- From: Nigel Megitt <nigel.megitt@bbc.co.uk>
- Date: Thu, 30 Mar 2023 16:36:45 +0000
- To: TTWG <public-tt@w3.org>
- Message-ID: <8705C8DD-48A2-4C7E-B185-D7A6764A2756@bbc.co.uk>
Thanks all for attending today’s TTWG teleconference. Minutes are available in HTML format at https://www.w3.org/2023/03/30-tt-minutes.html
We made one resolution:
RESOLUTION: Publish DAPT FPWD based on ED and any editorial changes made in the next 2 weeks
The review period for this resolution, under our decision review policy, expires on 2023-04-13. Please file any objections as soon as possible.
Those minutes in text format:
[1]W3C
[1] https://www.w3.org/
Timed Text Working Group Teleconference
30 March 2023
[2]Previous meeting. [3]Agenda. [4]IRC log.
[2] https://www.w3.org/2023/03/16-tt-minutes.html
[3] https://github.com/w3c/ttwg/issues/247
[4] https://www.w3.org/2023/03/30-tt-irc
Attendees
Present
Andreas, Atsushi, Chris, Cyril, Gary, Nigel, Pierre
Regrets
-
Chair
Gary, Nigel
Scribe
cpn, nigel
Contents
1. [5]This meeting
2. [6]Charter
3. [7]DAPT
4. [8]IMSC HRM
5. [9]w3c/webvtt#512 Proposal from Apple about a WebVTT
metadata format for describing when flashing and strobing
lights occur in video.
6. [10]TPAC 2023
7. [11]Meeting close
8. [12]Summary of resolutions
Meeting minutes
This meeting
Nigel: Topics for today: news on the charter, status update and
issues on DAPT, also IMSC-HRM to understand the state
… We may be ready to think about CR exit criteria
… Also proposal from Apple to add to WebVTT metadata for
strobing in video
… TPAC 2023 planning, but may not get to that today
… Anything else to cover?
Chris: I'd like to cover TPAC, but not urgent
Charter
Nigel: The Council has concluded and written a report, but
needs Atsushi to talk about it
… Next step is some need to validate the updated charter with
everyone who commented. Plan is to have a 1 month extension, so
the new charter would start on 1 May
[Atsushi arrives]
Atsushi: The FO Council report is out, we need to ask every
reviewer to check the final version for a 1 week period,
starting today
… It should be settled by next Thurdsay. I hope to get
management approval in a week or so, so the new charter could
be installed by mid April, I believe
… We have a 1 month extension approved, so if we don't want a
gap, we can start the extension tomorrow
Nigel: Yes please
… Can I post a link to the Council report?
[13]W3C Council Report on the FOs against the TTWG Charter
[13] https://www.w3.org/2023/03/council-ttwg-report.html
Atsushi: It's public, I got approval to send to AC reviews, so
I think it's OK to post here
Nigel: I expected an announcement
… Can we set the charter end date to start date + 2 years?
Atsushi: Yes. If you want 2 weeks spare, you can extend to end
of April and start on 1 May, not sure if that would work
Nigel: I'm neutral on that. Any other views?
Atsushi: Not sure 2 weeks makes a difference for the review
Nigel: I think the charter has had plenty of review time
… Anything else on the charter?
Nigel: On the report, I've proposed a couple of changes to
Florian. Not sure what will happen with those, some were
editorial, others more formal
… For example, it says we didn't accept the proposed changes in
full, which I think we did
… But this shouldn't hold up the charter
Chris: I also sent you a comment directly
Nigel: OK, will feed that back to Florian too
DAPT
Nigel: Last time Cyril and I did an issue triage we identified
some to be resolved before FPWD
… The editorial ones have been done, needs an editorial pass,
but the document is now feature complete
… Cyril generated some more issues. Thank you Andreas for your
input
… I want to identify which issues we think need to be resolved
for FPWD, if any, and label them
Cyril: Do we think there are any? I don't think so, personally
… What's the expectation for FPWD? It doesn't need to be stable
Nigel: It's there to invite review from the group
Cyril: Would it trigger any communication from W3C?
Nigel: There'll be an announcement, and we could write a blog
post
<atsushi> [14]example for IMSC-HRM
[14] https://www.w3.org/blog/news/archives/9318
Chris: Also a patent exclusion opportunity, so worth getting in
the features if they have patent implications
Andreas: I found some issues that I may open. Should I do that
now or wait until it's published as FPWD?
Nigel: I prefer not to wait
Cyril: I agree
… Are those blockers for FPWD?
Andreas: I don't think so
Nigel: For the issues recently looked at, one is more
structurally substantive than the others, about changing script
types
… So we have a workflow script type and a separate application
script type, dubbing or AD
… Feels useful to do that sooner than later.
Cyril: I think you're right, but do we have agreement?
Nigel: There seems to be agreement from those who commented
… I'll label it as FPWD and assign to you
… Issue #75
Cyril: Also worth discussing the SSML integration
[15]w3c/dapt#121
[15] https://github.com/w3c/dapt/issues/121
[16]Clarify how to use SSML with DAPT
[16] https://github.com/w3c/dapt/issues/121
Cyril: Reviewing the AD part of the spec with colleagues, we
have TTML attributes that seem overlapping with SSML
… So what's the relationship? Can we use these attributes or
the SSML equivalent syntax or not?
… Proprietary data, not in DAPT or TTML namespaces. Extending
that example with SSML could be interesting
Nigel: Yes, definitely. We have to decide on the direction
here. Thinking about how TTML2 deals with styling, a lot is
imported from CSS
… Defined in TTML2 using styling vocabulary unique to TTML2
… Audio styling attributes: pitch and speak, are both based on
SSML semantics based on the prosody element
… What we found with TTML2 and CSS, is there's friction. We
could say in TTML2 we won't add more SSML attributes, but do it
by injecting SSML into the document
… That would mean defining precedence rules between two audio
attributes. I think that would allow unlimited addition of SSML
content
… Not sure if it can all be done in attributes, but think so
… Other direction is to define equivalent vocabulary in TTML2
for everything you may want to use in SSML
Cyril: Please no
Nigel: It's a choice we have, so prefer the first option
Cyril: A third option could be to say not use the TTML2
attributes and only SSML syntax
Nigel: If we do that, we would need to adopt the special URI
that's defined for the audio source attribute
… ttml/resource/#speech
… (reads definition)
[17]TTML2 <audio>
[17] https://www.w3.org/TR/ttml2/#embedded-content-value-audio
Nigel: It could work, but I think it needs some research on the
structure and how you'd inject SSML
Cyril: Don't have a strong opinion, just considering options.
Needs more study
Nigel: It's an obvious form of extension that people may want
to use
… So propose not doing that before FPWD
Cyril: We can add an issue to the spec to say that's the
direction, and get industry feedback
Nigel: I'll add an issue to do that, assign to myself
Cyril: Another issue to discuss is time expressions and
associated restrictions
… It's related to IMSC
… How much of a problem has it been to allow the time syntax
that looks like a SMPTE time code but isn't one
-> [18]w3c/dapt#123 Consider restricting time expressions
[18] https://github.com/w3c/dapt/issues/123
<Github> [19]w3c/dapt#123 : Consider restricting time
expressions
[19] https://github.com/w3c/dapt/issues/123
Pierre: It's a recurring issue, I get questions about it
Cyril: Consider restricting time expressions so there's no
confusion possible
Pierre: Absolutely. If the only option is time based media,
that's a very good idea
… People will still be confused, but there'll be a simple
answer
Andreas: I agree
Nigel: I don't think I object, but have a concern it may be
against current industry practice in authoring in some way
… The change may be sensible, but people may not want to
Pierre: People create files that pass validation but don't
behave as the author intended
… Use case is authoring house gets a proxy with SMPTE time code
burned in, they create an IMSC file with expressions that match
the SMPTE time code
… The time expressions in the TTML file then don't work down
the line
… Hard to explain to people why that happens. Easier to explain
if it's not supported in IMSC
… It's a common work flow
Cyril: Pierre and Andreas, please comment on the issue
Nigel: Other open issues recently commented on. Nothing obvious
to look at before FPWD
Cyril: EBU TTML source media identifier
… Issue 122
[20]w3c/dapt#122
[20] https://github.com/w3c/dapt/issues/122
<Github> [21]w3c/dapt#122 : Explicit reference to the Related
Media Object
[21] https://github.com/w3c/dapt/issues/122
Cyril: I was surprised there's no way to provide a link to the
source media document
Nigel: There's a defined element in EBU TTML for this
… Do we need to add something normative to the spec, or
recommend a schema to use?
Cyril: I'd like to have something in the spec, to avoid the
burden of having to refer to another spec
Nigel: Could be an example that shows the element and namespace
name is all that you'd need
… But do we need to be specific on how to do it, or point to
options that are available and allow people to define their own
Cyril: Let's start by saying here's one way to do it, see how
people react
… But not blocking FPWD
Nigel: Please look at the ED as it exists now. I'd like to
start a CfC to publish as FPWD
PROPOSAL: Publish DAPT FPWD based on ED and any editorial
changes made in the next 2 weeks
Nigel: Any objections?
<atsushi> +1
Cyril: I support it
Andreas: I support it
RESOLUTION: Publish DAPT FPWD based on ED and any editorial
changes made in the next 2 weeks
Nigel: There'll be a 2 week decision review period
Nigel: Anything else on this topic?
(nothing)
IMSC HRM
Nigel: No issues to be addressed before CR. We're waiting on
the TAG review
… The TAG milestone suggests they hope to look at it this week
… We also need to look at CR exit criteria. Pierre, any
proposals?
Pierre: We did that a while back
[22]Draft exit criteria at w3c/imsc-hrm#59
[22] https://github.com/w3c/imsc-hrm/pull/59/files
Pierre: Not finished, but the framework is there. We need to
finish the tests and invite getting the content. There's a wiki
page also
Nigel: For CR exit criteria, the proposal is in #59
… Please raise any concerns in the PR
Pierre: All we need to agree now is the exit criteria, then we
can fill in the actual tests during the CR exit period
… So I'll clean up the CR branch and then we can send for
review
Nigel: I think what this says matches, or goes beyond the
charter requirements, so we should be fine
… There's specific text about IMSC HRM in the Council report,
recommend looking at that
… They explicitly suggest that two validating implementations
would be a good way to demonstrate interop
Pierre: Yes, more is better, but not necessary
[23]w3c/webvtt#512 Proposal from Apple about a WebVTT metadata format
for describing when flashing and strobing lights occur in video.
[23] https://github.com/w3c/webvtt/issues/512
<Github> [24]w3c/webvtt#512 : VTT Type Proposal for time-coded
general-flash metadata
[24] https://github.com/w3c/webvtt/issues/512
Gary: Two issues, the main one here is about Apple proposing a
specific metadata format
… for WebVTT to describe when media has strobing or flashing
lights so that players or whatever
… could handle it in some way such as dimming the screen or
switching to an alternate video for that section.
… My main thought is that it probably shouldn't be in WebVTT
itself, such a format.
… Maybe another spec, or something else. I don't know what are
all the deliverables available for something like this.
… Also maybe, I didn't invite him for today but it might be
worth inviting them to a future call.
Nigel: Reminder that they are members - they might just need
advance notice of the agenda item
Gary: Yes. That's what I mean.
Chris: There is the issue of a constraint about VTT metadata
format, which Gary and I both have
… responded to say it risks breaking existing implementations
that use other formats.
… We're asking if there's some other way to signal the metadata
format used in the VTT metadata fields.
… It's open to suggestions about what might be possible.
… The other part is where such attributes or metadata schema
should be specified.
… Strobing is a pretty small feature in itself. Are there other
use cases that would warrant,
… e.g. a video metadata specification?
… This feels to me like what we have with WebVMT where it's a
separate application
… that extends WebVTT. An alternative approach to adding into
WebVTT itself.
Pierre: Wholeheartedly agree.
Chris: Not sure if this has a relationship to DataCue
Pierre: My interpretation is that WebVTT cues are the only way
to synchronise with the video element,
… so people are using it for everything.
Gary: Yes
Chris: So having an API more tailored to metadata?
Pierre: Yes exactly
Chris: I'll respond and ask about that
Pierre: Maybe now the time is right to have that discussion, to
figure out how to synchronise metadata
… with the video element.
Gary: That makes me think maybe one of the related enhancements
is on the Cue object, some
… format like JSON that can be automatically parsed, for use as
metadata.
Chris: Good thought, I'll capture that.
… Probably on DataCue if we want to encourage use of that
rather than VTTCue. But that's a separate discussion.
Gary: Yes
TPAC 2023
Nigel: We need to decide by 8 May. IBC is adjacent to TPAC. If
anyone knows they'll attend or know they can't, please let me
know
… Or if you have agenda topics
Pierre: Agree
Chris: I expect to be there
Gary: I will likely not be there in person. But is also
overlaps the Jewish new year
Nigel: Strange decision, first time that's happened in my 10+
years with W3C.
Meeting close
Nigel: Thanks everyone, we packed a lot in today. See you in 2
weeks. [adjourns meeting]
Summary of resolutions
1. [25]Publish DAPT FPWD based on ED and any editorial changes
made in the next 2 weeks
Minutes manually created (not a transcript), formatted by
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Received on Thursday, 30 March 2023 16:37:06 UTC