W3C

Timed Text Working Group Teleconference

07 November 2019

Attendees

Present
Cyril, Gary, Glenn, Nigel, Pierre
Regrets
Atsushi
Chair
Nigel
Scribe
nigel

Meeting minutes

Log: https://‌www.w3.org/‌2019/‌11/‌07-tt-irc

This meeting

nigel has changed the topic to: TTWG weekly webex. Today 1500 UTC. Agenda for 2019-11-07: https://‌github.com/‌w3c/‌ttwg/‌issues/‌77

Nigel: Hi everyone, today we have 3 TTML2 issues/pull requests to discuss.
… Any other business?

group: [no other business]

Nigel: I see Glenn just added a comment to the agenda asking to discuss #1128 first.

Text Combine example is incorrect/misleading. ttml2#1128

github: https://‌github.com/‌w3c/‌ttml2/‌issues/‌1128

Nigel: Looks like there's a collective desire for the image in the example and the text to match each other and show something useful?

Cyril: Yes. I don't mind the text being vague, but at the moment it is wrong because it isn't showing what is happening at all.

Glenn: I disagree with that.

Cyril: It only talks about half-width variants but none are selected in the example.

Glenn: It does have them.
… The AB34 on the right side are half width variants.

Cyril: Unless the image has changed they are quarter width, right?

Nigel: The "AB34" look like they're in one EM square width and heightwise.

Cyril: Yes, so they're not half width variants but quarter width.

Glenn: [thinks] Maybe we should remove the term "half width" entirely.

Cyril: Yes, that's one option.

Glenn: That I think is problematic. I could go back and remove that.

Cyril: Great, that's all I'm asking.

Glenn: Would you be ok with that Pierre?

Pierre: I'm happy with whatever Cyril is happy with!

SUMMARY: @skynavga to remove reference to "half width" for this example.

Clarify undefined semantics for text combine in ruby text (#978). ttml2#1171

github: https://‌github.com/‌w3c/‌ttml2/‌pull/‌1171

Glenn: There appears to be a difference of opinion between myself and Pierre.
… The intent of this was basically to say that in the context of ruby text that text combination has no semantics defined,
… so I had proposed a note that says this version of TTML does not define any semantics for text combine in the context
… of ruby text content and added that presentation processors may ignore text combine (treat as None) in the context
… of ruby text. Pierre doesn't seem to like the second part but I think it's a logical consequence of the first sentence.

Pierre: I'm going to repeat myself, but the second sentence specifies a permission and therefore a semantic so it has
… to be removed.

Glenn: It is in a note so is not normative.

Pierre: Equally it can be removed then.

Cyril: Is it the use of "may" that creates confusion?

Pierre: Yes, absolutely. I think it is true that there are no semantics, so there are none, period.

Glenn: We use "may" in notes.

Pierre: If there is no semantic there should be no suggestion one way or another.

Cyril: What is the intent, to say "don't use them together because you won't get interop"?
… Or that some implementations may do it right and others may not but if you are using conformant implementations
… then you can still use it.

Glenn: Is it the problem that it looks like conformance language.

Pierre: That is not my problem, although it is throughout TTML2, I've said before.

Nigel: Could we water down the second sentence to say "For example, ... could ignore"?

Pierre: And add a contrary example too.

Glenn: either would work for me.

Cyril: Me too, it's okay.

Glenn: We have "for example" elsewhere in notes.

Cyril: That means implementers could expect to encounter content with this.

Glenn: I wouldn't say should expect but it is possible.

Cyril: Is there a defined behaviour?

Glenn: This is there to put authors on notice that they should not expect a particular behaviour.

Cyril: So we should say do not use it.

Glenn: That's going too far.

Pierre: I agree with Cyril, the intent is to warn authors not to use it because the implementation is undefined.

Glenn: We cannot say "should not be used" in a note - we don't do it in a note.
… In many cases we give fair warning to readers that it is inadvisable.
… This is how we do it.

Pierre: Here it is more than that, something could happen, it might not be ignore.

Nigel: We're agreeing about the reality of what is specified, just discussing what the best advice is to readers.

Cyril: Are we agreed to advise people not to use?
… If we agree that because this feature is not specified people should not rely on it or use it because they might get
… any behaviour? If so then we can work on the text.

Glenn: Generally we don't say in TTML that authors should use or not use something. That's a profile question.

Cyril: Do you agree on the intent here, that "unspecified behaviour" means anything could happen?

Glenn: I agree, we don't want users to use something that is undefined.

Cyril: I agree with Pierre that if we hint that it will be ignored people might rely on that.
… We could change the note to say in addition that other processors might do something completely wrong.

Glenn: Let me see if I can come up with some language like an advisory that doesn't say "should not" but takes the
… form of a recommendation to authors not to use it and see how people like that. How's that sound?

Pierre: Sounds good, thank you for considering my comment.

Glenn: Sure.

SUMMARY: @skynavga to propose alternate wording advising non-use of textCombine in the context of ruby

Improve anonymous span prose, generalize ordered rule convention (#1139). ttml2#1179

github: https://‌github.com/‌w3c/‌ttml2/‌pull/‌1179

Glenn: Before we start this, just to point out that this and the next issue today are marked for 3rd Ed so if we keep
… them there then we don't have to deal with them right now.

Nigel: Thank you, that's useful. If we have agreement now we can implement it, otherwise we don't need to stress too
… much about it.

Glenn: To summarise the situation, part of this was about prose to do with anonymous span concerning ordering
… that was possibly vague and we need to be clear about ordering of rules.
… There are two ways to do this. One is to add text directly about ordering like we have in some places,
… or prescribe a general rule about ordered lists and I chose to take the latter route because I realise that everywhere
… we have ordered lists in the text, and where the underlying XML document uses the `<olist>` syntax and it was
… used to define procedural steps it was always intended to be ordered sequentially and we could apply generic text.
… After analysing all the document I found that everywhere that the ordered lists were used for procedures it was
… always intended to be sequential, but that in a number of places where it was enumerating cases that were not
… procedures or steps that no order was implied, i.e. an unordered list of bullets could be used but I had used olist
… in order to allow referring to specific cases as opposed to steps. For example in the list of criteria under
… processor or document conformance we have items that are listed 1 through 3 and so forth that could have been
… bulletted items but then I would have no way to refer to each criterion as a numbered item.
… My proposal was to have a rule that said wherever ordered lists appear in procedures as ordered steps then they
… are always in the indicated order and we can take out any text in the inline prose that talks about it being ordered
… and use the general rule instead. But Nigel I think you have a slightly different opinion that you want it to be defined
… inline instead.

Nigel: Yes, I want to keep the current approach so as to avoid promoting use of unordered lists that lead to a list
… of steps that we cannot then reference. It's useful to know that there's already a case there.

Pierre: My preference is to make fewer changes and just add the "this is an ordered list" text to the one specific list
… that gave rise to the issue and do nothing else. If that's not acceptable then defer this.

Glenn: I was just counting the number of places where there is an ordered list missing the language of ordered steps,
… 31, and the number that could be unordered lists, 10. There's a case that the default rule could apply to ordered
… lists being ordered always, numerically. One option would be to change everything to unordered lists that are criteria
… or cases which would remove the ability to refer to specific cases or criteria unless we name them, which is somewhat
… of a negative.

Nigel: It's a blocker for me.

Glenn: Maybe the best thing is to do as Pierre suggests, to handle this one case specifically by adding the language
… about "ordered" and move this general issue into 3rd Edition.
… Then we can deal with that later.

Cyril: I would like this last proposal, we should not do major changes at this stage. We should not change parts that
… are not broken because we think it would be better.

Glenn: I'm fine with that, it would deal with the immediate issue about span processing.

Nigel: Works for me.

Glenn: OK I will create a new issue regarding the ordering and point at this and create a new PR dealing with just the
… original issue. OK?

Nigel: Any objections?

group: [no]

Glenn: And I'll deal with the original issue in 2nd Ed CR.

SUMMARY: @skynavga to add ordering language to deal with original scope of issue, and raise new issue for general ordering of steps, targeted at 3rd Ed.

Clarify escape in literal convention (#987). ttml2#1173

github: https://‌github.com/‌w3c/‌ttml2/‌pull/‌1173

Nigel: We seem to be trying to escape backslashes here without defining an escape mechanism.
… Perhaps we don't need to do anything here?

Glenn: In TTML2 we introduced something absent from TTML1. In `<quoted-string>` in TTML2 we introduce an
… escaping mechanism.

`<quoted-string>` in TTML2 ED

Nigel: We invoke a backslash in the syntax there.

Glenn: If you look at TTML1 3rd Ed ... It's there.

Nigel: TTML1 3rd Ed has it under `<familyName>`

Glenn: [looks] it's in TTML1 2nd Ed too, maybe I didn't look well enough and it's in 1st Ed too!
… It wasn't in 1st Ed, we added it in 2nd Ed. So it's been around a while, but not in the very beginning. We didn't use it
… in any of TTML1 in the syntax descriptions, we didn't use the double backquote.
… When we normalised the syntax in TTML2 we changed all the literals to string literals; we had used character literals
… with single quotes in TTML1 2nd and 3rd Edition.

Nigel: Why don't we do something really simple here, to say where we use `\\` what we mean is a single backslash?
… The PR has a "for example" but I'm proposing making it not an example, but the rule.

Glenn: Problem is you could escape quotation marks.

Nigel: But we don't

Glenn: But we could

Nigel: But we don't

Glenn: The quotation marks are only significant only after escape processing should ...

Nigel: But it's our choice in the spec if we use that anywhere and I don't believe we do, so we don't need this.

Glenn: Ah I see what you're saying. Are you sure we don't?

Nigel: It's worth checking

Glenn: You're correct we don't at present do that.

Nigel: So the only thing we need to define is that \\ means \ in the document content.

Glenn: Just remove "after escape processing"?

Nigel: Also make the note in 2190-2192 in this PR normal spec text and remove "For example,"

Glenn: Oh I see what you're saying.

Pierre: If I understand, instead of making a blanket statement about escaping, merely state this specific case?

Nigel: Yes

Pierre: I agree with that, it's the simplest and safest approach.

Glenn: OK, regarding lines 2188 and 2189, shall I revert those to the original text?

Nigel: I would say so, yes.

Glenn: Ok so revert those and then change 2190-2193 to normative text and remove the "for example" and that's it.

Nigel: Yes

Glenn: Sounds good, I can do that. I'll change this to 2nd Ed CR milestone.

Nigel: Brilliant, thank you.

SUMMARY: @skynavga to make changes as minuted above.

Meeting close

Pierre: Do you know what is happening with IMSC 1.2 FPWD?

Nigel: I'm not actually sure, I haven't managed to chase that up yet.

Pierre: Let me know how I can help, I'm getting a little concerned that nothing happened this week.

Nigel: Understood.
… For today, we're out of agenda and out of time, so I'll adjourn. Same time next week unless there's a big pile of
… agenda requests in which case we can extend to 2 hours as per normal operation. Thanks for getting through
… so much today everyone. [adjourns meeting]

Minutes manually created (not a transcript), formatted by Bert Bos's scribe.perl version Mon Apr 15 13:11:59 2019 UTC, a reimplementation of David Booth's scribe.perl. See history.