Meeting minutes
This meeting
Nigel: Agenda today: reminder to rejoin the group, MPEG Liaison, Review and look-ahead, Presentation customisation requirements
… AOB?
atsushi: Wondering whether to remove the old iCalendar files, and to inform everyone that the URL of spec-timeline has been changed.
Pierre: Need to drop off at half past
Recharter: requirement to rejoin group
Nigel: After rechartering, which we just did to adopt Patent Policy 2020, if you haven't rejoined the group, please do.
Pierre: Only your AC rep can do it for you. Your AC rep has to nominate your organisation to join, then you can nominate people to join the group.
… It's not as simple as just clicking that link.
Nigel: I get thrown by this every time it happens. I wish it was simpler and clearer about what is going on!
… I raised #168 for updating the Charter link on the home page. I think that's done now.
Atsushi: I believe so.
MPEG Liaison #167
Nigel: Just to let you know I sent this last night and closed the issue.
… It's archived in member-tt, and we got an acknowledgement back that it has been received.
… Thanks for the reviews. I hope it's useful.
Cyril: Yes, I think it is useful.
Review of 2020, and look-ahead to 2021
Nigel: [goes through slide deck quickly]
… Pointer to slides
… And end up with what are your priorities for 2021?
… Not expecting an answer now, but I'd like everyone to reflect on what they can bring and what we can deliver next year.
… It's been a tough year for everyone in 2020, we should be pleased by what we have delivered.
Pierre: The holy grail is alignment with CSS. That's a real pain point, and it's entirely within W3C members' ability to do.
… Especially in the case of some of the features that the broader web community (fillLineGap!) where users are looking for
… that functionality for general use, not only subtitles.
… If we manage to achieve that it would be great for the web community in general.
… The other one that is a lot more complicated, and maybe not for W3C, is more interop testing of subtitle implementations.
… We've created a lot of tests, but don't have a lot of interop testing, and many implementers are not W3C members.
… It's something for the industry as a whole. Certainly solving the CSS issue would be my main goal.
Andreas: On this point, do you think it would be beneficial to link interop testing, e.g. in HbbTV or ATSC, to W3C or is that out of scope
… for our group?
Pierre: I'm not sure. I think it's valuable but I'm not sure W3C is the right place.
Nigel: I think it's worth bringing up, thinking especially about WPT and the way the same orgs do that and W3C specs.
Mike: Worth bringing in DASH-IF and dash.js? It's an open platform and probably has, via imsc.js, the best conformance with IMSC as far as I know.
… They also have a content validator, that could be integrated.
… It's DASH-centric, but the world's going there anyway.
Nigel: I'd be interested in completing the AD work, but also
… seeing if others want to standardise the format of data for passing customisation information into players.
Pierre: Sounds like a great topic to me.
Gary: I'd like to finally get back on the horse with WebVTT.
… I know for me it's a bit harder because I'm basically the only person working on it.
… Without having other people working on it too it's harder to remember and justify looking at things.
… As for working with CSS WG, that would be good. We tried to meet them at TPAC but didn't end up doing it so it
… would be nice to schedule some time with them. We have things that it would be worth working on with them.
… The player options for caption styling is also something interesting.
Mike: By caption styling you mean like user preferences?
Gary: Yes
Mike: I don't know if you shared CEB35 with others but there's a CE document we did that maps the common user preferences
… onto 708 and IMSC1.
Nigel: I didn't, I've been trying to implement it for IMSC 1 and would like to share as an end of year demo if that's okay?
Presentation customisation requirements
Nigel: Following on from that, I've been trying to implement some of the stuff in CEB35 as modifications to imsc.js.
… [shares prototype renderer based on imsc.js with sliders for user preferences]
Cyril: Why is this relevant to IMSC?
Nigel: The options object passed to the player is something that captures the user preferences, and could be a candidate for standardisation.
… You'd want different players to behave in interoperable ways given the same user preferences.
Cyril: I like the idea. An aspect that could be interesting is the challenge of getting the content authored in a way that
… works with the preferences. Brainstorming, I'm wondering if we could use this options parameter could be included in delivery requirements
… saying "must look okay when options.value changes from x to y"
Nigel: Good point, we had an exact example of that with different lines being delivered in different regions, which we had to post-fix.
Mike: It's tricky to scale the region because you have to have heuristics. If you keep text in the same region
… you should get consistent results.
Cyril: Unfortunately people do different things!
Mike: I've seen different behaviours. There may be some edge cases. Keeping the regions together may need explanation.
… This is pretty cool - having some standard way to do this would be interesting.
… Some people don't see colours well or have both hearing and visual impairments.
… It's more of an accessibility requirement at least in the US.
… When you scale you assume you want it to go towards the edge of the display region. That's not unreasonable,
… but you've assumed a lot of interesting behaviour that varies from implementation.
Nigel: Not so much. The region isn't moving, but displayAlign and textAlign are staying the same.
Andreas: On the one side you have a UI that allows users to customise presentation. This is already done, as part of hardware or OS
… like iOS or Android, that have the ability to change the subtitle presentation where they can detect it.
… Then you have the format like IMSC that represents the author's intent, and in between a lot of things are happening.
… As Cyril noted, when user preferences are applied it's not IMSC or the format any more, it's user preferences and the language
… like HTML and CSS. This is already happening, for example in Germany using HbbTV there is a customisation feature where the input
… format is a subset of IMSC, and it is well defined what you can do so it all works fine.
… There needs to be some work done so the format and the UI work together to avoid destroying the authors intent.
… You may need to author in a way that allows the preferences to be applied.
… And it needs to be format agnostic. In iOS for example it needs to work on WebVTT, SRT and variations of TTML.
Mike: What's your intent for this activity?
Nigel: I'm using it as a test-bed at the moment, on the BBC fork. imsc.js is a reference player so if there's a standardised way to
… pass user preferences in, then it would be a good place to put it.
Mike: Colour customisation is important too.
Nigel: Thinking about a colour map to allow users to define their own palette.
Andreas: Some user preferences allow users to override settings, but at their own risk.
… Even then you need to make sure that background and foreground colour are applied in a set, because if you change your foreground
… colour preference and then there's a white background then you would see nothing.
Mike: Preferences are set by the viewer, so they can fix it.
Nigel: I tend to prefer giving tools to avoid users getting into that situation.
Andreas: Others might be interested too, APA WG and some manufacturers.
Mike: In the US this is driven by FCC in a regulatory manner.
… At least in the US there is specific behaviour that is expected. We need to be conscious about how we do it as engineers,
… and keep in mind regulatory requirements.
Cyril: It's a BBC fork? I looked at GitHub, is it there?
Mike: I'd to share this with some colleagues too
Nigel: I'd be happy to talk with them if they're happy to do that. This work is on a branch in the BBC fork at the moment.
Cyril: I'm interested in this activity - it would be great to have a video of this demo, if you can share that?
Nigel: Interesting thought!
AOB
Nigel: You wanted to know about removing the old ics files?
Atsushi: Yes just housekeeping. We have both composited and individual meeting files.
… There are around 20 files in the directory. We could remove all the 2020 calendar invites. Is that fine for all?
Nigel: Makes sense to me. No need to keep them for posterity.
Atsushi: In any case they'll be there in an old commit.
Nigel: Exactly.
… I think just do it!
Atsushi: Yes
… Another point is just info to share. To include the spec timeline in the onboarding email new members receive when they join TTWG,
… there's a customisation template. Nigel included a link to spec-timeline in that but we may forget to update the link year by year so now
<atsushi> https://
Atsushi: we have removed the 2019 year from the URL and used a non-dated link, so please be careful to check if you have it.
… It is ^^ now
Nigel: Good stuff, thank you!
Meeting close
Nigel: Thanks everyone, wishing you all a good break and new year if you're celebrating it. Our next meeting will be on 7th January.
… I'm wondering about user presentation customisation as a potential topic for a future f2f by the way.
group: [general mutual good wishes for the holiday period and the new year]
Nigel: [adjourns meeting]