IRC log of tt on 2019-02-01

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07:36:25 [trackbot]
Meeting: Timed Text Working Group Teleconference
07:36:25 [trackbot]
Date: 01 February 2019
07:36:33 [nigel]
Log: https://www.w3.org/2019/02/01-tt-irc
07:36:57 [nigel]
Agenda: https://www.w3.org/wiki/TimedText/F2F-jan-2019#Day_2_.2808:30-13:30.29
07:37:09 [nigel]
scribe: nigel
07:38:20 [nigel]
Present: Andreas, Pierre, Thierry, Glenn, Matt, Marco_Slik, Frans
07:38:33 [nigel]
Chair: Nigel
07:39:43 [nigel]
Present+ Gary
07:40:19 [nigel]
Topic: This meeting
07:40:46 [nigel]
s/This meeting/Introductions
07:41:08 [nigel]
Andreas: Welcome everyone to this joint meeting of the W3C Timed Text Working Group and EBU Timed
07:41:22 [nigel]
.. Text groups.
07:41:42 [nigel]
.. I chair the EBU group, and Nigel is a chair of both of the groups.
07:42:07 [nigel]
Nigel: Do we all know each other?
07:42:29 [nigel]
Andreas: We mostly met yesterday but introductions could be useful for some people.
07:42:51 [nigel]
Marco: I'm Marco Slik, an R&D engineer at NPO in the Netherlands involved in the very broad spectrum
07:43:29 [nigel]
.. of playout distribution and access services, I joined the EBU group a few years ago.
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07:48:16 [nigel]
Gary: Hi, I work at Brightcove, we do online video with video.js and the web player and I focus on WebVTT
07:48:27 [nigel]
Thierry: Thierry Michel, W3C team contact for this WG
07:49:35 [nigel]
Nigel: Just an admin statement for me, which is that as a W3C WG meeting any IPR contributed here
07:49:52 [nigel]
.. needs to be cleared. TTWG members have already made this commitment, if any non-TTWG members
07:50:10 [nigel]
.. contribute any substantive material that ends up in a W3C Recommendation track document then as
07:50:22 [nigel]
.. Chair I will need to get a similar commitment from the contributor.
07:50:33 [nigel]
.. That's the formality over, in terms of IPR!
07:50:58 [nigel]
.. Can I check everyone is aware of IRC and the minuting of this meeting?
07:51:17 [nigel]
Andreas: Yes, I will send the links around too.
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07:52:39 [nigel]
Nigel: Just to let everyone know that this meeting will be scribed on IRC and that the log will be
07:52:55 [nigel]
.. turned into public-visible minutes after the meeting. If you do not wish something to be minuted
07:53:02 [nigel]
.. please tell me before you say it!
07:53:08 [nigel]
Topic: This meeting
07:53:31 [nigel]
Andreas: One of the reasons we meet together today is the shared interest in live TTML.
07:53:46 [nigel]
.. We had a discussion at the TPAC meeting in Lyon a few months ago and also some other discussions
07:53:55 [nigel]
.. in the EBU group about this.
07:55:23 [nigel]
.. There was a discussion of the submission of EBU-TT Live to W3C. At TPAC we decided we needed
07:55:38 [nigel]
.. more information about the plans of the groups regarding live and standards activities.
07:55:49 [nigel]
.. So we thought this meeting would be a perfect opportunity to discuss this.
07:55:56 [nigel]
.. The main part will be dedicated to this topic.
07:56:11 [nigel]
.. By introduction we have some example from operation, Nigel from BBC, and the open source
07:56:18 [nigel]
.. activity of the EBU-TT Live Interoperability Toolkit.
07:56:32 [nigel]
.. Matt from Red Bee, and Marco from NPO and I will bring in requirements from some German
07:56:35 [nigel]
.. broadcasters.
07:56:42 [nigel]
.. After that we will look at the live standards activity.
07:56:50 [nigel]
.. Also as we're here today we can widen the scope a little bit.
07:57:05 [nigel]
.. I talked to people before. My interest would be to check how much we can bring TTWG and EBU TT
07:57:18 [nigel]
.. activities together and doing more work in W3C.
07:57:24 [nigel]
.. [missed a bit]
07:57:44 [nigel]
.. We have concrete examples of multiRowAlign and linePadding.
07:57:56 [nigel]
.. The order is not fixed yet, we have a list of topics on the wiki page.
07:58:04 [nigel]
.. We can discuss where to start.
07:59:06 [nigel]
Nigel: Thanks for that, as you have said we have a list of topics on the wiki page.
08:02:27 [nigel]
.. Looking at the schedule, what should we look at first?
08:02:40 [nigel]
Andreas: Let's begin concrete with EBU extensions and then dive into live.
08:02:49 [nigel]
.. Then come back to cooperation and collaboration of the groups at the end of the meeting.
08:04:34 [nigel]
Topic: EBU Extensions to TTML
08:04:50 [nigel]
Andreas: Some information I shared
08:05:32 [nigel]
-> [pointer to Andreas summary mail] Andreas's summary text
08:05:55 [nigel]
Andreas: The main question is if the two vocabulary items ebutts:multiRowAlign and ebutts:linePadding
08:07:04 [nigel]
.. If it makes standards work of W3C easier we would be able to allow them to be maintained in the TTWG.
08:07:13 [nigel]
.. If there's interest in W3C group to do this.
08:07:22 [nigel]
.. Otherwise we can keep it in the EBU TT group scope.
08:07:37 [nigel]
.. I sent an email to the EBU reflector making a proposal, and have had no objections to that proposal.
08:08:01 [nigel]
.. From whatever date, multiRowAlign and linePadding are maintained and at the end controlled no longer
08:08:33 [nigel]
.. by EBU but by W3C. EBU will not make any changes to them.
08:08:56 [nigel]
.. If there is another EBU spec then it can reference any updated definition in a W3C spec.
08:09:14 [nigel]
.. This allows easier maintenance and adoption of bug fixes found during W3C activities.
08:09:24 [nigel]
.. The general idea is to update the items for clarification and bug fixing.
08:09:36 [nigel]
.. If completely new requirements come up that are not satisfied by them then it may be better to add
08:09:51 [nigel]
.. two completely new items in the TTML namespace. If for some reasons semantics change then it is in
08:10:04 [nigel]
.. the interests of the EBU group that they are backward compatible with the existing EBU definitions.
08:10:27 [nigel]
.. If W3C has control then they maintain it and it is their decision process how to deal with updates.
08:10:54 [nigel]
.. We currently have at least 4 members who are in both groups then I do not see any conflict.
08:11:00 [nigel]
Matt: Is there any precedence for this?
08:11:05 [nigel]
Frans: I'm not aware of this exact case.
08:11:19 [nigel]
Glenn: When you say hand over control are you assuming a namespace change?
08:11:23 [nigel]
Andreas: No
08:11:41 [nigel]
Glenn: The proposal is a syntactic transfer but cede control to the W3C of that subset of the EBU owned
08:11:42 [nigel]
.. namespace?
08:11:45 [nigel]
Andreas: Yes
08:12:05 [nigel]
.. Pierre as editor of IMSC, the question is if there is any benefit. I think it is clear it would be maintained
08:12:06 [nigel]
.. in IMSC scope.
08:12:19 [nigel]
Pierre: There's always a benefit in having a single forum to address issues.
08:12:37 [nigel]
Glenn: If the formal definition moves to IMSC, would it be feasible to define, say in TTML3, two new
08:12:45 [nigel]
.. attributes of the same name but in the TTML namespace?
08:12:53 [nigel]
Pierre: To me that's a separate issue.
08:12:59 [nigel]
Glenn: Well they're both in W3C control
08:13:03 [nigel]
Pierre: That's true today
08:13:09 [nigel]
Matt: Would they be equivalents?
08:13:20 [nigel]
Glenn: I've objected to including foreign namespaces in TTML in the past.
08:13:36 [nigel]
.. That's not true for IMSC which is a profile that adds vocabulary from other places like EBU-TT.
08:13:50 [nigel]
.. That was completely appropriate in IMSC, but it has never been the case that TTML refers to foreign
08:14:03 [nigel]
.. namespaces. If we do this then we should have a plan or intent to bring them into the TTML style
08:14:09 [nigel]
.. namespace and define them equivalently.
08:14:17 [nigel]
Pierre: That's orthogonal, we could do that today.
08:14:29 [nigel]
Glenn: If you think that's possible, then that's okay.
08:14:48 [nigel]
Andreas: Your proposal is to duplicate semantics but give it a different name or namespace?
08:15:09 [nigel]
Glenn: 1. Move formal definition into IMSC, same namespace, words etc so it is consistently defined.
08:15:22 [nigel]
.. 2. Define the same names and semantics in a TTML namespace. At that point the IMSC spec could be
08:15:38 [nigel]
.. updated to refer to the TTML namespace semantics if it wants to and also say it is available in the EBU
08:15:39 [nigel]
.. namespace.
08:15:56 [nigel]
Andreas: This has been discussed in the past and EBU has said that is not the intent to duplicate existing
08:16:10 [nigel]
.. vocabulary items, and that duplication makes no sense. Personally I think that is the best strategy.
08:16:24 [nigel]
.. We use the EBU vocabulary items because they are established, implemented and we don't want to
08:16:34 [nigel]
.. make other implementations have to change to a new vocabulary with no need.
08:16:51 [nigel]
.. This is formally not needed but it goes together. If the overall intent is to duplicate the EBU namespace
08:17:08 [nigel]
.. items without adding new functionality that would not really justify bringing over the control of the
08:17:19 [nigel]
.. EBU namespace items. We had this discussion in the past and the position has not changed.
08:17:37 [nigel]
Glenn: We have to recognise that IMSC and TTML are different and have different conventions.
08:17:53 [nigel]
.. We have followed different restrictions. As a primary language definition it does not reference any
08:18:07 [nigel]
.. foreign namespaces, just the core XML namespaces and those defined in TTML itself.
08:18:47 [nigel]
.. Other than this potentially we have never discussed a proposal or accepted one to refer to foreign namespace.
08:18:59 [nigel]
Pierre: I don't see why we need it.
08:19:17 [nigel]
.. W3C could decide today to create a duplicate attribute. We've had that discussion. I don't see what is different.
08:19:35 [nigel]
Glenn: Bringing them in to IMSC will not satisfy requirements for TTML that are not IMSC users.
08:19:44 [nigel]
.. Everything is in the TT namespaces.
08:19:50 [nigel]
Pierre: We can have that discussion (again).
08:20:18 [nigel]
Glenn: I have no objection to making use of the EBU technology. It is great, proven, deployed, and I don't
08:20:26 [nigel]
.. want to seem like I'm denigrating EBU in this regard.
08:20:40 [nigel]
.. As Editor of the primary core language definition I have to stand by certain principles of language
08:20:49 [nigel]
.. consistency and this is one I'm going to insist on.
08:21:03 [nigel]
Andreas: Possibly it is best to follow Pierre's proposal and concentrate on what is on the table.
08:21:28 [nigel]
.. This would be to hand over control of the items multiRowAlign and linePadding only into W3C for
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08:21:32 [nigel]
.. adoption by IMSC and nothing else.
08:21:40 [nigel]
.. What is the opinion of the other members present?
08:21:52 [nigel]
Matt: I think it seems sensible. The one question for me is the overall strategy and context?
08:21:56 [nigel]
Frans: Pragmatism
08:22:11 [nigel]
Matt: It doesn't make sense to have multiple definitions of the same thing and then the community would
08:22:15 [nigel]
.. need to do the same work twice.
08:22:30 [nigel]
.. We would like to contribute to the biggest circle in the venn diagram unless there's a proposal that is
08:22:45 [nigel]
.. hyper-specific. We would like to break down the notion that captions and subtitles are different from
08:22:56 [nigel]
.. country to country because in my experience they are not. Interoperability is the goal.
08:23:13 [nigel]
Frans: I totally agree, this makes sense and we should be pragmatic not thinking about not invented here
08:23:14 [nigel]
.. concerns.
08:23:24 [nigel]
Andreas: I see nodding from Marco, no objection from W3C side.
08:23:49 [nigel]
.. I will share the proposal from the EBU with the Timed Text group.
08:24:11 [nigel]
Pierre: I think a liaison is needed, and an issue on IMSC to adopt in the next version.
08:25:02 [nigel]
Nigel: I'm not sure if a liaison is needed.
08:25:17 [nigel]
Pierre: For future generations a standalone piece of paper that explains what happened would be useful.
08:25:30 [nigel]
Andreas: I can make a proposal offline and check it with both groups to go forward.
08:25:34 [nigel]
Nigel: That is okay for me too.
08:25:50 [nigel]
Topic: Overview of EBU standards
08:26:13 [nigel]
Andreas: [shows list of EBU specs]
08:26:41 [nigel]
.. EBU-TT Part 1 v1.2, the base of every standard we published, intended originally for exchange and archive,
08:26:52 [nigel]
.. as the successor to STL.
08:27:01 [nigel]
.. Not in TTML2: linePadding, multiRowAlign
08:27:23 [nigel]
.. Not in IMSC: smpte, clock timebase, markerMode, clockMode, cell length metric except for linePadding
08:28:05 [nigel]
.. EBu-TT-D, same scope as IMSC, a subset of IMSC. Includes multiRowAlign and linePadding.
08:28:25 [nigel]
.. EBU-TT Live, subtitle contribution over IP. As well as multiRowAlign and linePadding, there are four
08:28:47 [nigel]
.. attributes not in TTML2 or in IMSC, sequenceIdentifier, sequenceNumber, authorsGroupIdentifier,
08:28:52 [nigel]
.. authorsGroupControlToken.
08:29:07 [nigel]
.. EBU-TT Part M is definition of metadata elements, no compatibility issue because TTML and IMSC allow
08:29:10 [nigel]
.. adding metadata.
08:29:17 [nigel]
.. Also we have some complementary documents.
08:29:29 [nigel]
.. A recommendation how to map EBU STL to EBU-TT Part 1.
08:29:40 [nigel]
.. A recommendation for carrying EBU-TT-D in ISO BMFF.
08:30:05 [nigel]
.. A carriage spec for carrying EBU-TT Live over WebSocket.
08:30:08 [nigel]
..
08:30:21 [nigel]
.. A question I have is for not just EBU-TT Live, but also part 1 and EBU-TT-D how they could converge
08:30:33 [nigel]
.. with the TTML specs. Later we have an EBU group meeting, this will be one part of the discussion there.
08:30:50 [nigel]
.. Looking at the minimal part that is not inside IMSC or TTML I see some option really to possibly
08:31:07 [nigel]
.. make use of some W3C specs to satisfy the use case we originally thought of with part 1 and Live.
08:31:18 [nigel]
.. EBU-TT-D is already solved by IMSC, EBU-TT-D is just more restricted.
08:31:49 [nigel]
Glenn: The idea is to identify areas of difference as you have summarised, and then find ways to...
08:32:04 [nigel]
.. I guess I'm not clear on the next step - update the EBU specs? Or some action on W3C side?
08:32:17 [nigel]
Andreas: The background is the situation that if you go to the industry and ask about information about
08:32:31 [nigel]
.. TTML they say there are so many profiles they don't know which ones to support. They don't implement
08:32:44 [nigel]
.. a complete set. That's not a good situation, so I think it would help to limit the set of standards that
08:32:57 [nigel]
.. needs to be implemented, and I really like simple solutions so in my simplified view, for example for
08:33:12 [nigel]
.. part 1 we could say for production and exchange, just use IMSC, but then check if everything in IMSC
08:33:28 [nigel]
.. now satisfies this use case, and if not, make an addition or some other change so that, out there, where
08:33:40 [nigel]
.. we need implementation, people know they just need to implement IMSC.
08:33:53 [nigel]
Glenn: Thinking aloud, I'm wondering if part of the problem with all these profiles is that very few clients
08:34:08 [nigel]
.. if any actually do the profile processing that is defined by TTML in the sense that it actually verifies
08:34:21 [nigel]
.. if the profile asks for features to be supported and acts accordingly if they are not.
08:34:36 [nigel]
.. I felt always bad about the history of the EBU's adoption of TTML when it ruled out use of the profile
08:34:49 [nigel]
.. system which I thought then and still think is a mistake because it removes the ability of the client to
08:35:05 [nigel]
.. refer to the author defined profile information. I'm not suggesting anything, but it may be that the fact
08:35:35 [nigel]
.. that very few clients use the profile is part of the problem.
08:35:45 [nigel]
Andreas: Try to look forward not backward.
08:36:41 [nigel]
Glenn: I agree.
08:37:08 [nigel]
Nigel: Chicken and egg problem - if profile adoption is not there then it is hard to specify it, and TTML
08:37:21 [nigel]
.. implementation is already big enough without including profiles.
08:37:52 [nigel]
Andreas: Question for Pierre, do you see a path to adding EBU-TT Part 1 syntax into IMSC if there's a gap?
08:38:20 [nigel]
Pierre: We can look at it, it is not worth creating another flavour/layer/profile but if they are useful
08:38:37 [nigel]
.. in production only but not distribution then maybe there is genuinely a need for another flavour.
08:38:55 [nigel]
Frans: There has been little drive to change the production side, more the distribution side.
08:39:00 [nigel]
.. So EBU-TT has not been well adopted.
08:39:29 [nigel]
Matt: We've made a lot of EBU-TT output, everything for BBC since 2014. We probably could derive some
08:39:38 [nigel]
.. useful stats on the number of EBU-TT documents.
08:39:53 [nigel]
.. Ofcom has recently published a statement about the extension of accessibility regulation to online
08:40:04 [nigel]
.. video platforms, which included something about standards support. There was an attempt to try to
08:40:24 [nigel]
.. persuade the regulator to add guidance or stronger to direct content providers to use particular formats.
08:40:43 [nigel]
.. We have one client for whom we make 13 or 14 different variants of the same data. That's driven by
08:40:57 [nigel]
.. probably no good reason, but the proliferation has caused fogginess. Anything we can do to reduce
08:41:21 [nigel]
.. that will be very valid and valuable. If you read that statement, [missed a bit] those are not small
08:41:35 [nigel]
.. amounts of money, having one format that could be propagated to every platform would be very
08:41:37 [nigel]
.. useful.
08:41:59 [nigel]
Andreas: Useful comments. From my experience IMSC for example [missed a bit]
08:42:19 [nigel]
.. but the value of having one format overweights possibly the extra work for features that may not be
08:42:33 [nigel]
.. needed. Most of the things we leave out are not really a problem in the implementation. It is more the
08:42:51 [nigel]
.. parts we brought in, with multiRowAlign, lineGap etc are the tricky parts.
08:43:05 [nigel]
.. To actively give the message that you need to implement full IMSC coming from different standards
08:43:20 [nigel]
.. organisations would definitely help I think. One of the main questions we can look at already for
08:43:37 [nigel]
.. IMSC is timecode. We had discussions with lots of people, lots of stakeholders are not yet ready to
08:43:40 [nigel]
.. go away from timecode.
08:43:55 [nigel]
Pierre: And a lot of them use it badly. We really have to understand the use cases extremely well.
08:44:11 [nigel]
.. In the modern world timecode will not work 99.99% of the time with component based media.
08:44:20 [nigel]
Frans: I can only agree it must be use case driven.
08:44:31 [nigel]
.. That's the most important for production.
08:45:04 [nigel]
Marco: When you want to transition you have to support some things... [missed a bit]
08:45:11 [nigel]
Pierre: It will not work with online media.
08:45:28 [nigel]
Marco: I will not manage to get away from smpte timecode in 3 years, but we could maybe start the timecode
08:45:32 [nigel]
.. clock at zero for example.
08:45:47 [nigel]
Pierre: I don't think saying timecode can not or must be used is the answer, it's a lot more nuanced.
08:46:18 [nigel]
Andreas: I do not think we can say we see a better future and will not help you now.
08:46:28 [nigel]
.. For German broadcasters we need an incentive to change from STL.
08:46:39 [nigel]
.. We thought we did that with EBU-TT but they did not use it.
08:46:54 [nigel]
Frans: When we started the work the premise was that STL can not do the things we want but in
08:47:01 [nigel]
.. production people have not hit that wall yet.
08:47:18 [nigel]
Matt: Yes, we have not hit that inflection point. We're getting more foreign languages, like Mandarin.
08:47:35 [nigel]
.. We can't do live captioning in Mandarin, in 608 or Teletext, but we need an answer before people
08:47:41 [nigel]
.. invent something that won't work.
08:47:46 [nigel]
Glenn: A character coding issue?
08:47:58 [nigel]
Matt: Yes but the broadcast standards don't support those characters.
08:48:16 [nigel]
Pierre: Contribution of HD single language content is a solved problem. We're not competing with ATSC or 608.
08:48:24 [nigel]
.. We're talking about worldwide online distribution of content.
08:48:36 [nigel]
Matt: Precisely. We're working with an online entity that has no SDI platform.
08:49:06 [nigel]
Andreas: That's a good start into the discussion, I propose we move over.
08:49:19 [nigel]
Pierre: On that topic, since we're all together, if we are serious about trying to rationalise this it would
08:49:32 [nigel]
.. probably be a good idea to set aside a day at a workshop to really get to the bottom of it, and get
08:49:45 [nigel]
.. people to tell us what they are doing and want to do otherwise we will make a wrong decision.
08:50:03 [nigel]
Frans: We tried to do this a number of years ago for EBU-TT Live.
08:50:13 [nigel]
Pierre: For instance EBU-TT Part 1, who are the target users?
08:50:19 [nigel]
Andreas: Everyone who uses STL.
08:50:31 [nigel]
Matt: I can collate data from most UK broadcasters.
08:50:47 [nigel]
Frans: I do think there is point to verifying proposed pain points with users.
08:51:06 [nigel]
Andreas: From the experience of the live workshop it was a bit chaotic and was hard to bring together.
08:51:19 [nigel]
.. It was good at that time, but as you say everyone goes to their domain and community and we come
08:51:25 [nigel]
.. back maybe in the same kind of circle.
08:51:34 [nigel]
Pierre: Next opportunity is maybe IBC.
08:52:00 [nigel]
.. It would be awesome to end up with a single format across the entire chain, not for old applications.
08:52:13 [nigel]
Andreas: yes and if we are committed I'm sure we will get others onboard.
08:52:23 [nigel]
Matt: Clients ask us how to give flesh to the ecosystem
08:52:29 [nigel]
Frans: We need to give a roadmap
08:52:36 [nigel]
Matt: And state the benefits.
08:54:25 [nigel]
Nigel: That Live workshop was in the same room as this meeting in 2012, and one of the reason it was
08:54:43 [nigel]
.. chaotic was that people wanted to address not just the workflow we had in scope but at least one step
08:54:49 [nigel]
.. further, like speech to text engines.
08:55:02 [nigel]
Frans: I agree, we need to focus on the use cases.
08:55:16 [nigel]
Topic: Live subtitle contribution
09:12:28 [nigel]
nigel: [describes EBU-TT Live and the Live Interoperability Toolkit] - Frans took notes.
09:12:39 [nigel]
Matt: Background to fit into that.
09:12:42 [nigel]
.. [shows slides]
09:13:03 [nigel]
.. We're a subtitle vendor, and a few years ago wanted to replace our live captioning platform. We were
09:13:16 [nigel]
.. surprised at the lack of forwards thinking in the market. I was in this group already at that point and
09:13:29 [nigel]
.. could see that the world would change and Teletext would not work.
09:13:46 [nigel]
.. We built our own java based captioning tool called Subito.
09:13:53 [nigel]
.. Effectively internally it makes TTML.
09:14:19 [nigel]
.. Can output Teletext, Nufor, 608, Cavena, EBU-TT Live, and can do those simultaneously, applying
09:14:24 [nigel]
.. the constraints in real time.
09:14:57 [nigel]
.. We did our first presentation at PTS 2 years ago, and did some work using the LIT. We had a basic but
09:15:07 [nigel]
.. brittle proof of concept. More recently using for our customers.
09:15:38 [nigel]
.. Development challenges, managing pre-conceptions of HTML and XML ignoring good EBU documentation
09:15:58 [nigel]
.. ignoring format details because of lack of understanding of the use case, so deviating from the spec.
09:16:10 [nigel]
.. Partly caused by lack of reference examples and material.
09:16:38 [nigel]
.. Bad habits like using line breaks for positioning.
09:16:50 [nigel]
.. Ignoring test materials that are free like the Interop Toolkit.
09:17:11 [nigel]
.. Challenges about reformatting, we focused on conveying the intent of the captioner to the stream.
09:17:26 [nigel]
.. But how to cope if presentation format is a different aspect or applies other constraints?
09:17:42 [nigel]
.. In the implementation side we didn't think enough about that. No practical constraints, but need to
09:17:48 [nigel]
.. avoid developers making inappropriate solutions.
09:18:31 [nigel]
.. We created a multichannel Distribution Node. Originally we required consumers to connect in, what we now
09:18:55 [nigel]
.. have is scalable and supports multiple destinations.
09:19:08 [nigel]
.. Testing is difficult, need a 24/7 delivery destination.
09:19:25 [nigel]
.. Security: not an issue with 608 or Nufor, wide open or limited in format.
09:19:40 [nigel]
.. We've implemented Auth0 with security based on IPv4 lockdown approach.
09:19:58 [nigel]
.. Haven't implemented handover functions, the idea that you may have more than one source of
09:20:12 [nigel]
.. caption documents, and we have a model in Part 3 for passing over control seamlessly so everyone
09:20:27 [nigel]
.. knows who is in control and where their data is going. Needs more ecosystem, lacking at the moment
09:20:32 [nigel]
.. for testing and demonstration.
09:21:15 [nigel]
.. "flying hours" - if we have used libraries with memory leaks etc then eventually things will go wrong.
09:21:32 [nigel]
.. Until we have solid real world use we can't be 100% sure it is robust.
09:21:55 [nigel]
.. Used for Department of Parliamentary Services, Australia with a web feed.
09:22:06 [nigel]
.. Extended proof of concept, due to launch imminently.
09:22:35 [nigel]
.. Second is "Intersub", real time transcript service. Currently Newfor, plan to migrate to Part 3, which
09:22:49 [nigel]
.. will simplify the stack and remove newfor handling deduplication code.
09:23:21 [nigel]
Andreas: Really good, thank you, very interesting!
09:23:27 [nigel]
.. Next up, Marco.
09:23:57 [Frans]
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09:25:03 [nigel]
Marco: [trouble presenting]
09:25:10 [nigel]
Andreas: I will take over and we come back to Marco.
09:25:33 [nigel]
.. Our broadcasters are fine most of the time. They look for new solutions if current tech cannot solve
09:25:36 [nigel]
.. their use cases.
09:25:52 [nigel]
.. One problem in the past is live streaming of broadcast programmes with closed captions, not burned in,
09:25:55 [nigel]
.. on the distribution channel.
09:26:09 [nigel]
.. All of the chain is standardised especially at the end. There are stable and good standards to package
09:26:21 [nigel]
.. EBU-TT-D and IMSC into MP4 and deliver it with DASH and HLS.
09:26:39 [nigel]
.. To encourage implementation we did a demo that has been online for 1 or 2 years where we use the
09:26:55 [nigel]
.. live broadcast signal and take out the subtitles and bring it into IMSC and deliver it over HLS and DASH.
09:27:14 [nigel]
.. [shows live Bavarian broadcaster BR's output]
09:27:21 [nigel]
.. Teletext subtitles translated into IMSC.
09:27:50 [nigel]
.. How it works: for the encoding and packaging, receive SDI with embedded teletext subtitles in the VANC.
09:28:07 [nigel]
.. They decode it and then translate it to TTML and package it in MP4 for the client. That works.
09:28:25 [nigel]
.. But what if you have a non-broadcast workflow, for an online only platform with no broadcast chain.
09:28:41 [nigel]
.. And our broadcasters say they have a couple of internet-only live events and they do not want to buy
09:28:58 [nigel]
.. whole broadcast systems for these events to subtitle them. One way it could be done is that at the
09:29:17 [nigel]
.. packaging side you receive the video and audio together and synchronise it and deliver as MP4 to the client.
09:29:32 [nigel]
.. The scenario we would like to solve is to use EBU-TT Live for the contribution to the encoding layer.
09:29:45 [nigel]
.. Also we would like to get people together like we did in the past with this CMAF/DASH demo.
09:29:56 [nigel]
.. The challenge we have at the moment is to find a packager and encoder that would implement
09:30:04 [nigel]
.. EBU-TT Live and the synchronising mechanism.
09:30:21 [nigel]
.. It would also be possible to use a legacy format like Newfor and transmit teletext information. That is
09:30:35 [nigel]
s/That is
09:30:50 [nigel]
Matt: Newfor is not an open standard. Everyone who has a copy of it has inherited it rather than been
09:30:53 [nigel]
.. able to obtain it!
09:31:03 [nigel]
Andreas: And all of them use a different variation of this protocol.
09:31:07 [nigel]
Pierre: Who created Newfor?
09:31:28 [nigel]
Matt: Sysmedia, a guy called Andrew Lambourne who now works at the University of Sheffield Hallam I think.
09:31:42 [nigel]
.. It's a simple serial style wrapper around the core Teletext page instruction, with a session, flow management,
09:31:50 [nigel]
.. and wraps up what literally should be on the screen.
09:32:10 [nigel]
Andreas: What we see as a chance is the next Olympics. We have heard they want to offer much more
09:32:23 [nigel]
.. online than on broadcast, and they need to provide captions. That's the goal and we are really looking
09:32:29 [nigel]
.. for a good working solution here.
09:32:58 [nigel]
Matt: We did some work with Channel 4 in the UK, who broadcast the paralympics. They wanted to make
09:33:17 [nigel]
.. it all accessible online and the only solution was to hire a crate of kit from the US, go to SDI and back
09:33:34 [nigel]
.. out again, and doing that all cost quite a lot of money. The requirements really do exist.
09:33:46 [nigel]
Andreas: Marco, can we hand over to you?
09:33:54 [nigel]
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09:34:04 [nigel]
Marco: [presents slides]
09:34:09 [nigel]
.. [Status subtitle market]
09:34:34 [nigel]
.. Global overview of what you all said, to make clear the Europe subtitle volume is extensive.
09:34:53 [nigel]
.. Most countries have regulation with additional European regulation that will probably end up with
09:35:12 [nigel]
.. having 100% hearing impaired subtitling. About 50% of Europe uses translation subtitles as well.
09:35:32 [nigel]
Pierre: Checking my assumption, 5 years ago a lot of subtitling for translation but there is no [missed]
09:35:37 [nigel]
Frans: Different per country
09:35:50 [nigel]
Marco: The view is that accessibility needs to be at a higher level.
09:36:01 [nigel]
Frans: Increasing pressure, depends how far people can go because of money.
09:36:11 [nigel]
Pierre: On the accessibility standpoint, what is the coverage in Europe?
09:36:28 [nigel]
Frans: Subtitling only (captioning), 100% in NW Europe.
09:36:37 [nigel]
Marco: 95% on all content.
09:36:50 [nigel]
Matt: Many countries it is only the public service broadcaster.
09:37:07 [nigel]
Andreas: In Germany main channels 100%, major public ones, commercial ones down to 20%.
09:37:16 [nigel]
Marco: Will change with new EU regs.
09:37:20 [nigel]
Frans: Not sure timing
09:37:29 [nigel]
Matt: Equivalent of the US regs
09:37:38 [nigel]
Pierre: Public and commercial broadcasters?
09:37:42 [nigel]
Frans: Not equal
09:37:53 [nigel]
Andreas: Media industry requirements not so strict.
09:38:10 [nigel]
Matt: Strange things - some countries have more stringent regs because of their governments but
09:38:16 [nigel]
.. tech affects ability to deliver.
09:38:28 [nigel]
Pierre: Statement that penetration will increase is because of regulation or cost?
09:38:33 [nigel]
Marco: Regulation mainly.
09:38:43 [nigel]
group: [everyone wants to see data on that!]
09:39:16 [nigel]
Marco: On the translating part, a lot of countries have burned in subtitles too.
09:39:31 [nigel]
.. Differs between countries, in Netherlands it is all foreign language.
09:39:38 [nigel]
.. [Subtitle market status]
09:39:45 [nigel]
.. Shift from linear broadcast to on-demand and OTT.
09:39:55 [nigel]
.. New requirement for different devices not knowing Teletext.
09:40:14 [nigel]
.. Teletext used in broadcast facilities, page 888 for the viewer, being phased out.
09:40:24 [nigel]
.. Equipment is end of life, end of support, no new companies offering solutions.
09:40:46 [nigel]
.. Typically something I run into, no Teletext support in encoders.
09:41:01 [nigel]
.. Current support only goes to 7 lines, I need 15 or 16!
09:41:21 [nigel]
.. Current tech support is cut off but IP protocols not there - we really need to do something new.
09:41:30 [nigel]
.. New players on the market, mainly internet startups.
09:41:43 [nigel]
.. Know a lot about new world interfaces.
09:41:51 [nigel]
.. Need standardisation to get this streamlined.
09:42:06 [nigel]
.. Increasing demand for good access services and customisation on client side, so not sending
09:42:22 [nigel]
.. a rendered subtitle image but sending text so the front ends can customise.
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09:42:33 [nigel]
.. New volumes - non-audio videos without subtitles
09:42:38 [Zakim]
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09:42:55 [nigel]
.. Looking at new functionality for web players, extra metadata etc.
09:43:03 [nigel]
.. [EBU-TT as replacement]
09:43:28 [nigel]
.. File based, not for today. Teletext based - all proprietary, being phased out.
09:43:44 [nigel]
.. [Live transport in the chain] - picture from EBU spec, slightly modified.
09:43:59 [nigel]
.. Live part from authoring facility to playout, then playout to encoding.
09:44:12 [nigel]
.. EBU-TT Live -> EBU-TT-D/IMSC for player rendering and DVB
09:44:20 [nigel]
.. [NPO's live subtitle chain]
09:44:41 [nigel]
.. Live subtitle department done with one editor for simple programmes, and 3 editors for more complex
09:45:00 [nigel]
.. talking heads programmes, with respeaking, correcting and cueing, with video delays. Very demanding
09:45:11 [nigel]
.. for respeaking, so change editor roles during the programme.
09:45:23 [nigel]
.. Also trying to do automated subtitling, really a challenge at the moment.
09:45:36 [nigel]
.. Then playout, file based with STL and Cavena at the moment, need to go real time to encoder.
09:45:52 [nigel]
.. As Andreas said, Newfor and Teletext are the old world. Looking toward having a new world approach
09:46:03 [nigel]
.. where styling and formatting are equal and extendable through all devices.
09:46:22 [nigel]
.. So we want block based subtitling, handover between editors, time relationship is SMPTE based but
09:46:44 [nigel]
.. not always 'do it now' but could be late file delivery with overlaid live subtitles, then ingested during
09:46:51 [nigel]
.. playout for replay later.
09:47:10 [nigel]
.. Looking at media timecode in next generation which should last at least 3 years.
09:47:18 [nigel]
.. Need to fan out to multiple destinations.
09:47:36 [nigel]
.. Timebase processing (delay compensation)
09:47:46 [nigel]
.. Lowest delay NOW (remote capability) is needed
09:47:51 [nigel]
.. Same for file based playout.
09:48:10 [nigel]
.. SMPTE timecode, timebase correction, fan out to multiple destinations, timed metadata.
09:48:33 [nigel]
.. A TTML based approach really important for timed metadata.
09:48:58 [nigel]
.. In encoder, fan-in from multiple sources, then synchronise ABR and DVN stream transport,
09:49:05 [nigel]
.. subtitles and timed user metadata,
09:49:11 [nigel]
.. join other worlds like HbbTV.
09:49:24 [nigel]
.. [Needed] Widest standardization as possible.
09:49:37 [nigel]
.. Currently have momentum to get rid of old world possibly, but tools not available for new world yet.
09:49:40 [nigel]
.. Really frustrating.
09:49:54 [nigel]
.. Good to mention need for multiple languages including right to left. We have a huge amount of Arabic
09:49:57 [nigel]
.. in Holland.
09:50:18 [nigel]
.. Near real-time in parallel to SMPTE 2110 ideally in future, encapsulated in distribution for client renderers.
09:50:34 [nigel]
.. I hope to have some support for aligning positioning especially for converting from Teletext to new world.
09:50:43 [nigel]
.. EBU-TT Part 2 includes some guidance.
09:50:53 [nigel]
.. Would like to do the translation as early as possible in the chain.
09:51:08 [nigel]
Andreas: Thank you for that honest but realistic view of what is happening and what the challenges are.
09:51:26 [nigel]
.. Propose a break now for 15 minutes maximum.
09:51:31 [nigel]
.. Return at 11:05.
09:52:13 [nigel]
Nigel: Thank you for those presentations - they were really great!
09:52:19 [nigel]
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10:11:00 [nigel]
.. [return from break]
10:11:18 [nigel]
Andreas: Can we start with a summary from yesterday?
10:11:26 [nigel]
Nigel: Not sure exactly what you're referring to?
10:11:44 [nigel]
Andreas: Yesterday it came up what could be done with EBU-TT Live and how to handle it in W3C.
10:12:14 [nigel]
.. TTWG will have a new kind of layout a bit like CSS, where some functionality is taken out of the main
10:12:28 [nigel]
.. specification and put into modules. This opens up a more flexible approach to address current
10:12:38 [nigel]
.. requirements and parallelise activities so they do not block each other.
10:12:51 [nigel]
.. In this context one of the proposals was to take the functionality and possibly the vocabulary of
10:13:07 [nigel]
.. EBU-TT Live in a module published by W3C which then can be used by any profile of TTML, could be
10:13:11 [nigel]
.. EBU-TT, IMSC or whatever.
10:13:20 [nigel]
.. From my impression that's where it ended, it's a feasible approach.
10:13:36 [nigel]
.. There are other questions how it could look at the end and the mechanics e.g. a submission from EBU
10:13:56 [nigel]
.. as a W3C member. It is a feasible approach.
10:14:08 [nigel]
Glenn: Clarifying my thinking on modularisation approach and how it is not exactly like CSS.
10:14:21 [nigel]
.. In CSS they carved up the existing functionality of CSS2 into pieces and called them modules.
10:14:37 [nigel]
.. I'm not assuming and would oppose doing the same thing here with TTML3 because there are so many
10:14:50 [nigel]
.. interlinked semantics between the different components and it would create quite a bit of effort to
10:15:04 [nigel]
.. carve it into pieces and I don't see any advantage in evolution because it is fairly stable.
10:15:19 [nigel]
.. What I see happening is in the context of TTML3 creating a new framework for modules to allow
10:15:28 [nigel]
.. new functionality to exist that is not in TTML2.
10:15:40 [nigel]
.. To the extent that we can put it into different module documents proceed on that basis.
10:15:54 [nigel]
.. It may turn out that there are some substantive changes not in TTML2 2nd Ed that are appropriate
10:16:13 [nigel]
.. for making in the core of TTML3 that are not in modules, but to the extent that we don't separate
10:16:32 [nigel]
.. functionality then that would be the best approach, allowing parallelisation of work and editorial activities.
10:16:42 [nigel]
.. Especially for new well identified groups of functionality such as live.
10:16:54 [nigel]
.. Just communicating my understanding because that's what I'm going to operate on.
10:17:01 [nigel]
.. If people differ from that I'd like to hear about it.
10:17:14 [nigel]
Andreas: I think it would work well for this use case, and it would also be good to discuss why we have
10:17:31 [nigel]
.. the discussion. Right now EBU-TT Live is complete and is out there. What are the benefits of bringing
10:17:34 [nigel]
.. into W3C?
10:17:52 [nigel]
.. 1. To encourage vendor support, by having a global solution.
10:18:10 [nigel]
.. 2. I know there are ideas and requests for updates of functionality. Here it is better to do it in one
10:18:21 [nigel]
.. group rather than separate groups.
10:18:39 [nigel]
Nigel: Add one more, which is it would allow us to make a thing like IMSC Live, which currently seems to
10:18:58 [nigel]
.. be excluded by EBU-TT Live even though in principle it is possible to make IMSC-conformant EBU-TT Live
10:19:14 [nigel]
.. documents, I don't think that seems obvious to the wider world.
10:19:37 [nigel]
.. Also there are some useful constructs permitted in IMSC that are excluded by EBU-TT Live.
10:19:55 [nigel]
Andreas: That's right, and you also point to an important issue that EBU-TT Live is first a description
10:20:12 [nigel]
.. of how a live TTML workflow should look, with some additional syntax and semantics.
10:20:28 [nigel]
.. It is bound to EBU-TT syntax definition, so limited to what is in EBU-TT Part 1.
10:21:02 [nigel]
Marco: Two main topics: The transport mechanism and the syntax of the documents.
10:21:05 [nigel]
Andreas: Right.
10:21:22 [nigel]
Nigel: In the EBU specs we've tackled them as separable things.
10:21:48 [nigel]
Andreas: So 3 things: Workflow, Carriage mechanisms, and the payload.
10:22:47 [nigel]
Marco: What I meant was the transport and how we encapsulate the handshake in mechanisms.
10:23:06 [nigel]
Andreas: There are clear benefits also in the EBU group, and everyone involved in standardising EBU-TT Live
10:23:12 [nigel]
.. is convinced of the usefulness here.
10:23:29 [nigel]
.. It would be useful to hear from others in TTWG, Pierre, Glenn.
10:23:45 [nigel]
Pierre: Yes, I don't have a very strong opinion about applying only to IMSC or to TTML as a module, I'm
10:23:51 [nigel]
.. happy either way, whichever works best.
10:24:01 [nigel]
.. I think it would be good to apply to IMSC somehow if it is possible.
10:24:20 [nigel]
.. Last time I saw it it was merely a couple of additional attributes with no impact on visual presentation.
10:24:30 [nigel]
.. The only feedback on the document that I have already shared is it is too long.
10:24:44 [nigel]
.. Otherwise it seems like a good idea. I like the idea of trying to focus development on the technical
10:24:57 [nigel]
.. specifications in a single place. The requirements can come from other groups.
10:25:03 [nigel]
group: [general agreement]
10:25:11 [nigel]
Frans: I totally agree, that is the main point.
10:25:24 [nigel]
.. A second point is ease of marketing, branding, so considering a complete IMSC based future could be
10:25:39 [nigel]
.. very attractive as the main thing people know about. We should embrace the best candidate we have
10:25:49 [nigel]
.. and it is IMSC, that gives us the biggest chance of adoption.
10:26:15 [nigel]
Pierre: Specifically on EBU-TT Live and authoring, with SMPTE 2110 and the brave new world, it would be
10:26:32 [nigel]
.. really good for this community to help folks pick the right technology, or someone will pick SMPTE-TT
10:26:37 [nigel]
.. and say that's what we're doing now.
10:26:52 [nigel]
.. My feedback to Nigel is the more we can do to narrow what goes over 2110 the better otherwise we
10:27:07 [nigel]
.. will have disappointment, otherwise someone will implement TTML over 2110 and it won't work
10:27:11 [nigel]
.. between vendors.
10:27:40 [nigel]
Matt: I would like to see removal of specific protocols for individual markets, in favour of global ones
10:27:53 [nigel]
.. To avoid lossy transcode, reworking, and support new languages.
10:28:15 [nigel]
.. I've had conversations about Punjabi, Hindi, Mandarin, Cantonese (bizarrely), Arabic, they all need some
10:28:21 [nigel]
.. kind of kludge.
10:28:41 [nigel]
Pierre: Can we talk about 2110, how can we contribute positively?
10:29:45 [nigel]
Nigel: On the point about TTML vs IMSC for this, there are other uses of TTML than subtitles, which
10:30:00 [nigel]
.. may benefit from live contribution, like AD, as agreed yesterday, so it makes sense to put it there.
10:35:06 [nigel]
.. On the 2110 issue, have to use TTML because that is what has the IANA registration.
10:35:28 [nigel]
.. Also want to encourage use of codecs parameter from the beginning to avoid the non-adoption problem.
10:35:44 [nigel]
.. Also we will need other specs like in SMPTE, NMOS and EBU to complete the suite.
10:35:54 [nigel]
Frans: [scribe missed]
10:36:17 [nigel]
Andreas: We are here because we want to work more closely together. This work counts the same,
10:36:32 [nigel]
.. need to focus on working together and make sure as Pierre says that the major stakeholders align
10:36:38 [nigel]
.. on one approach to solving a specific problem.
10:36:45 [nigel]
.. Parallel solutions won't help.
10:37:01 [nigel]
.. I'm not so familiar with IETF. Two forms of collaboration. One is publish something and let the domain
10:37:20 [nigel]
.. submit some feedback, send comments back. This works not that well in the past because of workload.
10:37:34 [nigel]
.. The other is getting together in a room and talking through the problem.
10:37:52 [nigel]
.. I'm not sure about this particular work, BBC is submitter so that is helpful. The relevant people
10:38:04 [nigel]
.. should come together and at least discuss this paper and agree it is the right approach.
10:38:07 [nigel]
.. For SMPTE I'm not sure.
10:38:39 [nigel]
Nigel: I've already received a request to discuss in W3C TTWG and am happy to do that.
10:38:57 [nigel]
Frans: Putting together a timeline would be useful.
10:39:25 [nigel]
Pierre: To better understand 2110, there's a bunch of specifications for audio and video but is there any
10:39:28 [nigel]
.. about timed text today?
10:39:31 [nigel]
Nigel: No there isn't yet.
10:39:35 [nigel]
Pierre: I'd like to come back to that.
10:39:49 [nigel]
Andreas: Okay, from the feedback so far I haven't heard anybody objecting the approach to bring the
10:40:03 [nigel]
.. EBU-TT Live activity into W3C at least to mirror the most important parts of EBU-TT Live as a module
10:40:07 [nigel]
.. in a W3C spec.
10:40:41 [nigel]
Nigel: Is it clear to everyone what the syntax, semantics and general approach is?
10:41:12 [nigel]
Andreas: We may not have time to go through it.
10:41:27 [nigel]
Nigel: Just want to check if there is enough awareness to make a general decision.
10:41:34 [nigel]
Glenn: What's the decision
10:41:37 [nigel]
s/ion/ion?
10:41:47 [nigel]
Andreas: To bring the EBU-TT Live work into W3C
10:41:56 [nigel]
Glenn: Sounds good to me, mutatis mutandis.
10:42:00 [nigel]
Frans: To make IMSC Live?
10:42:19 [nigel]
Andreas: First to bring into TTML, second should we say it is our goal to make IMSC usable together with
10:42:30 [nigel]
.. this module, if it is a profile or an addition to IMSC has to be found out.
10:42:52 [nigel]
.. The other thing I think is also important is to bring over these two attributes like multiRowAlign.
10:43:05 [nigel]
.. Do we say the EBU-TT Live attributes are now handled in W3C space?
10:43:14 [nigel]
Glenn: A more practical question - do we have a prospective editor?
10:43:26 [nigel]
Andreas: We clarified this yesterday Nigel will be.
10:43:34 [nigel]
Pierre: Do we need to make a decision today?
10:43:45 [nigel]
Andreas: Let us see if we are ready for a decision!
10:43:51 [nigel]
Pierre: On the namespace?
10:44:07 [nigel]
Andreas: What do you mean? Concrete proposal: move the syntax and semantics into a TTML3 module
10:44:20 [nigel]
.. without changing syntax, then add to IMSC Live.
10:44:38 [nigel]
Glenn: I mentioned yesterday I would be amenable to enabling foreign namespace vocabulary in
10:44:48 [nigel]
.. modules, so that could work for this and for multiRowAlign and linePadding.
10:45:04 [nigel]
.. That would also in my mind be a potential incorporation of those into the TTML core but that is a
10:45:17 [nigel]
.. future process to think about. By then it may be that we have acceptance of the use of foreign
10:45:19 [nigel]
.. namespaces in TTML.
10:45:33 [nigel]
Pierre: On the relationship with IMSC, maybe the jury is still out, but my understanding is that these are
10:45:43 [nigel]
.. timing attributes added to a TTML document?
10:45:46 [nigel]
Glenn: Almost like metadata.
10:47:14 [nigel]
Pierre: Exactly, they're permitted additions that don't affect presentation.
10:47:19 [nigel]
Andreas: Apart from timebase clock
10:47:46 [nigel]
Nigel: Like a pre-processor that affects the time during which the document is active, otherwise yes the same.
10:47:51 [nigel]
Pierre: We can just do it.
10:48:02 [nigel]
Andreas: Both a technical and a marketing side to this.
10:48:18 [nigel]
Frans: So we could end up in an ideal case in a few years with everything IMSC and the world is simple,
10:48:28 [nigel]
.. that would be the best solution, forgetting TTML, EBU-TT all the rest of it.
10:48:45 [nigel]
Matt: It is being adopted already without a second thought, seemingly, so it is free of geographical boundaries
10:48:49 [nigel]
.. already I would say.
10:49:03 [nigel]
Andreas: I don't think we need a final decision on this depth, but if we agree then we should prepare the
10:49:17 [nigel]
.. next steps and propose it and do something similar as the two styling attributes.
10:49:29 [nigel]
.. For me it is clearer we should handover maintenance and control of this to W3C.
10:51:47 [nigel]
Nigel: If we are writing a liaison, a piece of paper, we can either cover all of it, or have two, one for
10:51:50 [nigel]
.. styling and one for live.
10:52:04 [nigel]
.. I've heard enough that there is consensus on our requirements issue to take it forward for this year.
10:52:15 [nigel]
Pierre: A member submission would be the best thing.
10:52:33 [nigel]
Nigel: Quite a lot of overhead in doing that, I'd rather start in W3C with an empty thing.
10:53:07 [nigel]
Andreas: Proposing to hand over control over EBU-TT Live to TTWG, to republish EBU-TT Live as a module,
10:53:19 [nigel]
.. further updates of EBU-TT Live done in the TTWG and not the EBU Timed Text group.
10:54:26 [nigel]
Nigel: EBU should have the freedom to iterate its specs if it wants to do so.
10:54:37 [nigel]
Frans: Query if we want to update EBU-TT Live or brand everything as IMSC Live.
10:55:02 [nigel]
.. That's an important consideration. I would be in favour of steering everything towards IMSC.
10:55:36 [nigel]
Nigel: I don't disagree, maybe EBU should publish something explaining this position to the world.
10:55:49 [nigel]
Andreas: We are making an important shift, we may need to discuss this further. For me it makes more
10:56:04 [nigel]
.. sense to make a cut and say we transfer it now to another organisation and will not update further.
10:56:20 [nigel]
.. For the two vocabulary items we hand over control and if there are further EBU specfications we can
10:56:29 [nigel]
.. publish a new spec referencing.
10:56:37 [nigel]
Frans: What if there is a bug in EBU-TT Live?
10:56:55 [nigel]
Andreas: If there is a short term need then we can do that otherwise we should not.
10:57:03 [nigel]
Frans: I am not sure what timelines we are talking about.
10:57:18 [nigel]
Marco: Isn't it about securing EBU requirements in a future spec?
10:57:22 [nigel]
Frans: I feel confident about that.
10:57:38 [nigel]
Andreas: We have enough shared members, we can collect requirements from the EBU and bring it into
10:57:47 [nigel]
.. the new W3C spec but do not publish in EBU scope.
10:57:55 [nigel]
Marco: That makes it clearer to the rest of the world.
10:58:06 [nigel]
Frans: It is all about simplicity. In spirit we all agree.
10:58:18 [nigel]
Andreas: Long term goal is agreed, need to figure out how it would work in the short term.
10:58:59 [nigel]
Nigel: Checking in on the agenda, we've covered almost all the topics, 15 minutes to go.
10:59:35 [nigel]
.. Pierre asked to come back to SMPTE 2110, and Andreas you wanted to come back to something too?
10:59:54 [nigel]
Topic: EBU and W3C collaboration
11:00:03 [nigel]
Andreas: [shares screen]
11:00:16 [nigel]
.. We have these two attributes, and part 1, and EBU-TT-D and part M.
11:00:30 [nigel]
.. Starting with EBU-TT-D, one approach we could take that would benefit industry is to say we stop
11:00:52 [nigel]
.. work on EBU-TT-D and point to IMSC for any future update, or missing functionality or bug fixes.
11:00:56 [nigel]
.. That would be a clear message.
11:01:07 [nigel]
.. We should try to elaborate if we can do something similar for Part 1 and Live.
11:02:44 [nigel]
Nigel: I think a key point here is how we handle smpte and clock timebases, which are in EBU-TT and TTML
11:02:51 [nigel]
.. for a reason, and not in IMSC also for good reasons.
11:03:01 [nigel]
Marco: As a broadcaster, I can say it won't work for the next 3 years.
11:03:27 [nigel]
s/reasons./reasons. Can media time only work in playout scenarios?
11:03:38 [nigel]
Andreas; Stick with what works and is available.
11:03:53 [nigel]
Pierre: Exactly, that's what you have to do.
11:04:24 [nigel]
.. You can adopt EBU-TT Part 1 today and constrain it. 3 works is a realistic horizon to work with
11:04:38 [nigel]
.. vendors and service providers and say in 3 years we plan not to use timecode for those workflows.
11:04:51 [nigel]
Marco: We always have legacy from our archives so we need some timebase transcoding somewhere.
11:05:06 [nigel]
.. It's already on my list. I think I'm forward looking within the range of broadcast views!
11:05:21 [nigel]
Frans: Absolutely. This is a very critical thing, we need to spell out the transition scenario, how does this
11:05:33 [nigel]
.. work, what do you encounter in practice. If we cannot we are not in a good situation.
11:05:46 [nigel]
Marco: We have to guarantee that what is in EBU-TT now remains the same in large part for IMSC.
11:05:54 [nigel]
Pierre: Looking at the differences, is that the sum total?
11:06:13 [nigel]
Andreas: Those are the main things on a quick look. The really substantive things are timecode and cell.
11:06:27 [nigel]
.. Cells are manageable by translation to %.
11:06:41 [nigel]
Pierre: Especially with IMSC 1.1 we have rh and rw so there is a lossless 1:1 translation from cell.
11:06:47 [nigel]
Andreas: There's more work to be done that's clear.
11:07:06 [nigel]
.. To say it is simple, everything IMSC, wherever it is, I see some kind of agreement that this is the long
11:07:22 [nigel]
.. term goal, and possibly to come together and discuss it maybe at IBC. We can try to set up a new
11:07:35 [nigel]
.. joint meeting at IBC.
11:07:49 [nigel]
Pierre: What's the timeline for submission of EBU-TT Live and EBU-TT Part 1?
11:07:56 [nigel]
.. And starting that convergence process.
11:08:12 [nigel]
Andreas: For Part 1 it is different, we haven't started the discussion. For Live it is easier, depends on
11:08:16 [nigel]
.. Nigel who has the most work on it.
11:08:27 [nigel]
Pierre: That could be part of what we try to do this year with IMSC.
11:08:33 [nigel]
Frans: To do the transfer, this year?
11:08:47 [nigel]
Pierre: Yes, as well as other additions to IMSC that we have discussed, like embedded fonts.
11:09:03 [nigel]
Nigel: I'm not clear what needs to be done to IMSC though?
11:09:14 [nigel]
Pierre: Exactly, that is why I am optimistic.
11:09:28 [nigel]
Andreas: The live module can be done this year.
11:09:39 [nigel]
Pierre: And make a goal to resolve differences with EBU-TT Part 1.
11:09:52 [nigel]
Andreas: That is more complex, I don't see Part 1 alignment this year.
11:10:02 [nigel]
Pierre: If we are targeting 3 years it would be ideal to do it this year.
11:10:14 [nigel]
.. I think it would be different if there had been broad adoption of EBU-TT Part 1.
11:10:24 [nigel]
Frans: I agree. We need a clear understanding of how it is used.
11:10:41 [nigel]
Marco: For example live ingest - how do you translate that to time expressions in a Part 1 document.
11:11:02 [nigel]
Pierre: What we saw yesterday is the bigger issue with live is not the timebase, but the separation of
11:11:11 [nigel]
.. flows of audio/video and subtitles.
11:11:16 [nigel]
Frans: But part 1 not live.
11:11:25 [nigel]
Pierre: This will never be used in live?
11:11:31 [nigel]
.. What would it be used for?
11:11:42 [nigel]
Frans: Prepared content
11:11:45 [nigel]
Pierre: Why use timecode?
11:11:54 [nigel]
Marco: To synchronise with the playout server.
11:11:59 [nigel]
Frans: Longer discussion!
11:12:18 [nigel]
Andreas: We can schedule for live in W3C, for part 1 we need further discussions and we should have
11:12:22 [nigel]
.. this kind of coming together.
11:12:29 [nigel]
.. What about this goal to be at IBC.
11:12:58 [nigel]
Nigel: Logistical issue of timing of meetings - TPAC is very close to IBC, I can't be at both probably.
11:13:10 [nigel]
Frans: IBC is where we can collect user input. We need that.
11:13:28 [nigel]
Andreas: We don't necessarily need the people in the room but we need the feedback channeled through us.
11:13:36 [nigel]
Frans: IBC is an opportunity to meet industry people.
11:13:44 [nigel]
Pierre: Do we present results or gather feedback?
11:14:02 [nigel]
Frans: Both, there is not enough time to gather information about timecode usage at IBC
11:14:21 [nigel]
Andreas: A half day workshop would be useful, after the standards people get together.
11:14:27 [nigel]
Pierre: So present results at IBC.
11:14:30 [nigel]
Frans: That would be great.
11:14:47 [nigel]
Pierre: I'm pretty confident that North America is happy to use IMSC for production, I'll hear more in 2 weeks.
11:14:51 [nigel]
.. For live I don't know.
11:15:13 [nigel]
Matt: Live is typically 608 originated and delivered straight into EEG or Evertz encoders. It is ripe for evolution.
11:15:29 [nigel]
Pierre: I don't know about live, I'm pretty sure IMSC will be good enough, I've not heard any objection to that.
11:15:34 [nigel]
.. Would be good to hear from EBU members.
11:15:42 [nigel]
Frans: It is an extremely early stage.
11:15:52 [nigel]
Andreas: We can cover Live and EBU-TT-D at IBC.
11:16:07 [nigel]
.. Then we can start to get out the message about part 1 but I agree with Frans it is more complicated.
11:16:11 [nigel]
.. This overall meeting would be good.
11:16:18 [nigel]
.. Nigel you say they are close together?
11:16:56 [nigel]
Pierre: The only way I could do TPAC is to be there for a day and a half.
11:17:13 [nigel]
Andreas: For the TTWG we had the idea to move the regular meeting out of TPAC. That would be a question
11:17:21 [nigel]
.. if we would move the meeting to Amsterdam.
11:17:40 [nigel]
Pierre: Tokyo would be a lot closer in travel time than Fukuoka!
11:18:13 [nigel]
.. By the way I did complain to W3M and they said they don't have IBC and NAB on their calendars!
11:18:17 [nigel]
.. They said it would be a good idea.
11:18:29 [nigel]
.. The AC meeting is right on top of NAB and TPAC on top of IBC.
11:18:48 [nigel]
Andreas: To sum up we try to move forward offline with EBU-TT Live as quickly as possible and we also
11:18:57 [nigel]
.. have some discussion about EBU-TT-D and Part 1 and share info soon.
11:19:10 [nigel]
.. Then we propose to both groups to have a domain meeting where we present our results but also a
11:19:32 [nigel]
.. face to face meeting that would be joint EBU and TTWG. We have absent TTWG people today so we have
11:19:45 [nigel]
.. to propose it.
11:19:57 [nigel]
Pierre: If you're organising meetings at IBC you're not going to make it to TPAC.
11:20:15 [nigel]
Matt: I would go to IBC but not TPAC.
11:20:24 [nigel]
Frans: So hold an industry meeting and a joint meeting both at IBC?
11:20:34 [nigel]
Matt: I'd request immediately before IBC or after, not during.
11:20:43 [nigel]
.. So we travel to Amsterdam once and stay.
11:20:52 [nigel]
.. If we could do it on the Thursday that would be good for me.
11:20:58 [nigel]
.. I will be busy after then.
11:21:08 [nigel]
Andreas: That makes sense.
11:21:14 [nigel]
Matt: I'm usually exhausted by the Tuesday.
11:21:22 [nigel]
Andreas: We need to discuss this in the TTWG.
11:21:42 [nigel]
Pierre: If TTWG is not going to meet at TPAC that would be good to know as early as possible.
11:21:54 [nigel]
Andreas: It would be good to send a message out at IBC.
11:22:07 [nigel]
Matt: Possibly arrange a presentation, say in the innovation presentation area.
11:22:31 [nigel]
Andreas: Those are the things that come to my mind. Anything else we need to discuss or finalise?
11:22:37 [nigel]
kge,
11:22:43 [nigel]
s/ kge,/
11:22:50 [nigel]
Pierre: Is it bad not to attend TPAC?
11:23:05 [nigel]
Thierry: There's nothing mandatory but it is convenient for coordinating with other groups. There are no
11:23:12 [nigel]
.. rules about it, it is just for convenience.
11:23:18 [nigel]
.. The dates for meeting would be?
11:23:25 [nigel]
Andreas: We need to check it offline.
11:23:44 [nigel]
Pierre: Either Thursday 12th Sep or Tuesday 17th.
11:23:55 [nigel]
Andreas: If nothing else we can close the joint meeting.
11:24:59 [nigel]
Nigel: Thank you everyone, a good morning's work and good discussion, we can adjourn now.
11:25:03 [nigel]
.. [adjourns meeting]
11:25:08 [nigel]
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12:34:41 [nigel]
i/Matt: Background to fit into that/BBC subtiltes 100%, includes all live programmes.
12:34:53 [nigel]
i/Matt: Background to fit into that/Stateful Teletext based (legacy) technology is used for this.
12:35:05 [nigel]
i/Matt: Background to fit into that/Does NOT support future requirements, such as live streaming of bespoke events, cloud encoding, etc.
12:35:14 [nigel]
i/Matt: Background to fit into that/When studying the standards supporitng this authoring-to-encoding part of the workflow.
12:35:34 [nigel]
i/Matt: Background to fit into that/EBU-TT was the obvious choice (the BBC was already producing in EBU-TT).
12:35:46 [nigel]
i/Matt: Background to fit into that/EBU-TT-Live (Tech 3370) specifies how you can send a stream of text chunks to facilitate this scenario; with 0 or 1 documents 'active' at any time.
12:36:08 [nigel]
i/Matt: Background to fit into that/The EBU-TT-Live Toolkit validated the spec and helps implement it: https://github.com/ebu/ebu-tt-live-toolkit
12:36:22 [nigel]
i/Matt: Background to fit into that/Timed changes do not have to be explicit ('just send a new document') as was demoed in the SwissTXT demonstration at EBU PTS 2019 for example.
12:36:34 [nigel]
i/Matt: Background to fit into that/SMPTE timecode is not allowed (as you cannot do match on it).
12:36:42 [nigel]
i/Matt: Background to fit into that/Carriage using web sockets has been defined.
12:36:53 [nigel]
i/Matt: Background to fit into that/EBU-TT-Live / TTML carriage in RTP for use in SMPTE 2110 ("IP replacement of SDI") is being worked on; BBC has submitted an RFC for TTML carriage in RTP.
12:37:31 [nigel]
rrsagent, make minutes
12:37:31 [RRSAgent]
I have made the request to generate https://www.w3.org/2019/02/01-tt-minutes.html nigel
12:39:45 [nigel]
s|s/That is||
12:39:58 [nigel]
s/transmit teletext information. That is/transmit teletext information.
12:40:20 [nigel]
s/.. New requirement for different devices not knowing Teletext./Marco: New requirement for different devices not knowing Teletext.
12:40:41 [nigel]
s/.. New players on the market, mainly internet startups./Marco: New players on the market, mainly internet startups.
12:40:59 [nigel]
s/.. New volumes - non-audio videos without subtitles/Marco: New volumes - non-audio videos without subtitles
12:41:15 [nigel]
s/.. new functionality to exist that is not in TTML2./Glenn: new functionality to exist that is not in TTML2.
12:41:28 [nigel]
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12:41:28 [RRSAgent]
I have made the request to generate https://www.w3.org/2019/02/01-tt-minutes.html nigel
12:44:21 [nigel]
scribeOptions: -final -noEmbedDiagnostics
12:44:24 [nigel]
rrsagent, make minutes
12:44:24 [RRSAgent]
I have made the request to generate https://www.w3.org/2019/02/01-tt-minutes.html nigel