See also: IRC log
<scribe> scribe: nigel
Glenn: [can only stay 45 minutes]
Nigel: Thanks for letting us
    know.
    ... Any other time constraints from anyone?
group: [silence]
Nigel: Today we have TTML2 issues
    if there are any for CR2, and any comments to be
    ... raised on the CfC.
    ... I should also raise the way that we are responding to
    comments raised during the CfC period.
    ... I don't think we have anything on TTML1. Anything on
    IMSC?
Pierre: There's one issue we ought to discuss, #372 re rw and rh, because you were surprised Nigel.
Nigel: Yes, let's add that.
Pierre: Also, based on feedback
    I've received I'm about to open another issue against the
    ... requirements for rubyAlign which we could usefully discuss.
    It's already there actually.
    ... Actually we already discussed rubyAlign so we don't need to
    cover that.
Nigel: We have one action on CSS.
Glenn: I have a couple of issues
    to discuss on TTML2.
    ... There are 5 pull requests approved pending merge.
Nigel: Let's come to that, just doing the agenda now.
Glenn: I have a couple of items on TTML2 to get to.
Nigel: I don't expect anything on
    WebVTT. I haven't got a TPAC agenda item, but just to
    ... remind everyone registration is open.
    ... I've started to work on a list of topics to cover in a
    potential joint meeting with the M&E IG
    ... which I will share.
    ... Anything else for the agenda today?
group: [silence]
Nigel: Ok let's go.
Nigel: Status report: CfC is more
    than half way through and there are some pull requests
    ... that address comments received during the CfC period. I
    want to treat those as CfC
    ... review comments and merge the fixes for those soon, but
    alert everyone to the fact
    ... that is happening and encourage you to be aware when
    reviewing.
    ... We have 5 approved pull requests pending merge, and I would
    propose that we merge
    ... them as soon as possible.
    ... Any objections to doing that?
Pierre: Not an objection, just
    confirmation that
    ... changes to the feature list are going to be treated
    editorially, so we can make those
    ... changes prior to PR?
Glenn: I would support that.
Pierre: I thought we had discussed it.
Glenn: I think you could argue it
    both ways. The feature system is on the one hand a
    meta-feature
    ... in the sense that it is about features and it is not
    defining new features but labelling them.
    ... On the other hand the standard profiles are normative so
    every time we add or change
    ... one of the profiles files it is changing some normative
    text in the document. I would
    ... prefer to take your point of view.
Pierre: I agree with your assessment.
Glenn: If we do it that way then
    we should say that in the SoTD to give ourselves
    permission
    ... to do that, which could result in objections from external
    readers that we would have
    ... to deal with. We should raise that in the transition
    request.
Nigel: The transition request has
    gone through but we can amend it.
    ... I'm not hugely comfortable with this.
Pierre: If we are not comfortable
    with it there may be alternatives but we should talk
    about
    ... it because there's a significant risk that we may have to
    modify features and the way
    ... they are formulated, just because of the sheer number of
    them.
Glenn: Changing the feature list
    is not adding or subtracting syntactic or semantic
    ... components of the specification.
Nigel: Here's a test: if an
    implementation supported a feature and that feature
    definition
    ... was changed then it could cause that implementation to
    become non-conformant, so
    ... from that point of view it is a normative provision and the
    change would be substantive.
Pierre: I agree.
Glenn: I agree.
Pierre: Then if we don't give ourselves that permission then what can we do?
Glenn: We can move it to TTML2
    2nd Ed. We could note informatively that we intend to
    ... make certain changes but that due to timing we were not
    able to do it in 1st Ed.
Nigel: Previously we tried to make editions non-substantive in change.
Glenn: It would have to go
    through the CR process again.
    ... I wouldn't be surprised if we don't have other normative
    changes given the large number
    ... of features.
Pierre: I understand the rules as
    they're written right now, but this is pretty
    inefficient.
    ... Refactoring features is highly unlikely in practice to
    cause interoperability issues.
Nigel: I disagree.
Pierre: Can you point to such an implementation?
Glenn: Back to the point about
    making implementations non-compliant, it depends on the
    ... implementation. If the implementation depends on the
    override route, the first processing
    ... step of construct effective processor profile, then the
    implementation can set it to
    ... whatever it wants. How many processors will not take that
    route?
Nigel: We have to apply this rule
    to content conformance and that is more likely to be
    ... affected.
Glenn: If you define a content
    profile and use it for validation and then add a new
    feature
    ... that could not have been prohibited but add that
    prohibition based on the new feature
    ... then that's not going to be a problem. If you change the
    semantics of existing designators
    ... then you may end up prohibiting syntax that was not
    previously prohibited.
Nigel: If you're going to create
    the content profile mechanism then you have to allow it
    to
    ... be used safely.
Glenn: Ok. Clearly we can make
    changes on the way to 2nd Ed if we go through a CR
    process.
    ... So going back to the question about practical issue? I am
    of a mind that it is very low risk
    ... in causing a practical issue.
Nigel: That may be true, but it's not the test.
Glenn: That's correct.
    ... If we have a consensus in the group we can present
    that.
Nigel: Can I make a proposal that
    we add a bullet to the at risk feature list to notify
    readers
    ... that the definitions of feature designators may change. If
    we can do that for features
    ... and then make the substantive change at PR then I'm willing
    to see if we can do it for
    ... feature designators too.
Glenn: I like it.
    ... Just adding a #profile-version-2 bullet to the at risk list
    might do it.
Nigel: My understanding is that
    the at risk list is for features that can be dropped but
    not
    ... changed.
Thierry: You're only allowed
    "drop".
    ... If you change a feature and it is substantial then you have
    to issue a new CR.
Nigel: Pierre, are you concerned
    that you won't be able to complete a review of the TTML2
    ... feature designators during the review period?
Pierre: I expect to be done ahead of next week.
Nigel: In that case do we really need to worry about this?
Glenn: I'd be satisfied to not
    change the at risk list and if we get a request to change
    then
    ... use the standard route to deal with it, i.e. to add
    informative text until the next edition.
Nigel: I think that might be the best way.
Glenn: We already have a changes
    document. Eventually we will probably have a new section
    ... changes from CR2 to PR and by definition they would all
    need to be marked as editorial
    ... but we could prominently point out editorial changes of
    this type, that are warnings to
    ... the reader that something we found will be changed in the
    near future.
Nigel: Sounds like a good idea to
    me.
    ... I think we've circled round on this one and concluded that
    we will take no action.
    ... Any other views?
    ...
    ... Ok that's a 'no' so let's move on.
    ... This arose from the question about merging approved pull
    requests now. Any other
    ... questions or points on that?
    ...
    ... I'm taking silence as assent, so Editor(s) you can go ahead
    and merge the following pull
    ... requests: #836, #842, #843, #844 and #845.
    ... Noting that 843, 844 and 845 are labelled
    "substantive".
    ... Any more issues from you on TTML2 Glenn?
Glenn: No.
Nigel: The other point I wanted
    to raise is that we're making change to the document
    ... during the CfC and it would seem fair to allow it to
    stabilise. Are there any other
    ... pull requests expected?
Glenn: There's one for issue 830
    and the other for 834 which tweaks the base-related
    ... features. It is going to involve adding a new feature
    called #base-general. To make it
    ... consistent with other definitions and the ability to
    prohibit the more general use of #base
Nigel: There are several editorial issues too.
Pierre: Glenn and I discussed 846
    and realised it hadn't been opened as an issue yet.
    ... I expect to be done tomorrow with my review so hopefully
    we'll be very close tomorrow.
Nigel: Can we set a target to merge all the pull requests by the end of tomorrow?
Pierre: Monday is more realistic.
Glenn: I agree.
Nigel: OK
    ... I issued the CfC on Wednesday 13th June, so end of Tuesday
    is the end of the CfC.
    ... So that gives 1 day for final post-pull-request-merge
    reviews before the end of the CfC.
    ... It's pushing the limits a little!
Glenn: Starting on the 26th, if
    we finish merges on the Monday, I plan to do the normal
    ... pubrules and link checking which requires some minor tweaks
    which will require at least
    ... one pull request. I'll need someone at hand to approve
    those quickly so I can merge them.
    ... By the end of the 27th I need a package to send to staff
    for upload for CR2 if it is going
    ... to be published on the 28th.
Thierry: The webmaster usually needs 2 days.
Glenn: If we get that done on the 26th would that be adequate?
Thierry: Yes it would be better
    at the end of the 26th if you can submit a package then
    ... I can take care of it late on the Tuesday or early morning
    Wednesday my time.
Glenn: OK I'll make that a date
    then. I'll probably start doing the pubrules and have it
    done
    ... by the 25th as well.
Nigel: That'd be good, thank you.
Glenn: I'll need help from another committer who can approve requests over the weekend.
Pierre: I plan to be around.
Nigel: With notice I will be able to also.
Glenn: If you could be able to
    check your email once a day between now and Monday that
    ... would be adequate.
Nigel: Ok, with the proviso that
    if there's anything strange or unexpected or complicated
    ... then I will probably block merging. We really need to ramp
    down the significance of
    ... any changes from now on!
Pierre: +1 with a proviso that we
    need to avoid substantial changes. But if there is a real
    ... blocker then it is not a reasonable answer to wait until
    2nd Ed. especially if everyone agrees on the solution.
Nigel: If something substantive
    does come up that needs a significant change then I would
    ... rather wait a few more days now than wait until 2nd Ed.
Pierre: Exactly.
Nigel: Included in the scope of
    those changes to be merged as soon as possible is the
    ... branch with the updates to changes on that you were working
    on Glenn.
Glenn: I can get that done by tomorrow.
Nigel: Then we can modify the transition request to point to the ED.
Glenn: [has to drop off the call]
Nigel: I think we had one issue to look at, #372.
github: https://github.com/w3c/imsc/issues/372
Nigel: My understanding of rw and rh was that they are beneficial especially with fontSize.
Pierre: Today you can achieve the
    same effect using `c`. It's not pretty but you can
    achieve
    ... that effect.
    ... We have discussed those requirements for many months and
    nobody has suggested we
    ... add them. I think it is in the "too late" category. I'd be
    more sympathetic if there were no
    ... other way to achieve it.
Nigel: Why are we too late?
Pierre: We are about to go to CR2 and there's a cost for supporting container related dimensions.
Nigel: A syntactic cost, given that the semantic is already feasible.
Cyril: It's not because it's been
    there for months that we cannot change it. We have to
    ... acknowledge we have mostly been working on TTML2 to finish
    it, so we should give
    ... ourselves some quality time to look again at the
    requirements for IMSC 1.1.
Nigel: +1 My time has been taken up by TTML2 mainly and I would like that opportunity.
Pierre: There's a cost to
    implementing it.
    ... So far nobody has made the argument why it is required.
    Don't get me wrong, I think
    ... it might be useful, but just nobody has explained why it is
    required.
Nigel: From my perspective the
    requirement is driven by the errors that I see when QAing
    ... TTML documents that I see, where people get the %
    calculations wrong.
Pierre: I don't expect anyone to adopt it.
Nigel: If it is absent from IMSC 1.1 then hypothetically EBU could not adopt it say in EBU-TT-D.
Pierre: If there were a liaison
    from EBU saying they wanted it then it would make the
    argument,
    ... but there is not one.
Nigel: I'm making this comment
    from my own experience, that c units cause difficulties
    ... and we should move towards rw and rh.
Cyril: I don't want to take a closed decision now - I need time to think about this.
Pierre: If this is needed then it should be raised as an issue against the requirements.
Nigel: Arguably Stefan has raised this issue on the wrong repo.
Pierre: Cyril, if Netflix is
    interested in adding rw and rh I ask that you do it super soon
    so
    ... we can get it in and get it done.
Cyril: I don't think we need it but I will cross check today or tomorrow.
Pierre: Super. Nigel, if EBU has
    IMSC 1.1 adoption on its roadmap and has strong feelings
    ... about rw and rh it would be good to know.
Nigel: I am not expecting any such statement.
Pierre: Or from anyone who plans to use IMSC 1.1 and has substantive input, now is the time.
Nigel: I've raised w3c/imsc-vnext-reqs#33 for this.
SUMMARY: Feature discussed, different viewpoints currently remain, requirements issue raised.
github-bot, end topic
Pierre: I'm making great progress
    and should have something to present for review later
    ... today, refactoring the features table to match TTML2 and
    fix some of the outstanding issues.
Nigel: Great! Did you have a view on the labels and colours question?
Pierre: Yes, I really liked where
    you and Stefan ended up. I plan to implement something
    ... along the lines of what you have, putting the background
    and rounded corners on the
    ... permitted/deprecated/permitted-deprecated label itself.
Nigel: Looking forward to seeing that.
Pierre: Thank you for doing all
    the prototyping work, that makes it a lot easier.
    ... I plan to address that at the last moment when we are happy
    with the features table.
    ... Can we talk about #366?
github: https://github.com/w3c/imsc/issues/366
Pierre: My impression is that we
    have trained people not to use origin and extent on
    content
    ... elements. Certainly in IMF and ATSC we have trained people
    not to do it.
    ... imsc.js and TTPE and EBU-TT-D does not support it, so in
    fact I think the trend has
    ... been the opposite, that we have reiterated that you cannot
    do it. We have been saying
    ... that for the past 2 years and I'm finally getting to the
    point where I'm not seeing it anymore.
Nigel: Now I really want to make
    sure it is on the at risk list for TTML2 because I really
    ... don't want to support it.
Pierre: Based on my experience in
    imsc.js the feature really breaks the way TTML was
    ... designed. Unless someone stands up to say they really want
    it I don't think we should do it.
Nigel: It is not on the at risk list for TTML2 CR2.
Pierre: TTPE doesn't support it in TTML1, I'm not sure if it supports it in TTML2.
Nigel: Does anyone want to take
    the action to raise an issue to add the
    ... `#region-implied-animation ` to the at risk list for
    TTML2?
Pierre: I think it's reasonable to add it.
Nigel: If we can close this
    meeting early then I'll go ahead and do that.
    ... Going back to the issue you want to only allow position on
    region? Is that only on text profile?
Pierre: The same restrictions on tts:origin should be placed on tts:position, whatever those are.
Nigel: Don't you want position on image?
Pierre: You put it on the region that the image is in.
Nigel: And you only allow one image per region?
Pierre: Correct, just like in IMSC1.
RESOLUTION: We will not support `#region-implied-animation ` in IMSC 1.1.
Nigel: We also have another resolution to do what the issue requests.
RESOLUTION: Apply the same constraints that exist on `tts:origin` to `tts:position`.
github-bot, end topic
action-512?
<trackbot> action-512 -- Pierre-Anthony Lemieux to Raise an issue with css wg requesting support for lineshear -- due 2018-06-21 -- OPEN
<trackbot> https://www.w3.org/AudioVideo/TT/tracker/actions/512
Nigel: The due date is today!
Pierre: Realistically I will not get to this for another two weeks or so.
Nigel: I've updated the due date to 5th July.
Nigel: We've completed our agenda for today, thank you everyone. [adjourns meeting]