Timed Text Working Group Teleconference

01 Oct 2015

See also: IRC log


nigel, mike, tmichel, pal, Frans, Courtney, Andreas, plh


<trackbot> Date: 01 October 2015

<scribe> Scribe: nigel

This meeting

nigel: We'll cover TPAC, IMSC, TTML and WebVTT mapping, short profile names registry, WebVTT
... AOB?

mike: Can we cover IANA registration under the profile registry section?

nigel: Yes.

TPAC 2015


nigel: Opening up so people have the opportunity to raise questions, issues, agenda topic suggestions etc.

group: nothing for now



<trackbot> action-424 -- Thierry Michel to Download and upload to implementation report page the test render mp4 -- due 2015-10-01 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/424

tmichel: That's done - it can be closed.

close action-424

<trackbot> Closed action-424.


<trackbot> action-425 -- Thierry Michel to Send a prompt/thank you to the potential test result contributors for imsc. -- due 2015-10-01 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/425

tmichel: I've reminded all the implementors that we pinged and thanked the implementor who sent us the MP4 file.
... I think pal has a new implementor?

pal: I've asked them for the right contact so as soon as I know I'll let you know.

action-425: [meeting 2015-10-01] leaving open pending a new implementor - pal to tell tmichel when he knows

<trackbot> Notes added to action-425 Send a prompt/thank you to the potential test result contributors for imsc..

TTML and WebVTT Mapping Document

tmichel: I think the proposal for the short name is ttml-webvtt-mapping
... It's not so short but its fine by me if everyone's okay with that. We had agreement from David and Nigel proposed it.

<pal> ttw-map

Courtney: I think it's fine.

Andreas: I think so also.

nigel: I think we've got consensus!

plh: I think that's the best one otherwise it will be hard to remember.

tmichel: Now I need to ask plh to agree to it!

plh: I'm happy to agree but you still need to send an email to the chairs list. Consider it approved.

tmichel: Okay I'll send to you CC chairs.

plh: Thank you


<trackbot> action-427 -- Nigel Megitt to Write up an issue for webvtt for chapterisation etc. -- due 2015-10-01 -- PENDINGREVIEW

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/427


<trackbot> issue-447 -- Mapping is only for presentation, i.e. subtitle and captions, and other types of WebVTT document are possible -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/447

close action-427

<trackbot> Closed action-427.

nigel: I did this - it's issue-447. Is that okay Courtney and Andreas?

Andreas: I had a quick view on this issue, as with others. For a lot of the mapping issues I
... propose that we postpone the detailed discussion to TPAC where we can have a closer look
... at the issues with time to think about them beforehand.

reopen issue-447

<trackbot> Re-opened issue-447.


<trackbot> action-426 -- Thierry Michel to Tmichel to work with courtney to get the ttml webvtt mapping to look right with respec -- due 2015-10-01 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/426

Courtney: It's perfectly beautiful now!

close action-426

<trackbot> Closed action-426.


<trackbot> issue-415 -- TTML2 is confusing -- pending review

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/415

Courtney: We changed the mapping TTML profile name to TVTT to avoid the 2

mike: It's better. The 2 was my main concern. I wonder if people might be confused by the 'TV' in it.

Andreas: I think we should leave it for now and if we find a better name later we can still change to it.

mike: I'm good with this.

close issue-415

<trackbot> Closed issue-415.

Andreas: I want to thank everyone who has looked at the document and raised feedback.
... I think all the issues are very valuable. I'd encourage everyone to look at the complete
... document before TPAC. The TVTT profile has had a lot of focus but it's only a part of it.
... I think it's really important to look at this as a complete document and then discuss it and
... see the profile as one part of it only.

mike: I didn't file an issue on this but there's been reflector traffic. I remained concerned that
... when we're all done with this mapping activity then the subset that results won't meet
... anyone's needs. I won't raise an issue until we're done. But if the resulting profile doesn't
... for example allow us to create captions that meet FCC needs then it won't get used.

Courtney: Mike, I understand and share your concern but it's hard to address such a high level
... statement. It would be good to have the analysis to show us what's missing.

mike: Absolutely - and that's why I haven't filed an issue.

Courtney: When you talk about the 708 features, there may not be complete support for every
... 708 feature.

mike: IMSC is pretty tight on 708 and I thought WebVTT was too. The burden is on me to
... suggest any issues or raise specific concerns.

Andreas: The comment and pal's on the reflector are very helpful. But the document has more
... as well - the profile is only there to be helpful for the process of conversion. The document
... itself targets all kinds of TTML documents not just one profile. If there are implications then
... we can discuss that at TPAC. At the moment we really thought of all the TTML documents
... that are produced at the moment and how they can be translated into WebVTT. Of course
... it's not the only mapping. We're also looking at the WebVTT to TTML mapping. We should
... keep this in mind when we discuss the issue.

mike: I understand the exercise. It's an important issue and it's good that this work has been done.
... I'd note that IMSC1 and EBU-TT have been getting the most attention, so it's important to
... keep them in mind when we do this exercise.

pal: I understand the engineering process but I'm also trying to anticipate what users might
... see in the document, which could be different. They might naturally try to follow the profile
... for authoring for ease of conversion. There may be options, but I'm not super excited by
... the status quo.

Andreas: I agree there are several options. This is something we should discuss at TPAC.
... One option is to bring the profile closer to an existing one that will be used in practice.
... Another is to highlight that this possibly is not the right starting profile, and you may still
... need to do mapping from e.g. EBU-TT-D and IMSC to this profile.
... What we tried to achieve is to bring TTML document structure as close as possible to WebVTT.
... That is of course much tighter than what is written in EBU-TT-D and IMSC.

pal: Another possibility is that if we find out we're 90-95% there and the remaining 5-10%
... are found to be not relevant we may wish to rethink IMSC 1 or EBU-TT-D.

Andreas: Agreed.

mike: I second what pal said. If we're really close and we can tweak other profiles to bring them
... into alignment then we should bear that in mind.

Courtney: We should continue this at TPAC. The charter deliverable doesn't focus on a particular
... profile.

mike: Sure. And please don't take our concerns as a criticism of the work. It's really important
... and we wouldn't be having this discussion without the work. Let's work towards interoperability.

pal: I second that. If we'd found that TTML and WebVTT could be converted losslessly then
... we wouldn't be having this conversation either.

Courtney: Right.

Andreas: I agree. I think this is a good approach too. We did notice that IMSC is an important
... reference. We did discuss that in Las Vegas. At the moment we hope that the TVTT profile
... should be a subset of IMSC. As pal and mike both said it's possible to do a bit of tweaking
... to get to alignment. I hope that at TPAC we can turn this into concrete actions.

Profile short name registry


<trackbot> action-428 -- Thierry Michel to Check if we can update the ttml iana media registration in a standalone note or if we need to do it in a rec -- due 2015-10-01 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/428

mike: I can summarise. A number of W3C registrations have been done using WG Notes. About
... half a dozen. Clearly if it's a Rec then you want to follow up. For reasons I don't know some
... groups have used Notes, so W3C can do that. It looks like they are exceptions that need
... Director approval. The action would be to draft a note and push up to the Director.

tmichel: Yes, that's what I understood from plh's email too.

mike: I think that email was pretty clear. So the question is, unless there's an objection, I'll
... draft a note and we'll follow the processes to get into a publishable state.
... There are actually 2 things: the registry itself and the media registration note.

nigel: I don't have a view - I don't see why they shouldn't be in the same note - it may make
... the process easier.

PROPOSAL: Draft a WG Note describing the profile short name registry and updating the IANA media registration, based on what's in the current profile registry wiki page plus the addition of the codec parameter to the existing TTML media type registration.

nigel: Does that address Cyril's concern about using the codec profile?

mike: Yes, without going into all the details, the RFC is out of date, but we can independently
... proceed here with tidying up, to resolve any public use or adoption. Cyril is concerned
... more globally about non-W3C infrastructure issues. We can solve ours locally.

RESOLUTION: We will draft a WG Note describing the profile short name registry and updating the IANA media registration, based on what's in the current profile registry wiki page plus the addition of the codec parameter to the existing TTML media type registration.

<scribe> ACTION: mdolan draft a WG note for the profile short name registry and TTML media type registration [recorded in http://www.w3.org/2015/10/01-tt-minutes.html#action01]

<trackbot> Created ACTION-429 - Draft a wg note for the profile short name registry and ttml media type registration [on Mike Dolan - due 2015-10-08].

close action-428

<trackbot> Closed action-428.


nigel: I think the question is about the WebVTT editor's draft

Courtney: Which issue?

tmichel: It seems that the editors are not able to publish on W3C.

Courtney: I think this is resolved. Simon Pieters is the new editor. He moved the spec to the
... whatwg repository on github and we asked him to move it back, which I believe he agreed
... to do, though he hasn't done it yet.

tmichel: It would be nice to have Simon call into a meeting.

nigel: I believe he's not a participant in the TTWG.
... Does that cause us any difficulties?

Courtney: We're working on the spec regardless of its location.

nigel: Does it cause us any difficulties having an Editor who is a member of the WG?

plh: Not immediately - Opera is a member.
... So it's Opera who has made the commitment.
... The last draft was in 2014. Is it time to update it?

Courtney: I think we need to move more aggressively on this spec. The goal is to get to CR by
... November and PR by March 2016. As part of that I have several action items. I need to update
... the diff against the FPWD, and we're also working through ~80 open issues. We closed 8 of
... them yesterday.

plh: My recommendation is don't wait for all of that to be done before updating the draft.
... I recommend you ask the TTWG to update the WD sooner rather than later - it can be every
... week if you want! I don't know how many changes there have been since the FPWD.

Courtney: That's why I was gathering the diffs.

plh: My other question is related to the repository. So you asked Simon to move it back? To the CVS server?

Courtney: I think they want to use github/w3c a bit like the media stream capture spec.

plh: That would be my recommendation too.

Courtney: Ok.

plh: If you need any help on that please let me know.

Courtney: Eric Carson proposed doing that, and we thought we could do it without assistance.
... I'll check.

plh: You'll probably need me or tmichel to create the github/w3c/XXX repo

Courtney: Thank you

plh: We have tools now to keep track of contributions into our github repositories for patent
... policy reasons.

nigel: We're out of time - I think we've covered everything. Thanks everyone! [adjourns meeting]

Summary of Action Items

[NEW] ACTION: mdolan draft a WG note for the profile short name registry and TTML media type registration [recorded in http://www.w3.org/2015/10/01-tt-minutes.html#action01]
[End of minutes]

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$Date: 2015/10/01 16:37:32 $