15:00:26 RRSAgent has joined #tt 15:00:26 logging to https://www.w3.org/2019/06/20-tt-irc 15:00:28 RRSAgent, make logs public 15:00:28 Zakim has joined #tt 15:00:30 Meeting: Timed Text Working Group Teleconference 15:00:31 Date: 20 June 2019 15:00:36 scribe: cyril 15:00:41 chair: nigel 15:01:01 agenda: https://github.com/w3c/ttwg/issues/43 15:03:18 Present+ Nigel 15:03:38 Log: https://www.w3.org/2019/06/20-tt-irc 15:03:52 Present+ Cyril, Gary 15:04:01 Regrets: Pierre, Glenn 15:04:10 Regrets+ andreas 15:04:44 Topic: this meeting 15:04:52 nigel: we have WebVTT 15:05:04 ... for TTML we don't have the right people 15:05:11 ... profile registry 15:05:19 ... Mike declined for this meeting 15:05:27 ... progress on PNG PQ 15:05:39 ... update on charter 15:05:55 ... AOB: karaoke 15:06:17 Topic: WebVTT 15:06:25 nigel: gary has done a snapshot 15:08:05 gkatsev: it's marking 4 things at risk 15:08:26 ... text combine upright, text wrap balance, line and position alignment 15:08:49 ... the last 2 are probably supported in Firefox and vtt.js but it's safer to mark them at risk 15:08:58 nigel: what are we doing with unsigned long? 15:09:20 gkatsev: silvia mentioned that there is not int in WebIDL? 15:09:46 ... we can use the regular long, it's the right range but allows negative values 15:09:56 ... however the spec says that negative values should throw 15:10:34 ... for now I've split the test into an int range that passes 15:12:39 nigel: your change should work 15:12:49 gkatsev: I should update my PR to remove the second test 15:13:22 nigel: In a way it was a weird thing for the spec to say that it should throw for neg values when they were not possible 15:13:31 gkatsev: I'll update that today 15:13:40 nigel: to see the snapshot what do we have to do? 15:14:51 -> https://htmlpreview.github.io/?https://github.com/w3c/webvtt/blob/f071ae65389148c8195102e3fb2483de7e408dd0/archives/2019-06-19/Overview.html current at-risk snapshot 15:15:31 nigel: I'll review that 15:15:55 s/I'll/we'll/ 15:16:51 nigel: the summary for this week is you made tests, we approved but they are not merged yet 15:16:58 ... could you review them? 15:17:06 gkatsev: yes they pass in Safari and Firefox 15:17:48 ... there was the issue regarding the cue box sizes 15:17:57 ... and it seems a reasonable change 15:18:04 ... but I probably don't want to do it now 15:18:10 ... yet another moving part 15:18:38 ... Is make such change just before CR ok? 15:18:51 nigel: It can be done but it depends on the impact of the change 15:18:58 ... I'm not clear on the impact for this one 15:19:08 ... I would like to have PLH's input on this one 15:19:18 ... If you can demonstrate 2 implementations 15:19:28 ... is it related to writing direction 15:19:43 gkatsev: if you have text alignment left or right, the position is correct 15:19:56 ... but if start or end, it won't be aligned properly 15:20:00 nigel: so it's a bug 15:20:08 gkatsev: start and end were added a bit later 15:20:19 nigel: the implementations do what the spec says? 15:20:22 gkatsev: yes 15:20:35 nigel: so if you fix the spec, the implementations will have to change? 15:20:38 gkatsev: yes 15:21:33 ... making a normative change feels that it would take longer to get the CR out 15:21:51 ... I will ping PLH on the issue directly 15:22:01 nigel: yes that needs more thought 15:22:21 ... the impact is that for right to left if you rely on start or end it won't work 15:22:29 ... so there is a work around? 15:22:32 gkatsev: yes 15:22:49 nigel: it doesn't sound that the impact is massive if we don't fix it now 15:22:52 gkatsev: yes 15:23:12 nigel: anything else on VTT? 15:23:23 Topic: TTML2 luminance gain 15:23:37 scribe: nigel 15:23:40 github: https://github.com/w3c/ttml2/issues/1117 15:24:01 Cyril: The context is that I started discussing internally at Netflix 15:24:20 .. with teams who implement HDR on games consoles, asking how to render luminanceGain. 15:24:35 .. People looking at the spec for the first time were confused by the term "gain". 15:24:52 .. It's an absolute luminance but called a gain. Initially they thought it was gain relative to graphics white. 15:25:06 .. You can discuss with the TV to know what its graphics white luminance is. They interpreted it 15:25:17 .. as compared to that and not compared to 18 nits which the spec says. 15:25:34 .. The spec is not unclear, but they had an assumption. 15:25:46 .. We agree with what is written in the spec and Fox proposed this clarification. We think 15:25:48 .. it is a good one. 15:26:12 Nigel: Will you propose a pull request? 15:26:28 Cyril: Yes, it will be a Note saying that the gain is relative to 18 nits and not to a relative value 15:26:39 .. corresponding to the device graphic white, or something along those lines. 15:26:50 Nigel: Ok, looking forward to seeing the pull request for that. 15:27:43 Topic: TTML Profile Registry The codecs parameter should have a formal definition of the use of the combination operators. #71 15:27:53 github: https://github.com/w3c/tt-profile-registry/issues/71 15:28:21 Nigel: It's been a while since we opened this and we haven't managed to get to it. 15:28:25 Cyril: I haven't had a chance to work on it. 15:29:04 Nigel: Comment from 11 April, we need Cyril, Mike and Glenn on the call. Let's move on for today, since we don't have all those people. 15:29:08 github-bot, end topic 15:29:18 scribe: cyril 15:29:33 Topic: PNG in PQ HDR 15:31:32 cyril: this seems purely editorial 15:31:35 nigel: yes 15:31:45 ... I have changed the link on the repo, as requested on the repo 15:32:08 ... and I have created a PR to add link to the editor's draft in the readme 15:32:21 -> https://github.com/w3c/png-hdr-pq/pull/9 Pull request #9 15:32:52 Topic: AOB - Charter update 15:34:02 s/Charter update/Karaoke/ 15:34:12 scribe: nigel 15:34:24 Cyril: I have made a first editor's draft of the Karaoke module. 15:34:41 .. For the record, I'm uneasy with the term Module, and have had lengthy conversations with Glenn. 15:34:53 .. My position is if we promote the term Module to a bigger state, to be more visible, we will have 15:35:31 .. terms like Specifications (TTML), Profiles (IMSC), Features (feature designators), 15:35:48 .. and my view is the term is only in TTML in the two tables in ยง5 which list the modules as a collection 15:36:02 .. of elements or attributes. I think it is confusing for a new specification to say it is a module. 15:36:18 .. What people will care about is the module defines one or more features, which a profile can then 15:36:23 .. include. That's the only thing that is needed. 15:36:34 .. I'll follow what the group decides but I think it's confusing. 15:36:46 .. I know CSS uses the term Module so maybe people are familiar with that. 15:37:02 .. It is related to the text in TTML3 that talks about public/private modules and the module registry. 15:37:14 .. To me this is too much, we don't need to introduce all these notions to define a new specification. 15:37:35 .. I called this an extension not a module, with reference to HTML5 MSE and EME. 15:37:49 .. Glenn noted we have extension designators already in TTML so the term is used. 15:37:55 .. I'm open to a different terminology. 15:38:32 Gary: I agree there are a lot of different names and limiting the terminology is a plus. 15:38:37 .. I'm not sure the best direction. 15:39:06 Nigel: I agree that we don't need the additional terminology in TTML3, and have made that pretty clear 15:40:13 .. in a comment on TTML2 pull request 1066 15:40:22 -> https://github.com/w3c/ttml2/pull/1096#pullrequestreview-242593523 pull request 1066 comment 15:40:35 s/1066/1096/ 15:40:40 Cyril: We merged the change to TTML3 though? 15:40:50 Nigel: Yes I feel we were pushed into that and I don't like it. 15:41:07 .. So I agree about using less terminology where we can. 15:41:27 .. Where I think I do agree with Glenn is the word "module" to be a specification that defines some 15:41:44 .. additional features seems fine to me, especially since those features are grouped by some 15:41:54 .. technical theme. 15:42:12 .. If using Module means less change to TTML that's a good thing. 15:42:26 Cyril: You would say the new spec is the Karaoke module but don't introduce internal/external, 15:42:36 .. and just remain silent. We don't need to define what the module is? 15:42:38 Nigel: Yes 15:42:43 Cyril: Okay I could live with that. 15:43:28 Nigel: I think we just can say in the Karaoke module that it is a specification that defines some TTML2 15:43:33 .. features. We don't need anything more. 15:43:53 Cyril: I won't define any profile. 15:43:56 Nigel: That's clean 15:44:15 Cyril: My intention is we would add a new profile elsewhere, IMSC1.1K or whatever (don't know the name) 15:44:38 .. I tried to define this module by adding the minimum number of elements and attributes. 15:44:44 .. There are no new elements, only 3 attributes. 15:45:10 .. One of them is a styling attribute tts:imageEmphasis, building on the semantics of textEmphasis 15:45:22 .. but replacing the text by an image when textEmphasis is set to "auto". 15:45:37 .. Initially you could have thought about changing textEmphasis to add a URL but that would have been 15:45:47 .. backwards-incompatible and existing implementations would break. 15:46:04 .. So I preferred creating a new attribute. If it is ignored the emphasis will be a text not an image, 15:46:11 .. so there is graceful degradation. 15:46:15 Nigel: I like the sound of that! 15:47:14 Cyril: Glenn asked if an attribute should be a parameter or a style attribute, saying we only put 15:47:23 .. parameter attributes on the root element so it should be a style attribute. 15:47:50 -> https://w3c.github.io/tt-module-karaoke/ Karaoke module 15:48:32 Nigel: I see, ttp:karaoke to define a _section_, no, I agree that doesn't look like a parameter attribute. 15:48:47 Cyril: Styling properties have a notion of inheritance and applicability, but that doesn't apply here. 15:50:08 .. A karaoke section allows the presentation processor to override the semantics for the relevant section. 15:50:24 .. For example a song inside some other content that is used for karaoke 15:50:43 .. I wanted to raise the general question - what is the philosophy behind a parameter attribute? 15:51:08 Nigel: My understanding is that a parameter attribute sets up the processor with some settings or 15:51:19 .. constraints that apply when processing the entire document, so it only makes sense to have them 15:51:22 .. on the root element. 15:51:41 .. This karaoke attribute does not feel like a parameter attribute. 15:51:48 Cyril: Ok, I'll change it. 15:51:51 Nigel: But what to? 15:52:01 Cyril: A styling attribute, applicable only to body and div 15:52:19 Nigel: That works, or you could use a new namespace 15:52:24 Cyril: No, we have enough of those! 15:52:41 .. The last thing is the general philosophy of the spec is that you could do limited karaoke with TTML2 15:52:48 .. today, because you have a set and animate element. 15:52:50 .. Two problems: 15:53:06 .. 1. When the processing engine sees an animation it does not know it is karaoke, so no semantics 15:53:23 .. associated with it. The engine cannot apply its own settings on the basis that it is karaoke. 15:53:31 .. We want to detect if content is karaoke. 15:53:48 .. 2. TTML2 is limited - the bouncing ball above the text cannot be specified. 15:54:02 .. This spec adds semantics to identify where the karaoke content starts and animations can be 15:54:09 .. overridden, and adds more animation types. 15:54:45 .. karaokeMode allows the emphasis to be applied with text emphasis or with colour. 15:54:55 .. Please read, open issues and I will propose changes. 15:55:43 Nigel: We should find a way to get the word out on this. 15:55:54 Gary: Maybe Crunchyroll? 15:56:11 .. I know a lot of people in anime community do karaoke for the opening songs. They might be interested. 15:56:29 Nigel: It would be good to get input from this as soon as possible. 15:56:57 Cyril: Glenn said this should be TTML1 applicable not just TTML2. Nigel what do you think? 15:57:08 Nigel: If you need textEmphasis you have to depend on TTML2, it isn't in TTML1 15:57:29 Gary: Maybe say "if textEmphasis available then this applies" rather than the direct dependency on TTML2. 15:57:32 Cyril: Yes 15:57:37 Nigel: Good idea, if that can work 15:57:52 Cyril: I may define one feature for emphasis based karaoke and another for colour based and in TTML1 15:57:58 .. only the colour based karaoke could work. 15:58:02 Nigel: Good idea 15:58:22 Cyril: Please open issues and we can discuss that. 15:58:26 Nigel: OK, thank you! 15:58:55 Topic: Meeting close 15:59:48 Nigel: Thanks everyone, we couldn't discuss the charter etc because Philippe couldn't make it - he tells 16:00:18 .. me by IRC that he is in the thick of some deep discussion. So we'll adjourn for today. [adjourns meeting] 16:00:21 rrsagent, make minutes 16:00:21 I have made the request to generate https://www.w3.org/2019/06/20-tt-minutes.html nigel 16:08:12 Regrets+ Thierry, Philippe 16:10:52 Regrets+ Mike 16:11:21 s/your change should work/[does some binary maths] your change should work 16:11:57 s/is it related to writing direction/is it related to writing direction? 16:13:19 s/gkatsev: yes/gkatsev: yes, the workaround is use right or left instead of start or end, depending on the writing direction 16:14:03 rrsagent, make minutes v2 16:14:03 I have made the request to generate https://www.w3.org/2019/06/20-tt-minutes.html nigel 16:14:55 a/andreas/Andreas/g 16:15:02 s|a/andreas/Andreas/g|| 16:15:06 s/andreas/Andreas/g 16:15:09 rrsagent, make minutes v2 16:15:09 I have made the request to generate https://www.w3.org/2019/06/20-tt-minutes.html nigel 16:15:50 scribeOptions: -final -noEmbedDiagnostics 16:15:52 rrsagent, make minutes v2 16:15:52 I have made the request to generate https://www.w3.org/2019/06/20-tt-minutes.html nigel 17:30:31 Zakim has left #tt