Timed Text Working Group Teleconference

<scribe> scribe: nigel

This meeting

Nigel: Today, we will look at the PQ in PNG Note, and the CSS features in TTML wiki page,
... which I need to be able to share with TAG tomorrow prior to meeting them next week,
... I don't think there's much to discuss for IMSC or TTML or WebVTT this week. AOB?

Andreas: No other business from me.

HDR in PNG

Nigel: We said we'd propose to publish this week. Any feedback received?

Pierre: I've not received any further feedback.

Nigel: I don't have anything to add on this.

Andreas: Not from me either.

PROPOSAL: Publish the png-hdr-pq document as a WG Note

Nigel: I'm not sure about the practicalities of publishing this.

Pierre: Can we use echidna?

Nigel: I don't know!

Pierre: I'm happy to follow up with Thierry.
... The Echidna tool says it can publish Notes with a group decision and a token.
... I should be able to request the token if it doesn't have one already and just do it.

Nigel: Great.

RESOLUTION: Publish the png-hdr-pq document as a WG Note.

Nigel: I raised this as an issue on the repo:

Publish as a Note #5

CSS styling equivalents of TTML2 and IMSC features

action-497?

<trackbot> action-497 -- Nigel Megitt to Invite csswg to joint meeting at tpac 2017, with list of topics. -- due 2017-06-15 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/497

Nigel: I've been in discussion with Alan Stearns about this - there has been a bit of early
... discussion of CSS WG feedback for TTML2 in the CSSWG reflector.
... I've also updated the CSS Requirements wiki page.

TTML and IMSC styling features that are hard to reproduce in CSS

Nigel: I think this is okay now but I don't know if anyone has any comments on it or suggestions
... for anything to change?

Andreas: I haven't had the chance to review it.

Nigel: I plan to share it by end of play tomorrow so any feedback really needs to come soon please.

Pierre: David Baron went to some length previously.

David Baron email feedback 2016-11-23

Florian's email discussion thread to www-style 2017-07-14

Pierre: It would be good to involve them in the discussion at least.

Nigel: Yes, I assume David will be there at TAG next week but I'm not certain.
... It's a good point I should make sure his analysis is represented in the wiki page.
... I also noticed that there are some attributes like rubyOverhang and rubyOverhang class
... that are missing from Dae's list on imsc#218 so I pinged him there to ask but he hasn't
... yet replied.

Pierre: Do you have textOutline on there too?

Nigel: No, can that not be done with text-shadow?

Pierre: No, it cannot be done in CSS except with one proprietary (Apple) extension.

Nigel: OK I'll add that.
... Oh, rubyOffset seems missing too.

Pierre: I think everything else you've already covered or it has good support already.

Nigel: Oh I've just spotted inlineAreaBreak too, which is needed for linePadding - that's
... something that needs an extension relative to CSS, but I think that's already being
... discussed in CSSWG if I remember rightly.
... If there's anything else you see, especially in terms of accuracy of language, please let
... me know and/or edit the document to fix it.

Pierre: I think the key step is to get agreement to include subtitles and captions in the core
... functionality of CSS, then the details can follow from there, with give and take as needed.

Nigel: It's interesting to compare tts:displayAlign with CSS, and how it can be implemented.

Pierre: It turns out that you need to use flex to meet the vertical positioning and I believe
... horizontal positioning too.
... Flex is the only way to preserve aspect ratio as well.
... To make TTML work reliably in my experience you must use flex.
... You may be able to do it with tables but that has other implications, like its not
... recommended - everyone says don't do it!

Nigel: Okay I have some actions to tweak the document for now, as well as incorporating
... any review comments over the next 24 hours.

IMSC

Pierre: I fixed the tests so line breaks are consistent and created two pull requests to
... do that and also to fix some broken renders.

TTML2

Thierry: I had some responses for the wide review, but mainly "I'm submitting your liaison
... to the appropriate people". I should forward them to the member list to track them.

Nigel: Yes please.

Thierry: No substantial comments so far.

Nigel: OK given that half of us have to disappear off for other things and we've covered
... as much of our agenda as we usefully can today, let's adjourn until next week. [adjourns meeting]