Timed Text Working Group Teleconference

10 Apr 2015

See also: IRC log


glenn, pal, tmichel, nigel, Courtney, tai, loretta


<scribe> scribe: nigel

Agenda today

nigel: Yesterday's minutes are visible at http://www.w3.org/2015/04/09-tt-minutes.html
... Last night during an out-of-meeting discussion some of us noticed that now that tts:bpd can make a content
... element taller than its contents maybe we need to permit displayAlign to define the relative alignment.

glenn: Yes, I've been thinking about that too. I'll create an issue for it.

nigel: tts:ipd can apply to div, p and span but tts:textAlign only applies to p and span so maybe its needed there.

glenn: I'll create an issue for that too.


<trackbot> issue-384 -- tts:displayAlign may need to apply to content elements -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/384

reopen issue-384

<trackbot> Re-opened issue-384.


<trackbot> issue-385 -- tts:textAlign may need to apply to div, body -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/385

reopen issue-385

<trackbot> Re-opened issue-385.

nigel: My last thought on this one is that the empty spans with ipd and bpd shouldn't be pruned.
... This is related to issue-368


<trackbot> issue-368 -- The [Construct Intermediate Document] process erroneously prunes empty <br> elements -- open

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/368

issue-368: [Meeting 2015-04-10] Any empty content element that generates an area e.g. by setting ipd or bpd must not be pruned either.

<trackbot> Notes added to issue-368 The [Construct Intermediate Document] process erroneously prunes empty <br> elements.

nigel: As there are no more thoughts from yesterday, let's crack on with the planned agenda.

IMSC 1 Test Suite and Implementations


pal: The test suite seems pretty stable. I know we've had some comments back that have been corrected.
... As far as I know its available for people to test. I was recently at an event where a couple of people
... tried to run the test suite for documents wrapped into MXF. I think people are trying it and experimenting.

tai: Do they run the TTML tests too?

pal: I don't know about that - but the maximum rate tests do exercise a lot of feature areas.
... I'm focusing on the IMSC 1 tests.
... I know that some folk have tried this but getting them to contribute their tests to W3C is a challenge.
... They're not quite sure how the work is going to be used.

nigel: So maybe we need some better comms here to help people understand.

pal: A lot of implementors will not be W3C members because the web isn't their main business.
... So how do we manage this?

nigel: Another data point here is an example I had recently - I was talking to someone whose dev team
... was in another part of the world and they didn't feel they could push that team to do extra work, but
... when they had delivered they would be able to try it. So maybe its lead time too.

glenn: For TTML1 we had a template spreadsheet.

tai: For manufacturers to proceed without guidance can be quite difficult. There may be a win win if
... we can also help them with their implementation work, in providing guidance, advice etc. on the spec.

pal: Another obstacle that's related but different is that some manufacturers have as a policy non-disclosure
... of results until a spec is published, to avoid appearing to have non-compatibility with the spec until it has
... been formally finished.

tmichel: You don't necessarily have to make public the implementor's name - they can be anonymised, as long
... as we know in the group which one is which.

glenn: I heard you use the word "compatibility" which they don't have to claim, for our purposes.

pal: That's a good point.
... W3C has implementation before standardisation - that's different from other groups where they
... standardise, implement and then fix the standard if needed.

tai: We do see that in e.g. XML too where products area available before the spec is a recommendation.
... For commercial vendors if you give clear guidance and offer work together that would help.
... Another possibility is to see if there's an open source implementation.

pal: That would be ideal.

tai: In my experience with open source groups they are quite keen and do want real example content as
... well as test content.
... For presentation, that would be more a player like VLC for example. IRT has been in touch with them as
... part of the HBB4ALL group, and when we discussed with them the EBU-TT-D standard and the other related
... standards the VLC groups were quite interested in implementing when there is test content available.
... They gave me the impression they might implement based on examples rather than the spec.

dakim: Caption vendors always ask for an xsd.

pal: If you give them the maximum rate subtitle stuff, that has some useful coverage of styles, timing etc.

nigel: Have we issued a formal invitation to provide implementations?

tmichel: We did that formally when we published CR.

nigel: Who saw that?

tmichel: W3 groups, members. It was on the W3 home page.

pal: A lot of the implementors won't have seen that.

tmichel: If we know who we want to target I can help send the comms to them.

glenn: It's best not to ask for general input.

pal: I really like the idea of a form.

nigel: Like a WBS form that's open to non-members?

pal: Could be, or even a PDF form.

nigel: I think there are two actions here: 1. Create the set of questions; 2. Collate the list of recipients.

pal: I'd be happy to provide the list as I know it. I'd like some help with the form, since something similar
... has already been done.

tai: What does this mean for the schedule?

tmichel: I was proposing to start by contacting potential implementors by email, and then maybe invite
... them to attend a telecon. Another thing is to invite people as invited expert during the implementation
... period.

nigel: I think that sounds a bit heavyweight - we don't need the invited expert bit IMO.

tai: It's important not to make joining as an invited expert a requirement because the process isn't so easy, to join.

pal: Does W3C have a presence at IBC?

tai: EBU does.

glenn: W3C has a presence at NAB.

pal: That's a little soon, being tomorrow!

tai: There may well be presentations at the IBC EBU booth - if you're there we can check with the EBU group and
... Frans if we can mention IMSC too. We get feedback that there's confusion about how all the different standards
... relate to each other.

nigel: Sounds good to me (wearing my EBU group co-chair hat).

<scribe> ACTION: pal Collate list of potential implementors of IMSC 1. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action01]

<trackbot> Created ACTION-387 - Collate list of potential implementors of imsc 1. [on Pierre-Anthony Lemieux - due 2015-04-17].

<scribe> ACTION: tmichel Start preparing the IMSC 1 Implementation report form. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action02]

<trackbot> Created ACTION-388 - Start preparing the imsc 1 implementation report form. [on Thierry Michel - due 2015-04-17].

<scribe> ACTION: tai Check with EBU group if we can have a combined event at IBC with EBU group and IMSC/W3C [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action03]

<trackbot> Created ACTION-389 - Check with ebu group if we can have a combined event at ibc with ebu group and imsc/w3c [on Andreas Tai - due 2015-04-17].

nigel: I found a couple of issues from a colleague who implemented the linePadding and multiRowAlign tests
... and from Andreas.
... 1. The example PNGs don't honour the displayAlign="center" setting (because I forgot that in the HTML)
... 2. The region doesn't begin 10% down
... 3. The text is so long that in real world implementations it doesn't necessarily fit on a line.
... I think we need to regenerate the PNGs to match the TTML, and also make the text shorter.

<scribe> ACTION: nigel Update the multiRowAlign and linePadding TTML files to have shorter lines of text [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action04]

<trackbot> Created ACTION-390 - Update the multirowalign and linepadding ttml files to have shorter lines of text [on Nigel Megitt - due 2015-04-17].

<scribe> ACTION: nigel Update the multiRowAlign and linePadding PNGs to match the TTML [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action05]

<trackbot> Created ACTION-391 - Update the multirowalign and linepadding pngs to match the ttml [on Nigel Megitt - due 2015-04-17].

tai: I also noticed that the document order of the <p> elements is different from the display order of the regions
... So the first subtitle with the green background is rendered at the bottom and the second subtitle with
... the black background is rendered at the top. I think it would confuse people so I'd suggest to change that.
... It may just be a distraction.

pal: I'll be happy to change that.

nigel: This came from pal's original examples. I didn't change it because although it looks surprising it isn't
... wrong. I almost quite like it!

Action-390: Also change the region ordering to be more intuitive.

<trackbot> Notes added to Action-390 Update the multirowalign and linepadding ttml files to have shorter lines of text.

nigel: Some of the other example have it too, e.g. forcedDisplay1.ttml

<scribe> ACTION: pal tweak the examples with multiple regions so that they appear in a more intuitive order. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action06]

<trackbot> Created ACTION-392 - Tweak the examples with multiple regions so that they appear in a more intuitive order. [on Pierre-Anthony Lemieux - due 2015-04-17].

Action-392: (nigel will do the multiRowAlign and linePadding ones as per Action-390)

<trackbot> Notes added to Action-392 Tweak the examples with multiple regions so that they appear in a more intuitive order..

nigel: I'd like to show a prototype implementation that my colleagues at BBC R&D have put together based on
... gstreamer, using MPEG DASH to publish the content. I asked them to put the multiRowAlign and linePadding
... examples through it. They had to make a tweak because they're not actually valid EBU-TT-D as they use
... time expressions like "1s" where EBU-TT-D requires "hh:mm:ss.sss" type format.

pal: Okay let's change that in the examples.

Action-390: Change the time expressions to EBU-TT-D compliant ones too.

<trackbot> Notes added to Action-390 Update the multirowalign and linepadding ttml files to have shorter lines of text.

nigel: There are some tests that could be EBU-TT-D compatible too with these changes.

Action-392: Also change the time expressions to be EBU-TT-D compliant on all that could be compliant

<trackbot> Notes added to Action-392 Tweak the examples with multiple regions so that they appear in a more intuitive order..

pal: Can we add this to the implementation report?

nigel: Yes, as far as I'm concerned we can do that. Thierry is there any reason why not?

tmichel: No reason why not. It would be good to post the videos too.

nigel: They're large files, but otherwise no problem.

tai: So for the BBC implementation they could just submit that they've passed those two tests?

tmichel: Yes, that's fine. And it's okay to show even one test being passed by any implementation. Each
... test does need to have at least 2 implementations.

tai: Is there any requirement to double check that the claims of passing the test are true?

tmichel: We've relaxed this. Previously we would show the implementations working, but now it's based on
... trust. The only thing we should avoid is a misunderstanding of the output that you're supposed to get. You
... have to compare the output with some proof - it could be a video, a textual description, an image, or an SVG
... file etc.

tai: Or it could be a member verification?

pal: Yes, I was just asking nigel if BBC could submit this.

tmichel: Each company should add their entry on the implementation report, using the form we're going to make.

pal: There's space on the wiki so until we have the form we could just add a table to the results section
... on the implementation report, and then we can update when we have a fancier system.

<scribe> ACTION: nigel Send pal details of implementation and tests passed so he can create a table in the implementation report [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action07]

<trackbot> Created ACTION-393 - Send pal details of implementation and tests passed so he can create a table in the implementation report [on Nigel Megitt - due 2015-04-17].

nigel: So we have a good news story - at least one implementation of two of the tests.

IMSC 1 schedule and CR publication

pal: Let's look at today's schedule.


pal: According to our schedule interop testing would have ended and we'd be publishing a CR2 around now.
... Interop testing is ongoing, and we have made some changes to the spec. Should we have a second CR?
... Should we proceed with that now, or wait for interop testing and feedback. Do we need a second CR at all?
... If we decide on a second CR we should maybe just do it according to our schedule.

tmichel: I think it's better to publish a second CR now because there are no implementations yet and so its
... easier to justify the changes to the director. If you wait until PR then it's a tougher sell.

pal: So maybe that answers that question!

tmichel: The second issue is, if we publish a CR2, we might start thinking about at risk features if there are
... any, that we may want to remove to make going to PR easier.

nigel: We currently have no at risk features marked.

pal: That's right. The three that were in my mind most "at risk" due to implementations were multiRowAlign,
... linePadding and image. We've seen an implementation of multiRowAlign and linePadding this morning so
... they're not at risk, and I've seen plans for doing image already. So I don't believe there should be any at
... risk features.

nigel: You've created the CR diff. Are there any open issues?

pal: The only open issue is the one on begin, that we opened yesterday. Issue-382.
... Based on our discussion I think the answer is clear but I want to check on that some more.
... We also have issue-375.


<trackbot> issue-375 -- Use of the ebutts:linePadding and ebutts:multiRowAlign in IMSC 1 -- pending review

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/375

pal: In the CR it used to say "may be used" and now has "with the following provisions" and there's also the
... note added.

tai: After we filed the first issue we found some additional points. Originally we wanted to allow the extension
... attributes to be permitted on the content elements, in contrast to EBU-TT-D that only allows them on style
... elements.
... There was a minor thing about the wording of the note to make clear that there is a difference between
... IMSC and EBU-TT-D and I proposed some wording that Pierre has added.
... I've read the updated text and am happy with it. There may be a small grammar issue - adding a 'the'.

nigel: I've read it too.

pal: I'm going to make that grammar change right now.

dakim: What's the plan for referencing TTML2 from IMSC?

pal: The plan is to make an IMSC 2 that references TTML2. Since both are similarly delayed it makes sense to
... stay with that plan. Let's discuss more after we're done with IMSC 1 here.
... I've pushed the grammar change now.

close issue-375

<trackbot> Closed issue-375.

nigel: Great, now we have only one open issue.

pal: So it sounds like the overhead for a second CR is low based on tmichel's input.

tmichel: Yes, let's not say that these are substantial changes.

pal: Yes. Some of them are normative provisions. Are they extensive or substantially affect the overall scope...

glenn: Historically in this group our criteria has been: does it change the syntax in any way? If yes, it's substantive.
... If it significantly alters the compliance rules then we've also considered it substantive.

nigel: What does that mean?

glenn: There's some subjectivity in the word "significantly", which is a group choice.

pal: So let's review the changes and determine that.

glenn: We've also got some changes under the wire by saying that they fix a mistake, or haven't been implemented etc.


pal: §6.6 Removal of frame rate relationship with related video object. One of the issues here is that you can't
... realistically test this without some video. In other words the impact is nil because we couldn't test this anyway.
... Any implementations that enforce the old language are still compliant. So the practical impact of this
... change is practically nil.

tmichel: the exact wording in the W3C process defines substantive in http://www.w3.org/2014/Process-20140801/#substantive-change

glenn: In the past we have not considered the 3rd bullet in point 3 above to be substantive.

tmichel: This is the new process though.

pal: By the letter here any change that affects a normative provision falls into point 3.

tai: What's the consequence if some changes are substantive?

tmichel: In that case we need to have a director call.

nigel: Even if we have some substantive changes I'm happy to take the Director through them.
... This specific change to §6.6 falls under the third bullet in point 3, so it does affect conformance;
... therefore under the new process it does count as substantive.
... The next one is in §6.7.1.

pal: Again this is relaxing a constraint that used to bind a value in the TTML with an external object.
... The first change in this section is in the same category as the previous one we just discussed.

nigel: Right, so this is classed as substantive.

pal: The next one, removing the conformance regarding aspectRatio and extent is substantive for sure
... because it removes an enforceable check in the document.

nigel: The third change in this section is the removal of a note.

pal: That one is editorial by definition.

nigel: The next change is in §7.4. This changes the initial value of tts:displayAlign.

pal: That would affect presentation, i.e. processor behaviour.

nigel: This is also classed as substantive.
... Next one is the same for textAlign.
... This is also classed as substantive.
... The next one is the set of changes to linePadding and multiRowAlign.

pal: I think they have to be substantive because they clarify the situation relative to the previous version.

nigel: Agreed.

pal: I'd like the group believe that they are extensive enough to warrant doing wide review again for example.
... In my opinion the answer is no, but maybe we can have a group consensus to take to the Director.

nigel: This is also classed as substantive.
... That was the last change.
... On the point about wide review, some of the changes are relative to SMPTE-TT so arguably we should
... give them the chance to respond.
... Just sending to SMPTE is narrow review though not wide review.
... My view is that this doesn't need wide review. One of the changes was in response to the previous
... wide review.

pal: Yes, that arrived beyond the feedback deadline and we chose to defer knowing that we might have other
... changes.

nigel: When we've completed the one remaining open action I'll raise a proposal in a future meeting to request
... transition to CR for the updated ED.

Steps for exiting CR for IMSC 1

pal: Thierry, what are the steps for exiting, once we've published CR2?

tmichel: First we have to publish CR2!
... We have to organise the request and the Director's call because there are substantive changes.

pal: I will come back with a proposal for closing the last remaining issue.

nigel: In the CR we have exit criteria, which are just about implementation. For CR2 we will need a new 'earliest
... date'?

tmichel: Yes, at least 4 weeks beyond CR2 publication.

nigel: So I think the steps are: 1) Complete the implementation report to meet the criteria, 2) request transition to PR.

pal: And we have actions from earlier to help with 1.
... On the timeline, we will hopefully do CR2 in April, and probably not make PR in June. While that's going
... on we can start drafting IMSC 2.
... The only thing that will be tough is that SMPTE wanted IMSC 1 to reach Rec in July so they can reference it.

nigel: That's still possible.

pal: True.

nigel: If SMPTE has that goal and can encourage implementations then that will help them.

pal: The plan for IMSC 2 is to base it on IMSC 1 and add any TTML 2 features such as Ruby or SMPTE requested
... features that people want.

nigel: [5 minute break]

WebVTT FPWD Feedback handling

Loretta: How do the CG and the WG work together?

nigel: For Rec track stuff that has to come from the WG and feedback to go back to the WG.
... If there are any technical changes to the spec needed then it would be bad if the CG isn't happy with them.

Courtney: It can be tricky to get consensus from the CG.

tmichel: The WG has done a wide review. We received comments from i18n and CSS WG. We're expecting
... review from accessibility. That will close the debate on the wide review, as it will represent feedback from
... all the groups we have dependencies with.
... The only group missing is HTML and I'm expecting a statement that they're satisfied.

nigel: I want to explore that some more - for IMSC 1 we took the view that wide review goes beyond just
... W3C group dependencies and to the wider world.

tmichel: That's even better if we can demonstrate that review, but it's not essential.

nigel: I was expecting more. For example to include the liaisons with external groups.

tai: David Singer did post on the EBU group asking for wide review. That group hasn't provided any formal feedback.

nigel: As a statement of fact, I don't believe there has been any feedback from any external group. I don't have
... visibility of any other requests David may have made.


nigel: We had a conversation by email about the process for responding and collecting wide review dispositions.


Loretta: who has the action to take that forward?

tai: I think Dave offered to do it, on April 2.

nigel: That email, https://lists.w3.org/Archives/Public/public-tt/2015Apr/0003.html says he doesn't
... see a problem with doing it, but that's not the same as taking the action, right?
... He offered to do bridging, and my follow-up was attempting to isolate where the bridging is needed.

Courtney: I think what he means is he's asked Silvia to do it.
... There's another email thread about CSS WG feedback, where a more concise version of it.
... We should have an ETA and know who is writing the dispositions document we discussed last week.

Loretta: presumably the CG is blocking that?

tmichel: The bridging also includes acceptance by this group of any proposals made by the CG.

pal: In the case of IMSC 1 step 1 was to document every comment, which tmichel did. Then a proposed
... response was created and the commenter accepted or not and we discussed it. That's exactly what's
... required by the Director. The first step would be to document every comment received.

tai: The working model between CG and WG is new as tmichel noted last week.

nigel: I agree on both tai's and pal's points and don't think they're exclusive.

pal: So the issues could be in the bug tracker.

Loretta: Can we tag that they're comments so we can formally collate them?

pal: There's also the recurring issue of IP - if the CG creates new IP in the course of responding to the comments,
... how do we ensure that the IP meets the requirements of W3C, in a continuous way?

nigel: If there's a spec change made by a CG member who is not a WG member then the IP needs to be cleared
... on a case by case basis.

Courtney: Is this only what's in the spec?

tmichel: Only the spec changes need to be cleared.

Courtney: If the IP question is based on versions of the spec...

pal: Then you might want to do another clearance call.

tmichel: This is so complicated! I've been tracking people from the CG that have been active contributors and
... some never responded and are listed in the acknowledgement section as active contributors.

Courtney: Part of the problem is that it's taken so long that people may have moved on.
... It sounds like we need to talk to Dave and maybe Silvia and get clarity on what everyone needs to be produced
... and a date for when it will be done and who is doing it. Let's get a schedule and then work to it.

tmichel: Now it's in the tracker the CG should make proposals for the comment, as a first step IMO. The
... second step is for the TTWG to approve them.

Courtney: We don't need to do that piecemeal for every comment.

nigel: Part of the problem is we didn't set a review feedback end date on the FPWD of WebVTT so when do we stop?

Courtney: We can get a specific date for accessibility review.

tmichel: I'll do that.

Courtney: Then we have to make a decision point - do we have wide review?

nigel: We should check the process too on that. I have reservations on this. Let's review the process and charter.
... The process wants the charter's dependencies specifically to have been contacted. I don't think there's
... any archived evidence of Dave emailing them all, just the W3C groups in 3.1 of the charter. 3.2 and 3.3
... seem to be missing. The general public has been told, due to publication on the W3C homepage.
... In terms of appropriate times, the end date for feedback was not clear on the FPWD.
... One way to proceed here is to issue a second WD and a specific call for wide review with an end date
... and process any feedback from that, having solicited from all the dependencies on the charter.

tmichel: That would be a good way to proceed.

Courtney: I think that sounds like a good set of next steps for getting the wide review done. What's next after
... that?

tmichel: Then we move to CR.

nigel: Part of the CR is to specify exit criteria, which must include implementation experience.

tmichel: In the pipe we also have issues regarding styling for example, such as inline or external stylesheets.
... Do we want to have those resolved in the current version or a later version?

Courtney: IMO we should defer to a later version.

Loretta: I would really like it in this version.

Courtney: Then we have to get implementations. I see the value of having it in there but we don't have
... consensus on the design.

Loretta: To my mind the conversation on this happens in the CG, and I think I saw a consensus emerging.

Courtney: It's been quiet in the CG for the last 6 weeks.

tmichel: Even if we went to CR for the current version I don't think there's evidence of implementation for
... the whole spec.

Courtney: I don't agree. We've been supporting this in Apple since last fall in two separate implementations.
... In addition Google has an implementation.

Loretta: It's not complete yet. The parsers and encoders support it, but Chrome does not. It doesn't do regions.
... What counts as an implementation?

nigel: We can choose that in the CR exit criteria. We have some flexibility.

tmichel: We also need test suites. In my experience browser implementations don't implement a lot of features
... completely.

tai: This is the same conversation as we had for IMSC, and we decided that we don't need single implementations
... that pass all the tests, just that every test is passed by at least two implementations.
... Silvia has started on the test suite in git.

Courtney: We've been working on the tests too but don't have anything to share yet.
... So first we get evidence of wide review then we define the exit criteria, which could be passing tests in a
... test suite?

nigel: Yes.

Courtney: Going back to the inline styling question, because I'm interested in getting to a published version
... as soon as possible.

nigel: Thinking about the existing CSSWG response, and other potential responses, in my opinion it's quite
... high risk to omit inline styling and require styling from a host HTML page.

Loretta: I support the desire to get to Rec quickly.
... Previously the issue with inline styling was about syntax - the CG didn't agree it.

Courtney: I think the action there is to contact David and Silvia and get a status on that.

pal: Whatever decision they make, if there's a formal comment made then this group has to approve the response
... and the commenter's response to that may be positive or negative.

tai: So the WG has to approve the edit and that the comment has been addressed. Do we have the expertise
... on the spec to state that?

nigel: My understanding is that we can't proceed without the expertise but that we have enough members
... from the CG like Silvia, Dave, Courtney, Loretta and Philip that we do have enough expertise.

Courtney: So we have a 4 step process:
... 1. Get feedback.
... 2. Someone from the CG writes a proposed response.
... 3. The WG reviews the response and maybe edits.
... 4. Get the response form the original commenter.

nigel: Step 2 is interesting - ideally I'd prefer for an individual who is a member of both the CG and WG and
... can be representative of the CG, so that at least we have some WG backing for the responses immediately.

Courtney: I agree with that. I'm happy to talk to Dave about that - he may already have someone in mind to do that.

nigel: I want to record the actions - can I just check it makes sense to put them in the WG tracker? They're
... WG actions.

tai: Makes sense.

Courtney: We're at a hand-over point between CG and WG.

tmichel: Does it make sense to use the dispositions tracker for this?

nigel: I would defer that until we know who is doing it.

Loretta: have other groups used different tools?

tmichel: You can do whatever you want. You can produce an Excel document or an HTML page that describes it
... You do need links to the archive for reference. The dispositions tool tracks the process steps.

Loretta: In practice does everyone use it?

tmichel: no.

glenn: people use github and a variety of tools.

nigel: Let's record the actions.

<scribe> ACTION: Courtney Determine who is responsible for putting together the dispositions of comments document and get a schedule from them. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action08]

<trackbot> Created ACTION-394 - Determine who is responsible for putting together the dispositions of comments document and get a schedule from them. [on Courtney Kennedy - due 2015-04-17].

<scribe> ACTION: tmichel Chase the accessibility WG for a date for getting WebVTT feedback [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action09]

<trackbot> Created ACTION-395 - Chase the accessibility wg for a date for getting webvtt feedback [on Thierry Michel - due 2015-04-17].

Courtney: if our response to comments is to change the spec do we have to redo the request for wide review?

tmichel: If you publish a new WD then you only need to ask for comments on the delta.
... If we publish a new WD for wide review we should send an email to the groups on the charter and
... make sure it's archived. If Dave did that before then the emails are not on the archive.

nigel: For IMSC 1 we sent to all the charter dependency groups and the W3C external liaisons filtered by
... interest area, BCCing the member-tt list so they were archived.

<scribe> ACTION: dsinger produce evidence of request for wide review for WebVTT, for the archive [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action10]

<trackbot> Created ACTION-396 - Produce evidence of request for wide review for webvtt, for the archive [on David Singer - due 2015-04-17].

nigel: So we're deferring the decision on a second WD dependent on the disposition of comments.
... Are the region semantics in WebVTT stable?

Loretta: I think that's at risk. Philip doesn't like the way it's specced currently. AFAIK it's only implemented in
... Apple's players. It's not in Chrome, IE, Firefox or Opera.

Courtney: Why is it at risk?

nigel: I'm asking because I couldn't identify a resolution or consensus in the CG about the syntax and semantics.

tmichel: The WG has published it so it is a consensus in that sense.

Loretta: If it's not implemented widely then that won't do us any favours.

tmichel: What about the ::past and ::future pseudo-classes? I couldn't see support for that on any browser.

tai: From reading the spec I'm unsure in general how much CSS feature support is required.

nigel: While we're listing things we're curious about, what about the red box in §6.1 of the FPWD, which
... looks incomplete? We can't go to CR with that there, right?

Courtney: It's not like that in the latest ED.

nigel: In that case there have been changes.

Loretta: There will be an action if we want to take a new snapshot. Someone needs to do a diff.

nigel: That's an Editor's job.

Loretta: Someone needs to understand what has changed in the ED to establish the diffs. The changes may
... be unrelated to comments.

nigel: I've filed bug #28464 https://www.w3.org/Bugs/Public/show_bug.cgi?id=28464 for §6.1

tmichel: Does WebVTT do ruby support?

Courtney: Yes it supports ruby but not to the extent that's in TTML2.

nigel: One of my key points is to make sure that there's alignment between new features in TTML and WebVTT.
... If the WebVTT Ruby implementation blocks future extension to get to the support level of TTML2 then
... we should file a bug.

tmichel: Who decides?

nigel: That's a WG decision.

Courtney: We can use that as a criterion for evaluating new feature proposals.

nigel: +1

tmichel: Another thing that has been discussed is if the CSS feature list should be a whitelist or a blacklist.
... Dave, Nigel and I had different views of what the current wording means, and ought to mean.

Courtney: Can CSS support profiles?

glenn: No it does not, and there's no standard way to tell if a feature is implemented. There are some heuristics
... and javascript libraries like modernizr that can be used to mitigate those issues.
... One of the things I do is to set a value to something other than its initial value and then read its computed
... value. It's not a guarantee that the feature is implemented, but it's a good hint if you can't even get that far.

nigel: Let's adjourn for lunch!

group: Strong agreement!

WebVTT <--> TTML Mapping

Courtney: We don't have too much to discuss with the group yet, but want to let you know about our plan.
... We discussed this in Geneva and I've been unable to make much progress since then. We want more
... structure around this so we can get it done. Andreas and I are working on a timeline and an outline for
... a document. We welcome help from anyone who wants to contribute text. Andreas and I will divide it up
... otherwise but if anyone else wants to help that would be great.

nigel: What will that look like?

Courtney: We haven't finalised anything. But let's think about the approach. Glenn brought this up in
... Geneva, that mapping from TTML to WebVTT directly isn't the way to go, instead to go from ISD to WebVTT.
... What we thought we could do is to map from IMSC to WebVTT.

glenn: There is a spec for the ISD format in TTML2, but the mapping semantics need to be inferred from the
... rest of the spec but it's not perfect yet. A tool I've been working on, open source, based on TTX (TT transformer)
... will take an arbitrary TTML document and spit out a sequence of ISDs. So that's an examplar of what the
... semantics should be, but they're not written in detail in the spec.

Courtney: If our goal was to write sample code we could use that but our task is to write a document.

glenn: What that tool does is to flatten out the timeline and create a document for each interval during which
... no changes occur, and also flattens out the styles into the ISD documents. So a lot of the complexity in TTML
... disappears in that domain, and then it's easier to do a translation into some target format. If you don't do that
... but focus on IMSC you still have to deal with the complexity of the styling system.

Courtney: Does IMSC require sequential timelines?

pal: No, not unless you have progressivelyDecodable set.

Courtney: My feeling is that its easier to start with a subset of TTML and then extend it later.

tai: It makes sense to start with IMSC because it simplifies things, has a similar target usage, to WebVTT, and
... we might even start with a first draft based on something even more restricted to support the most
... commonly used features. Then we can add more as it is needed. From a formal perspective for an algorithm
... I think it may be the way to go to use ISDs, but it makes sense in the document to tackle certain features
... like position, timing, style, explain how it works in each spec, and then at least readers will understand the
... context and how it works. Even if any algorithm specified isn't used at least readers will be able to make
... their own. I think we made a good start in Geneva that is well minuted.
... Another thing we started is to work on the test files that we have that need to be built up for WebVTT. All
... these features can best be described using examples. The missing test files for WebVTT could also be
... generated.

Courtney: I think we're going to do some more work on this next week (me and Andreas). In our conference
... call in 2 weeks we should have an outline and a schedule that we can share and discuss. We could circulate
... it on email too.

nigel: It might make sense to use Mercurial to store it and allow it to be shared, or some other versioning tool.

tai: That's publicly visible right?

nigel: yes.

Courtney: It would be good to have versioning.

tai: I think it's important to do a first draft and then take it step by step.

Courtney: I wanted to know if anyone wanted to contribute additionally.

Loretta: Speak to me about this - I'll see what I can do.

Courtney: It will also be good for developing the test suite.

Loretta, tai, Courtney: discusses actual plans for getting together to work on this.

nigel: Are there any particular inputs that you need e.g. in terms of expertise, understanding etc.

Courtney: I think we may need to call on Glenn for TTML expertise and Silvia for WebVTT!

glenn: One of these days someone will ask me to output WebVTT from my tool, and then I'll have to learn it!

Courtney: Are you available to do that?

glenn: Yes. The tool is all Java and is open source.
... There's another project called the TTV Timed Text Validator. TTX is the transformer layer on top of that.
... So this new timed text presentation engine is a layer on top of TTX, so it validates the TTML input,
... translates it into ISDs and then formats them.

tai: Is there a place where we collate implementations?

glenn: It would be a good idea to add that to the wiki.

nigel: Sounds good to me.
... though we wouldn't necessarily endorse them.

tai: It's good to let people know about this activity on the mappings in case people are also working on it.

Loretta: Probably good to make some progress before raising expectations that we then discover we can't meet.

nigel: Have you looked at the idea of picking the features that are easiest to match, even if they're from TTML2
... like the tts:position attribute?

tai: I think we should start with TTML1 because it's more useful.

Courtney: We can certainly look at some low hanging fruit.

nigel: An outcome of this work might be to identify subsets of the two specs that easily map to each other,
... and also any small additions to one spec or the other that would make the mapping much easier. We should
... capture those as outputs of the work if possible.

tai: That would help with a more general desire to align the specs.

nigel: Knowing where the semantic overlap lies would be useful.

glenn: Sure, where there are things like ruby, let's make sure they align semantically.

nigel: I'm just saying if observations like that are made then we should capture them.

tai: If there are possibilities of making mapping easier, like in TTML2 to map the semantics to CSS then in
... the long run that will make it easier.

nigel: Looking at our charter, there are other documents that we could be working on, like the Note on live,
... and the mapping of 608/708 to WebVTT. Where's that last one up to?

Courtney: Silvia wrote a second draft of that.

nigel: Has Silvia done that in the CG - if it's in our charter I'd hope to publish it from here.

Courtney: It's on the CG at the moment.


nigel: I see there's quite a lot of work there - great!

Courtney: Yes, and it's been updated recently.

tai: She also proposed a mechanism for putting inline styles into VTT.

Loretta: I don't think that's in the WebVTT spec yet. Certainly the original syntax for inline styles was never
... adopted into the VTT spec.

tai: So a new proposal might overwrite this?

Loretta: Sure if a new syntax is adopted then that document should be updated to include it.

nigel: Thanks for making progress on the WebVTT TTML mapping document - it'll be good to make some
... progress there.
... Do you have a longer term schedule in mind?

Courtney: We're hoping for something in time for the Sapporo face to face but it's too early to commit to a
... schedule until we've started working on it.

tai: Also we might size the task to fit a particular timescale, at least for a first iteration.
... One last comment: is there an idea to have a common telephone conference where the WebVTT and TTML
... communities can come together? Would that be of use?

Courtney: I think, speaking for myself, in the past it's been tough for Silvia because she's in Australia. So
... finding a good time could be difficult. A standing meeting might not have much support but we can
... schedule specific reviews as we need them.

tai: That would be good to have.

Loretta: We're ideally located to make finding meeting times maximally difficult!

Courtney: Some working groups rotate it.

pal: My suggestion is make sure there's a really clear agenda if you want people to get up in the middle of the night.

nigel: Here in a meeting of 7 members and 1 observer, approximately half the members here today have an
... interest in WebVTT, so we're already doing it.

Loretta: Of course not all the skills are here though!



<trackbot> action-379 -- Nigel Megitt to Obtain png images for #linepadding and #multirowalign test cases. -- due 2015-03-19 -- PENDINGREVIEW

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/379

nigel: I did those PNGs but now they need fixing.
... But that's captured in Action-391, so I'll close this one.

close action-379

<trackbot> Closed action-379.


<trackbot> action-381 -- Pierre-Anthony Lemieux to Prepare new list of changes to imsc 1 since cr1. -- due 2015-03-26 -- PENDINGREVIEW

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/381

pal: The next step is to close the outstanding issue and then prepare CR2.

close action-381

<trackbot> Closed action-381.

nigel: I think we need a new date for the SOTD and a summary of differences since CR1.

<scribe> ACTION: pal Prepare CR2 transition version (after closing one remaining issue on IMSC 1) [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action11]

<trackbot> Created ACTION-397 - Prepare cr2 transition version (after closing one remaining issue on imsc 1) [on Pierre-Anthony Lemieux - due 2015-04-17].

nigel: We also have two overdue actions, action-365 and action-378 which we can't complete either of yet.

pal: That's right. Do we want to make the request to SMPTE as part of the wide review request on the next WD
... of TTML2?

nigel: We could, I'm not sure. No particular reason to wait that I know of.

pal: Okay, well that's ongoing.


nigel: I don't believe we have any pending review issues - no we don't.


<trackbot> issue-382 -- Require a computed non-indefinite begin time -- open

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/382

pal: So just to confirm, if I list the TTML1 features, there's a #timing feature.

glenn: That's a very generic feature.

pal: Okay, so there's no granularity to build on.

glenn: By the way the process for coming up with the features was subjective, and we used it to drive our
... tests. You're supposed to test features, but very few specs list features. So we took the approach of creating
... more fine grained features.

Sapporo TPAC F2F

nigel: Looking at the survey results there's already enough backing for a meeting to say there's consensus
... to hold a meeting in Sapporo.
... There's a clear preference for the Monday and Tuesday and no objections to that, so it's clear that we
... should prefer those days.
... In terms of joint meetings, someone has suggested CSS-WG, and another suggestion is HTML WG.

glenn: This is going to be difficult unless we make it short and extremely focused, like a single specific question
... to answer. Otherwise it will be a waste of time.

nigel: My question is, what do people want to do there?

glenn: Bert Bos has made comments on WebVTT. He might be interested in the line balancing algorithms.

pal: I mistakenly hit the button for HTML WG and am going to unclick it.

tai: We mentioned over lunch that working with HTML to understand how TTML TextTrackCues can work.

glenn: We have a spec I wrote called the TTML API Level 1 and Level 2 (two specs) that try to define some
... things on top of the TextTrackCue interface that somewhat mirror the WebVTTCue. But there are lots of
... issues getting browser vendors to implement them. Microsoft and Opera might have an interest but
... Google, Apple and Mozilla don't seem to be interested. But my position is that it would be a pretty good
... way to go to use Javascript to populate a set of HTMLCues. Then you could transform into HTML on the
... server and feed it using Ajax and HXR to populate it, or have client side javascript that translates the TTML
... file locally, though that would probably be more complicated and less efficient than doing it on the server.
... That approach would allow either browser based HTML rendering or create a fragment containing SVG with
... a pre-rendered version of the cue. It turns out that inside the implementation in Webkit and Blink the
... same approach is used, to convert WebVTT to HTML and use that.

pal: If this group has a consensus view that would be a good reason to meet with the HTML WG.

glenn: The most likely answers are either 1) no or 2) write that as an extension spec and bring it to the HTML WG.
... There are various reasons for doing that - it's easier not to touch the HTML5 spec. Creating extensions is
... easier, so that's how I would approach it. If that's the likely response then we could organise our inputs to
... feed their expectations.

pal: There'd be value in saying how to do it, though we don't have a volunteer for how to do that yet.

glenn: The whole area of text cues in HTML5 is problematic in terms of testing and interoperability because
... they used a subjective process for getting to Rec. Those areas were marked as at risk during the CR process.
... Instead of addressing that they just published anyway.

tai: But it's in the Rec?

glenn: It is, so its final. The question is what comes next. The formal way that the HTML WG has decreed is that
... if you want to do something that doesn't fix 5.0 or add features for 6 then bring it as an extension.

nigel: How does that approach interact with the WebVTT TTML mapping work?

Loretta: It's orthogonal.

glenn: +1
... You can say that the lack of a TTMLCue is a motivator for the mapping work, because you could use the
... mapping as a playback mechanism. I think its worth proposing a more generic cue proposal to the group
... at some point.

nigel: That sounds like a great idea; so far we have nobody wanting to volunteer to work on that.
... Just to test the view of the group, do we have consensus that an HTMLCue would be a good way to do it?

tai: +1

pal: +1

glenn: The good thing is that with a generic cue type then you can use any input format as long as you have
... javascript to create it. I already have a fairly complete proposal from Opera proposing a way to do this in
... blink.

tai: But that's not public.

glenn: Eric Lindstrom who was at our meeting in Geneva wrote it.

pal: Could we bring that document to the group for review and take it to HTML WG?

glenn: It's blink specific so it would need to be made more generic.
... Maybe we could ask Eric if he wants to take this forward.

tai: I can contact Eric if you give me an action.

<scribe> ACTION: atai2 Contact Erik Lindstrom re HTMLCue [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action12]

<trackbot> Created ACTION-398 - Contact erik lindstrom re htmlcue [on Andreas Tai - due 2015-04-17].

glenn: Opera has membership of this group via Philip Jägenstedt.

nigel: We do have consensus here that this is a good way to go, i.e. to propose to HTML WG HTMLCue as an extension
... That's everything from the survey results that I need for my response to the organisers. That doesn't
... close the survey - any new or amended responses will still be taken into account.
... But it does mean we will go ahead with a Monday and Tuesday meeting.
... Is there anything that we want to cover in that meeting?

tai: We should reserve some time for the mapping, regardless of what state we're in.

pal: Hopefully we'll be done with IMSC 1 but if not we should address any blockers. We should also work on
... a 1st draft of IMSC 2, that should exist at that time. The hope is that IMSC 2 is simpler as a document
... than IMSC 1 because all the features will be a subset of TTML2.

glenn: You will probably want an informative section mapping IMSC 1 features into IMSC 2 if they're no longer
... present in IMSC 2. I imagine you might want to say something about migration, continuing use of old content etc.

nigel: For TTML2 maybe we should be targeting implementation reports.

glenn: I definitely hope we'll be in CR by then.

pal: When will you be able to show implementations of your tool?

glenn: The TTPE presentation tool I've been writing should be available at end of June. Probably end of August
... to finalise the arabic, hebrew and bidi additions to it.

pal: That will remove a huge risk to TTML2.

glenn: I'm hoping to be able to get a lot of the new features into it as well. So we can have at least one
... system to pass tests. I'm also adding support to the TTML Validator to validate the new constructs.
... So in a sense we could point to the Validator as one implementation and the presentation engine as the
... other implementation even though one is built on the other.

nigel: There is a question the Director will ask about who wrote the implementations. In this case we could have
... an answer which is that the spec and both implementations were written by the same individual. I don't think
... that he'd be that happy with that!

tai: A quick question about what TTPE does: from the documentation I'm not clear what the outputs are?

glenn: [draws on the whiteboard] There are 3 layers: TTV, TTX and TTPE. Generic TTML files can feed into
... TTV - TTML1 or TTML2. It validates every feature of TTML1 and I’m enhancing it as I go to support TTML2
... features. TTX converts into ISDs in a sequence which consists of multiple instances of an ISD.
... TTPE then does two things: layout and then rendering. It takes the ISDs and creates an area tree which
... is very similar to what's in XSL-FO, or a box tree in CSS terms. It has things like block areas, line areas,
... glyph areas, space areas that fill the lines up. The rendering process then turns that into the chosen output
... format (specified on the command line) - one of XML for debug, SVG or PNG. I've also specced out renderers
... for html and vtt that I and the other engineers working on this haven't built yet. They just take the area
... tree as the input and then write out whatever is needed to create the same visual output as is specified.
... It's very easy for SVG. TTV and TTX are both in the TTV project in github. TTPE is a separate project.

pal: When that implementation is available, that removes a huge risk for TTML2 because there's at least one
... baseline implementation for features. So it's hard for me to imagine not being able to enter CR in August.

Loretta: It looks like there's a lot of input for the TTML to WebVTT mapping there.

glenn: The question is how to map from the area tree to WebVTT. It's hard to work out how to do the positioning in WebVTT.
... Since WebVTT doesn't have pixel positioning I may have to use the regions feature to do the layout.
... One of the things about the mapping is that you can lose information without losing everything. At the basic
... level I could pull the text out of the area tree and blast it into a WebVTT cue. That would lose a lot of information!
... It's a question how to include positioning properly.

Courtney: Another item for the F2F in Sapporo should be the WebVTT progress.

dakim: Do you think the ruby stuff is important for WebVTT v1?

Courtney: I think it's less important than inline styling, and also we need to figure out how to do it in terms
... of the design. A lot of what we need is already in CSS so maybe if you do inline styling in CSS maybe you
... get all the ruby functionality you need.

dakim: I've got a bug open with Philip that you can't annotate the rt tag.

Courtney: If that's a minor change to the spec then we could consider adding that. I want to balance the features
... against getting to a spec as quickly as possible.

nigel: Obviously that's a consensus issue for the group.

Loretta: the call is when it's needed not whether it's needed.

TTML2 topics continued

pal: I'd like to ask about ttp:contentProfiles "any"
... I'd like to walk through the positioning of images in TTML2 also

dakim: I'm wondering why people would use extent and origin on content elements to define inline regions instead of just ipd and bpd

nigel: For ttp:contentProfiles what sense does "any" make?

glenn: I see what you mean - I can't see why an author would claim conformance with at least one of but not
... all of a set of content profiles.


<trackbot> issue-386 -- There's no apparent use case for the "any" term in ttp:contentProfiles -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/386

reopen issue-386

<trackbot> Re-opened issue-386.

nigel: The next point was also raised by pal: the positioning of images in TTML2

pal: How do you position images?

glenn: If it's a background image then use the background position properties. If it's a non-background image
... then you can treat it like a block or inline area so the rules apply, like ipd and bpd. Extent and origin do
... not apply to content elements - they create regions.
... There are two ways to do it - you can put a background image on a region. That's intended to support
... non-content images. For content images e.g. with rasterised text in them one should not use the
... backgroundImage mechanism but instead use image like in html. Put it in a block context e.g. as a child
... of a div or in a p. So if you put a span with an ipd and bpd then it's now an inline block with an image in it.
... If you want to do fine positioning you have to use spans with ipd and bpd.

pal: So if I wanted an image 80% from the top and 20% from the left of the viewport.

glenn: I'd create a region and define its position using the position attribute or origin. Then I'd put a div in it
... with a single image inside that div. That would be the easiest way to position it.
... If that's the only content in the region it would position it. You can also use ipd and bpd.

nigel: Have we got scaling semantics for images if we use ipd and bpd?

glenn: I thought so - I don't believe there's an issue.


<trackbot> issue-387 -- Consider applying ipd or bpd to content images -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/387

reopen issue-387

<trackbot> Re-opened issue-387.

pal: When I read the document the simple option wasn't obvious.

glenn: By the way displayAlign and textAlign would apply to it.
... I think you may also be permitted to put an image in a body without a div.
... No, body has to have div in it, div can have embedded class like image or other divs or ps.

nigel: The last point to raise is that content elements can have style attributes extent, position, origin, ipd and bpd all applied
... simultaneously. I think the semantics are clear but some readers of the documents will find it hard to
... understand. It may be useful to add non-normative examples or text to explain this scenario.

glenn: That's a feature of languages as they get bigger. I have an issue already to add recommendation text
... to say that style attributes should not be put on content elements where they do not apply and can not be
... inherited from.

nigel: It might also be useful to include an example document or non-normative text somewhere to remove
... or reduce the likelihood of confusion there.
... The last question I have is where we're up to on the CSS semantics mappings?

glenn: I have a proposal out for mapping to html that will generate that, but I don't have the resource to do that
... at the moment.

tai: Didn't you have some draft material for that?

glenn: jdsmith picked up some work from Sean re change proposal 5 but that needs further attention.


glenn: When we started this work there was an idea that someone could create a Javascript shim that would
... generate HTML/CSS.
... CP5 needs to be carefully reviewed because the time evaluation algorithm wouldn't work. It also attempts
... to specify some algorithms on how to resolve styles. We already have some normative language on
... style resolution in the spec. My plan was to take that information and also timing rules and wrote them
... into the spec in a readable fashion in the context of an ISD sequence then it would eliminate talking about
... style and timing resolution in the context of an HTML mapping.

nigel: I was expecting equivalence notes under the style attributes to say what the equivalent CSS semantics
... are to the already stated XSL semantics. I think CP5 is something different and much more complex.

glenn: I'm not sure how useful that would be.

nigel: I think it would be extremely useful.

glenn: In § and §, when we originally talked about a CSS mapping the intent was to define
... two subsections of § one based on XSL-FO and the other on CSS. That means taking part of the
... material from CP5 and formally doing it in a way that is congruous with the XSL-FO.

tai: I understood this activity to be as Glenn described, but even just additional notes as nigel described would
... have a big impact on readability, especially if the CSS semantic is first.

glenn: I'd be happy to put the CSS equivalents first.

tai: People don't know how close the features already are to CSS so it would make the document much more
... accessible.

glenn: It would be insufficient just to create an equivalence table for each style attribute. We'd also have to do an equivalent
... algorithm in §

nigel: I agree with that.

glenn: Nobody has been pushing me to do this much!
... I won't be confident about the algorithm until I've seen it in code though. I'd be happy to use CP5
... as a starting point at least though.

nigel: I think that's all on this and everything I had on the queue to deal with. In terms of your spreadsheet
... glenn did you have any remaining technical questions?

glenn: I don't think so - I have a pretty good idea on most of the remaining things and I will come to the group
... if there are any other questions. For example on disparity if there's anything unclear in the issue.
... I'd like a response from SMPTE to know that they'll be satisfied with what we've proposed.

nigel: pal has the action to draft that. Good to know that there's a pressing need for that.

glenn: I'd like to draft some of the members to do some work particularly on the examples and images of
... examples.
... I have about 25 entries that have to do with creating example source content or images or both. I could do
... it but my time would be better spent creating technical solutions. There's also an annex Q about a CEA708
... mapping that it would be useful to have someone look at.

pal: Just point to RP2052-11 which already does it.

glenn: Does that point to SMPTE additions to TTML?

pal: I doubt it - it doesn't use image. I'm just offering an easy way to do that.

glenn: I don't know if that's going to be sufficient - it needs to be reviewed.

pal: I don't think we need that section - if nobody volunteers to write it we can remove it.

glenn: We've added 6 metadata items preceded with cea708 and others preceded cea608. I have a note to
... elaborate those with reference to 608 and 708. If someone could sign up for doing some of the related
... work items that would be useful.
... In the end with TTML1 where we did this everyone had a role bringing some spec text in.

nigel: Okay, I appreciate the request and think that's a really good idea. It's not necessarily a good moment
... to start assigning tasks now, but let's think about that and how to take it forward.

glenn: I reserve the right to ensure consistency of language and edit contributions.

nigel: Okay, we have the spreadsheet available (see yesterday's minutes) - everyone have a look at that and if
... you want to contribute something contact me or glenn and let's share out those tasks.

glenn: nigel you raised issues on appendix L.

nigel: I've done the work to guess the new values for the conformance column against requirements - it's in the issue.

glenn: In Appendix M the element derivation needs to be updated for the new properties.
... It would be useful to have a list of elements and attributes to add or change on the tables in M.
... By the way you could edit the source document itself if you're set up to run ant, and I could help you set
... up your build environment so you can run the authoring tools. We have an old process for generating the
... spec using an XSLT-based translation process with a DTD. The language we write the spec in is governed by
... XMLSpec that came out of the XML WG.
... There's a stylesheet too.

nigel: Okay, that's interesting - let me know if you're interested in setting that up.

Meeting ending!

nigel: Thanks to netflix for sponsoring this meeting, and to Glenn for buying lunch.

glenn: And thanks to Netflix for sponsoring that lunch.

nigel: I think we've had a really productive two days, so thanks everyone for attending and contributing.

tai: And thanks for chairing and scribing too!

nigel: Thanks!
... We've done all our goals for this meeting and also handled issues or at least come up with action plans.
... So well done everyone!
... [adjourns meeting]

Summary of Action Items

[NEW] ACTION: atai2 Contact Erik Lindstrom re HTMLCue [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action12]
[NEW] ACTION: Courtney Determine who is responsible for putting together the dispositions of comments document and get a schedule from them. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action08]
[NEW] ACTION: dsinger produce evidence of request for wide review for WebVTT, for the archive [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action10]
[NEW] ACTION: nigel Send pal details of implementation and tests passed so he can create a table in the implementation report [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action07]
[NEW] ACTION: nigel Update the multiRowAlign and linePadding PNGs to match the TTML [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action05]
[NEW] ACTION: nigel Update the multiRowAlign and linePadding TTML files to have shorter lines of text [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action04]
[NEW] ACTION: pal Collate list of potential implementors of IMSC 1. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action01]
[NEW] ACTION: pal Prepare CR2 transition version (after closing one remaining issue on IMSC 1) [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action11]
[NEW] ACTION: pal tweak the examples with multiple regions so that they appear in a more intuitive order. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action06]
[NEW] ACTION: tai Check with EBU group if we can have a combined event at IBC with EBU group and IMSC/W3C [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action03]
[NEW] ACTION: tmichel Chase the accessibility WG for a date for getting WebVTT feedback [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action09]
[NEW] ACTION: tmichel Start preparing the IMSC 1 Implementation report form. [recorded in http://www.w3.org/2015/04/10-tt-minutes.html#action02]

Summary of Resolutions

    [End of minutes]

    Minutes formatted by David Booth's scribe.perl version 1.143 (CVS log)
    $Date: 2015/04/20 18:24:09 $