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16:01:56 <Zakim> Meeting: Timed Text Working Group Teleconference
16:02:03 <nigel> Present: Nigel, Gary
16:02:08 <nigel> Chair: Nigel, Gary
16:02:16 <nigel> scribe: nigel
16:02:42 <nigel> Previous meeting: https://www.w3.org/2021/01/07-tt-minutes.html
16:02:50 <nigel> Present+ Atsushi
16:03:17 <nigel> Present+ Andreas
16:04:16 <nigel> Agenda: https://github.com/w3c/ttwg/issues/172
16:05:01 <nigel> Present+ Glenn
16:05:05 <nigel> Topic: This meeting
16:05:21 <nigel> Present+ Cyril
16:05:38 <cyril> cyril has joined #tt
16:05:41 <atai> atai has joined #tt
16:05:53 <nigel> Nigel: I've added to the agenda two TTML2 topics, and a placeholder for the workplan for this year.
16:06:11 <nigel> .. The TTML2 topics are issue 1215 about lineHeight and Exiting CR.
16:06:21 <nigel> .. Any other business?
16:06:32 <nigel> group: [no other business]
16:07:00 <nigel> Topic: Permit implementations to use fontSize and fontFamily when computing line height w3c/ttml2#1215
16:07:09 <nigel> github: https://github.com/w3c/ttml2/issues/1215
16:07:26 <nigel> Glenn: I'm able to open a PR maybe by tomorrow as per Nigel's most recent proposal. I'm fine with that approach.
16:07:31 <nigel> Nigel: Okay, great, thank you.
16:08:29 <nigel> Glenn: I wanted to add one comment, that I didn't necessarily make it clear.
16:08:50 <nigel> .. Based on my analysis, my conclusion was that an implementation that does _not_ take font*** into account now is non-compliant.
16:09:07 <nigel> .. Your original description was that some implementations might not follow that semantic, and my conclusion was that
16:09:16 <nigel> .. not doing so would make it non-compliant according to the letter of the current spec.
16:09:30 <nigel> .. I would agree that it is not easy to pull out that thread of logic from the spec because it requires a fairly good
16:09:45 <nigel> .. understanding of XSL-FO, which since we're talking about CSS might make one wonder.
16:09:52 <nigel> .. The semantic model is fairly clear.
16:10:08 <nigel> .. The way we did the derivation of attributes might make it seem like it's not semantically tied to the XSL-FO definitions.
16:10:12 <nigel> Nigel: Thanks for that.
16:11:02 <nigel> SUMMARY: @skynavga to prepare a pull request on TTML2
16:11:14 <nigel> Topic: TTML2 - Exiting CR
16:12:30 <cyril> scribe: cyril
16:12:44 <cyril> nigel: my goal was to find out what minimally we needed to do
16:12:50 <cyril> ... the IR contains a large number of tests
16:13:07 <cyril> ... what wasn't clear to me was how it related to the exit criteria
16:13:13 <cyril> ... [reading the exit criteria]
16:13:43 <cyril> ... there is a document that lists all the changes
16:13:52 <cyril> ... I went through all of the substantive changes
16:13:59 <cyril> ... and tried to map them to the features
16:14:05 <cyril> ... some don't and some do
16:14:12 <cyril> ... from each PR to the feature or features
16:14:27 <cyril> ... what sort of tests do we need: validation vs presentation
16:14:31 <cyril> ... there are 22 changes made
16:14:45 <cyril> ... that related to a feature
16:14:58 <cyril> ... there are fewer features because some changes relate to multiple features
16:15:24 <cyril> ... when we look at all of the tests that are in the current IR, some of them test things that are not changed in the 2nd ed
16:15:44 <cyril> ... they are good tests, nothing wrong, but they are not needed for the exit criteria
16:15:51 <cyril> ... my goal is to simplify
16:16:26 <cyril> ... [working on an example in the spreadsheet ...]
16:17:24 <cyril> nigel: looks possible indicate if we could pass exit criteria for a change
16:18:52 <cyril> glenn: in that language you quoted about the definition of what needs to be tested, keep in mind that the word 'feature' can mean one of 2 things and it's not defined precisely.
16:19:22 <cyril> ... It could mean a semantic feature or a designated feature with a #
16:20:07 <cyril> ... second comment is that when I created the tests my model was for which PR required a test, I used whether we decided if it was substantive or not
16:20:38 <cyril> ... lastly, you said a validating processor can flag the error, I think you meant 'must' flag the error
16:20:52 <cyril> ... otherwise it's not a compliant validator
16:21:14 <cyril> nigel: on the last one, it's not clear
16:21:33 <cyril> glenn: we don't say that a validating processor must do X, we don't do that in general
16:21:45 <cyril> ... definition of valid vs invalid is defined further up in the document
16:22:19 <cyril> ... even though that particular text does not use a must, it is still a must if you adhere to other semantics
16:22:32 <cyril> nigel: on the point on the 'substantive' issues, I also factored that
16:22:54 <cyril> ... I also found anyway a significant number of tests that don't relate to 2nd edition changes
16:23:00 <cyril> ... we could remove them from the IR
16:23:06 <cyril> glenn: I'm surprised of that
16:23:10 <cyril> cyril: me too
16:23:23 <cyril> nigel: I do plan on sharing the spreadsheet
16:23:36 <cyril> glenn: one example would be interesting to check your logic
16:23:47 <cyril> nigel: there are a bunch of ISD related tests
16:23:57 <cyril> ... and I don't think there were any substantive changes to ISD
16:24:25 <cyril> glenn: it had to do with the fact that the definition of the size attribute was changed to xsd:nonNegativeDefinition to a new one
16:24:39 <cyril> nigel: there was a change like that
16:24:46 <cyril> ... maybe I misunderstood that
16:25:04 <cyril> glenn: all the tests are changing that semantic change in TTML2 2nd ed
16:25:17 <cyril> ... I'm pretty sure all the changes can be traced back to a real change
16:25:29 <cyril> ... if not, let me know, I can try to give a rationale
16:26:17 <cyril> nigel: anyway there are definitely tests which we are not able to demonstrate indep implementations
16:26:41 <cyril> pal: another column could be added as ttval
16:26:58 <cyril> ... which is a constrained validator for TTML2
16:27:22 <cyril> ... I'm not sure it's worth spending a lot of time on ttval by if a minor change can clean some rows, maybe we should do it
16:27:35 <cyril> nigel: the other observation is about the structure of the IR
16:28:04 <cyril> ... the structure of the IR doesn't match the exit criteria
16:28:48 <cyril> ... in several cases, you discover that the features are implemented by 2 implementations but the current report does not show that
16:28:57 <cyril> ... it should be more traceable and easier to see the results
16:29:19 <cyril> ... that would help us check if we pass the exit criteria
16:29:46 <cyril> nigel: I recall that earlier we required 2 validation implementations and 2 presentation implementations
16:29:56 <cyril> s/nigel:/glenn:/
16:30:04 <cyril> ... you're suggesting changing that?
16:30:08 <cyril> glenn: yes
16:30:22 <cyril> ... I won't argue with that but for the 1st edition we went beyond that
16:30:53 <cyril> nigel: I haven't checked the 1st edition exit criteria but in this case we need 2 implementations total
16:31:26 <cyril> ... we currently have 2 reports: TTV and BBC but we could report ttval and imscjs
16:32:09 <cyril> glenn: although I haven't filled in the table, I have made progress on some of them (shear, opacity, ruby ...)
16:32:43 <cyril> ... I think there is only or 2 (font selection strategy lineheight normal) that I did not touch
16:32:50 <cyril> ... I don't have audio playback on TTPE
16:33:20 <cyril> nigel: for audio, we probably already have a pass already because TTV does validation and Adhere passes presentation
16:33:47 <cyril> ... this is one example of one feature where we have 2 implementations
16:34:36 <cyril> glenn: this model of IR was created by Cyril by taking the first IR and plugging in the relevant entries for the 2nd edition
16:34:46 <cyril> ... we had a stronger requirement in the 1st edition
16:35:05 <cyril> ... I don't have any objections to use a new model for the IR
16:35:16 <cyril> q+
16:36:32 <cyril> ack cy
16:36:46 <cyril> cyril: it would be good to know if the tests are relevant for IMSC
16:37:01 <cyril> nigel: I think I have done that pass already
16:37:19 <cyril> ... so I should have that information, but that's a good idea
16:37:37 <cyril> nigel: I also tried to map the current tests in the IR to the changed features
16:37:55 <cyril> ... I was doing it manually and realized it's already in the JSON files
16:38:32 <cyril> ... so my next task is try to extract the 'since2e' tests
16:39:18 <cyril> cyril: the purpose would be to rewrite the IR with feature, tests, implementations
16:40:32 <cyril> nigel: if anybody has lines of code, please let me know otherwise I'll go ahead
16:41:16 <cyril> glenn: we are using the same manifest for different versions
16:41:29 <cyril> nigel: it's really useful
16:41:41 <cyril> glenn: nothing is using and I haven't validated it
16:42:43 <cyril> nigel: any other thoughts/questions/comments on exit CR for TTML2?
16:43:09 <cyril> nigel: I'm reassured from this discussion that we can do this if we focus on it
16:43:28 <cyril> Topic: Placeholder for workplan for this year
16:43:52 <cyril> nigel: last time the things that people wanted to work on was WebVTT and TTML2 to Rec
16:44:05 <cyril> ... and beginning the journey of user customization
16:44:23 <cyril> nigel: does anybody has anything else?
16:45:06 <cyril> glenn: I was watching an movie about the creation of the Oxford dictionnary that took a while and hope we can be faster than that
16:45:21 <cyril> pal: thanks so much for getting TTML2 to Rec
16:45:43 <cyril> ... on the customization thing, it would be great to get the world to agree on a framework to customization
16:45:56 <cyril> ... I would caution us to do that on our own
16:46:10 <cyril> ... going down one path that works well for one constituent
16:46:26 <cyril> ... anything we can do to get people on the table is great
16:47:57 <cyril> nigel: as having worked on a fork of IMSC.js to add some customization in a particular work, I could be one constituent for who it works but I'm aware it couldn't work for others
16:48:40 <cyril> pal: one thing we could do is: many of us are involved in many forums and we could share that
16:48:54 <cyril> ... we could also draft something and share through liaisons
16:49:27 <cyril> nigel: that'd be a good first step
16:49:43 <cyril> pal: the privacy aspect is not something that many folks think about
16:50:00 <cyril> ... so including in the problem statement would be useful
16:50:11 <cyril> nigel: not everybody share the same view of the possible impact
16:50:18 <cyril> ... it needs thoughts and considerations
16:50:31 <cyril> ... but I don't think it's a problem that concerns everybody
16:51:44 <cyril> nigel: for people who were not at the meeting last time, and if you have topics to add, I'm happy to add them, discuss here or have a private chat
16:52:11 <cyril> ... we are chartered till the end of this year
16:52:32 <cyril> ... I wonder if there is a view that having got to IMSC1.2 and TTML2 that this group has completed its work
16:52:40 <cyril> ... have a feeling that some people think that
16:52:50 <cyril> ... and it does not feel right
16:53:09 <cyril> ... it'd be interesting to know the problem space that needs further work
16:53:31 <cyril> pal: we've reached an inflexion point in market adoption
16:53:47 <cyril> ... and until we have broad adoption, I don't expect more spec work
16:53:54 <cyril> ... people in this call are pioneers
16:54:05 <cyril> ... we'll see much much broader adoption
16:54:15 <cyril> ... and as new people come in we'll have more issues
16:54:26 <cyril> ... I expect this year and maybe the next year to be quiet
16:54:37 <cyril> ... but I'm not a big fan of saying we're done
16:55:25 <cyril> gkatsev: I wonder if the work, the meta work TTML to WebVTT draft, could be interesting
16:55:52 <cyril> nigel: in terms of spec work, I'd like to push the Audio Description Profile of TTML2
16:55:56 <cyril> ... I expect spec work
16:56:14 <cyril> ... it falls in the category of additional work to use the core specs
16:56:51 <atsushi> https://www.w3.org/blog/2021/01/wcag-3-fpwd/
16:57:15 <cyril> nigel: they've just released the FPWD
16:57:24 <cyril> ... it may have an impact on the customization work
16:57:49 <nigel> scribe: nigel
16:58:00 <nigel> Cyril: In general the topic of subtitle quality is of interest to Netflix.
16:58:08 <nigel> .. I don't know if the group would be happy to work in this direction,
16:58:27 <nigel> .. facilitating verification of reading speed, or detections of errors, for example typos, missing words.
16:58:54 <nigel> .. We had an interesting session at Netflix where we brought in Deaf customers and asked them what they were missing
16:59:07 <nigel> .. when it comes to subtitles. Maybe we could do the same in W3C, ask users of subtitles what is missing,
16:59:21 <nigel> .. what would help them, identify gaps that we could fill to help them.
17:00:12 <nigel> Nigel: That's an interesting point - our core constituency in W3C is the users and we have very little direct engagement from
17:00:17 <nigel> .. users, so there's definitely something there.
17:00:39 <nigel> Cyril: W3C has access to a lot of communities, so maybe it is a good opportunity to reach out and find out if there are frustrations
17:00:45 <nigel> .. with how subtitles are done in general.
17:01:02 <nigel> Andreas: That's a really important point - the question is if it is a topic for a technically focused group.
17:01:28 <atsushi> q+ use tech video for upcoming AC meeting (possible) to show our interest?
17:03:04 <nigel> Nigel: True, there may be a crossover for example - is there a technical solution to varying the amount of editing and the word rate?
17:03:07 <nigel> ack atsushi
17:03:50 <nigel> Atsushi: We could make a video to show at the AC meeting to show the possible directions of our work.
17:04:41 <nigel> Topic: Meeting close
17:04:56 <nigel> Nigel: We're a few minutes over today, so let's adjourn for today. Thanks everyone. [adjourns meeting]
17:05:00 <nigel> rrsagent, make minutes v2
17:05:00 <RRSAgent> I have made the request to generate https://www.w3.org/2021/01/21-tt-minutes.html nigel
17:07:39 <nigel> s/ for today//
17:07:47 <nigel> Present+ Pierre
17:21:56 <nigel> s/on the last one, it's not clear/on the last one, it's not clear what a validation processor needs to do if the requirement is for the presentation processor to ignore
17:26:03 <nigel> s/thanks so much for getting TTML2 to Rec/thanks so much for your work helping us get TTML2 to Rec
17:26:52 <nigel> s/I'm aware it couldn't work for others/I'm aware it might not work for others and don't want to impose a "BBC" solution
17:28:18 <nigel> i/http/Gary: I just saw the notice that WCAG 3 work has begun - maybe there's work we should do to help them with accessibility for subtitles and captions.
17:28:53 <nigel> rrsagent, make minutes v2
17:28:53 <RRSAgent> I have made the request to generate https://www.w3.org/2021/01/21-tt-minutes.html nigel
17:30:40 <nigel> s/Gary: I just saw the notice that WCAG 3 work has begun - maybe there's work we should do to help them with accessibility for subtitles and captions.//
17:31:04 <nigel> i/nigel: they've just released the FPWD/Gary: I just saw the notice that WCAG 3 work has begun - maybe there's work we should do to help them with accessibility for subtitles and captions.
17:31:06 <nigel> rrsagent, make minutes v2
17:31:06 <RRSAgent> I have made the request to generate https://www.w3.org/2021/01/21-tt-minutes.html nigel
17:31:54 <nigel> scribeOptions: -final -noEmbedDiagnostic
17:32:03 <nigel> zakim, end meeting
17:32:03 <Zakim> As of this point the attendees have been Nigel, Gary, Atsushi, Andreas, Glenn, Cyril, Pierre
17:32:05 <Zakim> RRSAgent, please draft minutes v2
17:32:05 <RRSAgent> I have made the request to generate https://www.w3.org/2021/01/21-tt-minutes.html Zakim
17:32:08 <Zakim> I am happy to have been of service, nigel; please remember to excuse RRSAgent.  Goodbye
17:32:12 <Zakim> Zakim has left #tt
18:56:39 <nigel> rrsagent, excuse us
18:56:39 <RRSAgent> I see no action items