IRC log of tt on 2015-09-24

Timestamps are in UTC.

13:57:03 [RRSAgent]

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logging to http://www.w3.org/2015/09/24-tt-irc

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RRSAgent, make logs public

13:57:05 [Zakim]

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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

13:57:08 [trackbot]

Date: 24 September 2015

14:01:47 [pal]

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14:04:10 [Frans]

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14:04:23 [nigel]

Present: pal, nigel, tmichel, frans

14:04:25 [nigel]

chair: nigel

14:04:30 [nigel]

Regrets: Andreas

14:05:08 [courtney]

courtney has joined #tt

14:05:26 [nigel]

Topic: This meeting

14:08:13 [nigel]

nigel: Proposes we look at Action Items, IMSC, TTML and WebVTT mapping and codecs registry.

14:08:15 [nigel]

... AOB?

14:08:24 [nigel]

group: none.

14:08:57 [nigel]

Topic: Action Items

14:09:15 [nigel]

action-420?

14:09:15 [trackbot]

action-420 -- Pierre-Anthony Lemieux to Follow up with glenn on issue-406 -- due 2015-09-10 -- OPEN

14:09:15 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/actions/420

14:09:34 [nigel]

pal: Glenn has provided the input needed to make progress, that #uax14 feature is unique in

14:09:46 [nigel]

... TTML in that it controls whether the processor uses the uax14 algorithm to determine line

14:09:59 [nigel]

... breaks but it is not communicated in the document. It has to be specified by the profile.

14:10:12 [nigel]

... I'm trying to find out if in general implementors follow the uax14 recommendations so we

14:10:26 [nigel]

... can determine if it should be mandated in IMSC 1. So I have enough information to proceed.

14:10:55 [nigel]

... If you know of implementations and if they follow uax14 recommendations let me know.

14:11:09 [nigel]

nigel: We should take HTML/CSS implementations as a data point.

14:11:17 [nigel]

pal: CSS3 seems to mandate it.

14:11:50 [nigel]

close action-420

14:11:50 [trackbot]

Closed action-420.

14:11:54 [nigel]

issue-406?

14:11:54 [trackbot]

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

14:11:54 [trackbot]

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

14:12:59 [nigel]

issue-406: [meeting 2015-09-24] IMSC 1 should mandate that processors shall/shall not implement uax14 or say nothing about it.

14:12:59 [trackbot]

Notes added to issue-406 #lineBreak-uax14 is never 'used' by a document?.

14:13:25 [nigel]

pal: Here's a link to the CSS3 spec: http://www.w3.org/TR/css-text-3/

14:14:27 [nigel]

Topic: IMSC stuff

14:14:55 [nigel]

pal: I've received a render from an implementor for one of the test suite tests, probably

14:15:09 [tmichel]

tmichel has joined #tt

14:15:33 [nigel]

... the most complex one. It's an MP4 file for track6-frag0-sample1-subs0.ttml

14:15:45 [nigel]

... I stepped through the render and it seems good to me. We should add it to the results and

14:16:00 [nigel]

... use it to encourage others. That implementor now plans to continue with the other tests.

14:16:16 [nigel]

... tmichel, can we post that and add a link to the implementation report?

14:17:46 [nigel]

tmichel: Yes, I've missed that somehow - if you can resend it to me?

14:17:57 [nigel]

pal: I'll upload it to somewhere we can all see it, so you can pick it up from there.

14:18:21 [nigel]

Action: tmichel to download and upload to implementation report page the test render MP4

14:18:21 [trackbot]

Created ACTION-424 - Download and upload to implementation report page the test render mp4 [on Thierry Michel - due 2015-10-01].

14:19:03 [pal]

http://sandflow.com/public/GIC_IMSC_DEMO_H264_30s_20150829_1.mp4

14:19:27 [nigel]

nigel: Last week we said we'd discuss how to proceed with encouraging implementors .

14:20:28 [nigel]

pal: I think a prompt update email from tmichel wouldn't harm. I have another name to add also.

14:20:48 [nigel]

nigel: Is that the best thing to do? Would it help to have a message from the chair too?

14:21:00 [nigel]

pal: We can kick around some ideas offline about this.

14:21:27 [nigel]

nigel: Okay, but for the time being tmichel should send a prompt email?

14:21:37 [nigel]

pal: Yes, and we should also thank the contributor of this test result.

14:22:19 [nigel]

Action: tmichel Send a prompt/thank you to the potential test result contributors for IMSC.

14:22:19 [trackbot]

Created ACTION-425 - Send a prompt/thank you to the potential test result contributors for imsc. [on Thierry Michel - due 2015-10-01].

14:22:40 [nigel]

nigel: And pal will send tmichel a new name/address.

14:22:42 [nigel]

pal: yes.

14:24:21 [nigel]

issue-417?

14:24:21 [trackbot]

issue-417 -- #writingMode constraint inconsistent in image profile -- raised

14:24:21 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/issues/417

14:25:12 [nigel]

pal: This is about features and dependent/contained features. #writingMode 'may' be used in

14:25:25 [nigel]

... both profiles, but image profile doesn't actually permit vertical writing mode, so it's just a

14:25:36 [nigel]

... matter of moving it to the individual profiles from the common set.

14:25:40 [nigel]

reopen issue-417

14:25:40 [trackbot]

Re-opened issue-417.

14:25:51 [nigel]

issue-429?

14:25:51 [trackbot]

issue-429 -- Glyph vs code point in HRM -- raised

14:25:51 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/issues/429

14:26:19 [nigel]

pal: This is a tricky one. The HRM today is written in terms of glyph but what the document

14:26:34 [nigel]

... talks about is code points. You don't know how code points get turned into glyphs until

14:26:52 [nigel]

... the text is rendered because it depends on the font and the context. It's complex.

14:27:32 [nigel]

... I'm trying to find out if the intended term was code points or glyph.

14:27:38 [nigel]

reopen issue-429

14:27:38 [trackbot]

Re-opened issue-429.

14:27:50 [nigel]

issue-431?

14:27:50 [trackbot]

issue-431 -- Example of documents that fail the HRM -- raised

14:27:50 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/issues/431

14:28:19 [nigel]

pal: This should be pretty straightforward to put together.

14:28:24 [nigel]

reopen issue-431

14:28:24 [trackbot]

Re-opened issue-431.

14:29:21 [nigel]

nigel: There are a whole load of pending review issues on imsc 1. Are there any to call out?

14:29:47 [nigel]

... Otherwise we can give a 2 week review period and if there are no queries/problems then

14:29:49 [nigel]

... close them.

14:30:52 [nigel]

pal: I've sent Glenn a summary and really he should review the resolutions.

14:32:06 [nigel]

nigel: I've checked all the check-ins and most of the issues, so they're looking good to me

14:32:12 [nigel]

... at the moment, but I need to double check.

14:32:19 [nigel]

pal: Okay, then I'll look at the now open ones.

14:32:37 [nigel]

Topic: TTML and WebVTT mapping document

14:32:43 [nigel]

action-422?

14:32:43 [trackbot]

action-422 -- Courtney Kennedy to Update the mapping document status of this document to include feedback mechanism. -- due 2015-09-24 -- PENDINGREVIEW

14:32:43 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/actions/422

14:32:56 [nigel]

courtney: I've done that.

14:33:34 [nigel]

https://dvcs.w3.org/hg/ttml/raw-file/tip/ttml-webvtt-mapping/mappingbetweenTTMLandWebVTTW3C.html

14:33:56 [nigel]

close action-422

14:33:57 [trackbot]

Closed action-422.

14:34:28 [nigel]

Courtney: There's another action and an issue that I have proposed resolutions for and then

14:34:40 [nigel]

... there's a whole bunch of others I'm still thinking about, and want to discuss with Andreas.

14:34:56 [nigel]

action-423?

14:34:56 [trackbot]

action-423 -- Thierry Michel to Check the license on the ttml to webvtt mapping document -- due 2015-09-24 -- PENDINGREVIEW

14:34:56 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/actions/423

14:35:13 [nigel]

courtney: I figured out how to put the right licence in there.

14:35:28 [nigel]

tmichel: It's true that the right copyright is in there, which is fine. Now the document has

14:35:41 [nigel]

... changed from Editor's draft to Unofficial draft. Is that because you couldn't make it an ED?

14:35:54 [nigel]

courtney: I'm using respec as you suggested and it's hard to control. When I make it an ED it

14:36:14 [nigel]

... gets broken links. Making it a UD fixed the links but broke the licence. The respec guys

14:36:35 [nigel]

... helped me to fix the link and the copyright but the effect is it's a UD.

14:36:51 [nigel]

... If I use the template from tmichel then it puts a wrong link in.

14:37:07 [nigel]

tmichel: Let's discuss offline. In the meantime there's no problem having an Unofficial Draft.

14:37:25 [nigel]

courtney: I'm not sure it matters at the moment. The right copyright statement and no bad links is more important.

14:38:28 [nigel]

nigel: I've also noticed that it says 'Latest Recommendation' which is a bit misleading.

14:38:52 [nigel]

Action: tmichel tmichel to work with courtney to get the TTML WebVTT mapping to look right with respec

14:38:53 [trackbot]

Created ACTION-426 - Tmichel to work with courtney to get the ttml webvtt mapping to look right with respec [on Thierry Michel - due 2015-10-01].

14:39:07 [nigel]

close action-423

14:39:07 [trackbot]

Closed action-423.

14:39:14 [nigel]

issue-415?

14:39:14 [trackbot]

issue-415 -- TTML2 is confusing -- pending review

14:39:14 [trackbot]

http://www.w3.org/AudioVideo/TT/tracker/issues/415

14:39:55 [nigel]

courtney: I'm a bit confused by this but what I think he's asking for is not to use '2' in the T2VP

14:40:15 [nigel]

... profile for mapping. He also said the constraints are against IMSC 1 which is not correct.

14:40:27 [nigel]

... I changed the name of the profile to TVTT as a response to the '2' issue.

14:41:34 [nigel]

issue-415: [meeting 2015-09-24] Numeral 2 removed from name of mapping profile to avoid confusion with TTML2. Profile is not based on IMSC 1 however note Issue-446 requests this.

14:41:34 [trackbot]

Notes added to issue-415 TTML2 is confusing.

14:42:20 [nigel]

nigel: Let's point mike back at this to review.

14:42:38 [nigel]

courtney: Thanks to Mike and Pierre for the detailed review - I really appreciate it.

14:42:49 [nigel]

... Andreas is on vacation and I really want to discuss some of these with him before deciding

14:43:17 [nigel]

... on how to resolve them. Our idea in defining a new profile was just to structure a mapping

14:43:33 [nigel]

... strategy. At least in my mind it wasn't something that you'd publish and author to. It was

14:44:39 [nigel]

... just a way to structure the mapping. The feedback is really interesting though. I want to think about this some more though.

14:44:52 [nigel]

nigel: I had the same take as you Courtney but we should recognise the feedback - if we

14:45:07 [nigel]

... define a profile then people might use it! We should think about how formal we make the profile

14:45:10 [nigel]

... document.

14:45:37 [nigel]

courtney: The goal of splitting the mapping into two parts was 1) to reduce the semantics

14:45:51 [nigel]

... and 2) to convert the syntax. The benefit that Andreas pointed out was that then you always

14:46:08 [nigel]

... have a valid conformance-checkable document at every stage. I thought that was a nice

14:46:23 [nigel]

... benefit of dividing things up this way. Because that was our intent, the profile isn't related

14:46:38 [nigel]

... to IMSC or other TTML profiles so much. It's just about defining a subset of TTML that is

14:46:42 [nigel]

... the same as WebVTT functionality.

14:46:57 [nigel]

pal: It makes perfect sense and is a great process. From a user's perspective, the end result

14:47:11 [nigel]

... is that if a document meets the constraints defined in the document it can be converted

14:47:38 [nigel]

... losslessly into WebVTT, to the temptation will be to author to that.

14:47:50 [nigel]

courtney: That's interesting - it's true, but the converse it not true. Just because you don't

14:48:01 [nigel]

... start with this profile doesn't necessarily mean that the mapping will be lossy.

14:48:32 [nigel]

pal: It will look like a very tempting option to author for lossless mapping to WebVTT.

14:48:46 [nigel]

... If that happens to be a subset of IMSC 1 then that's great because implementors can just

14:49:01 [nigel]

... use a subset of IMSC 1 to target mapping to WebVTT. If it's not then we should see if IMSC1

14:49:03 [nigel]

... needs to change.

14:49:17 [nigel]

courtney: I think we should do that exercise and we may find that we're very close to IMSC 1

14:49:31 [nigel]

... already. Then we should think if it makes more sense to use IMSC 1 and restructure the

14:49:44 [nigel]

... document to discuss the timing conversions that are allowed in IMSC 1. I agree that this is

14:49:56 [nigel]

... a pragmatic approach that needs more discussion and I'd like Andreas to be part of it.

14:50:13 [nigel]

pal: Absolutely. It may be worth just noting that the TVTT profile is a subset of IMSC 1.

14:50:39 [nigel]

... It doesn't necessarily require a major document restructure.

14:51:27 [nigel]

nigel: It may be that we defer this discussion until TPAC to manage everyone's availability.

14:52:15 [nigel]

nigel: Looking at all the issues raised, is there any reason not to open them all?

14:52:32 [nigel]

courtney: I haven't looked in depth at all of them yet. I think the forced display one is a bit different.

14:52:45 [nigel]

... I think that will result in some additional text in our document describing how to mark

14:53:28 [nigel]

... WebVTT as forced. I think it depends on the carriage/wrapper too e.g. HLS, BMFF, HTML web page.

14:53:46 [nigel]

pal: I think we could mention that you may need two or more separate WebVTT tracks.

14:54:11 [nigel]

courtney: In my experience content creators like to deliver the forced subtitles as a separate

14:54:23 [nigel]

... track so they can adjust the timing relative to non-forced subtitles.

14:54:41 [nigel]

pal: That's interesting. So the forced/non forced subtitles are delivered as two separate files?

14:54:47 [nigel]

courtney: Not always but often.

14:55:04 [nigel]

... That's a beyond-the-format question. But we could put in the mapping document how to

14:55:10 [nigel]

... approach that problem in different containers.

14:56:39 [nigel]

nigel: A related point is that WebVTT documents can be constructed for chapters by extracting

14:56:45 [nigel]

... metadata from the TTML div structure for example.

14:56:59 [nigel]

Action: nigel write up an issue for WebVTT for chapterisation etc.

14:57:00 [trackbot]

Created ACTION-427 - Write up an issue for webvtt for chapterisation etc. [on Nigel Megitt - due 2015-10-01].

14:59:56 [nigel]

Topic: TTML profile registry.

15:00:13 [nigel]

nigel: Mike has done some work on this, discussions are ongoing on the reflector.

15:00:44 [nigel]

... He's moved it to https://www.w3.org/wiki/TTML/ProfileRegistry

15:02:04 [nigel]

nigel: The main direction to note is that we're merely hosting the short codes and separating out their usage.

15:02:21 [nigel]

... There's also a question arising, perhaps to tackle offline, whether we can create a standalone

15:02:30 [nigel]

... Note to update the Media Registration with IANA.

15:02:35 [nigel]

tmichel: Let me check on that.

15:02:59 [nigel]

Action: tmichel Check if we can update the TTML IANA Media Registration in a standalone Note or if we need to do it in a Rec

15:03:00 [trackbot]

Created ACTION-428 - Check if we can update the ttml iana media registration in a standalone note or if we need to do it in a rec [on Thierry Michel - due 2015-10-01].

15:03:59 [nigel]

nigel: Thanks everyone - we got through a lot, and skimmed past a lot in that meeting, but we're

15:04:12 [nigel]

... 3 minutes over so I'll adjourn for now. See you all next week. [adjourns meeting]

15:04:27 [nigel]

rrsagent, draft minutes

15:04:27 [RRSAgent]

I have made the request to generate http://www.w3.org/2015/09/24-tt-minutes.html nigel

15:06:08 [nigel]

Present+ courtney

15:06:22 [nigel]

s/none/no other business

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s/implementors ./implementors.

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s/address./address?

15:12:37 [nigel]

rrsagent, draft minutes

15:12:37 [RRSAgent]

I have made the request to generate http://www.w3.org/2015/09/24-tt-minutes.html nigel

15:13:51 [nigel]

scribe: nigel

15:14:33 [nigel]

scribeOptions: -final -noEmbedDiagnostics

15:14:36 [nigel]

rrsagent, draft minutes

15:14:36 [RRSAgent]

I have made the request to generate http://www.w3.org/2015/09/24-tt-minutes.html nigel