13:59:56 RRSAgent has joined #tt 13:59:56 logging to http://www.w3.org/2017/06/08-tt-irc 13:59:58 RRSAgent, make logs public 13:59:58 Zakim has joined #tt 14:00:00 Zakim, this will be TTML 14:00:00 ok, trackbot 14:00:01 Meeting: Timed Text Working Group Teleconference 14:00:01 Date: 08 June 2017 14:00:56 mike has joined #tt 14:01:12 scribe: nigel 14:01:14 Present: Nigel 14:01:16 Chair: Nigel 14:01:19 Regrets: Glenn 14:01:29 Present+ Andreas 14:01:47 Present+ Mike 14:02:12 Present+ Thierry 14:02:26 Present+ Pierre 14:04:35 Topic: This Meeting 14:05:18 Nigel: For today I think the main topics are IMSC, and moving IMSC1.0.1 to CR, and TTML2 14:05:29 .. is there anything else? 14:05:31 atai has joined #tt 14:05:38 Thierry: TPAC 14:05:53 Topic: TPAC 2017 14:06:08 Nigel: The draft schedule has us meeting on Thursday and Friday, with Web and TV IG 14:06:21 .. on Monday, and CSSWG on Monday and Tuesday, with a suggestion that we invite 14:06:58 .. CSSWG for a joint meeting during our meeting at some time. 14:07:24 Thierry: Will the CSS WG be around on Thursday and Friday? 14:07:29 Nigel: We can ask! 14:08:35 ACTION: nigel Invite CSSWG to joint meeting at TPAC 2017, with list of topics. 14:08:36 Created ACTION-497 - Invite csswg to joint meeting at tpac 2017, with list of topics. [on Nigel Megitt - due 2017-06-15]. 14:08:51 Nigel: I'd like to get a draft list of CSS features that we would need for subtitle and caption 14:09:02 .. presentation, arising from our work on TTML generally. 14:09:43 Pierre: For IMSC1 the obvious ones are multiRowAlign and linePadding. 14:09:49 Andreas: What about line gap? 14:09:54 Pierre: Yes and that too now. 14:10:23 Nigel: I suspect Glenn and/or Dae will be able to list some Ruby features too. 14:10:48 Nigel: It would be good to have CSSWG issues open for those too. 14:11:03 Pierre: Look at #218 on imsc, which indirectly indicates where there is (not) CSS support. 14:11:28 .. For example rubyReserve and rubyOverhang are not supported in CSS. I think Dae did 14:11:41 .. an initial pass at doing that so it probably makes sense to start from there. 14:11:45 Nigel: Thank you I will do that. 14:12:51 Topic: IMSC 14:13:01 Nigel: What are our next steps to move to CR? 14:13:15 .. Thierry, you collated some wide review feedback this week? 14:13:26 Thierry: Yes, since yesterday I need to do more updates because Pierre has been answering 14:13:36 .. more comments so I will continue to update that wiki page. 14:13:49 Pierre: My suggestion is to run down the list of issues. 14:14:20 -> https://www.w3.org/wiki/IMSC1.0.1_Comments_tracker IMSC 1.0.1 Wide Review Comments collated Wiki page 14:14:49 pal has joined #tt 14:15:16 -> https://github.com/w3c/imsc/issues/224 Clarify whitespace handling when xml:space="default" #224 14:15:24 Pierre: This is trivial, there's not much to be said here. 14:15:49 s/224/244 14:16:03 s/Clarify whitespace handling when xml:space="default" #224/Add diff from IMSC 1.0.0 and update substantive-changes-summary.txt #244 14:16:21 Pierre: I'll take care of that at the last minute like last time. 14:16:24 .. The next is: 14:16:38 -> https://github.com/w3c/imsc/issues/243 Recommended character sets considered harmful #243 14:17:02 Pierre: I have both a question of substance and of process. This question came out of the 14:17:20 .. i18n and we were not involved in the discussion being filed. Part of the issue is there's 14:17:34 .. been a misread of the specification, folk reading more into non-normative text compared 14:17:48 .. to normative text. My take is that this is a misunderstanding, and I'm trying to find the 14:17:54 .. best way to resolve the misunderstanding. 14:18:40 .. There are two other i18n issues, which fall into a similar category. How do we resolve those? 14:18:59 Nigel: Were they all filed by Addison? 14:19:08 Pierre: One was, the others by Richard. 14:19:44 Nigel: I'll invite Richard and Addison to attend this meeting next week so we can talk through 14:19:54 .. the issues and check we understand properly what their thinking is. 14:20:39 Mike: We could raise pull requests to clarify the language. 14:20:50 Nigel: I agree, that was my thinking, but I'm worried that we might not address whatever 14:21:06 .. caused the misunderstanding, if we don't discuss it and find out by conversation. 14:22:23 Nigel: I think it will be most effective if we find a way to discuss this first. 14:22:47 ACTION: nigel Invite i18n to discuss IMSC 1.0.1 issues 14:22:47 Created ACTION-498 - Invite i18n to discuss imsc 1.0.1 issues [on Nigel Megitt - due 2017-06-15]. 14:23:23 Pierre: In #243 I don't know what clarification can be made. 14:23:35 -> https://github.com/w3c/imsc/issues/241 Requirement to support certain Code Point #241 14:24:01 Pierre: My conclusion is we can improve the text to refactor the recommendation to use 14:24:15 .. certain metrics with the recommendations for certain character sets. I don't disagree that 14:24:32 .. the current text is not the most straightforward. I'm reluctant to do this in IMSC 1.0.1, so 14:24:43 .. since it is not exactly a blocker I would prefer to defer it to IMSC2. 14:24:59 Andreas: The text is there and I think it is correct but could be read differently so there is 14:25:10 .. maybe no strict requirement to update it, though it could help to do so. What would be 14:25:27 .. helpful is if the reader is clear that the code points listed are not ones for which support 14:25:40 .. is mandatory, so it is just about the metrics. From the text you could read that if you have 14:25:55 .. this code point and render it then you should produce a glyph sequence which is identical 14:26:24 .. to the reference fonts. Maybe the edge case is that if someone has no glyph in the font 14:26:41 .. for the code point then he may nevertheless render it with a substitute glyph. So if the 14:26:56 .. condition is there (because the glyph is being rendered) then the glyph sequence 14:27:30 .. rendering must be identical to the reference font, which is circular because it implies 14:27:34 .. that the code point must be supported. 14:28:21 Pierre: There are two conditions - §7.3 Reference fonts only is supposed to apply when the 14:28:25 .. glyphs are supported. 14:28:30 Nigel: I never understood it that way. 14:28:48 Pierre: The reference font section §7.2 says which code points should be supported. Then 14:29:04 .. §7.3 says "if you're going to support a code point for a reference font AND it is in the list 14:29:49 .. in Annex A" then you must end up with the same result, but it does not compel support 14:29:53 .. for all the code points. 14:30:27 Andreas: Would it be possible to add explicitly a condition that it only applies when all 14:30:40 .. the code points are supported by the font used to meet the reference font requirements? 14:30:48 Nigel: +1 14:30:58 Pierre: I don't think that would be controversial - it is the intent already. I would be happy 14:31:01 .. to clarify that. 14:31:26 .. [adds a note to the issue] I will generate a pull request that clarifies this. 14:32:22 -> https://github.com/w3c/imsc/issues/239 Clarify "All regions shall not extend beyond the root container" #239 14:32:58 Pierre: There's a pull request open for that. 14:33:09 Nigel: I just added an approval for that (it was wording suggested by me). 14:33:30 -> https://github.com/w3c/imsc/issues/237 Why exclude hebrew and arabic proportional reference fonts? #237 14:33:41 Pierre: This is an i18n comment. I think we ended up rewording one of the sentences and 14:33:52 .. Nigel you suggested a tweak, so I'm tempted to generate a pull request to use as input 14:33:55 .. to our discussion. 14:34:29 Nigel: Makes sense. 14:34:36 Pierre: I will generate a pull request [adds note]. 14:34:51 -> https://github.com/w3c/imsc/issues/236 Should the character sets be minimum *font* requirements? #236 14:35:08 Pierre: The recommended character sets is worded as an authorial requirement rather than 14:35:24 .. a processor requirement. This occupied a lot of discussion for IMSC 1 so I'm reluctant in 14:35:31 .. IMSC 1.0.1 to change it into a processor requirement. 14:36:01 .. I propose a "won't fix" for IMSC 1.0.1 and add it to the list of things to discuss with i18n. 14:36:12 Nigel: Ok. 14:36:23 -> https://github.com/w3c/imsc/issues/235 imsc1-all.xsd has a bad pointer for SMPTE-TT schemas #235 14:37:19 Mike: The current IMSC 1 uses the SMPTE 2010 namespace and I'm on a mission to develop 14:37:31 .. some tight schemas for IMSC 1. When I started digging into this I discovered that the 14:37:43 .. backgroundImage wasn't documented until the 2013 namespace, so if you were to try 14:37:58 .. to write a comprehensive schema you would get stuck there. It is trivial of course, as per 14:38:15 .. the email I sent. The question is how to go about addressing this. We could write to 14:38:26 .. SMPTE and note that 2010 is missing backgroundImage, but the answer would probably 14:38:53 .. be to use 2013. Or we could write it ourselves but it would be a little weird to write 14:38:59 .. something in the SMPTE namespace. 14:40:07 .. It would be disruptive to switch to the 2013 namespace because it is incompatible 14:40:10 .. with the 2010 namespace. 14:40:37 Pierre: To Mike's suggestion, we or SMPTE could conceivably create a 2010 schema. 14:40:51 Mike: All we need is one attribute of type xs:anyURI. 14:41:07 Pierre: We either create that one definition and move on, or get SMPTE to write it so that 14:41:10 .. they have control of it. 14:41:24 Mike: There's maybe a hybrid where we ask SMPTE to do it but offer to do the work. 14:41:54 Pierre: Or we could create it, send it to SMPTE and ask them to publish it. 14:44:47 Nigel: This is informative only. [traces through the SMPTE references] 14:47:21 Mike: There's an example in ST2052-1-2010 where smpte:backgroundImage has a URI 14:47:38 Nigel: I see there's a substantive issue here in that the normative specification isn't completely 14:47:49 .. clear that backgroundImage takes a URI, though it can be inferred. Possibly we need to 14:48:02 .. add a clarification to IMSC1.0.1. On the schema, which is informative I'm not so bothered. 14:48:20 Mike: That's why 2013 was done! I think it would be good to clarify in IMSC 1 and offer a 14:49:02 .. proposed update to the 2010 schema to include it. While we're writing to SMPTE we can 14:49:14 .. also ask to verify that it is supposed to be an xs:anyURI. 14:49:40 Mike: I'll draft the liaison to SMPTE, and we ought not to touch IMSC1 until we get an 14:49:52 .. answer back and then there will probably be a follow-up action to modify the spec. 14:51:11 Nigel: [adds note to issue] 14:51:37 Mike: Aside from this issue, the question I have for this group is, if I write all these schemas 14:51:51 .. and post them as a contribution, how do we attach them to IMSC1. 14:52:18 s/1./1? 14:53:38 Nigel: We can just add it to the linked documents we publish. Another alternative is we 14:53:59 .. could create a new repository just for the schemas and link to that. It is much easier for 14:54:04 .. people to use that way too. 14:54:07 Mike: Sounds good to me. 14:54:11 Pierre: +1 14:54:29 Mike: Then it provides a good way to update it in case any changes are proposed later. 14:54:31 Nigel: Agreed. 14:55:08 Nigel: Should we add a new repo? 14:55:25 Pierre: The schemas are already in the spec repo. We could keep it there as a directory 14:55:40 .. and when it feels right to create a repo, do that. We can do everything we want on a 14:55:53 .. separate branch on the IMSC repo and when we're ready create a separate repo. 14:56:03 Mike: I like the first part, maybe we don't need to create a new repo. 14:56:29 Nigel: Okay, works for me. 14:57:32 -> https://github.com/w3c/imsc/issues/232 Recommend avoiding tab characters #232 14:57:37 Pierre: There's a pull request: 14:57:53 -> https://github.com/w3c/imsc/pull/242 Recommend avoiding tab characters #232 14:58:09 Pierre: As you point out Nigel, it seems valuable to explain this unusual exception. I also 14:58:16 .. do not like informative text. Glenn seems to oppose it. 14:58:44 Nigel: Glenn says a note would be acceptable but bad practice. 14:58:56 Pierre: I'm happy to not have it, put it in the text or put it in a Note. 14:59:01 Nigel: I prefer to put it in a Note. 14:59:33 Pierre: The text will say "should not use the TAB character" and the note will say that no 14:59:49 .. presentation semantics are specified for the code point. 14:59:53 NIgel: +1 15:00:39 Pierre: [adds note to pull request] 15:00:55 -> https://github.com/w3c/imsc/issues/228 Determination of the color in leading in tts:fillLineGap #228 15:01:09 Pierre: I left the ticket open because we need disposition comment from the commenter, 15:01:15 .. but we have a conclusion in the group. 15:02:03 Nigel: Where did this come from originally? 15:02:07 Pierre: From the ARIB liaison. 15:03:12 Nigel: I believe that we only need to send a message back to the commenter explaining 15:03:24 .. the disposition, and offering a last opportunity to comment. 15:03:37 Mike: We can send a link to the ED to make it easier, and to the issue. 15:03:39 Nigel: Yes. 15:03:56 Thierry: We don't need to publish a new WD say. 15:05:20 Nigel: We have so few comments here I don't think we need a tool. 15:05:59 Thierry: Yes, I think manually will be good enough. We can use GitHub also, if the commenter 15:06:01 .. adds a note. 15:06:09 Nigel: That's good for i18n say but not for ARIB. 15:06:15 Thierry: So for ARIB we will send an email. 15:07:12 -> https://github.com/w3c/imsc/issues/227 ittp:activeArea clarification #227 15:07:26 Pierre: this is in the same category as the previous one - we have agreement here, and need 15:07:30 .. to confirm the disposition. 15:07:45 -> https://github.com/w3c/imsc/issues/226 Create tests for CR exit criteria #226 15:07:53 Pierre: I created the tests, so I think we can close this. 15:08:58 Nigel: Can we review what the exit criteria actually are? They're the same as we used for 15:09:00 .. IMSC1, right? 15:09:06 https://github.com/w3c/imsc/blob/4f199de739945656838423d18ff8df6235be4277/imsc1/spec/ttml-ww-profiles.html 15:09:21 Pierre: This has actually been merged into the ED. 15:09:40 http://w3c.github.io/imsc/imsc1/spec/ttml-ww-profiles.html 15:10:13 Pierre: It is the same as we used in IMSC1 but only applying to new features. 15:10:35 Thierry: Looks good to me. 15:10:40 Nigel: The implementation report is a wiki page. 15:10:44 Pierre: Like for IMSC1. 15:11:05 Nigel: The Exit Criteria Test Suite is a 404. 15:11:47 Pierre: Yes that is because github.io won't let you browse directories - it needs to point to 15:11:51 https://github.com/w3c/imsc/tree/4f199de739945656838423d18ff8df6235be4277/imsc1/spec/exit-criteria-tests 15:12:17 https://github.com/w3c/imsc/tree/master/imsc1/spec/exit-criteria-tests 15:13:07 Pierre: That directory has TTML files and PNGs. 15:13:47 Nigel: And the examples match what is in the spec for fillLineGap. 15:13:54 Thierry: And there are just two. 15:14:11 Pierre: I think that is sufficient for this particular case. 15:14:14 Thierry: Yes. 15:14:28 Pierre: Especially since the fillLineGap test is pretty gnarly. 15:14:31 Nigel: Agreed. 15:14:47 Nigel: Any other comments? 15:14:51 group: [silence] 15:15:17 Nigel: Okay that's a decision to accept those proposed CR exit criteria and test suite. 15:15:24 Thierry: If we need more tests we can add them later. 15:15:32 Pierre: [closes issue] 15:15:51 -> https://github.com/w3c/imsc/issues/221 Attribute syntax definition: missing spaces #221 15:16:06 Pierre: This is contingent on whether or not spaces are allowed alongside delimiters in 15:16:19 .. tts:fontFamily. I think we are getting close to a resolution, so when we get there I will 15:16:29 .. generate a pull request for IMSC1. 15:16:38 .. I have not seen any comments back on the reflector about this issue. 15:16:42 Nigel: Me neither. 15:17:11 Pierre: And Nigel and Glenn prefer option 2 so I think we will go with that. 15:17:32 Nigel: If we have not had any more comments by this time next week shall we just go with 15:17:36 .. that option? 15:18:11 Pierre: Yes. 15:18:37 -> https://github.com/w3c/imsc/issues/212 Copy referenced schema to the schema directory for ease of validation #212 15:19:06 Pierre: We are waiting on you for this Nigel. The last I heard you were going to give it a try. 15:19:55 Nigel: When I tried this I got into all sorts of trouble but I accept that it *should* work 15:20:05 .. without copying the referenced schemas in. 15:20:46 Nigel: [closes issue] 15:20:57 Andreas: [leaves] 15:21:11 Pierre: That completes the review of IMSC 1.0.1 issues scheduled for CR. 15:21:51 Nigel: So the next step is to complete the disposition with i18n and write to ARIB about 15:24:24 .. two issues. Thierry please could you find the usual boilerplate, and send it to Pierre? 15:24:29 Thierry: Yes I will do that tomorrow. 15:24:36 Pierre: I will draft the email. 15:24:39 Nigel: Thank you both. 15:25:19 Topic: TTML 15:26:16 -> https://github.com/w3c/ttml2/issues/384 Appendix R [June 4 ED] is overly constrained and does not represent current best practice #384 15:26:34 Nigel: I'm preparing a pull request for this. 15:28:02 .. I'm concerned that progressive decoding is not always possible. 15:28:19 Mike: My concern is that all of the text in the appendix should be removed, so I'd like to 15:28:31 .. start there, and then if someone argues the existing text is fine then discuss that. 15:28:34 Nigel: That works for me. 15:30:41 Nigel: I plan to add a section referencing ISOBMFF and EBU-TT Live explaining the temporal 15:30:47 .. fragmentation approach used there. 15:31:24 Mike: I would like to take the TTML1 approach out and just reference it as an alternative. 15:32:01 .. Then this appendix is shorter. I know there's a document by Cyril about this. 15:32:16 Nigel: Oh yes that's on github, written by Romain, Cyril and me. We could reference that 15:32:19 .. informatively. 15:32:28 Mike: I'm concerned about how stable that is though. 15:32:54 Nigel: Okay I understand, I'll submit a pull request along those lines for review. 15:33:06 .. I'll put a picture in too, because that's always helpful. 15:33:10 Mike: That sounds fine. 15:33:26 .. And rather than perpetuate the fragmentation mechanism, just point back to TTML1. 15:33:49 Nigel: Okay I'll make some changes and make that happen. 15:35:10 -> https://github.com/w3c/ttml2/issues/128 Support for conditional styling. #128 15:35:28 Nigel: I just want to check with you about this even in the absence of Glenn. 15:37:07 .. Is it okay not to be able to conditionally select a region for content based on whatever 15:37:22 .. input parameters are available? I think it might be because the properties of the selected 15:40:23 .. region can be conditionally set without having to choose a whole different version. 15:40:35 .. Otherwise we might end up needing to change the region attribute to IDREFS. 15:40:47 Pierre: I need to see use cases for this otherwise I don't know how to evaluate it. 15:41:04 Nigel: Makes sense to me. The way I'm thinking right now is that using condition to support 15:41:23 .. media queries (screen size) and user preferences (e.g. text size) would be helpful, even 15:41:35 .. in IMSC2 perhaps. But I'm not settled on a firm viewpoint on that just yet. 15:43:22 Mike: I second Pierre's concern here that we need to understand the requirements. 15:44:32 Nigel: Okay I agree that we need to address practical considerations primarily, and I haven't 15:44:45 .. any evidence so far to say that we should make any more changes relative to what is 15:44:49 .. present currently. 15:45:04 .. So I will not open a new issue on this right now. 15:48:10 Nigel: On the issue of foreign namespace elements and where they can go, we discussed 15:48:23 .. it in the context of IMSC 1 and TTML1 but there's no issue for it in TTML2 as far as I can 15:48:29 .. see. Maybe one is needed. 15:48:30 atai has left #tt 15:49:10 Nigel: I'm hesitant to raise an issue without checking that there actually is one, in case 15:49:15 .. changes have already been made to TTML2. 15:49:21 Mike: I can do that right now. 15:49:24 Nigel: Thank you. 15:50:05 .. I think we've run out of agenda, a little ahead of time, so I'll close for today. 15:50:10 .. Thank you all! [adjourns meeting] 15:50:27 rrsagent, make minutes 15:50:27 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:05:23 s|s/Clarify whitespace handling when xml:space="default" #224/Add diff from IMSC 1.0.0 and update substantive-changes-summary.txt #244/|| 16:05:55 s/Clarify whitespace handling when xml:space="default" #244/Add diff from IMSC 1.0.0 and update substantive-changes-summary.txt #244/ 16:06:20 s|https://github.com/w3c/imsc/issues/224|https://github.com/w3c/imsc/issues/244 16:09:00 s/Recommend avoiding tab characters #232/Discourage the use of tab characters in

and #242 16:11:03 rrsagent, make minutes 16:11:03 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:14:06 s|s/Clarify whitespace handling when xml:space="default" #224/Add diff from IMSC 1.0.0 and update substantive-changes-summary.txt #244| 16:14:08 Zakim has left #tt 16:14:18 rrsagent, make minutes 16:14:18 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:14:55 s|s/Clarify whitespace handling when xml:space="default" #224/Add diff from IMSC 1.0.0 and update substantive-changes-summary.txt #244| 16:14:56 rrsagent, make minutes 16:14:56 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:17:35 s/||/ 16:17:42 s/s|/ 16:17:45 s|/| 16:17:48 rrsagent, make minutes 16:17:48 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:19:15 s|/| 16:19:16 rrsagent, make minutes 16:19:16 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel 16:19:53 ScribeOptions: -final -noEmbedDiagnostics 16:19:54 rrsagent, make minutes 16:19:54 I have made the request to generate http://www.w3.org/2017/06/08-tt-minutes.html nigel