Re: Objections to TPAC resolutions on IMSC1.1

Hi Glenn,

David's exact words were:  "Netflix has proposed adding [IMSC1
extension definitions] to TTML2 with no modifications."

Do you agree with this proposal?

Best,

-- Pierre

On Mon, Nov 27, 2017 at 9:56 PM, Glenn Adams <glenn@skynav.com> wrote:
> I support the position laid out in Cyril's email, namely, TTML2 gets (in
> existing TTML namespaces)
>
> ttp:activeArea
> ttp:displayAspectRatio
> tts:fillLineGap
> tts:forcedDisplay
> tts:linePadding
> tts:multi[Row?]Align
>
> We ensure semantics are equivalent.
>
> I write tts:multi[Row?]Align because I would prefer tts:multiAlign since the
> term "Row" is semantically inaccurate; however, I would be willing to
> concede this point if others insist.
>
> Note that, as Cyril has outlined, there are syntactic modifications, so you
> should probably stop repeating the mantra "no modifications".
>
>
> On Mon, Nov 27, 2017 at 10:17 PM, Pierre-Anthony Lemieux <pal@sandflow.com>
> wrote:
>>
>> Hi Glenn,
>>
>> > > Netflix has proposed adding [IMSC1 extension definitions] to TTML2
>> > > with no modifications
>>
>> Do you remain opposed to this approach?
>>
>> Best,
>>
>> -- Pierre
>>
>> On Mon, Nov 27, 2017 at 6:04 PM, David Ronca <dronca@netflix.com> wrote:
>> >
>> >
>> > On Mon, Nov 27, 2017 at 3:34 PM, Pierre-Anthony Lemieux
>> > <pal@sandflow.com>
>> > wrote:
>> >>
>> >> Hi David,
>> >>
>> >> Thanks for sharing your thoughts.
>> >>
>> >> > Netflix has proposed adding them to TTML2 with no modifications
>> >>
>> >> At least participant indicated he would strongly object to this
>> >> approach during the F2F.
>> >
>> > Then we need to get the objections and specific concerns on the table so
>> > we
>> > can have a discussion towards resolution.
>> >>
>> >>
>> >> > This is exactly what we have proposed.
>> >>
>> >> In the case of itts:forcedDisplay, the changes proposed by Netflix are
>> >> drastic in syntax.
>> >
>> >
>> > Setting aside itts:forcedDisplay for the moment, what about
>> > ittp:ActiveArea,
>> > ittp:aspectRatio, itts:fillLineGap, and ebutts:multiRowAlign? These are
>> > not
>> > significant technical issues, assuming that TTML2 is updated to support
>> > the
>> > equivalents.
>> >
>> >>
>> >> > We believe that it is better to define the equivalent
>> >> > tts:multiRowAlign
>> >> > in TTML2 rather than reference the EBU spec.
>> >>
>> >> Can you expand on why Netflix believes it is better? This may help
>> >> folks change their position.
>> >
>> > Because we will have a single upper spec, TTML2, for which we profile
>> > down
>> > to a manageable subset for IMSC1.1.  That is a clean model.  Referring
>> > to
>> > EBU-TT for a single feature seems unnecessary.
>> >>
>> >>
>> >> Best,
>> >>
>> >> -- Pierre
>> >>
>> >> On Mon, Nov 27, 2017 at 3:24 PM, David Ronca <dronca@netflix.com>
>> >> wrote:
>> >> > Andreas Tai wrote:
>> >> >> We found resolutions in the f2f meeting on 2017-11-09 and 2017-11-10
>> >> >> based
>> >> >> on the consensus principle. These resolutions represent
>> >> >> already a compromise. With the formal objections we are now back to
>> >> >> zero
>> >> >> and need now come again to resolution by the
>> >> >> consensus principle in our next meetings.
>> >> >
>> >> > The F2F established an IMSC1 baseline; a reference point for the next
>> >> > round
>> >> > of discussion.  We have moved that forward with our objections, that
>> >> > were
>> >> > accompanied with specific recommendations for the spec.  We are not
>> >> > back
>> >> > to
>> >> > zero.  We now have a very specific set of issues and proposals that
>> >> > can
>> >> > be
>> >> > discussed.  If we can work through our concerns, then we will have a
>> >> > strong
>> >> > consensus.
>> >> >
>> >> > Pierre wrote:
>> >> >> for any IMSC 1.0.1 extension adopted by TTML2, semantics and syntax
>> >> >> should be modified as little as possible to avoid additional
>> >> >> testing,
>> >> >> training and unintended divergence
>> >> >
>> >> > This is exactly what we have proposed.  For the 4 IMSC features that
>> >> > are
>> >> > not
>> >> > currently covered by TTML2, Netflix has proposed adding them to TTML2
>> >> > with
>> >> > no modifications, and we have also volunteered to take on this work.
>> >> >
>> >> >> working with EBU to integrate features such as ebutts:multiRowAlign
>> >> >> in TTML2 is an opportunity to coordinate with an important adopter
>> >> >> of
>> >> >> TTML, and reduce the potential for divergence.
>> >> >
>> >> > We believe that it is better to define the equivalent
>> >> > tts:multiRowAlign
>> >> > in
>> >> > TTML2 rather than reference the EBU spec.
>> >> >
>> >> >> organizations that have recently adopted IMSC1 might lose confidence
>> >> >> with the TTWG process if IMSC 1.1 deprecates all IMSC1 extensions
>> >> >> and
>> >> >> replaces them with substantially different alternatives
>> >> > Netflix is such an organization, having recently adopted IMSC1.  I
>> >> > also
>> >> > expect that we currently have the largest IMSC1 asset library.  We
>> >> > don't
>> >> > take these changes lightly, but do so looking forward.  The real
>> >> > implication
>> >> > of deprecated features is that at some point in the future, in some
>> >> > future
>> >> > version of the spec, the deprecated features will no longer be
>> >> > supported
>> >> > in
>> >> > that version of the spec.  IMSC1.01 processors will exist for as long
>> >> > as
>> >> > there is a business case for them, and the translation from IMSC1 to
>> >> > an
>> >> > IMSC
>> >> > 1.1 that is fully a TTML2 subset is trivial.  Lastly, feature
>> >> > deprecation is
>> >> > a normal part of technology development, and certainly not new to
>> >> > W3C.
>> >> >
>> >> > On Mon, Nov 27, 2017 at 11:09 AM, Glenn Adams <glenn@skynav.com>
>> >> > wrote:
>> >> >>
>> >> >>
>> >> >>
>> >> >> On Mon, Nov 27, 2017 at 11:59 AM, Pierre-Anthony Lemieux
>> >> >> <pal@sandflow.com> wrote:
>> >> >>>
>> >> >>> Hi all,
>> >> >>>
>> >> >>> >> - IMSC1 has been adopted and deployed for interchange between
>> >> >>> >> multiple
>> >> >>> >> parties, whereas TTML2 has not
>> >> >>> > False.
>> >> >>>
>> >> >>> IMSC1 is a REC, which is referenced by multiple specifications,
>> >> >>> including ISO/IEC 23000-19, SMPTE ST 2067-2, ATSC A/343, and DVB
>> >> >>> A174.
>> >> >>>
>> >> >>> IMSC 1.0.1 is a Candidate Recommendation.
>> >> >>>
>> >> >>> TTML2 is a Working Draft.
>> >> >>>
>> >> >>> > But this has been the plan all along, so such organizations are
>> >> >>> > either
>> >> >>> > misinformed or not following the work of the TTWG.
>> >> >>>
>> >> >>> For TTML2 to be successful, TTWG needs to satisfy user needs, not
>> >> >>> its
>> >> >>> parochial interests.
>> >> >>>
>> >> >>> > Any resolution is subject to a period of at least two weeks to
>> >> >>> > obtain
>> >> >>> > confirmation from member organizations.
>> >> >>>
>> >> >>> I am not disputing the right for members to object to a resolution.
>> >> >>> I
>> >> >>> am disputing the assertion that "I cannot recall any formal
>> >> >>> objection
>> >> >>> to the synonym/alias proposal requested by Netflix". This assertion
>> >> >>> cannot be true since there was no opportunity for formal objection
>> >> >>> at
>> >> >>> TPAC since there was consensus on the resolution.
>> >> >>
>> >> >>
>> >> >> I do not agree. There was not a consensus, since we explicitly noted
>> >> >> at
>> >> >> the time that an opportunity must be given members to consider the
>> >> >> matter
>> >> >> (and that they had 2 weeks to object).
>> >> >>
>> >> >> A consensus does not exist.
>> >> >>
>> >> >>>
>> >> >>>
>> >> >>> Best,
>> >> >>>
>> >> >>> -- Pierre
>> >> >>>
>> >> >>> On Mon, Nov 27, 2017 at 10:45 AM, Glenn Adams <glenn@skynav.com>
>> >> >>> wrote:
>> >> >>> >
>> >> >>> >
>> >> >>> > On Mon, Nov 27, 2017 at 11:03 AM, Pierre-Anthony Lemieux
>> >> >>> > <pal@sandflow.com>
>> >> >>> > wrote:
>> >> >>> >>
>> >> >>> >> Hi Nigel et al.,
>> >> >>> >>
>> >> >>> >> I do not believe it is possible to fully capture the interactive
>> >> >>> >> and
>> >> >>> >> in-person discussions that led to the consensus resolution
>> >> >>> >> adopted
>> >> >>> >> at
>> >> >>> >> TPAC. Nevertheless, based on my notes, below is additional
>> >> >>> >> information
>> >> >>> >> that was shared by at least one member (not necessarily me)
>> >> >>> >> during
>> >> >>> >> these discussions:
>> >> >>> >>
>> >> >>> >> - for any IMSC 1.0.1 extension adopted by TTML2, semantics and
>> >> >>> >> syntax
>> >> >>> >> should be modified as little as possible to avoid additional
>> >> >>> >> testing,
>> >> >>> >> training and unintended divergence
>> >> >>> >
>> >> >>> >
>> >> >>> > We are not considering the adoption of non-TTML features in
>> >> >>> > TTML2.
>> >> >>> > We
>> >> >>> > are
>> >> >>> > defining core functionality that we have been discussing for some
>> >> >>> > time
>> >> >>> > now,
>> >> >>> > before the creation of either IMSC1 or IMSC1.0.1. Nevertheless,
>> >> >>> > there
>> >> >>> > is a
>> >> >>> > general agreement that common features should have similar
>> >> >>> > semantics.
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> - given the objective of aligning TTML and CSS, TTML2 can delay
>> >> >>> >> adoption of features in its namespace for which there is no CSS
>> >> >>> >> equivalent but for which industry extensions exist, e.g.
>> >> >>> >> ebutts:linePadding,
>> >> >>> >
>> >> >>> >
>> >> >>> > Given that such an addition to CSS would require years to obtain
>> >> >>> > in
>> >> >>> > a
>> >> >>> > REC,
>> >> >>> > it is entirely impractical to use this rationale with TTML2 (and
>> >> >>> > probably
>> >> >>> > TTML3).
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> - organizations that have recently adopted IMSC1 might lose
>> >> >>> >> confidence
>> >> >>> >> with the TTWG process if IMSC 1.1 deprecates all IMSC1
>> >> >>> >> extensions
>> >> >>> >> and
>> >> >>> >> replaces them with substantially different alternatives
>> >> >>> >
>> >> >>> >
>> >> >>> > But this has been the plan all along, so such organizations are
>> >> >>> > either
>> >> >>> > misinformed or not following the work of the TTWG.
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> - IMSC1 has been adopted and deployed for interchange between
>> >> >>> >> multiple
>> >> >>> >> parties, whereas TTML2 has not
>> >> >>> >
>> >> >>> >
>> >> >>> > False.
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> - working with EBU to integrate features such as
>> >> >>> >> ebutts:multiRowAlign
>> >> >>> >> in TTML2 is an opportunity to coordinate with an important
>> >> >>> >> adopter
>> >> >>> >> of
>> >> >>> >> TTML, and reduce the potential for divergence.
>> >> >>> >
>> >> >>> >
>> >> >>> > Adopting non-TTML vocabulary is contrary to the original
>> >> >>> > requirements
>> >> >>> > documented by TTAF1 for use in TTML.
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> > Given that I cannot recall any formal objection to the
>> >> >>> >> > synonym/alias
>> >> >>> >> > proposal requested by Netflix,
>> >> >>> >>
>> >> >>> >> There was no opportunity to raise formal objections during the
>> >> >>> >> TPAC
>> >> >>> >> meeting since the resolution was adopted by consensus.
>> >> >>> >
>> >> >>> >
>> >> >>> > Any resolution is subject to a period of at least two weeks to
>> >> >>> > obtain
>> >> >>> > confirmation from member organizations.
>> >> >>> >
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> Best,
>> >> >>> >>
>> >> >>> >> -- Pierre
>> >> >>> >>
>> >> >>> >> On Fri, Nov 24, 2017 at 9:13 AM, Nigel Megitt
>> >> >>> >> <nigel.megitt@bbc.co.uk>
>> >> >>> >> wrote:
>> >> >>> >> > All,
>> >> >>> >> >
>> >> >>> >> > This is a situation in which we do not currently seem to have
>> >> >>> >> > consensus.
>> >> >>> >> > It
>> >> >>> >> > appears that two camps exist, with mutually incompatible
>> >> >>> >> > visions
>> >> >>> >> > for
>> >> >>> >> > how
>> >> >>> >> > the
>> >> >>> >> > IMSC 1.1 and TTML2 specifications should incorporate some
>> >> >>> >> > features.
>> >> >>> >> >
>> >> >>> >> > Be reminded that W3C consensus means we have to find a
>> >> >>> >> > solution
>> >> >>> >> > that
>> >> >>> >> > everyone can accept, even though it might not be the one that
>> >> >>> >> > everyone
>> >> >>> >> > thinks is the best alternative.
>> >> >>> >> >
>> >> >>> >> > To summarise the technical issue as I understand it:
>> >> >>> >> >
>> >> >>> >> > * IMSC 1.0.1 includes extensions not in TTML1, defined using
>> >> >>> >> > syntax
>> >> >>> >> > in
>> >> >>> >> > namespaces not defined by TTML1
>> >> >>> >> > * We want to support the requirements met by those extensions
>> >> >>> >> > in
>> >> >>> >> > IMSC
>> >> >>> >> > 1.1
>> >> >>> >> > * We want to support the requirements met by those extensions
>> >> >>> >> > in
>> >> >>> >> > TTML2
>> >> >>> >> > * We want IMSC 1.1 to be a subset of TTML2 – there are varying
>> >> >>> >> > degrees
>> >> >>> >> > of
>> >> >>> >> > strength about this amongst the group members, i.e. some want
>> >> >>> >> > all
>> >> >>> >> > non-TTML2
>> >> >>> >> > features to be deprecated, others are happy to continue with
>> >> >>> >> > non-deprecated
>> >> >>> >> > extensions.
>> >> >>> >> > * It is important to some (maybe all) members that IMSC 1.1
>> >> >>> >> > processors
>> >> >>> >> > be
>> >> >>> >> > able to process IMSC 1.0.1 documents
>> >> >>> >> > * We discussed but rejected creating an IMSC 2 that is a pure
>> >> >>> >> > subset
>> >> >>> >> > of
>> >> >>> >> > TTML2 and does not natively support IMSC 1.0.1
>> >> >>> >> > * It is important to some (but not all) members that TTML2
>> >> >>> >> > defines
>> >> >>> >> > all
>> >> >>> >> > features in its own namespace
>> >> >>> >> > * The idea of adopting extensions into TTML2 and making them
>> >> >>> >> > features
>> >> >>> >> > with
>> >> >>> >> > no change to their existing namespace was discussed but not
>> >> >>> >> > adopted.
>> >> >>> >> > There
>> >> >>> >> > was a formal objection on the grounds that all TTML features
>> >> >>> >> > must
>> >> >>> >> > be
>> >> >>> >> > defined
>> >> >>> >> > in the TTML namespace. There was also a process point that we
>> >> >>> >> > would
>> >> >>> >> > need
>> >> >>> >> > to
>> >> >>> >> > seek permission from EBU for inclusion of EBU namespace
>> >> >>> >> > extensions.
>> >> >>> >> >
>> >> >>> >> > During the TPAC 2017 face to face meeting (minutes) we
>> >> >>> >> > resolved
>> >> >>> >> > one
>> >> >>> >> > of
>> >> >>> >> > two
>> >> >>> >> > approaches for each feature:
>> >> >>> >> >
>> >> >>> >> > 1. In TTML2: include a new feature in a TTML namespace. In
>> >> >>> >> > IMSC
>> >> >>> >> > 1.1:
>> >> >>> >> > deprecate the IMSC 1.0.1 extension AND include the TTML2
>> >> >>> >> > feature
>> >> >>> >> > AND
>> >> >>> >> > provide
>> >> >>> >> > a mapping from the deprecated extension to the new feature.
>> >> >>> >> > 2. In TTML2: do not include a new feature. In IMSC 1.1:
>> >> >>> >> > include
>> >> >>> >> > the
>> >> >>> >> > IMSC
>> >> >>> >> > 1.0.1 extension.
>> >> >>> >> >
>> >> >>> >> > Netflix has objected to some of those resolutions within the
>> >> >>> >> > WG's
>> >> >>> >> > review
>> >> >>> >> > period defined under the Decision Policy in the Charter. I
>> >> >>> >> > have
>> >> >>> >> > received
>> >> >>> >> > no
>> >> >>> >> > other objections within that period (which expires at the end
>> >> >>> >> > of
>> >> >>> >> > the
>> >> >>> >> > working
>> >> >>> >> > day today, California time). I have updated and where
>> >> >>> >> > necessary
>> >> >>> >> > reopened
>> >> >>> >> > the
>> >> >>> >> > relevant GitHub issues indicating the objection.
>> >> >>> >> >
>> >> >>> >> > * The idea of synonyms or aliases was raised (disclosure: by
>> >> >>> >> > me),
>> >> >>> >> > discussed
>> >> >>> >> > but not adopted, i.e. TTML namespace syntax for features where
>> >> >>> >> > each
>> >> >>> >> > feature
>> >> >>> >> > is a functional equivalent or superset of an IMSC 1.0.1
>> >> >>> >> > extension,
>> >> >>> >> > and
>> >> >>> >> > both
>> >> >>> >> > may be supported in IMSC 1.1 with a mapping to the canonical
>> >> >>> >> > TTML2
>> >> >>> >> > equivalent. The synonym may additionally be noted
>> >> >>> >> > informatively
>> >> >>> >> > in
>> >> >>> >> > TTML2.
>> >> >>> >> > The key negative point was that it would encourage the use of
>> >> >>> >> > both
>> >> >>> >> > sets
>> >> >>> >> > of
>> >> >>> >> > syntax in many documents with no clear end point to the
>> >> >>> >> > practice
>> >> >>> >> > and
>> >> >>> >> > no
>> >> >>> >> > practical benefit. However I cannot recall any formal
>> >> >>> >> > objection,
>> >> >>> >> > nor
>> >> >>> >> > find
>> >> >>> >> > one in the minutes.
>> >> >>> >> >
>> >> >>> >> > The Netflix objection essentially requests that this latter
>> >> >>> >> > model
>> >> >>> >> > be
>> >> >>> >> > adopted, whilst deprecating the IMSC 1.0.1 extensions.
>> >> >>> >> >
>> >> >>> >> > Given that I cannot recall any formal objection to the
>> >> >>> >> > synonym/alias
>> >> >>> >> > proposal requested by Netflix, I'd like to check if we
>> >> >>> >> > actually
>> >> >>> >> > have
>> >> >>> >> > consensus to adopt it already, i.e. if despite it not being
>> >> >>> >> > everyone's
>> >> >>> >> > favourite option, it is something that everyone can
>> >> >>> >> > nevertheless
>> >> >>> >> > live
>> >> >>> >> > with.
>> >> >>> >> >
>> >> >>> >> > Does anyone object to any of the Netflix proposals? If so,
>> >> >>> >> > please
>> >> >>> >> > be
>> >> >>> >> > specific about the nature of the objection. This will help us
>> >> >>> >> > to
>> >> >>> >> > construct
>> >> >>> >> > new proposals.
>> >> >>> >> >
>> >> >>> >> > This topic will be on the agenda for next week's call
>> >> >>> >> > (November
>> >> >>> >> > 30th),
>> >> >>> >> > but
>> >> >>> >> > if possible I would like to have a sense of the conclusion or
>> >> >>> >> > any
>> >> >>> >> > as
>> >> >>> >> > yet
>> >> >>> >> > unraised concerns before the meeting. If anyone would like a
>> >> >>> >> > call
>> >> >>> >> > with
>> >> >>> >> > me or
>> >> >>> >> > others to discuss this informally ahead of the meeting, I am
>> >> >>> >> > happy
>> >> >>> >> > to
>> >> >>> >> > support that, and can be available on Monday 1600-1700 UK
>> >> >>> >> > time,
>> >> >>> >> > Tuesday
>> >> >>> >> > 1630-1730 UK time or Wednesday 1500-1730 UK time.
>> >> >>> >> >
>> >> >>> >> > Nigel
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > From: Cyril Concolato <cconcolato@netflix.com>
>> >> >>> >> > Date: Wednesday, 15 November 2017 at 18:55
>> >> >>> >> > To: TTWG <public-tt@w3.org>
>> >> >>> >> > Subject: Objections to TPAC resolutions on IMSC1.1
>> >> >>> >> > Resent-From: <public-tt@w3.org>
>> >> >>> >> > Resent-Date: Wednesday, 15 November 2017 at 18:56
>> >> >>> >> >
>> >> >>> >> > Dear TTWG experts,
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > Following TPAC, Netflix would like to inform the group that it
>> >> >>> >> > is
>> >> >>> >> > not
>> >> >>> >> > satisfied with some of the resolutions regarding IMSC1.1 and
>> >> >>> >> > objects
>> >> >>> >> > to
>> >> >>> >> > them. Netflix thinks that two important goals must be
>> >> >>> >> > satisfied
>> >> >>> >> > in
>> >> >>> >> > defining
>> >> >>> >> > TTML2 and IMSC1.1:
>> >> >>> >> >
>> >> >>> >> > - IMSC1.1 must be a strict-subset of TTML2, aside from
>> >> >>> >> > deprecated
>> >> >>> >> > features.
>> >> >>> >> > We believe it is bad practice for W3C to define two TTML-based
>> >> >>> >> > standards, at
>> >> >>> >> > the same time, which are not compatible with each other.
>> >> >>> >> >
>> >> >>> >> > - TTML2 must limit its normative references to Web Platform
>> >> >>> >> > standards.
>> >> >>> >> > We
>> >> >>> >> > believe it is bad practice to have to compile multiple sources
>> >> >>> >> > of
>> >> >>> >> > information outside of the Web Platform to implement the
>> >> >>> >> > standard.
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > Netflix asks for the following actions:
>> >> >>> >> >
>> >> >>> >> > a) Marking ittp:activeArea deprecated in IMSC1.1, using a
>> >> >>> >> > reference
>> >> >>> >> > to
>> >> >>> >> > IMSC1.0.1 and no definition in IMSC1.1, in favor of
>> >> >>> >> > ttp:activeArea,
>> >> >>> >> > restricted to using two-component values such that
>> >> >>> >> > ttp:activeArea
>> >> >>> >> > can be
>> >> >>> >> > used to do no more than IMSC1.0.1 ittp:activeArea.
>> >> >>> >> >
>> >> >>> >> > b) Marking ittp:aspectRatio deprecated in IMSC1.1, using a
>> >> >>> >> > reference
>> >> >>> >> > to
>> >> >>> >> > IMSC1.0.1 and no definition in IMSC1.1, in favor of
>> >> >>> >> > ttp:displayAspectRatio.
>> >> >>> >> > There does not seem to be a need for restricting
>> >> >>> >> > ttp:displayAspectRatio.
>> >> >>> >> >
>> >> >>> >> > c) Marking itts:forcedDisplay deprecated in IMSC1.1, using a
>> >> >>> >> > reference
>> >> >>> >> > to
>> >> >>> >> > IMSC1.0.1 and no definition in IMSC1.1, in favor of a
>> >> >>> >> > combination
>> >> >>> >> > of
>> >> >>> >> > 'condition' and 'tts:visibility', with the appropriate
>> >> >>> >> > restrictions
>> >> >>> >> > on
>> >> >>> >> > condition such that it remains simple to implement, while at
>> >> >>> >> > the
>> >> >>> >> > same
>> >> >>> >> > time
>> >> >>> >> > offering more flexibility than forcedDisplay.
>> >> >>> >> >
>> >> >>> >> > d) Adding the definitions of itts:fillLineGap,
>> >> >>> >> > ebutts:linePadding
>> >> >>> >> > and
>> >> >>> >> > ebutts:multiRowAlign to TTML2, with no change to the
>> >> >>> >> > semantics,
>> >> >>> >> > but
>> >> >>> >> > in
>> >> >>> >> > the
>> >> >>> >> > TTML namespace; and marking the itts/ebutts version as
>> >> >>> >> > deprecated
>> >> >>> >> > in
>> >> >>> >> > IMSC1.1.
>> >> >>> >> >
>> >> >>> >> > e) IMSC1.1 should indicate that when TTML2 features are used
>> >> >>> >> > in
>> >> >>> >> > the
>> >> >>> >> > same
>> >> >>> >> > document at the same time as their non-TTML2 equivalent and
>> >> >>> >> > deprecated
>> >> >>> >> > features, the TTML2 features prevail. This insures that future
>> >> >>> >> > versions
>> >> >>> >> > of
>> >> >>> >> > IMSC can effectively remove the features marked as deprecated.
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > Netflix believes that this approach provides clearly designed,
>> >> >>> >> > forward
>> >> >>> >> > looking standards, reducing the complexity of the TTML
>> >> >>> >> > ecosystem.
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > Netflix is aware that this requires an effort of the TTML
>> >> >>> >> > community
>> >> >>> >> > as
>> >> >>> >> > follows:
>> >> >>> >> >
>> >> >>> >> > - IMSC1.0.1 renderers do not need to be updated, unless they
>> >> >>> >> > need
>> >> >>> >> > to
>> >> >>> >> > support
>> >> >>> >> > Japanese features. The changes required by the proposed dual
>> >> >>> >> > syntax
>> >> >>> >> > and
>> >> >>> >> > deprecation model are minor compared to them, as they can be
>> >> >>> >> > implemented
>> >> >>> >> > using aliases or simple transforms.
>> >> >>> >> >
>> >> >>> >> > - Authoring tools already supporting IMSC1.0.1 do not need to
>> >> >>> >> > migrate to
>> >> >>> >> > the
>> >> >>> >> > TTML2 syntax, as renderers are required to support both. They
>> >> >>> >> > only
>> >> >>> >> > need
>> >> >>> >> > to
>> >> >>> >> > be updated to support Japanese features. They would need to be
>> >> >>> >> > updated
>> >> >>> >> > when
>> >> >>> >> > the deprecated features are removed in a future version.
>> >> >>> >> >
>> >> >>> >> > - Specs need to be updated. Netflix is willing to update the
>> >> >>> >> > TTML2
>> >> >>> >> > and
>> >> >>> >> > IMSC1.1 specs as proposed above.
>> >> >>> >> >
>> >> >>> >> > - Test suites need to be updated. For each of the features
>> >> >>> >> > above,
>> >> >>> >> > 2
>> >> >>> >> > additional tests need to be provided: one with the TTML2
>> >> >>> >> > flavor
>> >> >>> >> > and
>> >> >>> >> > without
>> >> >>> >> > the IMSC1.0.1 flavor; and one with both (testing the override
>> >> >>> >> > model).
>> >> >>> >> > Netflix is willing to contribute these tests.
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > We suggest adding these points to the next meeting's agenda.
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >> > Best regards,
>> >> >>> >> >
>> >> >>> >> > Cyril
>> >> >>> >> >
>> >> >>> >> >
>> >> >>> >>
>> >> >>> >
>> >> >>
>> >> >>
>> >> >
>> >
>> >
>
>

Received on Tuesday, 28 November 2017 06:00:54 UTC