Timed Text Working Group Teleconference

27 Mar 2014

See also: IRC log


glenn, nigel, pal, plh, jdsmith, Frans_EBU


<trackbot> Date: 27 March 2014

<glenn> getting coffee, brb

<plh> https://lists.w3.org/Archives/Member/w3c-ac-members/2014JanMar/0069.html

<plh> http://www.w3.org/2014/03/timed-text-charter.html


<scribe> scribeNick: nigel

plh: Process: after 45 days people who didn't rejoin the group will be automatically kicked out. The 45 days start today.
... members need to go back to their AC rep and tell them to rejoin - should allow simple one click reappointment

nigel: Section 6 of the charter has a revised Decision Policy
... motivation is to clarify the situation especially as we will have two modes of working.

plh: this allows for better asynchronous decision making and has been adopted in other groups too.
... that's why it says 'for 10 days decisions are provisional'. We expect the WebVTT part of the group to work more asynchronously.

nigel: Thanks for doing the new charter!

plh: I made one small edit to the milestones - the TTML2 CR milestone is pushed back by one month to take into account the August 'dead month'
... and the WebVTT milestones were pushed by 3 months.

<plh> http://www.w3.org/2014/03/ttml-diff.html

plh: this is the link to a diff from the AC review version of the charter.

IMSC approach proposal (PAL)

pal: the plan so far for IMSC had been for IMSC to reference TTML2. We still have a long list of issues to resolve so it looks like it won't be ready when we intended it to be ready, which
... means that IMSC would be delayed, according to the current plan. THere are some users of IMSC that are really interested in it in its current form,
... and there are other users that are interested in it in a more extended form that would be dependent on TTML2.
... So I've been exploring a plan to deliver IMSC 1.0 based on TTML1 and follow up with IMSC 2.0 to go alongside TTML2.
... IMSC 1.0 could go today and there are implementations to demonstrate it. As TTML2 makes progress we'll work on IMSC 2.0 and publish that when it's ready.
... I've not heard any fundamental obstacles. The first step in the plan is to see if there's any reason not to go ahead with it.
... Then start the process by publishing IMSC 1.0 as a FPWD and get started on it.

nigel: notes that the charter milestones didn't push IMSC to match the end point of TTML2

plh: agrees that he didn't
... I'm no longer allowed to touch the charter!

nigel: Decision to deliver IMSC as two versions, v2.0 to roughly match TTML2 in milestones.

pal: I'm assuming that we won't get surprises in comments but maybe we will. I can start working on tweaking the current ED to match the new direction
... and to get the ED ready for a FPWD.

nigel: it would be good to have a summary document describing the publication approach for IMSC either to put on the wiki or publish as a note.

Action pal to draft a summary document on the wiki and post a link to it on the reflector

<trackbot> Created ACTION-277 - Draft a summary document on the wiki and post a link to it on the reflector [on Pierre-Anthony Lemieux - due 2014-04-03].

TPAC 2014


nigel: if members could respond to this then that would be helpful.

glenn: I think there should be a f2f and quite liked the Monday and Friday schedule, which was the least disruptive with respect to other groups.

nigel: the poll closes on 1st May and we can make the decision in May.


<trackbot> action-274 -- Nigel Megitt to Discuss with david singer possibilities for f2f before going ahead and adding ttwg to tpac agenda. -- due 2014-03-27 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/274

action-274: discussions have begun, still ongoing.

<trackbot> Notes added to action-274 Discuss with david singer possibilities for f2f before going ahead and adding ttwg to tpac agenda..

Action Items


<trackbot> action-276 -- Nigel Megitt to Request tracker default change to 'email' -- due 2014-03-27 -- OPEN

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/276

plh: I will find the request and ping them.

Issues discussed over the last week


<trackbot> action-215 -- Glenn Adams to Specify special semantics for tts:{extent, origin} on content elements to map to new inline region feature -- due 2014-04-01 -- PENDINGREVIEW

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/215


<trackbot> issue-176 -- Adding support for extent and origin attributes on block elements -- pending review

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/176

<glenn> https://dvcs.w3.org/hg/ttml/raw-file/tip/ttml2/spec/ttml2.html

glenn: this is technical and substantive - you can view it at the currently published ED link
... the main changes are in the terminology section 2.2 to define 'implied inline region' - there's already an 'inline region'
... and in the section 7.1.4 and 7.1.5 on div and p, wording on extent and origin creating an inline region.
... there's a matching change in the styling definition of tts:extent and tts:origin in 8.2.8 and 8.2.15 I added div and p as elements that the style attribute applies to
... and added a paragraph on each of those sections.
... The follow ons are in section 9.3.2 which is empty at the moment and I need to fill it in and discuss Implied Inline Regions here.
... finally in Appendix D.1 I've added an editorial note to add features for these.
... I applied this to both div and p though the original proposal was for p only. Both are block level elements that can generate regions so they should
... both have the opportunity to use implied inline regions.

nigel: what's the order of precedence if both a region reference and an extent and origin are specified?

glenn: it's possible to have more than one region already on a content element so this would map the content to all the regions including the inline implied region.
... I need to deal with those semantics in the tbs section 9.3.2. As a placeholder in the meantime I'll make an action.

<glenn> action glenn to add EDNOTE to 9.3.2 with reminder to deal with case of having multiple inline regions possibly with additional reference to out-of-line region

<trackbot> Created ACTION-278 - Add ednote to 9.3.2 with reminder to deal with case of having multiple inline regions possibly with additional reference to out-of-line region [on Glenn Adams - due 2014-04-03].

glenn: I've added this to the change list document

<glenn> https://dvcs.w3.org/hg/ttml/raw-file/tip/ttml2/spec/ttml2-changes.html

nigel: you've also updated CP2 to a PENDING REVIEW state

glenn: and I added a Resolution section.

nigel: Jerry you own CP2 so please could you review?



<trackbot> issue-285 -- Align rendered rows within a region to each other, and the set to the region -- open

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/285


nigel: I added use of the justify-content property and the mapping from multiRowAlign values


<trackbot> Issue-286 -- Extend the background area behind rendered text to improve readability -- open

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/286


nigel: last week pierre asked: Are TTML 1 processors expected to ignore TTML 2 attributes that are in the same namespace at TTML 1? Is this the case in practice?

glenn: what the spec says and what processors do and should do are separate questions.
... we'll probably need to put something in the conformance section of TTML2 on this subject and we may need to add some details to the abstract document type filtering mechanism
... that filters out foreign namespace. The normal behaviour should be to ignore anything not understood as long as it can still be parsed.
... A TTML1 doc with TTML2 features is not valid, strictly. But a TTML2 doc would be fine - then how does a TTML1 processor deal with that?
... We're not going to use a new namespace for TTML2 but extend the existing one so we need something in the document itself stating that it was
... authored with TTML2 features in mind. I believe there's a proposal to add a version attribute e.g. ttp:version to do just that. I haven't thought
... further than that.
... I will try to dig out the issue on this.
... this is Issue-276


glenn: issue-203 is closed but also relevant. It added ttp:version to TTML2


<trackbot> issue-302 -- Should background of a span be height of text in line or computed lineHeight? -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/302

glenn: I did some testing on this and verified that CSS behaviour results in backgrounds on spans that do not extend to the height of the line box
... that seemed to be consistent across browsers. What I don't recall is what I had implemented in the dfxp viewer because this came up then.
... It's not very well defined in CSS, what the right answer is. We do have the mapping to HTML/CSS issue. If we rely on CSS to implement
... the formatting we're going to work out how to live with this.
... notes that EBU-TT has already extended TTML to include padding. This isn't particularly easy to use.


<trackbot> issue-303 -- Permit HTML-style <a> elements to contain href links -- raised

<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/303

nigel: we don't have time to discuss this now!

Summary of Action Items

[End of minutes]

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Guessing input format: RRSAgent_Text_Format (score 1.00)

Found ScribeNick: nigel
Inferring Scribes: nigel
Present: glenn nigel pal plh jdsmith Frans_EBU
Regrets: tmichel
Found Date: 27 Mar 2014
Guessing minutes URL: http://www.w3.org/2014/03/27-tt-minutes.html
People with action items: 

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