See also: IRC log
<trackbot> Date: 08 October 2015
<scribe> scribe: nigel
nigel: Most of this meeting will
be dedicated to closing IMSC 1 pending review issues
... AOB?
... Mike has asked to postpone the incoming liaison from ATSC
issue.
pal: There's also the topic of profile designators - it would be good to talk about it.
nigel: Great, that's added.
Action-421?
<trackbot> Action-421 -- Nigel Megitt to Check with ttml player manufacturers if they're happy to be listed on our site. -- due 2015-09-24 -- OPEN
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/421
nigel: I did contact the
manufacturer we discussed and they said they'd check but
haven't yet confirmed.
... Do we have an implementations page?
tmichel: I don't think we have
one yet but I'd like to start one. I think we should have a
page
... per technology - one for TTML, one for WebVTT etc.
pal: We have a page for that - remember the contribution from the Web & TV IG?
nigel: Oh yes, I remember now.
https://www.w3.org/wiki/TimedText/
https://www.w3.org/wiki/TimedText/EffortsAndSpecifications is a better URL to use
It's linked from https://www.w3.org/wiki/TimedText under Timed Text Efforts and Specifications
nigel: I guess we could add it to
the group home page too - we probably should tidy up the
... group page vs wiki home page discrepancy. Having both isn't
especially helpful.
tmichel: In former times we had
the CVS hosted home page which was hard to edit. Now
... the wiki is simpler for people to add information to.
Everyone should be able to add their
... own product if they want to.
nigel: Is it worth an action to redirect from the home page to the wiki?
tmichel: I'll look into that. There's some information like how to join on the home page.
nigel: Yes. we'd have to migrate the key information.
tmichel: I'll look into it and propose something.
<scribe> ACTION: tmichel Look into merging the group home page and the wiki home page and propose something [recorded in http://www.w3.org/2015/10/08-tt-minutes.html#action01]
<trackbot> Created ACTION-430 - Look into merging the group home page and the wiki home page and propose something [on Thierry Michel - due 2015-10-15].
nigel: Netflix has just joined
the WG and would like to spend some agenda time on the
Thursday
... presenting on their open source TTML2 implementation
work.
... I'll add that to the topics/agenda page on the wiki.
tmichel: While we're talking
about new participants, SImon from Opera joined today replacing
Philip.
... Simon is the new editor of the WebVTT spec.
action-425?
<trackbot> action-425 -- Thierry Michel to Send a prompt/thank you to the potential test result contributors for imsc. -- due 2015-10-01 -- OPEN
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/425
pal: I've not heard back and am still chasing, so that's still open. No update despite best efforts.
pal: Related to Cyril's email
earlier today, which came out of this topic, I think from
an
... implementation standpoint he wants users to be able to
signal clearly in a TTML document
... what profiles a document conforms to. In IMSC 1 right now
there's a 'MAY user ttp:profile'
... statement but that's it. Maybe we can add more to IMSC 1 to
encourage people to label
... their documents. The challenge is, as we discussed before,
EBU-TT-D forbids ttp:profile.
... And ttp:profile supports only one profile. So if a document
conforms to both EBU-TT-D and
... IMSC 1 then you should not use ttp:profile but you should
use ebuttm:conformsToStandard
... and list both. If the document is not EBU-TT-D conformant
it probably isn't a bad idea to
... use ttp:profile and also include ebuttm:conformsToStandard
so I'm thinking of adding
... a recommendation to IMSC 1 along those lines.
nigel: I can see the logic to that, yes. It makes sense I think.
pal: I'd like to be responsive to the request.
nigel: I agree - there's a use
case we haven't spent a lot of time considering that is
obviously
... important. I'd like Andreas's and Frans's input on this
specific proposal too, but on the
... surface I think it makes a lot of sense.
... You can recommend using the URI designators.
pal: That would definitely be the
recommendation!
... From a tools perspective it would certainly help tools to
determine the document's profile.
nigel: We just need to be careful
that ebuttm:conformsToStandard is indicating document
... conformance in other words the equivalent to TTML2's
ttp:contentProfiles attribute.
... Whereas ttp:profile indicates a processor profile, so we
shouldn't mix the messages there.
pal: I don't know why we hadn't collectively thought about this before. I think it works in exactly the right way.
nigel: I can see how this would
work really well - if an IMSC 1 processor is needed then it's
on
... the ttp:profile attribute and if not, because an EBU-TT-D
processor is okay, then it would be
... omitted.
pal: I think we can file an issue
for this, especially given Glenn's email just now proposing
that
... IMSC 1 includes a 'should include ttp:profile attribute'
statement, then implement and review
... next week.
... [filing issue right now]
issue-448?
<trackbot> issue-448 -- Add recommendation for ttp:profile and ebuttm:conformsToStandard -- raised
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/448
reopen issue-448
<trackbot> Re-opened issue-448.
pal: I'm going to reply to the thread too.
nigel: I think it's worth pinging
back to EBU to check if they might reopen the discussion
on
... whether or not to permit ttp:profile on EBU-TT-D
documents.
... Of course if you have a stream of EBU-TT-D documents e.g.
in DASH then this is likely
... to be redundantly repeated data.
pal: Of course the packager could strip it out if it knows the data won't be needed downstream.
nigel: We may be putting
packagers in an uncomfortable situation of needing to modify
the
... samples they're given to wrap up.
pal: True - we're talking about a few bytes though and it's tiny in comparison with e.g. HTTP headers.
nigel: Let's go through Pending Reviews...
issue-404?
<trackbot> issue-404 -- Where is #image feature defined? -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/404
pal: I think this is unambiguous, well specified and can be closed.
nigel: +1
close issue-404
<trackbot> Closed issue-404.
issue-405?
<trackbot> issue-405 -- why is #nested-span prohibited on image profile? -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/405
nigel: This isn't even a proposal to change the spec. It's a question with an answer.
pal: I think Glenn would have responded if he disagreed.
close issue-405
<trackbot> Closed issue-405.
issue-406?
<trackbot> issue-406 -- #lineBreak-uax14 is never 'used' by a document? -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/406
pal: uax14 is mandated for
processors in the text profile and stated as not applicable to
document instances.
... The image profile is silent about it.
nigel: Do we permit the profile features to be listed in the document?
pal: We do. The presence of the
profile designator in the document requires that the
processor
... implements uax14. What the spec currently says is the
document constraints. The uax14
... feature is not applicable to constraints on the
document.
nigel: There's a niche issue for
the text profile: if the profile features are included then it
would
... be an error to state that the #linebreak-uax14 feature is a
'shall not use'.
... That would create a situation where an IMSC 1 text profile
conformant processor should
... reject an IMSC 1 text profile conformant document that
includes this profile feature as
... 'shall not use'.
pal: This is a strange and theoretical case, that applies only to the uax14 feature.
nigel: We could add a statement
that if profile features are included within a document
then
... they shall not conflict with the processor conformance
rules for IMSC 1.
<scribe> ACTION: nigel File issue re profile feature inclusion in IMSC 1 documents [recorded in http://www.w3.org/2015/10/08-tt-minutes.html#action02]
<trackbot> Created ACTION-431 - File issue re profile feature inclusion in imsc 1 documents [on Nigel Megitt - due 2015-10-15].
pal: We could add that to the
profile section for document conformance.
... Going back to issue-406, Glenn suggested to require the
feature. Shall we start the 2 week review clock on this
today?
nigel: yes, let's do that.
issue-408?
<trackbot> issue-408 -- Initial value of color -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/408
close issue-408
<trackbot> Closed issue-408.
issue-409?
<trackbot> issue-409 -- Font family of default means monospaceSerif -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/409
pal: IMSC 1 defines what it means
for "default" fontFamily, i.e. what a processor shall do
when
... the fontFamily is set to "default". Glenn points out that
this isn't always the right thing to do.
... My response to that is that authors should not rely on
default. TTML1 doesn't prohibit
... implementations from mapping the default font to a known
one.
nigel: I'm a bit nervous here -
Glenn hasn't proposed a solution, and I don't know why.
... For example we could include a table mapping language to
default font map or reference
... one in e.g. CLDR.
pal: Document authors can make their choice though if default won't work for them.
nigel: My nervousness here is
that we're making a language market-specific value for
default,
... which could make use of default less useful.
... However Glenn knows most about this from those here and he
hasn't picked it up.
pal: We should close this on the basis of no response in over 1 month. It can be reopened if someone is unhappy.
close issue-409
<trackbot> Closed issue-409.
issue-410?
<trackbot> issue-410 -- Constraints on #linePadding and #multiRowAlign -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/410
nigel: The problem with SHALL NOT
here suggests a syntactic conformance requirement whereas
... what you mean is that if the attributes are present then
they shall be ignored by implementations.
pal: We don't have Glenn's view
on this so it would be uncool if he doesn't agree.
... Don't forget the problem arose in EBU-TT-D.
nigel: The new EBU-TT Part 1 v1.1
might get us out of that problem - it defines the
features
... and states that they may be used in EBU-TT-D, and fixes the
gaps from the original definition.
<scribe> ACTION: nigel Nigel, pal, andreas and frans to hook up re changing IMSC 1 EBU-TT feature references to point to tech3350 v1.1 [recorded in http://www.w3.org/2015/10/08-tt-minutes.html#action03]
<trackbot> Created ACTION-432 - Nigel, pal, andreas and frans to hook up re changing imsc 1 ebu-tt feature references to point to tech3350 v1.1 [on Nigel Megitt - due 2015-10-15].
issue-410: [meeting 2015-10-08] See also Action-432 - it may be possible to avoid the problem by referencing tech3350 v1.1.
<trackbot> Notes added to issue-410 Constraints on #linePadding and #multiRowAlign.
nigel: We're out of time so I'll adjourn now.
pal: Maybe we could do 2 hours next week to get through the remaining issues ahead of TPAC?
nigel: That's fine for me.
pal: I'd like to have gone
through all of them - there's one that may need TPAC
discussion.
... Glenn brought up an excellent question about the HRM, in
relation to Arabic, where the
... mapping between code point and glyph is in the majority of
cases is not 1:1 and the shape
... depends on the context. That really messes up the glyph
buffer. I'm researching it.
... The glyph buffer was put in to support e.g. 608, 708 and
Teletext. Hopefully we'll have closed all the others.
nigel: Thanks both. [meeting adjourned]