IRC log of tt on 2016-08-18

Timestamps are in UTC.

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logging to
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Zakim, this will be TTML
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ok, trackbot
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Meeting: Timed Text Working Group Teleconference
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Date: 18 August 2016
14:01:29 [nigel]
Present: Nigel, Glenn
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Present+ Pierre
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Present+ Mike
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Topic: This Meeting
14:06:16 [tmichel]
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nigel: Today I had planned for an extra 30 minutes for Dave Singer to chair the agenda item
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... on WebVTT but he tells me the preparation isn't ready yet for that. So we can get the 30 minutes back or use it.
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group: Need to finish after 60 minutes
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scribe: nigel
14:07:18 [nigel]
chair: Nigel
14:08:13 [nigel]
nigel: Agenda for today is TPAC, TTML. AOB?
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group: No AOB.
14:08:27 [nigel]
Regrets: Andreas, Frans
14:08:41 [nigel]
tmichel: I sent a list today about a request from Amazon for TTML2 tests, so if we do have
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... up to date tests a pointer would be useful.
14:09:07 [nigel]
gadams: I followed up on that out of band and sent them a pointer to the TTT github repo
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... where there is some TTML2 test material, not W3C sanctioned at this point.
14:09:21 [nigel]
tmichel: Thank you Glenn!
14:10:37 [gadams]
I received the following from Mr Michel. The TTML2 test suite which will be created by the W3C for the purpose of validating the TTML2 specification is not yet available as a whole. However, there are some initial tests found under [1], primarily at [2] and [3]. This project TTT [1] is a work in progress, and support for TTML2 is currently being added, with scheduled completion of March 2017. Note that this project is not originated by W3C itself, but from a 3rd par
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party, namely my company. [1] [2] [3]
14:11:06 [tmichel]
Glenn maybe you could copy me your email response would be helpfull for a response from me.
14:11:33 [tmichel]
thanks Glenn
14:11:34 [nigel]
nigel: I will also respond CC Thierry to explain the status of the TTML2 work and when we will move to implementation/test stuff.
14:12:08 [nigel]
mike: They may or may not mean TTML2. They may have grabbed the latest spec but actually
14:12:25 [nigel]
... be interested in deployment of TTML1, specifically EBU-TT-D and IMSC1 so it would be
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... helpful to educate them on the status of those specs too, and their test materials.
14:12:39 [nigel]
nigel: +1
14:13:03 [nigel]
gadams: I don't know for a fact but it's possible that they've been talking to Netflix about TTML2 also.
14:13:12 [nigel]
nigel: There's no harm educating, so I'll do that.
14:13:41 [nigel]
Topic: TPAC 2016
14:13:47 [nigel]
nigel: Registration closes on Sep 2!
14:13:52 [tmichel]
FYI Amazon is NOT a W3C Member. We tryed to have them in for Digital publishing but they use their own KINDLE format and not EPUB.
14:13:56 [nigel]
14:14:00 [trackbot]
action-475 -- Nigel Megitt to Contact the chair of the web & tv ig to ask about schedule and joint meeting time. -- due 2016-07-28 -- OPEN
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14:14:41 [nigel]
tmichel: I will meet Yosuke next Tuesday so I'll ping him directly by voice then.
14:14:44 [nigel]
nigel: Okay, thanks.
14:15:06 [nigel]
tmichel: I will tell him it is a priority because TPAC is getting closer now.
14:15:29 [nigel]
nigel: True. On that topic I will give myself an action to put together a straw man agenda
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... that we can look at, adjust as needed before the meeting.
14:15:55 [nigel]
Action: nigel Put together a TPAC straw man agenda
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Created ACTION-476 - Put together a tpac straw man agenda [on Nigel Megitt - due 2016-08-25].
14:17:01 [nigel]
nigel: Next week I'm on vacation so if someone wants to step in and chair this meeting please
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... volunteer, otherwise we have 3 meetings before the face to face at TPAC.
14:17:28 [nigel]
nigel: Please let me know any agenda items especially if they may be unexpected.
14:18:05 [nigel]
glenn: We should probably coordinate on getting together on Sunday evening if we want to.
14:18:47 [nigel]
nigel: I'd be happy to meet up at say 2000 based on my arrival time.
14:19:28 [nigel]
glenn: Maybe those who are going to be there could let you know their locations and we
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... could triangulate.
14:19:51 [nigel]
nigel: Yes, sure, okay, also we usually put hotels etc on the wiki meeting page, so I'll set that
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... up as part of action-475
14:20:18 [nigel]
pal: I'll be there.
14:22:00 [nigel]
Topic: TTML1 & TTML2 issues, actions, PRs, editorial actions etc
14:22:18 [nigel]
14:22:18 [trackbot]
action-462 -- Glenn Adams to Create issue on ttml2 to add "mapping from other versions and profiles of ttml" -- due 2016-04-28 -- OPEN
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14:22:25 [nigel]
glenn: No progress on that yet.
14:24:22 [nigel]
nigel: [diverts topic to IMSC temporarily] Pierre do we need to talk about the IMSC roadmap PR?
14:24:40 [nigel]
pal: Not really, but I have been asked to update the wiki with the latest IMSC implementations
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... and plan to do that in the next week or so.
14:24:59 [nigel]
nigel: Is that also for test resources?
14:25:13 [nigel]
pal: For IMSC 1 we duplicated the implementation report so that we can add new results,
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... test vectors etc so that we could update this new page, so that may be the right place to
14:25:43 [nigel]
... list IMSC 1 implementations, because they will also have tests, test reports etc. Then I would
14:26:01 [nigel]
... add a link from the TTML and WebVTT implementations page to the new IMSC implementations page.
14:26:07 [nigel]
... While I'm doing that I will also apply the PR.
14:27:18 [nigel]
nigel: [Back on TTML2 topic] There have been some new issues also. What's best to discuss first?
14:28:19 [nigel]
nigel: Let's cover position syntax first:
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gadams: I was creating some test content for position and backgroundPosition style attributes
14:28:46 [nigel]
... that are new to TTML2 and I discovered that there was a missing rule in the grammar for
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... position that effectively made it different than what CSS3 uses for position. CSS3 Background
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... and Borders defines the CSS3 property position allows you to reverse the horizontal and
14:29:33 [nigel]
... vertical components of the position specification, but they allow vertical first and horizontal second.
14:29:56 [nigel]
... That was apparently an oversight when I transcribed the grammar.
14:30:11 [nigel]
nigel: How do you know which way round the values are, if that's not a stupid question?
14:30:24 [nigel]
gadams: That's a good question, particularly because the keyword "center" can apply to both.
14:30:44 [nigel]
... If you use top or bottom first then it's clear that you mean a vertical offset.
14:31:28 [gadams]
<style tts:backgroundPosition="center left"/> <!-- NG --> <!-- TTML does not support this valid CSS3 expression --> <style tts:backgroundPosition="center right"/> <!-- NG --> <!-- TTML does not support this valid CSS3 expression --> <style tts:backgroundPosition="top center"/> <!-- NG --> <!-- TTML does not support this valid CSS3 expression --> <style tts:backgroundPosition="bottom
14:32:01 [nigel]
gadams: I've pasted above the four test cases (not well formatted) that did not quite work.
14:32:15 [nigel]
nigel: In the issue you use offset-position-h and offset-position-v but in CSS the interchangeable
14:32:25 [nigel]
... terms are keyword-position-h and keyword-position-v.
14:33:02 [gadams]
14:34:13 [nigel]
gadams: For the 2 component value it was missing the reverse version. This is expanded
14:34:20 [nigel]
... out as opposed to abbreviated compared to the CSS3 spec.
14:35:04 [nigel]
nigel: At least one of the position keywords must be present to resolve reversed values.
14:35:14 [nigel]
gadams: That's right, and they have to be something other than "center".
14:35:29 [nigel]
... It is probably worth noting under the grammar that two linked or center values should
14:35:39 [nigel]
... be mapped to offset horizontal followed by vertical.
14:36:06 [nigel]
nigel: Okay, let's move on to
14:38:13 [nigel]
nigel: The background here is that it was unclear if implied anonymous regions should be
14:39:12 [nigel]
... implemented as new regions or modifications to current regions. Since then Glenn has
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... added a note to the issue to suggest that we add a parameter attribute to direct the
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... behaviour, which sounds like a good idea to me.
14:40:27 [nigel]
gadams: I hadn't thought about the modification option before you raised it Nigel but I'm
14:40:36 [nigel]
... willing to give it a try both in the specification and the implementation.
14:40:50 [nigel]
pal: What's the advantage of having both methods?
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gadams: The modification approach allows region styling to be maintained while applying an
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... anonymous set of the region origin and extent, for border, backroundColor etc.
14:42:17 [nigel]
pal: What's important to understand is whether the adopters of this syntax also intended to
14:42:34 [nigel]
... apply region styling with their method. For example if I use tts:extent and tts:position on a
14:43:18 [nigel]
... p then I cannot apply backgroundColor on that and hope that it applies. It would be good to know
14:43:31 [nigel]
... what they intended, and to dig deeper before concluding that we need to support both methods.
14:43:44 [nigel]
gadams: I'm assuming based on experience and having talked to people that their understanding
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... was based on creating a new region.
14:46:27 [nigel]
nigel: I suspect that the users of this syntax never added the complexity of region styling
14:46:56 [nigel]
... or even had temporally overlapping content. For those documents then it won't make
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... any difference which approach is used. For more complex uses then it would be helpful to have the choice.
14:48:31 [nigel]
gadams: One of the best arguments against the modification approach is the use of two
14:48:44 [nigel]
... temporally overlapping content elements in the same region. I also know Netflix has a
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... definite requirement for the flavour of creating a new region.
14:50:07 [nigel]
pal: There are tons of tools that put extent and origin on elements other than region. We're
14:50:37 [nigel]
... trying to reverse engineer that into TTML2. The other option that we should consider is
14:50:47 [nigel]
... simply allowing all the region styling on p and just apply to the anonymous region.
14:50:59 [nigel]
gadams: That doesn't work because we have a growing number of properties that apply to
14:51:15 [nigel]
... both content and region, like padding, border, bpd and ipd, and more. They apply
14:51:27 [nigel]
... independently to both content elements and regions. It would make the spec much more
14:51:42 [nigel]
... complicated if I have to try to explain how to handle those dual use properties.
14:56:02 [nigel]
nigel: I'm sympathetic to keeping things simple, and adding a new parameter is adding
14:56:15 [nigel]
... complexity, but in this case I think there's utility in both approaches so I would propose
14:56:43 [nigel]
... we add it in and then if necessary later put it in the at risk list for CR.
14:57:15 [nigel]
pal: Another approach is to say that if a region is not specified then it would mean 'new' or
14:57:34 [nigel]
... if a region is also specified then it would mean 'modified'. That would prevent the addition
14:58:14 [nigel]
... of features.
15:04:50 [nigel]
nigel: Ok, we're out of time so let's adjourn for today.
15:05:11 [nigel]
mike: By the way, I've just submitted
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... Do we want to review and merge it now?
15:05:31 [nigel]
nigel: Let's not rush for the sake of the meeting, and look at it offline - if we can add our
15:05:44 [nigel]
... "LGTM"s etc then we can merge on that basis.
15:05:48 [nigel]
mike: OK, thanks.
15:06:00 [nigel]
nigel: Shall we go ahead with a volunteer chair for next week?
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group: Skip next week.
15:06:10 [nigel]
nigel: Okay, see you in 2 weeks then.
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nigel: [adjourns meeting]
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rrsagent, draft minutes
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I have made the request to generate nigel
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s/then./then. Thanks all!
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rrsagent, draft minutes
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I have made the request to generate nigel
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