W3C

Timed Text Working Group Teleconference

01 August 2019

Attendees

Present
Andreas, Atsushi, Atsushi_irc-only, Cyril, Gary, Glenn, Nigel, Philippe, Pierre
Regrets
none
Chair
Nigel
Scribe
cyril, nigel

Meeting minutes

Log: https://‌www.w3.org/‌2019/‌08/‌01-tt-irc

<atsushi> no mic today, sorry

This meeting

Nigel: [iterates through agenda]

Nigel: AOB or other points

Glenn: 10 seconds on PR #1096 on TTML2

Nigel: OK

Glenn: If we can handle that right now, all I want to do is remind Cyril to review it.

Cyril: I know, I will get to it today.

Glenn: Thank you, that's all.

WebVTT

Gary: The main thing that's left is basically deciding if PR #460 is good to go and I can start to work with Philippe
… to get it through the CR process.

New snapshot with new at-risk items webvtt#460

github: https://‌github.com/‌w3c/‌webvtt/‌pull/‌460

Gary: This has the change for making the region lines a regular long from unsigned long
… as well as the change to clamp the lines property to the closest value that can be represented
… It also adds the at-risk items.

Nigel: Looks like the last significant change was 14 days ago and the positive review was older.

Gary: Yes, this incorporates changes that Silvia has also approved from other PRs.
… The biggest change is the rounding, where I looked at the HTML spec to see how to do it and want someone
… else to look at it and check it's okay.

Nigel: Nobody has done that yet?

Gary: Silvia approved #470 which was the PR that introduced this, nobody else has.
… If we're okay with just Silvia then we can go ahead.

Nigel: #470 was 17 days ago and Silvia approved it the same day.
… In this situation it has had 2 weeks and a positive review so we normally say go ahead and do it.

Gary: Awesome I'll go ahead then.

Nigel: What's the state of the tests for this?

Gary: I need to update the Lines PR to match it, to split the rounded and clamped/unclamped values but now we don't
… need to verify the unclamped values and can delete that portion.
… I was going to use the CR time to look through and fix VTT.js implementation and whatnot to get the other things in
… the IR to pass.

Nigel: From our normal process we can just go ahead at this point. Any objections?

Nigel: Silence, so go ahead.

Gary: Then I'll proceed, thanks.

Eliminate inconsistent use of xsd:nonNegativeInteger (#983). w3c/ttml2#1135

github: https://‌github.com/‌w3c/‌ttml2/‌pull/‌1135

Nigel: I added this to the agenda to discuss why we would move away from XSD defined types because generally
… speaking I feel we should use XSD defined types where they meet our needs.

nigel: this is your proposal glenn
… the first part is about the motivation
… the issue says there is non-consistency
… and the internal type does permit "-0"
… the consistency is a bit of a problem

glenn: the introduction of xsd nonNegative in 3 places
… the data @length, chunk @length, and isd @size
… was an oversight from my side
… I failed to record that we had a non-negative-integer
… if you look at TTML2 1st
… you'll find 17 matches on <digit+>
… one of them is the definition of non-negative-integer
… the only reason that we might want to have the xsd nonNegative is if we want +0 and -0 and +X be equal to X
… there is no reason to allow +0 or -0
… when we have a perfectly good type used in 17 places
… the other item is the introduction of xsd positiveInteger on the @version on isd
… in the text of the specification it already says the value must be greater than 0
… like repeatCount
… or numerator and denominator and framerate ...
… we should use the same mechanism
… I checked in today a series of test
… based on the proposed change
… I don't see a risk of making this non-backwards compatible change
… I'm very confident it's not going to affect anybody

nigel: I did a quick scan
… and in the place where the internal type is used, it would make no sense to use the xsd type

<Zakim> nigel, you wanted to note that in some places allowing the sign in numbers would be nonsensical, like in RGB values

nigel: although I like the idea of using xsd types, I'm happy to make this change

atai2: I want to understand the change
… so it's replacing a type with a more relaxed type
… that would increase the number of false positive during validation

nigel: we add pattern constraints on some xsd strings
… maybe we could do that here too

glenn: if we remove the optional sign, it's restricting the number of lexical representations, no increasing it
… one of the recent commit was to add more pattern
… I agree the current schema had been a bit inconsistent in that regard
… but I note that the schema is not normative
… my intent in this PR is to make things a bit more consistent

pal: do these changes make TTML closer to CSS?

glenn: none of these attributes are in the domain of CSS, they are not properties

pal: so I don't have a strong opinion

nigel: any objection to go ahead with this change?
… hearing none, let's proceed

glenn: I would appreciate your final review nigel
… like missing pattern

TTML Tests

nigel: I want to alert people that there are a number of open PRs on TTML test repo
… I like the approach of adding tests with PR on the spec
… a concrete example was about base64 encoded chunks of data
… where the spec change is to strip off spaces before passing it to the decoder
… and test does that by applying character entities
… that was a good thought exercise
… please do take a look at them and see if they match your expectations

3D extensions

nigel: andreas wanted some clarifications about the next steps

atai2: we continued the discussion for the requirements for 360 subtitles
… we are in a state where we can start drafting
… some specification text
… the question is about the right procedure
… I think that more people outside of this group are interested and may want to contribute
… it may be difficult to contribute
… there was the option to have a discussion in the WICG
… my thinking is to bring it to that CG
… but I don't know how it connects to this WG
… I want to make an explainer for the tag
… and draft a TTML module
… I could start over as a TTML module in the CG for example

<plh> -Requirements for subtitles and text in WebXR

atai2: and as plh is on the call, it'd be good to have a discussion on the interaction between the groups

<atsushi> my understanding of WICG is quite wide range of gathering (and no strong organization), and it should be fine to file new proposal as issue to the repository

nigel: not sure why it would be difficult for people to contribute?
… are they not W3C members?

atai2: the idea is that people active in W3C could contribute and would be motivated to contribute
… and having another place than the TTWG would be helpful for that
… and also for non-member
… they can comment on github issues but that's not sufficient, they would need to be invited members
… so having a community group would be helpful

plh: the link above is to where some discussions are happening
… in terms of doing incubation in CG, it is encouraged
… using WICG means you don't have to create a new CG
… people in the CG if they make an actual contribution will have to adhere to the contributing agreement
… if you want to have people from accessibility, the difficulty is to find the right time to switch to a WG
… and there is no formula for that
… if it is still an idea and trying different options, a CG is fine
… if it becomes a very serious idea, and you need a WG, at that time we need to check if the TTWG is good or not
… there was an inclusive XR workshop happening in NY and there was interest and discussions on captioning
… the CG option is the safest approach in my opinion

atai2: the idea is quite clear
… the requirements got clearer
… we need more experts on making it work
… we have a pretty good scope

plh: the challenge is making sure that the right people are there
… most of the people were not aware that W3C was working on that

atai2: the TTML module would define a basic
… vocabulary

plh: you are assuming people want to use TTML

atai2: it's obvious

plh: to you, may not to everybody

atai2: in the Web Community call, that was the response
… we found no other group or context to specify a solution for this requirement

plh: it seems the choice is either the WICG or to create your own CG

atai2: no the choice is either the WICG or the TTWG directly
… in the community group, we might attract more experts

atai2: one more question
… nigel asked for explainers for TTML
… are there explainers for other features submitted to TTML?

nigel: the one for the AD profile exists

<nigel> TAG template for Explainers

<nigel> -> https://‌github.com/‌w3c/‌tt-reqs/‌wiki

cyril: the karaoke module also has an explainer

TTML over RTP IETF draft

nigel: there is an IETF process point called WGLC (last call)
… at the IETF 105 meeting, this was brought up
… and the WGLC lapsed without comment
… the chair asked that even if there was no comment
… that this group would say that all comments have been taken into account
… what I propose to do
… is to say that there are no further comment
… do people agree or take extra time?

nigel: all of Mike's comments have been addressed
… hearing nothing more, I will take that as Yes, TTWG has no further comments on the document

TPAC Planning

<nigel> TPAC 2019 planning wiki

nigel: there is now a wiki page, thanks atsushi

pal: on the topic of liaisons and TPAC
… what's happening to add a new subtitle class to CLDR
… the unicode effort to create/document characteristics of languages across the world

<nigel> Our ticket on Unicode CLDR

pal: today CLDR has examples of character used for all languages
… they don't include examples for subtitles
… they had made a liaison
… and we recommended unicode to add examples to CLDR
… that was 4 years ago
… maybe TPAC is a good time to revive that

nigel: I checked a ticket on CLDR and some comments were made in May
… Addison asked for some more work
… happy to add this topic at TPAC

pal: maybe we should follow up before?

plh: do we need Addison or Richard Ishida?

glenn: or Mark Davis from Google

nigel: I'll give myself a task to get in touch with Addison

<nigel> TTWG issue 59

nigel: both things make sense: get in touch and follow up at TPAC

nigel: we will be collecting topics for TPAC, please add you names to the participants list
… if you haven't registered yet, please do
… registration is only until Sept 6th

glenn: I'm registered

TTWG Charter status update

plh: the good news is that I had approval from the Director yesterday
… I'm in the process of preparing the call for review
… for the AC

<plh> https://‌www.w3.org/‌2019/‌08/‌ttwg-proposed-charter.html

plh: I merged the PR as asked by the director
… it's ready to ship for review

nigel: we did not seem completely happy with some parts of it (the review part)
… we should make sure we look at that

plh: yes
… you may grumble about the horizontal review

nigel: I see you added "first" in "before first entering CR" addressing my issue, thank you for that.

plh: people can make comments as part of the AC review

Karaoke module

Cyril: Reminder please look at this - I have received no comments yet

Pierre: Is there an easy way to preview it?

Cyril: I will make sure there's a render somewhere.

Pierre: Thanks

Meeting close

Nigel: Thanks everyone, we're at time and have just completed the agenda. See you next week. [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.