IRC log of tt on 2017-06-15

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Meeting: Timed Text Working Group Teleconference

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Date: 15 June 2017

14:02:14 [nigel]

Present: Nigel, Mike

14:02:45 [nigel]

Regrets: Andreas, Glenn

14:02:50 [nigel]

Chair: Nigel

14:02:53 [nigel]

scribe: nigel

14:03:12 [nigel]

Present+ Pierre

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14:05:13 [nigel]

Present+ Thierry

14:05:53 [nigel]

Topic: This meeting

14:06:56 [nigel]

Nigel: Today we need to move forward with IMSC and TTML. I will briefly mention TPAC. Any specific points to cover, or other business?

14:07:07 [nigel]

Mike: The IMSC 1 issue regarding SDP-US

14:07:22 [nigel]

Topic: TPAC 2017

14:07:46 [nigel]

Nigel: I've had confirmation from the newly re-chartered Media and Entertainment IG (was Web and TV)

14:08:01 [nigel]

.. that we can meet them jointly for 30 minutes on the Monday.

14:10:06 [nigel]

.. I proposed a draft agenda of an update on subtitle and caption work including TTML2, IMSC 1.0.1, industry adoption

14:10:16 [nigel]

.. Seek input on IMSC 2 requirements

14:10:28 [nigel]

.. Gauge interest in a possible profile of TTML2 for AD

14:10:37 [nigel]

.. plus any other topics of interest.

14:11:19 [nigel]

.. I suggested afternoon would be better than morning in case there's any last minute preparation to done.

14:11:34 [nigel]

action-497?

14:11:34 [trackbot]

action-497 -- Nigel Megitt to Invite csswg to joint meeting at tpac 2017, with list of topics. -- due 2017-06-15 -- OPEN

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http://www.w3.org/AudioVideo/TT/tracker/actions/497

14:11:42 [nigel]

Nigel: I haven't progressed this yet.

14:12:10 [nigel]

.. I will gather together the details as discussed last week and hopefully progress that in the next week.

14:12:30 [nigel]

.. Registration is now open, as are the preferred rates for hotels - early booking is recommended.

14:13:42 [nigel]

Topic: IMSC

14:13:49 [nigel]

action-498?

14:13:49 [trackbot]

action-498 -- Nigel Megitt to Invite i18n to discuss imsc 1.0.1 issues -- due 2017-06-15 -- PENDINGREVIEW

14:13:49 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/actions/498

14:14:15 [nigel]

Nigel: I did invite Richard and Addison but they have not either joined or said they would be (un)able to do so.

14:14:25 [nigel]

.. However there has been some discussion offline.

14:14:53 [nigel]

Pierre: I suggested it would be easier to have the discussion live but we can go ahead and try to propose a solution and disposition

14:14:57 [nigel]

.. and deal with the response.

14:15:24 [nigel]

.. I'm fairly confident that the root of the issues is mainly a misunderstanding of the specification.

14:15:48 [nigel]

Nigel: Some of the github issues have been discussed offline.

14:16:07 [nigel]

Pierre: By the way I'm not blaming anyone, but conflating reference fonts with recommended character sets is a problem.

14:16:30 [nigel]

.. They are really separate. I hope I clarified some of that. Specifically the idea of recommended sets is for author to have confidence

14:16:47 [nigel]

.. that characters for a particular language will be displayed and for implementers to have confidence that they are supporting the

14:17:08 [nigel]

.. correct code points. Separately and independently there are a set of reference fonts that are specified, but the choice of recommended character

14:17:32 [nigel]

.. sets was made independently of the reference fonts. And the "rendering fidelity" associated with recommended character sets is whether they

14:18:00 [nigel]

.. display at all, period, whereas for reference fonts it is about metrics, line breaking positions etc. So I think this is where the misunderstanding lies.

14:18:28 [nigel]

.. So in a pull request I tried to clarify it. At some point we have to propose something and let them restart the discussion if they feel the issue is not

14:18:30 [nigel]

.. resolved.

14:18:51 [nigel]

Mike: I'm sympathetic - this is a complicated topic, but I also believe the spec is clear. I think we have done what we can.

14:19:29 [nigel]

-> https://github.com/w3c/imsc/pull/245 Clarified the requirement for processors to implement reference fonts #245

14:20:16 [nigel]

Nigel: This is for #237 and #241.

14:20:27 [nigel]

Pierre: It has also been discussed in relation to #236.

14:21:06 [nigel]

Nigel: From the discussion are there more changes you want to apply to resolve the misunderstandings?

14:21:11 [nigel]

Pierre: Maybe less not more!

14:22:00 [nigel]

Present+ Dae

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14:22:28 [nigel]

Pierre: The note "Since the flow of text..." is the one we maybe need to work on.

14:22:37 [nigel]

Nigel: Did you see my proposed alternate wording?

14:22:51 [nigel]

-> https://github.com/w3c/imsc/pull/245/files#r121123051

14:23:01 [nigel]

Pierre: I'm fine with it - I hope people won't read too much into it.

14:23:35 [nigel]

.. It's not only the flow of text but also the background, the effective size of the subtitle.

14:23:43 [nigel]

Mike: Yes, line height, characters per line.

14:23:49 [nigel]

Pierre: Gaps between lines.

14:23:58 [nigel]

Mike: It's sweeping so having the reference font is critical.

14:24:34 [nigel]

.. From a web browser perspective some of this must seem strange, but for this application the web approach doesn't really work.

14:24:39 [nigel]

.. I don't know how you say that in a note!

14:25:03 [nigel]

Nigel: So "flow of text" is too generic?

14:25:29 [nigel]

Pierre: Or not broad enough. It is the whole appearance of the subtitle - I think that's a true statement. We could try to list it all but

14:25:37 [nigel]

.. evidently it is not obvious.

14:28:05 [nigel]

Nigel: The other thing we maybe need to clarify is the scenarios where reference fonts apply - it maybe does not jump out

14:28:26 [nigel]

.. enough that reference fonts only come into play for a very specific subset of computed values of tts:fontFamily.

14:28:43 [nigel]

Pierre: That's extremely explicit though. Without Richard on the call I think we're grasping at straws.

14:29:17 [nigel]

.. In light of what we just talk about what should we do? Have a more generic note about the appearance of the subtitle?

14:29:28 [nigel]

Nigel: Yes, if you want to try to craft that I'd be happy to review it.

14:29:48 [nigel]

Pierre: I'll do it now and we can review it later.

14:30:04 [nigel]

.. My recommendation is to apply the pull request and propose it as a disposition and get the response.

14:30:14 [nigel]

Nigel: I think that's fair. Any other views?

14:30:17 [nigel]

Mike: No.

14:32:14 [nigel]

-> https://github.com/w3c/imsc/issues/221 Attribute syntax definition: missing spaces #221

14:32:47 [nigel]

Pierre: Option 2 was preferred and there was no reaction against it, so I've drafted a pull request on that basis assuming that TTML1 will

14:33:17 [nigel]

.. clarify that spaces are in fact permitted, and rejiggered IMSC to take that into account.

14:33:31 [nigel]

-> https://github.com/w3c/imsc/pull/230 Required spaces between non-terminal components of styling and parameter attributes (issue #221) #230

14:35:29 [nigel]

Pierre: This PR puts references into TTML1 for the sections on attribute syntax, and IMSC assumes it is permitted and says "you should not do that" (in document instances).

14:38:36 [nigel]

Nigel: I see you've specified no white space between digit tokens... That's not to say you can't distinguish numerator from denominator!

14:39:06 [nigel]

Pierre: No just between digits. If you look say at %age in TTML1 it is clear that no LWSP is permitted between them.

14:39:25 [nigel]

.. It is obvious to me, but it was obvious that there would be no spaces between fontFamily components, so I'd rather err on the side of completeness.

14:39:27 [nigel]

Nigel: +1

14:39:49 [nigel]

Nigel: Do you want to merge that then?

14:39:58 [nigel]

Pierre: Yes

14:40:09 [nigel]

Nigel: okay, nobody has any objections, go ahead.

14:40:19 [nigel]

Pierre: Done.

14:40:46 [nigel]

Nigel: We have one more, which is #242:

14:40:56 [nigel]

-> https://github.com/w3c/imsc/pull/242 Discourage the use of tab characters in <p> and <span> #242

14:41:24 [nigel]

Pierre: That's one day away from the 14 days and there have been no comments.

14:41:30 [nigel]

Nigel: I've just approved it by review.

14:44:13 [nigel]

Nigel: When it comes to Dispositions the main one we need to address is ARIB since all the other comments are W3 internal.

14:44:40 [nigel]

-> https://www.w3.org/wiki/IMSC1.0.1_Comments_tracker IMSC 1.0.1 comments tracker wiki page

14:45:27 [nigel]

Nigel: Thierry the ARIB liaison has listed on that wiki page that it is under review and not edited in the spec.

14:47:03 [nigel]

Thierry: That was the status about a week ago.

14:47:10 [nigel]

Nigel: I'm puzzled I thought it had been done.

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14:47:45 [nigel]

Pierre: Yes, they are #227 and #228 and they have been merged and are ready for review.

14:47:53 [nigel]

.. The proposed email states that.

14:48:28 [nigel]

.. You said that you and Thierry would review and send it after this meeting.

14:49:04 [nigel]

Nigel: The last email in the thread is:

14:49:05 [nigel]

-> https://lists.w3.org/Archives/Public/public-tt/2017Jun/0066.html

14:50:31 [nigel]

Nigel: OK I see. Does anyone have any comments or changes on the proposed response and dispositions?

14:50:36 [nigel]

group: [silence]

14:50:43 [nigel]

Nigel: In that case let us take that as approval!

14:50:50 [nigel]

Thierry: OK I will send that.

14:50:53 [nigel]

Nigel: Thank you.

14:51:41 [nigel]

Thierry: Just one thing - is 1 week response time enough?

14:51:57 [nigel]

Nigel: I think 1 week is very short.

14:52:10 [nigel]

Pierre: Do we have to get a response? Or can we proceed with no response after some time?

14:53:17 [nigel]

Thierry: The best is a response, but if not then we can go ahead to the Director in any case.

14:53:27 [nigel]

Pierre: Can we work backwards from when we want to publish the CR?

14:54:44 [nigel]

Nigel: I don't want to have our TTML2 and IMSC 1.0.1 publications clash.

14:55:00 [nigel]

Thierry: Only one is a transition - the other is just another WD.

14:56:34 [nigel]

Pierre: How about transitioning on July 6? Mid-July would not work for me.

14:56:49 [nigel]

Thierry: We can go straight to PR if we have implementation experience already. I've seen that before.

14:57:18 [nigel]

Nigel: I thought the Process sets a minimum duration for CR? But if not, then okay fine.

14:57:34 [nigel]

.. I believe we have one implementation of fillLineGap already, and implementing activeArea is trivial.

14:57:40 [nigel]

Thierry: I'll check the process.

14:59:45 [nigel]

Nigel: [also checks] - the 4 week minimum appears to be for getting comments on the way into CR not on the way out.

14:59:55 [nigel]

.. In that case when are other implementations expected?

15:00:32 [nigel]

.. I'm happy either way - we can go straight to PR otherwise CR.

15:00:39 [nigel]

Pierre: We can review that on July 6.

15:01:32 [nigel]

Nigel: July 6 is 3 weeks out, so we could offer 2 weeks.

15:01:39 [nigel]

Pierre: Then we could plan on transitioning on June 30.

15:02:31 [nigel]

Nigel: Accepting TTML2 is a WD only, it is much bigger so I would rather not schedule 2 document publications on the same day - I would rather wait until

15:02:35 [nigel]

.. July 6 for IMSC.

15:03:20 [nigel]

.. If we say that then we need a resolution to publish IMSC 1.0.1 as a CR (or PR) no later than next week's meeting.

15:03:50 [nigel]

.. That gives us this coming week to mop up any remaining open issues.

15:04:28 [nigel]

.. Thierry can we say 2 weeks for the disposition response?

15:04:37 [nigel]

Thierry: Yes

15:04:50 [nigel]

Pierre: I would say explicitly the date we plan to transition.

15:05:00 [nigel]

Thierry: We need to have the response before meeting the Director.

15:05:14 [nigel]

Pierre: Okay then 2 weeks for sure. I would be explicit about the planned transition dates too.

15:05:57 [nigel]

Nigel: I'm happy with the 2 weeks but I don't agree that we should include more dates of planned transitions etc - just say when we need the response back.

15:06:04 [nigel]

Pierre: Okay I'm fine with that too.

15:06:34 [nigel]

-> https://github.com/w3c/imsc/issues/246 SDP-US is listed as a normative reference, but it is not #246

15:07:15 [nigel]

Mike: This was prompted by a discussion with someone who thought that SDP-US is critical to implementation of IMSC1. However

15:08:02 [nigel]

.. implementation of SDP-US is not critical at all, so the normative reference is an error.

15:08:28 [nigel]

Pierre: Does a normative reference imply complete implementation of the referenced document or just the relevant bits?

15:08:31 [nigel]

Mike: The latter.

15:09:02 [nigel]

Pierre: That's my understanding too. The current text says "if the document conforms to SDP-US you shouldn't use ttp:profile".

15:09:10 [nigel]

Mike: That's poor choice of words and not IMSC1's business.

15:09:36 [nigel]

Pierre: Conformance with SDP-US is not IMSC1's business. If you want an SDP-US document do that. This is just a declarative note.

15:09:40 [nigel]

s/Pierre/Mike

15:09:53 [nigel]

Pierre: So you're arguing that's a statement not a conformance clause?

15:10:29 [nigel]

Mike: Yes absolutely. If you want to go there (and I don't), it's a declarative note only. It is not a conformance term for IMSC 1 and has nothing to do with

15:10:32 [nigel]

.. IMSC 1 conformance.

15:10:56 [nigel]

Pierre: My thinking is: as currently written it is evidently misleading, but not wrong. If we are going to move the normative reference to an informative one then

15:11:52 [nigel]

.. we should change this clause and remove any conformance.

15:11:59 [nigel]

Mike: I don't think we should wander into conformance here.

15:12:16 [nigel]

Nigel: There is also Annex I about compatibility with other TTML-based specifications.

15:13:32 [nigel]

.. Effectively the same wording is duplicated there.

15:13:42 [nigel]

.. And that's a useful service given the design goal to be a superset.

15:14:03 [nigel]

Pierre: Looking at §6.9 Profile Signaling...

15:15:58 [nigel]

.. SDP-US prohibits the ttp:profile attribute from being present.

15:16:24 [nigel]

.. In order for me to evaluate the clause in §6.9 I need to go and read SDP-US.

15:16:30 [nigel]

Mike: And it shouldn't make me do that.

15:17:00 [nigel]

Pierre: That's the root cause of this. You're suggesting that we should change the wording to be informative and move the reference to the non-normative section?

15:17:17 [nigel]

Mike: Yes, I'd like to refactor this to remove the normative reference.

15:17:36 [nigel]

.. The ramifications are editorial: the use of SHOULD originally was a bad choice.

15:17:47 [nigel]

Pierre: Section I.3 has the declarative statement.

15:19:40 [nigel]

Nigel: Just checking all the other references to SDP-US, they all seem to be declarative.

15:19:54 [nigel]

Pierre: We could reword §6.9 to match §I.3.

15:20:04 [nigel]

Mike: Why do we need to repeat it?

15:20:18 [nigel]

Pierre: Because it is important to clarify the profile signalling from TTML1.

15:20:34 [nigel]

Mike: I'm okay either a) deleting the sentence or b) restating it as a declarative statement.

15:21:32 [nigel]

.. There are a number of ways to remove this from the normative references.

15:21:56 [nigel]

Nigel: I don't have any objection to removing it from normative references. By the way it is only a WG Note, so it's a bit odd for us to normatively

15:22:05 [nigel]

.. reference it anyhow, I'm not sure how that slipped by.

15:22:22 [nigel]

Pierre: It could be just a missing ! - I can prepare a pull request.

15:22:29 [nigel]

Mike: I do believe this was just a mistake.

15:23:16 [nigel]

Pierre: I believe we will have to list this as a substantive change even though it has no conformance impact.

15:23:24 [nigel]

Nigel: I agree.

15:25:06 [nigel]

Pierre: I will prepare a pull request later today, if you could review it and let me know if there are any issues.

15:25:10 [nigel]

Mike: Thanks guys.

15:25:28 [nigel]

Pierre: Shall we go back to #245 which I have now updated?

15:25:37 [nigel]

Nigel: Given the time let's do that offline please.

15:26:26 [nigel]

Nigel: Summarising for the minutes, we have done what we can on the i18n issues, agreed the disposition response and made a plan

15:26:58 [nigel]

.. to make the resolution to transition to CR or possibly even PR in next week's meeting for a July 6 publication target.

15:30:43 [nigel]

Topic: TTML

15:31:39 [nigel]

Nigel: We said we would publish the WD for wide review by June 30, and that we would need a 2 week review period to approve it.

15:31:55 [nigel]

.. We have a number of open pull requests now and no final draft of the WD to review.

15:32:08 [nigel]

.. We also a number of open issues.

15:34:13 [nigel]

.. I wanted to propose that we merge all the current open pull requests and turn that into a draft that the group can

15:35:18 [nigel]

.. review prior to approving publication for wide review. That gives a 2 week review period for everyone. How does that grab everyone?

15:35:25 [nigel]

Mike: Okay for me.

15:36:33 [nigel]

Nigel: Clearly we can still make further changes prior to CR, or resolve issues with this version by pull requests in the next few days as long as there is

15:36:37 [nigel]

.. positive review from everyone.

15:36:51 [nigel]

s/everyone/enough key people, and no negative comments

15:37:25 [nigel]

Dae: I'm more interested in the deadline than having 2 full weeks. 1 week review is enough for me.

15:38:19 [nigel]

Pierre: Movielabs will abstain on this at this time.

15:38:50 [nigel]

Thierry: The proposal sounds reasonable to me.

15:39:15 [nigel]

Nigel: OK then I think we're agreed.

15:39:22 [nigel]

.. I will ask Glenn to progress that.

15:40:48 [nigel]

Nigel: Let's go through the pull requests then.

15:41:15 [nigel]

-> https://github.com/w3c/ttml2/pull/389 Issue 0384 streaming ttml appendix #389

15:41:56 [nigel]

-> https://rawgit.com/w3c/ttml2/04a3ea7dd0b15e9cb6451f4655a7d1aea38d32de/spec/ttml2.html HTML version

15:42:06 [nigel]

Nigel: It's appendix R

15:47:25 [nigel]

Nigel: I didn't quite do what we said last week in that I didn't reference the TTML1 appendix but left it in as a subsection.

15:47:37 [nigel]

.. I did that on the basis of one of Glenn's comments on the issue.

15:49:42 [nigel]

Mike: I would rather do what we said last week and diminish the relevance of the section that isn't common practice by making it a reference back to TTML1.

15:50:28 [nigel]

Nigel: I have limited time available in the short term to fix this so unless there are strong objections to what we have I propose to keep it as is,

15:50:41 [nigel]

.. or otherwise I'd welcome if anyone else wants to implement the reference change.

15:51:03 [nigel]

Mike: I haven't had time to check the detail on the rest of this.

15:53:05 [nigel]

Nigel: Unless there are any more issues or pull requests to discuss let's return to the IMSC topic.

15:53:15 [nigel]

Topic: IMSC (revisited)

15:53:35 [nigel]

Pierre: On the SDP-US issue the sentence above about EBU-TT-D has the same issue. I'm wondering if we should change that too.

15:54:10 [nigel]

Nigel: That's true.

15:54:19 [nigel]

Pierre: I'm thinking of dealing with that at the same time.

15:55:00 [nigel]

Mike: Having parallel language would probably be the best thing to do but since EBU-TT-D and SMPTE-TT are essential I'm not pushing for that.

15:55:11 [nigel]

Pierre: I'm asking for permission to make the two bullets consistent in language.

15:55:51 [nigel]

Nigel: I agree - please change "should not be present" to "is not present" for EBU-TT-D.

15:55:54 [nigel]

Mike: I'm happy with that.

15:56:04 [nigel]

Pierre: Okay I will do that and you'll see the pull request later today. Thank you.

15:57:41 [nigel]

Nigel: We're out of agenda, also time. Thanks everyone. [adjourns meeting]

15:57:45 [nigel]

rrsagent, make minutes

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I have made the request to generate http://www.w3.org/2017/06/15-tt-minutes.html nigel

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ScribeOptions: -final -noEmbedDiagnostics

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rrsagent, make minutes

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I have made the request to generate http://www.w3.org/2017/06/15-tt-minutes.html nigel

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