14:00:53 RRSAgent has joined #tt 14:00:53 logging to http://www.w3.org/2017/07/13-tt-irc 14:00:55 RRSAgent, make logs public 14:00:55 Zakim has joined #tt 14:00:57 Zakim, this will be TTML 14:00:57 ok, trackbot 14:00:58 Meeting: Timed Text Working Group Teleconference 14:00:58 Date: 13 July 2017 14:01:17 Present: Glenn, Thierry, Nigel 14:01:21 Regrets: None 14:01:27 Chair: Nigel 14:01:29 scribe: nigel 14:02:04 Topic: This meeting 14:02:14 Glenn: [needs to leave after 45 minutes] 14:02:51 Present+ Pierre 14:04:00 Present+ Dae 14:04:21 pal has joined #tt 14:04:50 dae has joined #tt 14:06:07 Nigel: Today we have a bit on TPAC/CSS, IMSC, TTML, HDR in PNG, WebVTT 14:06:24 .. Any other business or specific items to cover? 14:06:28 Present+ Andreas 14:06:42 group: [no other business] 14:06:56 Topic: TPAC / CSS 14:07:05 action-497? 14:07:05 action-497 -- Nigel Megitt to Invite csswg to joint meeting at tpac 2017, with list of topics. -- due 2017-06-15 -- OPEN 14:07:05 http://www.w3.org/AudioVideo/TT/tracker/actions/497 14:07:30 Nigel: I've begun to pull together the list of CSS features, at: 14:07:35 -> https://www.w3.org/wiki/TTML/CSSRequirements CSS Requirements wiki 14:08:00 Nigel: That's a work in progress - input very much welcome. 14:08:07 atai has joined #tt 14:09:28 Nigel: I've lifted the existing points - I don't know all the information. For example with 14:09:34 .. fontShear do we need it in CSS? 14:09:47 Glenn: fontShear is frequently used in Japanese subtitling, with more than one angle being 14:10:00 .. used in the same document. CSS does not support that at the moment, though you 14:10:49 .. could support it in SVG with 2D transforms. 14:11:26 Nigel: Let's keep this scoped to CSS, since that's this document's purpose. 14:11:37 Dae: "Ignore" means that's the fallback, in this case CSS can't do it at all. 14:11:43 Nigel: Thanks for the explanation. 14:12:37 .. Please could I ask everyone with an interest in this to add detail where they know it, and 14:12:43 .. if there are any missing features, add them. 14:14:10 Nigel: Some more context here - when TAG reviewed TTML2 they offered to facilitate a 14:14:22 .. joint meeting with CSSWG, and we invited CSSWG to our meeting at TPAC. In advance of 14:14:51 .. that TAG has invited me to discuss these issues with them around 26th July so there's a 14:15:37 .. deadline for sorting this document out so we can share it with TAG. I suggest getting 14:15:46 .. this to a shareable state by Friday 21st July. 14:16:03 Pierre: We need to add multiRowAlign too. 14:16:13 Nigel: Thanks I wasn't sure about that. Also you have some codepens too? It would be 14:16:18 .. useful to add those in please. 14:16:21 Pierre: Ok 14:17:19 Nigel: Regarding TPAC, Thierry created a wiki page for it 14:17:57 -> https://www.w3.org/wiki/TimedText/tpac2017 TPAC2017 TTWG page 14:18:28 Thierry: The dates are 6-10 November, and we are meeting on 9th and 10th. 14:19:04 Nigel: Plus we are meeting jointly with the Media and Entertainment IG on Monday 6th. 14:19:25 Topic: IMSC 14:19:41 Thierry: We have published the IMSC 1.0.1 CR today 14:20:00 .. This has triggered the Call for Exclusion of 60 days until Sep 11. 14:20:17 .. I think we should target, if we have enough implementations, a PR publication by Sep 15. 14:20:39 Nigel: Can we do a PR earlier and just delay Rec until the end of the CfE? 14:21:04 Thierry: If we want to go fast track we could ask for this - I have to check in the Process 14:22:00 .. how to do that. When do you think we can do that? In terms of implementation. 14:22:42 Nigel: Now we have published the CR I will go through the BBC processes to add our 14:22:44 .. implementation. 14:23:00 Glenn: I could add the new features to TTV as a second implementation. 14:24:15 Thierry: I'll send you the exact procedure if we want to go into PR review earlier than the 14:24:41 .. 60 days in case we meet the exit criteria earlier. Then it's another 4 week to Rec, so we 14:24:52 .. can envision a Rec before end of October if we keep to that schedule. 14:26:55 Nigel: Well done getting here, thank you everyone! 14:27:49 Thierry: We've been using the 2017 Process and therefore this allows AC review starting 14:28:05 .. after CR publication (it used to be PR) but now your AC Rep can from today review the 14:28:14 .. document and agree to Rec publication. 14:28:50 .. If we publish a new CR then it might trigger a new review. Your AC Rep will have 14:28:54 .. received a review form. 14:29:01 Topic: TTML 14:29:41 Glenn: I did a bit of administrative work after last week's meeting to organise the TTML1 14:29:51 .. issues into milestones, with the test related ones in a separate milestone. 14:30:09 .. I made sure that every issue had a milestone. 14:30:16 Nigel: On Tuesday I found 2 open issues with no milestone. 14:30:19 Glenn: I'll check that. 14:30:43 .. In TTML2 I'm soon going to ramp up work to resolve existing issues, hopefully in a week 14:30:45 .. or so. 14:32:00 Nigel: Last week I opened a pull request to address some formatting and a "silly" mistake 14:32:09 .. about the HDR thing. 14:32:14 Glenn: I'll look at that and merge it today. 14:33:45 Nigel: I also raised an issue for supporting font variation settings, with the use case of 14:33:51 .. number presentation. 14:34:05 -> https://github.com/w3c/ttml2/issues/400 14:34:16 Glenn: Now that you've raised that I'm keen to go ahead with it using the syntax in the 14:34:33 .. CSS fonts module. One of the criticisms of this feature is that its tied to TrueType and 14:34:53 .. OpenType, but practically pretty much all, or anyway most, fonts fit this category. If an 14:35:06 .. implementation provides a semantic mapping for other font formats then it can still be 14:35:12 .. used so I'm not concerned about that. 14:35:23 .. Just in case we get similar comments in the future. 14:35:44 .. One more thing: since it is a kind of open-ended extensibility mechanism for directing 14:35:55 .. the font and layout system to do something special we may want to create a registry 14:36:06 .. to give guidance to authors and implementors about which features are supported, 14:36:19 .. otherwise there will be no expectations for specific support, unless we define profile 14:36:26 .. feature designator. 14:36:48 Nigel: So in my case I would want the tnum value to be variable, so there would be a 14:36:55 .. feature designator for that? 14:37:08 Glenn: Right, though we would likely not publish a new designator for every individual 14:37:27 .. features. It could be that we put them in the extensions space for designators. It is 14:37:29 .. something to think about. 14:37:51 Nigel: Any other TTML comments right now? 14:38:17 Glenn: There's been some reflector conversation initiated by Viacom. 14:38:41 atai has left #tt 14:38:53 .. I would suggest you point the commenter towards your work on live contribution of TTML. 14:38:56 Nigel: Good idea. 14:39:02 s/you point/Nigel points 14:39:18 Glenn: It doesn't make much sense to do roll-up for pre-canned captions. 14:43:37 .. There are two features that I've considered adding in the past but never done so: 14:43:55 .. end="indefinite" and begin="now" for the live use case. 14:44:09 Nigel: The EBU-TT Live spec works around their absence okay. 14:44:27 Glenn: mediaOffset could be used for the begin="now" case. 14:44:42 Nigel: Actually I think it can't, but that is very similar to the reason I wanted to introduce 14:44:56 .. a tt element attribute "clipBegin" to carry the same meaning. 14:45:07 Topic: WebVTT 14:45:20 s/Topic: WebVTT 14:45:33 Thierry: The Wide Review of TTML2 started when the publication was released around 10 days ago. 14:45:47 .. I have sent calls for review to all the W3C groups and the external bodies, with one 14:46:00 .. remaining for the Japanese IPTV Forum. I need to send that and also I need to work on the 14:46:15 .. TAG questionnaire. So now I will be tracking those comments also for TTML2. 14:46:29 Nigel: Fantastic, thank you for doing that (and reminding me about it!). 14:46:38 Thierry: The review ends Sep 30. 14:46:51 Topic: WebVTT 14:47:08 Thierry: Silvia has done a lot of work on editing the WebVTT draft of the CG mainly fixing 14:47:23 .. broken links and linking to W3C HTML spec instead of WHATWG. 14:47:36 .. The draft was published today on TR as an ordinary draft. My understanding is we should 14:47:42 .. trigger another draft soon for wide review. 14:48:07 Nigel: It's also worth noting that Silvia has now joined the WG and has effectively taken on 14:48:12 .. shared Editing role with Simon. 14:48:43 Pierre: Who does Silvia represent? 14:48:48 Nigel: It's CSIRO in Australia. 14:49:22 Nigel: Any progress on looking at the Dispositions for the previous Wide Review? 14:49:27 group: [silence] 14:49:36 Topic: HDR in PNG 14:50:03 Pierre: All the comments filed on GitHub have been resolved. The only outstanding question 14:50:19 .. I know of is related to the supported bit depth of PNG. PNG supports only 8 and 16 bits, 14:50:36 .. and nothing in between. Some folk have pointed out that 8 is too little and 16 is too much. 14:50:55 .. 8 is too little for general use, but it's okay for subtitles and captions. Possibly we should 14:51:07 .. extend the note on bit depth to say that. I'm reluctant to state that until someone has 14:51:24 .. a concrete issue filed. I think this would impact only the informative note. I think this 14:51:27 .. is ready to be published. 14:51:57 -> https://github.com/w3c/ttml2/issues/400 Feedback on HDR compositing #400 14:52:11 Nigel: I forwarded some feedback to TTML2 that may be relevant here. 14:53:08 .. I think the overall comment is that in PQ both narrow and full range are in use so the 14:53:28 .. spec should support that. I am not sure if that also applies back to the PQ in PNG note. 14:53:44 Pierre: The note only deals with full range quantisation. We could conceivably add a row 14:53:55 .. for narrow range - technically that is easy to add to the document. I suggest that we 14:54:08 .. keep this a living document, and address that point if and when it is raised. 14:54:35 Nigel: OK - the point raised on TTML2 was about the range of the video rather than the 14:54:41 .. range of the image. 14:54:59 Pierre: Yes, though in a simple implementation a copy or blit of full range subtitle pixels 14:55:13 .. to narrow range video you would not get what you expected. That is less of an issue for 14:55:15 .. subtitles and captions. 14:55:24 Nigel: Why is that? 14:55:40 Pierre: If you get the luminance a bit off then it is not orders of magnitude difference. 14:56:06 Nigel: Great, shall we do one final review pass of the document and the comments before 14:56:12 .. proposing to publish it next week? 14:56:31 Pierre: Sure. And Thierry if you could look at it and check its suitability for publishing then 14:56:34 .. that would be useful. 14:56:43 Thierry: Okay I will look at it today or tomorrow. 14:56:47 Nigel: Thank you. 14:57:19 Topic: IMSC Tests 14:57:30 Pierre: I've been updating the tests and have just pushed a pull request to address the 14:57:38 .. spaces before line breaks issue we discussed last week. 14:57:52 .. There are 15 issues against the IMSC tests, all but that one being cosmetic, but that one 14:58:05 .. is important to get right. It affects only a few tests, but as you know Chrome, which is 14:58:20 .. used to generate the renders, seems not to suppress spaces before explicit line breaks 14:58:34 .. if those spaces are within a span. That's also something I've added to the wiki about CSS 14:58:45 .. and TTML compatibility. We really should understand if it is a Chrome bug or a divergence 14:59:05 .. between CSS and XSL-FO behaviour. To me it looks like a Chrome bug. 14:59:08 Nigel: Me too. 14:59:24 Pierre: It means that any implementation using CSS needs to include some extra manual work. 14:59:47 Nigel: Will you add the IMSC 1.0.1 exit criteria tests into the imsc-tests? 15:00:01 Pierre: Yes when I have confirmation from implementations that they're right. 15:00:16 .. It would be just a copy and paste since the format of the tests is the same in both 15:00:29 .. imsc-tests and the IMSC 1.0.1 exit criteria tests. 15:01:33 Nigel: We seem to have completed our agenda in an hour, which was secretly my plan all along, so thanks everyone! [adjourns meeting] 15:01:40 rrsagent, make minutes 15:01:40 I have made the request to generate http://www.w3.org/2017/07/13-tt-minutes.html nigel 15:11:11 s/its tied/it is tied 15:12:47 s/fonts fit/fonts in use fit 15:13:14 s/features. It could/feature. It could 15:14:09 s|s/Topic: WebVTT| 15:14:52 s/Topic: WebVTT/Topic: xWebVTT 15:14:58 s/Topic: WebVTT/ 15:15:05 s/Topic: xWebVTT/Topic: WebVTT 15:15:21 rrsagent, make minutes 15:15:21 I have made the request to generate http://www.w3.org/2017/07/13-tt-minutes.html nigel 15:23:39 scribeOptions: -final -noEmbedDiagnostics 15:23:40 rrsagent, make minutes 15:23:40 I have made the request to generate http://www.w3.org/2017/07/13-tt-minutes.html nigel 16:06:46 Zakim has left #tt 16:14:19 tmichel has joined #tt