IRC log of tt on 2015-10-08

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logging to http://www.w3.org/2015/10/08-tt-irc

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Zakim, this will be TTML

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I do not see a conference matching that name scheduled within the next hour, trackbot

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Meeting: Timed Text Working Group Teleconference

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Date: 08 October 2015

14:04:43 [nigel]

chair: nigel

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scribe: nigel

14:04:53 [nigel]

Regrets: Andreas, Frans, Mike

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Present: nigel, pal, tmichel

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I am connected but without any sound.

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I will rejoin webex

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Topic: This Meeting

14:07:19 [nigel]

nigel: Most of this meeting will be dedicated to closing IMSC 1 pending review issues

14:07:26 [nigel]

nigel: AOB?

14:07:51 [nigel]

nigel: Mike has asked to postpone the incoming liaison from ATSC issue.

14:08:09 [nigel]

pal: There's also the topic of profile designators - it would be good to talk about it.

14:08:15 [nigel]

nigel: Great, that's added.

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Topic: Action Items

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Action-421?

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Action-421 -- Nigel Megitt to Check with ttml player manufacturers if they're happy to be listed on our site. -- due 2015-09-24 -- OPEN

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http://www.w3.org/AudioVideo/TT/tracker/actions/421

14:09:49 [nigel]

nigel: I did contact the manufacturer we discussed and they said they'd check but haven't yet confirmed.

14:10:14 [nigel]

nigel: Do we have an implementations page?

14:10:26 [nigel]

tmichel: I don't think we have one yet but I'd like to start one. I think we should have a page

14:10:36 [nigel]

... per technology - one for TTML, one for WebVTT etc.

14:10:51 [nigel]

pal: We have a page for that - remember the contribution from the Web & TV IG?

14:10:56 [nigel]

nigel: Oh yes, I remember now.

14:11:17 [nigel]

https://www.w3.org/wiki/TimedText/

14:11:48 [nigel]

https://www.w3.org/wiki/TimedText/EffortsAndSpecifications is a better URL to use

14:12:20 [nigel]

It's linked from https://www.w3.org/wiki/TimedText under Timed Text Efforts and Specifications

14:12:40 [nigel]

nigel: I guess we could add it to the group home page too - we probably should tidy up the

14:12:57 [nigel]

... group page vs wiki home page discrepancy. Having both isn't especially helpful.

14:13:32 [nigel]

tmichel: In former times we had the CVS hosted home page which was hard to edit. Now

14:13:44 [nigel]

... the wiki is simpler for people to add information to. Everyone should be able to add their

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... own product if they want to.

14:14:27 [nigel]

nigel: Is it worth an action to redirect from the home page to the wiki?

14:14:41 [nigel]

tmichel: I'll look into that. There's some information like how to join on the home page.

14:14:52 [nigel]

nigel: Yes. we'd have to migrate the key information.

14:15:01 [nigel]

tmichel: I'll look into it and propose something.

14:15:19 [nigel]

Action: tmichel Look into merging the group home page and the wiki home page and propose something

14:15:19 [trackbot]

Created ACTION-430 - Look into merging the group home page and the wiki home page and propose something [on Thierry Michel - due 2015-10-15].

14:15:49 [nigel]

Topic: TPAC 2015

14:16:07 [nigel]

nigel: Netflix has just joined the WG and would like to spend some agenda time on the Thursday

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... presenting on their open source TTML2 implementation work.

14:16:47 [nigel]

nigel: I'll add that to the topics/agenda page on the wiki.

14:17:05 [nigel]

tmichel: While we're talking about new participants, SImon from Opera joined today replacing Philip.

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... Simon is the new editor of the WebVTT spec.

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Topic: IMSC stuff...

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action-425?

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action-425 -- Thierry Michel to Send a prompt/thank you to the potential test result contributors for imsc. -- due 2015-10-01 -- OPEN

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http://www.w3.org/AudioVideo/TT/tracker/actions/425

14:18:28 [nigel]

pal: I've not heard back and am still chasing, so that's still open. No update despite best efforts.

14:18:44 [nigel]

Topic: Profiles registry

14:19:35 [nigel]

pal: Related to Cyril's email earlier today, which came out of this topic, I think from an

14:19:50 [nigel]

... implementation standpoint he wants users to be able to signal clearly in a TTML document

14:20:05 [nigel]

... what profiles a document conforms to. In IMSC 1 right now there's a 'MAY user ttp:profile'

14:20:16 [nigel]

... statement but that's it. Maybe we can add more to IMSC 1 to encourage people to label

14:20:34 [nigel]

... their documents. The challenge is, as we discussed before, EBU-TT-D forbids ttp:profile.

14:20:56 [nigel]

... And ttp:profile supports only one profile. So if a document conforms to both EBU-TT-D and

14:21:09 [nigel]

... IMSC 1 then you should not use ttp:profile but you should use ebuttm:conformsToStandard

14:21:21 [nigel]

... and list both. If the document is not EBU-TT-D conformant it probably isn't a bad idea to

14:21:40 [nigel]

... use ttp:profile and also include ebuttm:conformsToStandard so I'm thinking of adding

14:22:00 [nigel]

... a recommendation to IMSC 1 along those lines.

14:22:16 [nigel]

nigel: I can see the logic to that, yes. It makes sense I think.

14:22:24 [nigel]

pal: I'd like to be responsive to the request.

14:22:38 [nigel]

nigel: I agree - there's a use case we haven't spent a lot of time considering that is obviously

14:22:56 [nigel]

... important. I'd like Andreas's and Frans's input on this specific proposal too, but on the

14:23:04 [nigel]

... surface I think it makes a lot of sense.

14:23:45 [nigel]

nigel: You can recommend using the URI designators.

14:23:58 [nigel]

pal: That would definitely be the recommendation!

14:24:15 [nigel]

... From a tools perspective it would certainly help tools to determine the document's profile.

14:25:11 [nigel]

nigel: We just need to be careful that ebuttm:conformsToStandard is indicating document

14:25:51 [nigel]

... conformance in other words the equivalent to TTML2's ttp:contentProfiles attribute.

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... Whereas ttp:profile indicates a processor profile, so we shouldn't mix the messages there.

14:27:43 [nigel]

pal: I don't know why we hadn't collectively thought about this before. I think it works in exactly the right way.

14:28:26 [nigel]

nigel: I can see how this would work really well - if an IMSC 1 processor is needed then it's on

14:29:19 [nigel]

... the ttp:profile attribute and if not, because an EBU-TT-D processor is okay, then it would be

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... omitted.

14:29:36 [nigel]

pal: I think we can file an issue for this, especially given Glenn's email just now proposing that

14:29:55 [nigel]

... IMSC 1 includes a 'should include ttp:profile attribute' statement, then implement and review

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... next week.

14:30:14 [nigel]

pal: [filing issue right now]

14:32:06 [nigel]

issue-448?

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issue-448 -- Add recommendation for ttp:profile and ebuttm:conformsToStandard -- raised

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http://www.w3.org/AudioVideo/TT/tracker/issues/448

14:32:11 [nigel]

reopen issue-448

14:32:11 [trackbot]

Re-opened issue-448.

14:32:21 [nigel]

pal: I'm going to reply to the thread too.

14:33:25 [nigel]

nigel: I think it's worth pinging back to EBU to check if they might reopen the discussion on

14:33:34 [nigel]

... whether or not to permit ttp:profile on EBU-TT-D documents.

14:34:53 [nigel]

nigel: Of course if you have a stream of EBU-TT-D documents e.g. in DASH then this is likely

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... to be redundantly repeated data.

14:35:16 [nigel]

pal: Of course the packager could strip it out if it knows the data won't be needed downstream.

14:36:08 [nigel]

nigel: We may be putting packagers in an uncomfortable situation of needing to modify the

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... samples they're given to wrap up.

14:36:32 [nigel]

pal: True - we're talking about a few bytes though and it's tiny in comparison with e.g. HTTP headers.

14:36:59 [nigel]

Topic: Issues

14:38:11 [nigel]

nigel: Let's go through Pending Reviews...

14:38:13 [nigel]

issue-404?

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issue-404 -- Where is #image feature defined? -- pending review

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http://www.w3.org/AudioVideo/TT/tracker/issues/404

14:38:32 [nigel]

pal: I think this is unambiguous, well specified and can be closed.

14:38:39 [nigel]

nigel: +1

14:38:41 [nigel]

close issue-404

14:38:41 [trackbot]

Closed issue-404.

14:38:51 [nigel]

issue-405?

14:38:51 [trackbot]

issue-405 -- why is #nested-span prohibited on image profile? -- pending review

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http://www.w3.org/AudioVideo/TT/tracker/issues/405

14:39:17 [nigel]

nigel: This isn't even a proposal to change the spec. It's a question with an answer.

14:39:32 [nigel]

pal: I think Glenn would have responded if he disagreed.

14:39:38 [nigel]

close issue-405

14:39:38 [trackbot]

Closed issue-405.

14:39:48 [nigel]

issue-406?

14:39:48 [trackbot]

issue-406 -- #lineBreak-uax14 is never 'used' by a document? -- pending review

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http://www.w3.org/AudioVideo/TT/tracker/issues/406

14:41:09 [nigel]

pal: uax14 is mandated for processors in the text profile and stated as not applicable to document instances.

14:41:21 [nigel]

... The image profile is silent about it.

14:41:30 [nigel]

nigel: Do we permit the profile features to be listed in the document?

14:41:54 [nigel]

pal: We do. The presence of the profile designator in the document requires that the processor

14:42:14 [nigel]

... implements uax14. What the spec currently says is the document constraints. The uax14

14:42:23 [nigel]

... feature is not applicable to constraints on the document.

14:43:23 [nigel]

nigel: There's a niche issue for the text profile: if the profile features are included then it would

14:43:41 [nigel]

... be an error to state that the #linebreak-uax14 feature is a 'shall not use'.

14:45:02 [nigel]

... That would create a situation where an IMSC 1 text profile conformant processor should

14:45:50 [nigel]

... reject an IMSC 1 text profile conformant document that includes this profile feature as

14:45:54 [nigel]

... 'shall not use'.

14:46:12 [nigel]

pal: This is a strange and theoretical case, that applies only to the uax14 feature.

14:47:05 [nigel]

nigel: We could add a statement that if profile features are included within a document then

14:47:30 [nigel]

... they shall not conflict with the processor conformance rules for IMSC 1.

14:47:48 [nigel]

Action: nigel File issue re profile feature inclusion in IMSC 1 documents

14:47:48 [trackbot]

Created ACTION-431 - File issue re profile feature inclusion in imsc 1 documents [on Nigel Megitt - due 2015-10-15].

14:48:03 [nigel]

pal: We could add that to the profile section for document conformance.

14:48:52 [nigel]

pal: Going back to issue-406, Glenn suggested to require the feature. Shall we start the 2 week review clock on this today?

14:48:56 [nigel]

nigel: yes, let's do that.

14:49:10 [nigel]

issue-408?

14:49:10 [trackbot]

issue-408 -- Initial value of color -- pending review

14:49:10 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/issues/408

14:51:11 [nigel]

close issue-408

14:51:11 [trackbot]

Closed issue-408.

14:51:41 [nigel]

issue-409?

14:51:41 [trackbot]

issue-409 -- Font family of default means monospaceSerif -- pending review

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http://www.w3.org/AudioVideo/TT/tracker/issues/409

14:52:22 [nigel]

pal: IMSC 1 defines what it means for "default" fontFamily, i.e. what a processor shall do when

14:52:38 [nigel]

... the fontFamily is set to "default". Glenn points out that this isn't always the right thing to do.

14:53:01 [nigel]

... My response to that is that authors should not rely on default. TTML1 doesn't prohibit

14:53:14 [nigel]

... implementations from mapping the default font to a known one.

14:55:56 [nigel]

nigel: I'm a bit nervous here - Glenn hasn't proposed a solution, and I don't know why.

14:56:13 [nigel]

... For example we could include a table mapping language to default font map or reference

14:56:17 [nigel]

... one in e.g. CLDR.

14:57:20 [nigel]

pal: Document authors can make their choice though if default won't work for them.

14:57:40 [nigel]

nigel: My nervousness here is that we're making a language market-specific value for default,

14:57:48 [nigel]

... which could make use of default less useful.

14:58:08 [nigel]

nigel: However Glenn knows most about this from those here and he hasn't picked it up.

14:58:32 [nigel]

pal: We should close this on the basis of no response in over 1 month. It can be reopened if someone is unhappy.

14:58:40 [nigel]

close issue-409

14:58:40 [trackbot]

Closed issue-409.

14:58:50 [nigel]

issue-410?

14:58:50 [trackbot]

issue-410 -- Constraints on #linePadding and #multiRowAlign -- pending review

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http://www.w3.org/AudioVideo/TT/tracker/issues/410

15:01:59 [nigel]

nigel: The problem with SHALL NOT here suggests a syntactic conformance requirement whereas

15:02:32 [nigel]

... what you mean is that if the attributes are present then they shall be ignored by implementations.

15:03:33 [nigel]

pal: We don't have Glenn's view on this so it would be uncool if he doesn't agree.

15:05:51 [nigel]

... Don't forget the problem arose in EBU-TT-D.

15:06:06 [nigel]

nigel: The new EBU-TT Part 1 v1.1 might get us out of that problem - it defines the features

15:07:11 [nigel]

... and states that they may be used in EBU-TT-D, and fixes the gaps from the original definition.

15:07:52 [nigel]

Action: nigel Nigel, pal, andreas and frans to hook up re changing IMSC 1 EBU-TT feature references to point to tech3350 v1.1

15:07:52 [trackbot]

Created ACTION-432 - Nigel, pal, andreas and frans to hook up re changing imsc 1 ebu-tt feature references to point to tech3350 v1.1 [on Nigel Megitt - due 2015-10-15].

15:09:27 [nigel]

issue-410: [meeting 2015-10-08] See also Action-432 - it may be possible to avoid the problem by referencing tech3350 v1.1.

15:09:27 [trackbot]

Notes added to issue-410 Constraints on #linePadding and #multiRowAlign.

15:09:59 [nigel]

nigel: We're out of time so I'll adjourn now.

15:10:14 [nigel]

pal: Maybe we could do 2 hours next week to get through the remaining issues ahead of TPAC?

15:10:35 [nigel]

nigel: That's fine for me.

15:10:57 [nigel]

pal: I'd like to have gone through all of them - there's one that may need TPAC discussion.

15:11:10 [nigel]

... Glenn brought up an excellent question about the HRM, in relation to Arabic, where the

15:11:25 [nigel]

... mapping between code point and glyph is in the majority of cases is not 1:1 and the shape

15:11:39 [nigel]

... depends on the context. That really messes up the glyph buffer. I'm researching it.

15:12:10 [nigel]

... The glyph buffer was put in to support e.g. 608, 708 and Teletext. Hopefully we'll have closed all the others.

15:14:15 [nigel]

nigel: Thanks both. [meeting adjourned]

15:14:20 [nigel]

rrsagent, draft minutes

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I have made the request to generate http://www.w3.org/2015/10/08-tt-minutes.html nigel

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s/I am connected but without any sound./

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s/I will rejoin webex/

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rrsagent, draft minutes

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I have made the request to generate http://www.w3.org/2015/10/08-tt-minutes.html nigel

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rrsagent, draft minutes

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I have made the request to generate http://www.w3.org/2015/10/08-tt-minutes.html nigel

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