Re: {minutes} TTWG Meeting 2016-01-28

Hello all,

We're starting to engage with subtitle program vendors for TTML2 support
and I'm hoping the following features will be preserved as-is to Rec:

initial
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#styling-vocabulary-initial

tts:position
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-position

tts:textEmphasis
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-textEmphasis

tts:ruby
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-ruby

tts:rubyAlign
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-rubyAlign

tts:rubyPosition
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-rubyPosition

tts:rubyReserve (specifically, "outside")
https://rawgit.com/w3c/ttml2/master/spec/ttml2.html?content-type=text/html;charset=utf-8#style-attribute-rubyReserve

If everyone can kindly review, I'd like to collect everyone's opinions on
these.


Cheers, Dae



*Dae Kim | Video Engineer | Encoding Technology*
*9420 94f4 a834 b038 2920 34b3 38ad b632 3738 942c 942f*

On Thu, Jan 28, 2016 at 8:34 AM, Nigel Megitt <nigel.megitt@bbc.co.uk>
wrote:

> Thanks all for attending today's TTWG meeting. Minutes can be found in
> HTML format at https://www.w3.org/2016/01/28-tt-minutes.html
>
> In text format:
>
>    [1]W3C
>
>       [1] http://www.w3.org/
>
>                 Timed Text Working Group Teleconference
>
> 28 Jan 2016
>
>    See also: [2]IRC log
>
>       [2] http://www.w3.org/2016/01/28-tt-irc
>
> Attendees
>
>    Present
>           nigel, andreas, pierre, shinjan, glenn, tmichel, dae
>
>    Regrets
>           frans
>
>    Chair
>           nigel
>
>    Scribe
>           nigel
>
> Contents
>
>      * [3]Topics
>          1. [4]This Meeting
>          2. [5]Action Items
>          3. [6]IMSC issues
>          4. [7]Commit policy on github
>      * [8]Summary of Action Items
>      * [9]Summary of Resolutions
>      __________________________________________________________
>
>    <tmichel> I will be a few minutres late ...
>
>    <scribe> scribe: nigel
>
> This Meeting
>
>    nigel: [Goes through likely topics for meeting]: Actions, IMSC
>    1 issues, TTML2, possibly profiles
>    ... Any specific topics to cover, or AOB?
>
>    pal: IMSC 1 issues please
>
>    nigel: Yes
>
>    glenn: I'd like to discuss commit policy on github
>
>    nigel: Okay
>
> Action Items
>
>    action-453?
>
>    <trackbot> action-453 -- Thierry Michel to Schedule between
>    tmichel and philippe the transition to cr3 with any director
>    call as needed. -- due 2016-01-21 -- PENDINGREVIEW
>
>    <trackbot>
>    [10]http://www.w3.org/AudioVideo/TT/tracker/actions/453
>
>      [10] http://www.w3.org/AudioVideo/TT/tracker/actions/453
>
>    tmichel: IMSC 1 CR3 is published and has been announced to AC
>    and Chairs, and triggered a 2 month patent exclusion
>
>    close action-453
>
>    <trackbot> Closed action-453.
>
>    tmichel: I had to extend the CR exit point to Feb 28 because we
>    moved the publication back by 2 days.
>
>    nigel: Thanks
>
>    pal: I'll modify that on github too - Feb 28?
>
>    tmichel: Feb 28 yes
>
>    nigel: Thanks everyone whose helped with publication of that
>    CR.
>
>    action-454?
>
>    <trackbot> action-454 -- Philippe Le Hégaret to Create stub
>    files to redirect from hg to github for ttml1 and ttml2 -- due
>    2016-01-28 -- PENDINGREVIEW
>
>    <trackbot>
>    [11]http://www.w3.org/AudioVideo/TT/tracker/actions/454
>
>      [11] http://www.w3.org/AudioVideo/TT/tracker/actions/454
>
>    glenn: I noticed on the CR3 that a message was issued, a call
>    for exclusions message. Is a call for exclusions a
>    ... multiple event or a single event? Normally in the past
>    process a call for exclusions only occurred on the first CR
>    ... but not subsequent CRs. Has that changed?
>
>    tmichel: It's actually the com team who does that. I don't
>    remember - I need to check if we sent an exclusion for the
>    ... 2nd CR and will look into it and let you know. My
>    interpretation is every CR publication triggers an exclusion
>    ... period of 2 months, but I will investigate.
>    ... It makes sense because if you add functionality into the CR
>    version then it may result in a patent exclusion.
>
>    glenn: I agree.
>
>    action-454?
>
>    nigel: Okay I guess we'll close this one.
>
>    close action-454
>
>    <trackbot> Closed action-454.
>
>    action-455?
>
>    <trackbot> action-455 -- Glenn Adams to Update ttml2
>    spec/readme to include config for keyword replacement. -- due
>    2016-01-28 -- OPEN
>
>    <trackbot>
>    [12]http://www.w3.org/AudioVideo/TT/tracker/actions/455
>
>      [12] http://www.w3.org/AudioVideo/TT/tracker/actions/455
>
>    action-445?
>
>    <trackbot> action-445 -- Andreas Tai to Propose to mdolan this
>    addition to the profile registry document. -- due 2015-11-06 --
>    OPEN
>
>    <trackbot>
>    [13]http://www.w3.org/AudioVideo/TT/tracker/actions/445
>
>      [13] http://www.w3.org/AudioVideo/TT/tracker/actions/445
>
>    atai: I checked with Mike and will make a proposal for a new
>    column for the profile registry table that shows where
>    ... the profile information can be found inside the TTML
>    document instance for the corresponding TTML profile
>    specification.
>    ... Some are for ttp:profile attribute, or element, or
>    ebuttm:documentConformsToStandard element.
>
>    mike: Andreas and I exchanged a couple of emails and it makes
>    sense to me.
>    ... I'm hopelessly behind on the profile document!
>
>    nigel: What can I do to help?
>
>    mike: The wiki is what I think we want to produce, in the text.
>    It's more about putting it into a document template
>    ... and using the tools to publish it in W3C.
>
>    nigel: Thierry, would you be able to assist?
>
>    tmichel: Yes, I'd be happy to help turn the wiki text into a
>    first version on github
>
>    action-429?
>
>    <trackbot> action-429 -- Mike Dolan to Draft a wg note for the
>    profile short name registry and ttml media type registration --
>    due 2015-10-08 -- OPEN
>
>    <trackbot>
>    [14]http://www.w3.org/AudioVideo/TT/tracker/actions/429
>
>      [14] http://www.w3.org/AudioVideo/TT/tracker/actions/429
>
>    action-429: [TTWG meeting 2016-01-28] tmichel to help this
>    along with a first draft on github
>
>    <trackbot> Notes added to action-429 Draft a wg note for the
>    profile short name registry and ttml media type registration.
>
>    close action-445
>
>    <trackbot> Closed action-445.
>
> IMSC issues
>
>    pal: I'd like to start with issue #127
>
>    [15]https://github.com/w3c/imsc/issues/127
>
>      [15] https://github.com/w3c/imsc/issues/127
>
>    nigel: Extensibility goals not documented
>
>    pal: The discussion is whether or how IMSC 1 can have an
>    opinion on IMSC 2 and how an IMSC 1 document will be
>    ... processed by an IMSC 2 processor and vice versa. Before we
>    have started on IMSC 2 it is very difficult to have a
>    ... good opinion. I think we should have that discussion when
>    we start on IMSC 2.
>
>    glenn: The issue here is whether we address this in IMSC 1 or
>    wait. I'm insisting on addressing it in IMSC 1 and not
>    ... waiting. I agree that it needs a bit of thinking. We don't
>    have to refer to IMSC 2, we can simply refer to future
>    ... versions. At least TTML2 talks about future and past
>    versions.
>    ... In retrospect we should have given more thought to
>    extensibility and at least documented our goals. I'm asking
>    ... for informative material that describes our goals. It would
>    be a sad state of affairs if we cannot document our goals now.
>
>    pal: I don't think this is as dire as you just painted it. IMSC
>    1 already allows foreign vocabulary, which allows for
>    ... straightforward extensibility.
>
>    glenn: It may be sufficient to describe those goals, for
>    example the goal of supporting vocabulary not in IMSC 1.
>
>    pal: That's §6.2
>
>    glenn: I'm asking for a specifically labelled section on goals,
>    in an annex, the introduction or somewhere else.
>
>    pal: Okay. I don't really know how to write that section. I'd
>    like to consider a concrete proposal.
>
>    glenn: I hope people already have goals in mind and could
>    articulate them.
>    ... Foreign vocabulary is one goal. The same comments are going
>    to apply with #126 on interoperability.
>
>    nigel: [opens up to group to offer options for extensibility]
>
>    glenn: Both forward and backward compatibility come into this
>    category. I would hope that a goal is to be as
>    ... forward and backward compatible as possible, as a generic
>    goal that applies to most of W3C development.
>    ... That doesn't mean it's not possible to create a breaking
>    change in the future. If we think that such a breaking change
>    ... could occur then we could document it as a discussion
>    point.
>
>    nigel: One of the points I think is probably implied is that
>    the purpose of the profile exercise is that extensions from
>    within TTML are excluded unless listed.
>
>    glenn: Since we don't list all the features there's an
>    implication that unlisted features from TTML 1 are permissible
>    in IMSC 1, yes?
>
>    pal: We put a significant effort in to list all TTML 1 profile
>    features.
>
>    glenn: Okay, so all features from TTML Annex D are listed as
>    prohibited or permitted, yes?
>
>    pal: Yes, that was the goal, and I think we achieved it.
>
>    glenn: We could argue about if that's extensibility or
>    interoperability, but it is possibly both, so we could discuss
>    that under extensibility goals.
>    ... I suggest we open this up for comments over the next couple
>    of weeks and that I will draft a proposal based on that.
>
>    nigel: Those comments should be on the github issue
>
>    pal: What are we asking people to do?
>
>    glenn: Give us opinions on what are and are not extensibility
>    goals.
>    ... I haven't written down my own thoughts on this yet. I'm
>    more struck by the absence of this topic than anything else.
>    That was my point in filing the issue.
>    ... I'm prepared to draft something but can't articulate my own
>    thinking on this right now.
>
>    nigel: I think we should be careful to understand if we need
>    this or if we can build on something already in TTML1
>    ... by inheritance?
>
>    glenn: I don't think we have extensibility goals described in
>    TTML1
>    ... which in retrospect we should have put in.
>    ... In TTML1 we used a QA guideline checklist. One of the
>    points there was a set of good practices. Number 18
>    ... states that if extensibility is allowed define an extension
>    mechanism.
>    ... I suggest we review what's in IMSC 1 and TTML 1 and go from
>    there.
>
>    nigel: Okay so action on everyone to complete this research and
>    record their goals in the issue.
>
>    glenn: Very much the same comments apply to the
>    interoperability issue.
>
>    pal: What's the time box that we have on this?
>
>    glenn: I can respond by mid-Feb with some material.
>
>    nigel: Okay, that sounds like 2 weeks to note extensibility and
>    interoperability goals in the github issues.
>
>    pal: How are we doing on #111 and #114?
>
>    glenn: I've got to draft some material based on a conversation
>    I had with Nigel, where we think we may be able to resolve both
>    of those.
>    ... Mid-Feb is reasonable for those too.
>
>    pal: #125 [16]https://github.com/w3c/imsc/issues/125 Unable to
>    normatively determine non-conformance when testing content
>    constraints.
>
>      [16] https://github.com/w3c/imsc/issues/125
>
>    glenn: At present IMSC 1 specifies that if a document is not
>    conformant then behaviour is undefined. Correct?
>
>    pal: Correct. The document does not specify a normative
>    behaviour in the presence of a non-conformant document.
>
>    glenn: A couple of points: 1. Since all behaviour re
>    non-conformance is unspecified then it is impossible to
>    normatively
>    ... test non-conformance because any outcome is possible, from
>    aborting to ignoring and anything in between.
>    ... I'm not happy with that state of affairs. Part 2, which I
>    did make a proposal for, is to introduce the concept of a
>    ... validating processor and to allow for some normative
>    behaviour in the face of non-conformance if and when the
>    ... IMSC processor is also a validating processor. So an IMSC
>    transformation or validation processor that also supports
>    ... validation and it is enabled then it is possible to define
>    some constraints on non-conformance.
>
>    atai: I thought the conclusion here from previous meetings when
>    we discussed this is that handling of non-conformant
>    ... files is out of spec and I agree with that. What Glenn
>    wants to define is behaviour on encountering non-conformant
>    documents.
>    ... I think that's out of scope of the spec. The topic came up
>    before and from what I read of the minutes the conclusion
>    ... was out of scope.
>
>    pal: That's my recollection, but it sounds like Glenn is
>    proposing something a little narrower, only for validating
>    processors.
>    ... So for those who choose to describe processors as
>    validating then this is the behaviour.
>
>    glenn: That's right. I don't disagree with Andreas but I think
>    we can do better than that at little or no cost to the
>    specification.
>    ... For example the TTT toolset has a presentation engine in
>    it. It performs validation processing as a precursor to
>    ... presentation. It's an existing implementation (also of a
>    transformation processor) that does implement the optional
>    ... features of validation. So we can go further than saying
>    it's completely out of scope and having normative
>    ... language that allows us to introduce defined behaviour.
>
>    pal: The particular thing here is that it's a class of
>    processors described as validating processors.
>
>    glenn: Yes, TTML2 introduces these all formally along with some
>    specific vocabulary for controlling it. I didn't want
>    ... to inject that into this proposal because that would be
>    going too far, but I took the semantics of what we're
>    ... proposing and put them into a form that we could adopt in
>    IMSC 1.
>
>    atai: Thank you for the clarification. It is of course a
>    different use case. I would like to see the concrete proposal.
>    ... There are of course existing possibilities to check
>    conformance, for example using an XML schema. This already
>    ... has a defined behaviour for how to identify
>    non-conformance. I'm not sure if we should also define
>    behaviour for
>    ... QC processes of TTML.
>
>    glenn: Take a look at #125 because there is a proposed set of
>    language there.
>
> Commit policy on github
>
>    glenn: There are two kinds of policies that are commonly used
>    in development - Review Then Commit, when a
>    ... consensus approval is obtained prior to a commit. Then
>    there's Commit Then Review, which allows a
>    ... retroactive veto. In the history of this group all of the
>    work on TTML1 and TTML2 in Mercurial and CVS was done
>    ... on a Commit Then Review (CTR) lazy consensus process. It
>    was based on the editor to decide when to commit
>    ... and then notify the group and make sure that they had log
>    info to give them a chance to review post facto and
>    ... object if necessary. Most teams follow a CTR process
>    because it provides the least barriers to making changes.
>    ... It can result in more bugs potentially. My experience is
>    I've worked with both kinds of processes. With github
>    ... which has a Pull Request mechanism it is possible to
>    snapshot the changes and call them out for review. We
>    ... discussed and agreed the move to github in Sapporo and
>    talked about the review process but I don't recall doing
>    ... so in depth. At the time I remember thinking it should be
>    up to the Editor to decide how to use that facility. I never
>    ... anticipated changing from CTR to RTC. Recently both Nigel
>    and Pierre have in the context of IMSC 1 been following
>    ... a RTC process in their thinking. I would object to that for
>    TTML2. I might be willing to agree to it for other work.
>    ... I find it a strong barrier to process. For example right
>    now I have 4 different issues that Pierre has delegated to me
>    ... to create PRs. All of those fixes are going to change the
>    same lines of code.
>
>    pal: I think there's a misunderstanding - you can create a PR
>    that covers multiple issues, and we've done that in the
>    ... past.
>
>    glenn: I agree that's possible.
>
>    nigel: github also provides a tool for merging work in other
>    branches to resolve the clashes.
>
>    glenn: I agree there are tools there but it's much more awkward
>    and difficult to do that. My basic point is that
>    ... we don't have a firm consensus on CTR or RTC as a policy.
>    Secondly even if we are using RTC on e.g. IMSC 1 I don't
>    ... think it should be a blanket policy but up to the Editor to
>    decide what policy to use. For trivial changes there's
>    ... no reason to follow the more time consuming process.
>
>    atai: I think we should check again what we discussed at TPAC.
>    I think we explicitly had some discussion about the
>    ... new policy with github and I thought we agreed but I'm not
>    sure.
>
>    nigel: We did discuss this in Sapporo and I'm pretty sure we
>    did agree that. For WDs we always followed a RTC process
>    ... and said that to reduce the time between ED updates and WD
>    publications and to use the automated WD publication
>    ... tool we would use PRs.
>
>    glenn: I do recall saying that I wouldn't be happy to adopt
>    this for TTML2.
>
>    nigel: I'm happy to review the notes on this and return to it
>    as a topic. In the meantime I would also like plh's views
>    ... and I would myself strongly recommend that we use pull
>    requests for everything including TTML2.
>
>    glenn: I don't mind using pull requests but I object to a 2
>    week period before a merge is permitted.
>    ... I think it should be up to the Editor or possibly the Chair
>    to decide to merge if a change is non controversial and
>    ... not to impose a 2 week delay on all PRs.
>
>    nigel: That's coincident with what we said in Sapporo. There
>    may be a middle ground there that is actually acceptable.
>
>    glenn and pal: [discussion without conclusion on who should be
>    allowed to merge pull requests]
>
>    nigel: We're out of time now so I'll adjourn. An hour again,
>    same time next week. Thanks everyone [adjourns meeting]
>
> Summary of Action Items
>
> Summary of Resolutions
>
>    [End of minutes]
>      __________________________________________________________
>
>
>     Minutes formatted by David Booth's [17]scribe.perl version
>     1.144 ([18]CVS log)
>     $Date: 2016/01/28 16:33:11 $
>
>      [17] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
>      [18] http://dev.w3.org/cvsweb/2002/scribe/
>
>
>
>
>
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