13:59:44 RRSAgent has joined #tt 13:59:44 logging to http://www.w3.org/2016/10/13-tt-irc 13:59:46 RRSAgent, make logs public 13:59:46 Zakim has joined #tt 13:59:48 Zakim, this will be TTML 13:59:48 ok, trackbot 13:59:49 Meeting: Timed Text Working Group Teleconference 13:59:49 Date: 13 October 2016 14:00:11 mike has joined #tt 14:00:43 Present: Nigel 14:00:47 Chair: Nigel 14:00:50 scribeNick: nigel 14:01:56 Present+ Mike 14:02:50 Present+ Glenn 14:05:15 Present+ Pierre 14:05:20 Topic: This meeting 14:06:26 Present+ Andreas 14:07:53 nigel: I've scheduled today for an hour and a half for those who can make it. 14:09:56 nigel: For today, the main topic will be TTML2. There are also some open issues on the TTML Profiles document, and on IMSC which we should cover. 14:10:27 nigel: There has been some activity on WebVTT but as far as I'm aware we aren't going to 14:10:35 ... spend any time discussing that today. 14:10:55 nigel: I'd like to think about a next F2F meeting too and check diaries. 14:11:01 nigel: Any other business to cover? 14:11:29 group: No other business. 14:11:46 Topic: Next F2F Meeting 14:15:46 group: [discusses dates] w/c 23rd January is a possibility. 14:17:30 nigel: At that time I would hope we are ready to discuss TTML2 CR exit criteria and transition to CR. 14:17:41 ... Also to scope the next IMSC. 14:19:40 Andreas: EBU Production Technology Seminar is 24-26 Jan in Geneva. 14:20:04 glenn: That week is not great for me - how would Jan 12/13 work? 14:20:25 tmichel has joined #tt 14:21:00 group: That works ok. 14:21:38 present+ 14:21:46 Present+ Thierry 14:22:41 nigel: Okay I'll send a note out to the group including expected location. 14:22:58 ACTION: nigel Propose 12 and 13 Jan to TTWG for a F2F meeting in London 14:22:58 Created ACTION-482 - Propose 12 and 13 jan to ttwg for a f2f meeting in london [on Nigel Megitt - due 2016-10-20]. 14:24:10 Topic: WebVTT 14:24:30 tmichel: There has been some activity by David and communication with a CSS WG and a 14:24:49 ... long email from David that I have not reviewed yet. I also noted that there are a lot of 14:25:02 ... substantive changes so a new WD is needed and a new wide review. We should wait 14:25:20 ... for the time being until David, Simon et al can attend. 14:25:49 nigel: Ok thanks for the update. 14:26:14 Topic: Profiles Registry 14:27:07 nigel: I opened a pull request https://github.com/w3c/tt-profile-registry/pull/28 14:27:31 tmichel: I also raised an issue for wrong URLs: https://github.com/w3c/tt-profile-registry/issues/29 14:27:50 mike: None of the updates I think are critical. It was important to get the published version 14:28:28 ... out with the updated RFC link in. I'd like to set a deadline for further comments and 14:28:45 ... deal with them. Maybe mid-November. 14:28:56 nigel: Okay that works, about 4 weeks from now. Do you want to leave the current stuff 14:28:59 ... as is for the time being? 14:29:15 mike: Yes, I can sit down and gather together all the pulls etc in one go. 14:29:28 tmichel: For information, I have set up the echidna automatic publishing tool for this 14:29:44 ... document so now it is very easy to publish, I can do it myself. The only thing I need is 14:29:51 ... a WG Resolution in the minutes to publish. 14:30:11 nigel: Ok ask us for that when we have a new version in a month or so please. 14:30:34 nigel: Anything to discuss right now? 14:30:54 mike: They seem editorial to now, the pull requests. 14:30:57 nigel: I think so. 14:31:34 Topic: IMSC 14:32:27 nigel: There is an open pull request for refactoring the repo, and there's the topic of 14:32:36 ... moving to gh-pages. 14:33:59 Pierre: I don't think there are any problems with the pull request so I plan to merge it. 14:34:14 nigel: https://github.com/w3c/imsc/issues/187 14:35:55 tmichel: Philippe recommends that we move to gh-pages. We have been doing this across W3C. 14:36:13 glenn: I remember reading about the use of gh-pages and the auto-publishing system so 14:36:17 ... that documentation should be available. 14:36:32 tmichel: Either we keep master or gh-pages but both is crazy. 14:36:48 glenn: I agree, we should not keep both. I have seen no problem with using gh-pages for TTML2 so far. 14:37:17 andreas: Also note that the TTML WebVTT mapping document uses gh-pages. 14:38:22 glenn has joined #tt 14:38:25 https://w3c.github.io/faq.html 14:40:46 nigel: There's no reason not to have a root level index.html page that provides an intro 14:41:07 ... to IMSC and has pointers to spec/imsc1.html or spec/imsc2.html for example. 14:41:17 Pierre: I would be happy to create such an index page. 14:42:02 glenn: You can choose which version of the head syncs with the gh-pages branch for 14:42:11 ... auto publishing - I suggest reading the faq I posted above. 14:42:16 Pierre: I will do that. 14:44:22 Topic: TTML 14:44:47 nigel: First, horizontal review 14:44:49 action-480? 14:44:49 action-480 -- Thierry Michel to Request schedule time for horizontal review of ttml2 -- due 2016-09-26 -- OPEN 14:44:49 http://www.w3.org/AudioVideo/TT/tracker/actions/480 14:45:11 nigel: One of these things is the security questionnaire. Thanks Thierry for updating our draft responses. 14:46:20 nigel: My understanding of "valuable data" is that it refers to something that can unlock 14:46:35 ... greater sources of data, such as credentials, or something that would allow authentication 14:46:43 ... as a particular user. I do not think this affects us at all. 14:46:48 tmichel: That's as I understand it too. 14:47:37 nigel: The next thing is 3.6 regarding if is a script. 14:47:59 mike: If TTML like animation in SMIL etc is not considered a security risk we should follow that. 14:48:13 ... The concern is that for everything else in TTML you can't cause harm, but if you create 14:48:22 pal has joined #tt 14:48:41 ... a maliciously crafted you could make a processor go off into a big loop and 14:48:45 ... deny the service. 14:49:04 glenn: Is that any different from creating a lot of content that changes at millisecond boundaries for example? 14:49:13 mike: No, but it may be easier to detect. 14:49:44 glenn: The HRM in IMSC 1 is one way to handle this - does it handle ? 14:49:48 Pierre: It does address 14:50:04 glenn: That's one way to do this, and we could do something similar in TTML now that we 14:50:08 ... have an example of this formalism. 14:50:35 Pierre: As I understand it in TTML1 is an authorial shorthand to create new ISDs, so 14:50:49 ... since the HRM works on ISDs whether the ISDs come from s or timings or captions 14:50:54 ... it makes no difference to the HRM. 14:50:56 nigel: +1 14:51:10 glenn: That's true. When we have the element it creates intra-ISD animation. 14:52:06 glenn: One way to deal with is to quantise to some degree at which point you 14:53:48 ... will have effectively generated a bunch of ISDs at some level. 14:54:25 nigel: One thing we do not have is something like the HTML 'time marches on' algorithm, 14:54:42 ... so processors need to be constructed well but badly made ones or those that cannot 14:55:02 ... deal well with the input documents could generate non-compliant behaviour. 14:55:24 glenn: It would be good to look up the SMIL and SVG animation language and see if they 14:55:29 ... have any impact on security. 14:55:35 tmichel: I can go and look at that. 14:55:37 nigel: Thank you 14:56:33 nigel: Mike spotted that there's a missing answer to 3.8, which is "No". 14:56:46 mike: The Media Type Registration's security considerations section are an integral part of 14:56:51 ... the spec even if they are not inline. 14:57:19 nigel: I assume there will be a normative reference from TTML2 to the TTML Profiles registration document, if there is not already. 14:57:23 mike: I would think that is essential. 14:58:05 mike: We may not be able to reference a Note normatively. 14:58:13 ... We could refer to the IANA document. 14:58:27 glenn: I will insist on using the same media registration. 14:58:37 ... This is a valid question and something we should address in the content. 14:58:50 ... One of the few additions I have made to the minimum profile requirements is that all 14:59:01 ... processors of TTML2 must support the ttp:version attribute which would be marked as 14:59:15 ... 2 or greater if it is not TTML1 so there is an internal mechanism for noting the version. 14:59:23 mike: That indirectly solves the TTML1 issue too. 14:59:28 glenn: Yes, it is required. 15:00:46 nigel: So Thierry are you happy to update 3.16 to say "Yes"? I see that http://w3c.github.io/ttml2/spec/ttml2.html#media-types-registration shows an issue to add the registration in. 15:00:57 glenn: I think that has been overtaken by events somewhat so I want to avoid defining a new 15:01:07 ... media type registration if possible and refer to something external. 15:02:48 nigel: Can we normatively reference the IANA registration? 15:02:57 mike: That seems the simplest thing to me. 15:03:05 glenn: I agree. 15:04:03 andreas: [has to leave] 15:05:38 nigel: The TAG has begun looking at TTML2 also at https://github.com/w3ctag/spec-reviews/issues/138 15:06:40 nigel: They have begun to look at the spec in ED form and have asked some questions. I 15:06:47 ... have added a quick response already. 15:07:27 nigel: By the way they do ask about the high level summary of differences, which I have the action to draft. 15:07:33 action-481? 15:07:33 action-481 -- Glenn Adams to Provide nigel with a list of new features in ttml2 to begin reviewing -- due 2016-09-26 -- OPEN 15:07:33 http://www.w3.org/AudioVideo/TT/tracker/actions/481 15:07:40 nigel: I haven't managed to do this yet. 15:07:48 ... But will do so tomorrow hopefully. 15:08:26 glenn: We can make reference to comments and responses in the TTML1 process if we get 15:08:41 ... pushback from CSSWG, e.g. why we change from hyphenated names to camel case. 15:09:02 ... And why we introduce new value vocabulary relative to CSS. Ultimately they point back 15:09:21 ... to our requirement for interoperability between content and feature requests from users. 15:10:19 glenn: It would not hurt to provide guidance for targeting CSS renderers and those presentation 15:10:23 ... semantics that may be missing. 15:10:37 Pierre: Do you have a list of those? A lot of TTML content will end up on the web and be 15:10:56 ... rendered using HTML. 15:11:19 glenn: I don't have an up to date one. There was some preliminary work generated by Sean 15:11:31 ... that could probably be taken from the change proposals. It would be out of date and need 15:11:45 ... updating. I can see putting an informative annex into our spec to cover this material. 15:11:49 ... I think that would be a good idea. 15:12:09 pierre: https://www.w3.org/wiki/TTML/changeProposal005 ? 15:12:10 nigel: Yes. 15:12:21 glenn: But we should not be limited by CSS. 15:12:38 pierre: I think that the use cases go beyond distribution is a compelling argument. Thanks for that. 15:13:17 nigel: Anything more on horizontal review? 15:13:39 tmichel: No, nothing more. I think the other groups are waiting for the WD on /TR. 15:14:16 glenn: On this topic, since we have some existence proof for SVG renderers, even when CSS 15:14:30 ... does not directly support a feature we can point to SVG to support that rendering. 15:15:26 nigel: Okay that's all for horizontal review, let's move onto pull requests. 15:15:37 ... https://github.com/w3c/ttml2/pull/197 15:15:57 glenn: I did address your point about should/must nigel. The other point about origin 15:17:10 ... being optional, since origin is optional on region, it seems worthwhile making it optional 15:17:14 ... on safe crop area also. 15:17:34 ... In my experience a generic use of this kind of thing is centered. I do not view the 15:17:45 ... complexity of making it optional to be a barrier. You had a question on some of the 15:17:59 ... computation I had put in place. I think you made one misinterpretation. 15:18:12 nigel: Ah, ok 15:18:29 glenn: The last point is designed to tackle the case that the safe crop area extends outside 15:18:47 ... the root container region, and pulls it in. I agree it would have been possible to specify 15:19:04 ... that percentages are less than 100%, however you still have to handle the case where 15:19:34 ... the extent goes past 100%. The only syntactic limitation is to be non-negative. That 15:19:40 ... algorithm will always put it inside the region. 15:23:48 https://github.com/w3c/ttml2/pull/197/files#diff-5ac39ab39265717d36dfd789d254ce1aR4932 15:24:22 http://rawgit.com/w3c/ttml2/issue-0173-safe-crop-area-editor/spec/ttml2.html#parameter-attribute-safeCropArea 15:25:12 pierre: I notice you did not take into account my comments about the name. 15:25:25 glenn: I think safeCropArea is easier to understand and I agree with Nigel on this one. 15:27:46 pierre: This is not a permission to crop. 15:27:54 glenn: No it's a prohibition from cropping within the area. 15:30:26 nigel: My other query is if we need higher level protocol or can just use document processing context. 15:32:05 glenn: I think there will be other places where we use it so I would like to use it here, if it turns out that there are no other places then I can remove it. 15:33:44 ... I will make the minor tweaks to remove "to" and change the should into a deferment to 15:34:26 ... the normative semantic. 15:35:32 ... Then I will merge this, since there are no objections to doing so. 15:38:14 nigel: Okay we're out of time. Thanks everyone. [adjourns meeting] 15:38:18 rrsagent, make minutes 15:38:18 I have made the request to generate http://www.w3.org/2016/10/13-tt-minutes.html nigel 15:42:54 http://concord-consortium.github.io/developer-notes/automating-gh-pages-integration.html 15:44:34 s|http://concord-consortium.github.io/developer-notes/automating-gh-pages-integration.html| 15:45:28 rrsagent, make minutes 15:45:28 I have made the request to generate http://www.w3.org/2016/10/13-tt-minutes.html nigel 15:46:09 ScribeOptions: -noEmbedDiagnostics -final 15:46:10 rrsagent, make minutes 15:46:10 I have made the request to generate http://www.w3.org/2016/10/13-tt-minutes.html nigel 16:38:24 Zakim has left #tt