IRC log of tt on 2017-06-15

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Meeting: Timed Text Working Group Teleconference
14:02:07 [trackbot]
Date: 15 June 2017
14:02:14 [nigel]
Present: Nigel, Mike
14:02:45 [nigel]
Regrets: Andreas, Glenn
14:02:50 [nigel]
Chair: Nigel
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scribe: nigel
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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)
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.. 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
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.. Seek input on IMSC 2 requirements
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.. Gauge interest in a possible profile of TTML2 for AD
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.. 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]
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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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]
14:13:49 [trackbot]
action-498 -- Nigel Megitt to Invite i18n to discuss imsc 1.0.1 issues -- due 2017-06-15 -- PENDINGREVIEW
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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]
-> Clarified the requirement for processors to implement reference fonts #245
14:20:16 [nigel]
Nigel: This is for #237 and #241.
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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!
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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]
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]
-> 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]
-> 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]
-> 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]
-> 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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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]
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]
-> 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]
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]
-> Issue 0384 streaming ttml appendix #389
15:41:56 [nigel]
-> 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]
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