14:01:23 RRSAgent has joined #tt 14:01:23 logging to http://www.w3.org/2017/04/13-tt-irc 14:01:25 RRSAgent, make logs public 14:01:25 Zakim has joined #tt 14:01:27 Zakim, this will be TTML 14:01:27 ok, trackbot 14:01:28 Meeting: Timed Text Working Group Teleconference 14:01:28 Date: 13 April 2017 14:02:23 Present: Pierre, Philippe, Nigel 14:04:18 Chair: Nigel 14:04:22 scribe: nigel 14:05:12 Present+ Andreas 14:05:32 Regrets: Glenn 14:05:47 Topic: This meeting 14:06:27 Nigel: I added to the agenda the TPAC 2017 advanced planning, and we have TTML and 14:06:39 .. IMSC topics. Any other things to cover? 14:06:50 Pierre: I'd like to discuss moving forward with the test vectors for IMSC 1. 14:06:57 Nigel: Great let's do that. 14:07:14 Topic: TPAC 2017 Advanced planning 14:07:29 Nigel: I believe we already agreed to meet at TPAC for at least 2 (and possibly 4) days. 14:08:00 Nigel: I will need to complete a survey saying how many days we want to meet for and if 14:08:07 .. we wish to meet any other groups. 14:10:22 .. TPAC this year is in Burlingame, 6-10 November. 14:10:53 -> https://www.w3.org/2017/11/TPAC/Overview.html 14:12:03 Nigel: I will also need to state the days preferences, our flexibility, and any overlaps with other groups to avoid. 14:12:12 mike has joined #tt 14:13:20 Nigel: There is another big event in San Francisco at the same time so flights and 14:13:28 .. accommodation will be limited - advice is to book early. 14:13:40 Present+ Mike 14:14:10 Nigel: Does anyone already know of any date preferences for our meetings? 14:15:12 Andreas: I will need to check - if we meet for 4 days then I will probably not join TTWG on all those days. 14:15:52 Nigel: OK I will come back to this next week - I have until mid-May to complete the 14:15:59 .. questionnaire on behalf of the Group. 14:16:17 Topic: IMSC 14:16:34 Nigel: Two things here: firstly liaisons, secondly test suite. 14:17:37 Nigel: For practical reasons I was unable to send the final liaison until yesterday but have 14:17:53 .. now done so, with apologies to the last group to receive the message, which gives them 14:17:58 .. a bit less time to deal with it. 14:18:53 Nigel: The next thing is the test suite. 14:19:16 Pierre: There's been a source of recurring complaint that there is no complete test suite 14:19:27 .. for IMSC so what I've done over the past couple of weeks is to combine tests from the TTML 14:19:42 .. test suite and the IRT test suite, and licences on both allow that. I have modified those 14:19:54 .. files to be conformant IMSC 1 and to make them more appropriate for generating test 14:20:09 .. vectors. Then I ran IMSC.js on them and generated a sequence of PNGs, one for each ISD 14:20:21 .. based on them. I would like to submit those back to W3C and make them the official 14:20:38 .. IMSC test vectors. One obvious objective is to help folk develop and test software, another 14:20:54 .. is if results differ then we can review that in an issue, in case it is an issue with the test, 14:21:08 .. IMSC.js or the spec. In practice I would create a pull request against the IMSC repo 14:21:15 .. replacing the test subfolder with the test vectors. 14:21:55 Nigel: One question is whether we base the IMSC 1.0.1 CR exit criteria on these tests or 14:22:02 .. part of them or if it is completely separate? 14:22:26 Pierre: This submission is not intended for the exit criteria of IMSC 1.0.1 - it could be but that is not my primary goal. 14:22:34 Nigel: Does it include tests for the new features? 14:22:42 Pierre: Not yet, but I would hope to add them in time. 14:23:25 Mike: One of the new features has no presentation output, so the test would be that it does 14:23:27 .. not break. 14:23:42 Nigel: Quite right, though a console output might log recognition of the activeArea. 14:28:41 Nigel: So the request is for W3C to host a test suite for implementors beyond CR. Philippe, is that commonly done? 14:29:17 Philippe: Yes, we could do that, but I would say that you should not out W3C staff in the 14:29:20 .. critical path. 14:29:41 .. I would recommend setting up a github repository for it and serving it, then we can 14:29:55 .. create a link to serve it from W3C with a redirect. 14:30:06 Nigel: So that repo could be the imsc repository, right? 14:30:21 Philippe: It could be but I would not recommend it. The test suite licence would be different 14:30:34 .. so we do not need to track the IPR in the same way. 14:30:53 .. I can create another repo in W3C - it is not complicated. If you really want one repository, 14:31:08 .. then be aware that any contributions from outside the group will be tracked for IPR and 14:31:13 .. you will not be able to accept them. 14:31:35 .. We have licences for tests, so having two licences for one repository would be a bit more 14:31:42 https://github.com/w3c/web-platform-tests/blob/master/LICENSE.md 14:31:50 https://github.com/w3c/web-platform-tests/blob/master/CONTRIBUTING.md 14:31:56 Philippe: complicated. For example the web platform tests have a separate repository. 14:32:05 .. The examples above don't look at all like what is in the IMSC repository. 14:32:18 .. The more I think about it they should be in a separate repo with a clearly different licence 14:32:30 .. and contribution guideline from the spec. 14:33:13 Pierre: Then I would propose to remove the tests from the spec repository. 14:33:28 Nigel: Will it be okay to set CR exit criteria based on tests outside the spec repo? 14:33:42 Philippe: Of course, the tests are not part of the spec. 14:34:00 .. I recommend that we create a separate repo for this, and then tell me where to link from 14:34:08 .. in the W3C website and I will do it. 14:34:19 Pierre: I will take an action item to point you exactly to where they are. 14:34:33 Philippe: Thank you, I am happy to fork an existing repo. 14:34:40 Pierre: I will try to make it simple for you. 14:35:11 Philippe: It would be easier for me to create the repo, and set the access rights the same as 14:35:16 .. the group's spec repos. 14:35:20 Pierre: OK. 14:36:03 https://github.com/w3c/imsc-tests 14:36:15 Philippe: That is a link to the repository. 14:36:52 Pierre: I will push the tests there. 14:37:12 Nigel: Great. Thank you! 14:38:16 Nigel: The existing CR implementation report is based on the tests in the spec repo, so it 14:38:29 .. wouldn't be great to remove them. 14:38:42 Pierre: Actually the IMSC 1 implementation report links to the Mercurial repo so nothing we 14:38:52 .. do here will affect the formal IMSC 1 implementation report. 14:39:08 Nigel: Ok then I guess you're free to clean up the IMSC repo as you like! 14:39:14 Pierre: Thanks, I'll suggest something. 14:39:39 Nigel: Now we need to begin thinking about the Exit Criteria for IMSC 1.0.1 CR. 14:41:15 .. My starting point would be for two independent implementations passing each of some 14:41:23 .. new tests for the new features, which would be: 14:41:45 w3c/imsc-tests should be all set 14:41:55 .. 1. Not failing when processing a document with ittp:activeArea present 14:42:10 .. 2. (perhaps) indicating on some console output the found value of ittp:activeArea. 14:42:33 .. 3. Successful presentation of the lineGap style as per the example in the spec, in other 14:42:39 .. words turning that example into a test vector. 14:43:14 .. I think we should set the shortest period that we are able to according to the Process, 14:43:31 .. which I think is a month? 14:43:36 Philippe: For CR it is 4 weeks. 14:43:38 Nigel: Thanks. 14:44:01 Nigel: That would be my proposal. Does anyone think we need anything more? 14:44:14 group: Nothing more needed. 14:44:35 Pierre: If you file an issue to remind me then I will add those. 14:46:24 -> https://github.com/w3c/imsc/issues/226 14:46:32 Nigel: Done, in above issue #226. 14:47:13 Topic: TTML 14:47:26 Nigel: Even in Glenn's absence I would like to discuss our working process. He has sent me 14:47:34 .. some written notes since he is unable to be present. 14:50:26 Nigel: Glenn's view as he's expressed it to me is that the ED is the Editor's prerogative to 14:50:39 .. work with, and that it does not necessarily represent the Group's consensus. 14:51:03 .. I would rather not work against each other here but work in harmony. However we do 14:51:21 https://www.w3.org/AudioVideo/TT/IMSC/tests/ 14:51:57 Nigel: seem to want a group consensus so one option is to create a new branch to serve 14:52:09 .. as the group's consensus and publish WDs based on that. 14:52:25 Pierre: This is also an issue because the ED is linked from the version on /TR. 14:53:23 .. Another issue is that if someone creates a PR based on an issue, especially if they have 14:53:36 .. been asked to, then the discussion on the PR should happen on that PR, so that everyone 14:53:49 .. can track what is changing. It is unreasonable to create a separate pull request and have 14:53:58 .. the discussion somewhere else, or no discussion in the case of an early merge, because 14:54:06 .. it makes it hard to compare with the original submission. 14:54:20 Andreas: Also, to reflect the earlier discussions, this relates to the position of the Editor in 14:54:34 .. the TTML1 and TTML2 activity, where the Editor has an extremely strong role. In my 14:54:46 .. experience this is even a bit stronger than usual, and maybe is not helpful for the group 14:54:58 .. dynamic, so we need to agree how the different roles work some time. 14:55:39 Nigel: In my role as Chair, I think I need to identify when there is or is not consensus. Right 14:55:51 .. now it is clear that there are changes being merged into the ED for which there is not 14:55:54 .. consensus in the Group. 14:56:53 Nigel: Glenn's view on how to proceed is to raise issues on the merged spec. I think we 14:57:06 .. should recognise that from a perspective of the end result document that could result 14:57:18 .. in an okay end result, even if it is not a happy process. 14:57:57 Mike: Looking at this from afar, it seems like we are not all agreed on the process we follow. 14:58:25 Nigel: Exactly, I would like to come up with some kind of action plan to resolve this. 14:58:37 .. Philippe, have you seen any other examples from other groups that we could take 14:58:40 .. inspiration from? 14:59:32 Philippe: If this doesn't work for you guys in the Group then it needs to change, that's the 14:59:59 .. bottom line. If the group wants to review stuff done in the Editor's own branch then that's 15:00:05 .. okay. 15:00:25 Nigel: Before I make any proposal are there any other thoughts for how to resolve this? 15:00:37 Mike: Step one is to talk to the Editor, and if that does not work then step two is for the 15:00:43 .. Chair to take control of merges to the draft. 15:00:47 Philippe: Yes. 15:01:06 .. There is an easy way - we can change permission settings to restrict who can merge 15:01:09 .. into the repository. 15:01:57 Nigel: Okay, that's fine. And regarding the point about the ownership of the ED, is there 15:02:04 .. anything in W3C or the Process about that? 15:04:42 Philippe: To be clear in lots of other groups the ED does not represent the consensus of 15:04:51 .. the group, even if the ED is linked from the /TR page. 15:05:05 .. Formal consensus is only represented in the WD. 15:05:27 Pierre: So do the CSS editors try to capture group consensus in the ED? 15:05:32 Philippe: No they don't. 15:05:57 Pierre: And are the changes to the ED made with pull requests or done unilaterally by the Editor. 15:06:10 Philippe: I would have to check. It used to be that they would be done unilaterally by the Editor. 15:06:29 .. In some cases the Group would ask for changes on moving to WD. 15:06:59 Pierre: The great thing about pull requests is you don't have to do that. 15:07:58 Philippe: I agree, but if you do not have that working method then it does not apply. 15:08:46 Mike: The goal is for the ED to reflect the current consensus. Forcing the members to try to 15:08:56 .. correct something that was not originally proposed is a lot of work that perhaps is not 15:09:20 .. necessary. It is odd at best to have the editor to do something different to what is in WD. 15:09:51 Mike: I believe it would be a better process to use pull requests and merge on consensus 15:10:05 .. into the ED. 15:10:19 Philippe: Nigel, you're right, the Process does not make any requirements on the ED. 15:11:30 .. If the editor cannot produce a draft that the group is willing to agree on then you may 15:11:37 .. need a different Editor. 15:12:51 Nigel: Okay we've discussed this enough today. In Glenn's absence I will not impose the 15:13:03 .. option to stop early merge as indicated in the agenda, however I will take an action to 15:13:18 .. talk to Glenn about this situation. Something will change one way or the other. 15:16:38 Nigel: In Glenn's absence are there any TTML issues that anyone wants to raise? 15:16:43 Andreas: I have to drop off the call now. 15:16:59 Nigel: The only one from my list on the agenda that I think we can easily cover is: 15:17:11 -> https://github.com/w3c/ttml2/issues/139 There's no apparent use case for the "any" term in ttp:contentProfiles 15:18:01 Nigel: I agree with Pierre (who raised the issue) that there's no meaning for "any" here and 15:18:07 .. we should simply remove it. 15:18:16 pal has joined #tt 15:18:19 Pierre: That was like 2 years ago. 15:19:07 Nigel: I've added a comment on the issue. 15:19:21 .. I've also labelled it as "Discussed and agreed". 15:19:53 Pierre: I'd like to look at 244 15:20:01 -> https://github.com/w3c/ttml2/issues/244 Signaling HDR pixels in PNG for use with 15:20:18 Pierre: I'm sympathetic to the point that TTML2 does not define any image formats. 15:20:31 .. However the proposal raised here is something the industry will do regardless, i.e. to put 15:20:51 .. PQ pixels in PNGs. Noting this in TTML2 seems reasonable because it is most likely to 15:21:03 .. happen in subtitles, and because W3C is the home of PNG. I had suggested adding it 15:21:16 .. as an informative annex in TTML2. An alternative perhaps is to create a WG Note, but I 15:21:27 .. think it is important to write it down somewhere otherwise people will do crazy stuff 15:21:44 .. all differently. The advantage of a WG Note is that if someone outside this Group wants 15:21:58 .. to make it more formal then it is easier to pull out. The drawback is it is further away 15:22:09 .. from TTML2 though there could be an informative pointer to the WG Note. 15:22:38 .. I think it is important to point to something but I'm not all set on it being in the TTML2 15:22:39 .. spec. 15:24:20 Nigel: From my perspective, it is easier to get consensus on a WG note and it does not need 15:24:40 .. to hold up TTML2, so I think if you want to draft something then go ahead. 15:24:53 .. Is a problem here that it is a misuse of PNG in some way? 15:25:32 Pierre: That's a really big question, on review I think not. PNG allows for arbitrary 15:25:49 .. gamma exponents but it only supports power law EOTFs and also arbitrary ICC color profiles, 15:26:07 .. so it is not clearly an abuse of PNG, just not using one of the built in EOTF gamma curves 15:26:32 .. defined today, instead using an ICC which is permitted. I think this is classed as a 15:26:52 .. permitted extension. It may be better if PNG were to support EOTFs other than just gamma, 15:27:01 .. but that's something that others in W3C may want to work on. 15:27:10 Mike: Would changes to PNG be made in ISO or W3C? 15:27:25 Philippe: It would be W3C. It certainly has been developed jointly in the past with ISO. I can 15:27:32 .. even give you the right contact in W3C. 15:27:49 Pierre: Maybe the sequence of events is to draft the WG Note and then see if there is further 15:27:51 .. interest. 15:28:33 Philippe: Chris Lilley created the Color CG with Mark Watson - Chris is the guy to talk to 15:28:39 https://github.com/w3c/strategy/issues/58 15:28:49 Philippe: in any case and he is also the one tracking our PNG stuff such as the above issue. 15:30:33 Nigel: WG Notes can be turned into Recs later, right? 15:30:40 Philippe: Yes they can or they can be parked. 15:30:54 Pierre: My position is we should publish the WG Note and then make it available to the Color CG, 15:31:06 .. and even bring Chris Lilley into that work. That makes it really concrete. 15:31:13 Nigel: I'm happy with that. 15:31:35 Mike: I don't have a particular plan in mind I just wanted to raise the question and see if 15:31:47 .. there is another group we should collaborate on it. This plan to publish a WG Note and 15:31:54 .. then work with others is a good plan. 15:32:07 Pierre: Ideally PNG would be updated to take into account these new use cases, but that 15:32:14 .. would take some work to get sufficient critical mass. 15:33:55 Nigel: I've added a comment to the issue on this. 15:34:01 Pierre: Could we create a repo for this? 15:34:50 Philippe: Sure, what name do you want? 15:37:30 Group: [some discussion] png-hdr-pq 15:38:01 Nigel: That allows for other HDR extensions to PNG, if needed, to be placed in other WG Notes 15:38:36 .. whose repositories would be called e.g. png-hdr-??? where ??? would be replaced. 15:39:03 Philippe: I'll get onto that. 15:39:07 Nigel: Thank you! 15:39:47 https://github.com/w3c/png-hdr-pq 15:41:07 Nigel: I've added a link to that and closed the issue - any request to create a reference to 15:41:14 .. the WG Note should be done in a separate new issue. 15:43:45 Pierre: I'll use Respec for this. 15:43:57 Philippe: I'll set it up for the WG Note. 15:44:10 .. I will also set up the master branch to be the one that github.io serves. 15:44:18 Pierre: That's great. 15:44:41 Philippe: I did the same thing for the imsc-tests repo as well. 15:44:58 .. And it is replicated on the W3C website. 15:46:01 ACTION: tmichel Update the TTWG homepage and publications pages for the new repos 15:46:01 Created ACTION-495 - Update the ttwg homepage and publications pages for the new repos [on Thierry Michel - due 2017-04-20]. 15:46:55 Nigel: I think we've run out of steam for today. Thanks all. We have 2 hours again next week. [adjourns meeting] 16:03:59 rrsagent, make minutes 16:03:59 I have made the request to generate http://www.w3.org/2017/04/13-tt-minutes.html nigel 16:10:37 s/you should not out W3C staff/you should not put W3C staff 16:12:57 s/.. new tests for the new features/Nigel: new tests for the new features 16:13:39 s/.. 1. Not failing/Nigel: 1. Not failing 16:18:00 rrsagent, make minutes 16:18:00 I have made the request to generate http://www.w3.org/2017/04/13-tt-minutes.html nigel 16:20:42 ScribeOptions: -final -noEmbedDiagnostics 16:20:43 rrsagent, make minutes 16:20:43 I have made the request to generate http://www.w3.org/2017/04/13-tt-minutes.html nigel 16:29:07 Zakim has left #tt