds 2, saves the value as 3 because it
15:58:17 [nigel]
.. doesn't understand it.
15:58:31 [nigel]
Pierre: There's a danger of getting rules that are so complex that nobody understands them.
15:58:58 [nigel]
Pierre: The TTML model is blunt but straightforward. Just get rid of everything you don't understand.
15:59:10 [nigel]
.. Maybe some stuff could have been kept, but at least it is predictable.
15:59:20 [nigel]
.. When the author wants the document to be compatible with an older version,
15:59:32 [nigel]
.. do it so that when you strip the newer stuff it's still valid for the older version.
16:00:05 [nigel]
SUMMARY: @nigelmegitt to make edits as discussed, @cconcolato to review, discussion to continue.
16:00:48 [nigel]
Topic: AOB
16:01:12 [nigel]
Cyril: there's an event happening where we're gauging appetite to talk about live captioning,
16:01:25 [nigel]
.. wondering if there's a TTWG view on it. It's on Monday.
16:02:12 [nigel]
Nigel: I don't think I can say anything about this as a Chair because we've not really discussed it in TTWG.
16:02:26 [nigel]
.. But I may be able to say something in my BBC role.
16:02:36 [nigel]
.. Can we take this offline please?
16:03:18 [nigel]
Cyril: Can we add this as an AOB for after the meeting so we can summarise the outcomes?
16:03:21 [nigel]
Nigel: Sounds like a good idea.
16:03:26 [nigel]
Topic: Meeting close
16:03:43 [nigel]
Nigel: We're 3 minutes over, thanks everyone! [adjourns meeting]
16:03:55 [nigel]
rrsagent, make minutes
16:03:56 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/11-tt-minutes.html nigel
16:08:26 [nigel]
scribeOptions: -final -noEmbedDiagnostics
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zakim, end meeting
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As of this point the attendees have been Atsushi, Nigel, Pierre, Gary, Matt, Cyril
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RRSAgent, please draft minutes v2
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I have made the request to generate https://www.w3.org/2024/04/11-tt-minutes.html Zakim
16:08:39 [Zakim]
I am happy to have been of service, nigel; please remember to excuse RRSAgent. Goodbye
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Zakim has left #tt
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rrsagent, excuse us
16:16:08 [RRSAgent]
I see no action items