IRC log of tt on 2014-12-04

Timestamps are in UTC.

14:59:53 [RRSAgent]
RRSAgent has joined #tt
14:59:53 [RRSAgent]
logging to
14:59:55 [trackbot]
RRSAgent, make logs public
14:59:57 [Zakim]
Zakim has joined #tt
14:59:57 [trackbot]
Zakim, this will be TTML
14:59:57 [Zakim]
ok, trackbot; I see SYMM_TTWG()10:00AM scheduled to start in 1 minute
14:59:58 [trackbot]
Meeting: Timed Text Working Group Teleconference
14:59:58 [trackbot]
Date: 04 December 2014
15:00:21 [Zakim]
SYMM_TTWG()10:00AM has now started
15:00:27 [Zakim]
+ +1.858.882.aaaa
15:00:37 [Zakim]
15:00:37 [mike]
zakim, aaaa is mike
15:00:37 [Zakim]
+mike; got it
15:01:38 [nigel]
nigel has joined #tt
15:02:02 [atai]
atai has joined #tt
15:02:06 [Zakim]
15:02:36 [Zakim]
15:02:41 [Zakim]
15:03:06 [Zakim]
15:03:21 [Zakim]
15:03:25 [jdsmith]
jdsmith has joined #tt
15:03:43 [nigel]
Present: glenn, pal, Thierry, Andreas, nigel, jdsmith, mike
15:03:46 [nigel]
chair: nigel
15:03:50 [nigel]
Regrets: Frans
15:04:02 [nigel]
scribeNick: nigel
15:04:14 [courtney]
courtney has joined #tt
15:05:08 [Zakim]
+ +1.408.771.aabb
15:05:12 [nigel]
Present+ courtney
15:05:18 [nigel]
zakim, aabb is courtney
15:05:18 [Zakim]
+courtney; got it
15:05:26 [pal]
pal has joined #tt
15:05:33 [nigel]
Topic: This meeting
15:05:43 [nigel]
nigel: is there AOB?
15:05:52 [nigel]
nigel: We should mention the ITU-R WP6B liaison
15:07:03 [nigel]
Topic: IMSC 1 transition to CR
15:07:43 [nigel]
nigel: Pierre and I met the Director and plh and Thierry yesterday to discuss transition of IMSC 1 to CR.
15:07:49 [nigel]
nigel: [result not minuted]
15:08:16 [nigel]
15:08:16 [trackbot]
action-333 -- Pierre-Anthony Lemieux to Create a one pager to cover the plan for the director's meeting for taking imsc1 to cr. -- due 2014-11-27 -- PENDINGREVIEW
15:08:16 [trackbot]
15:08:26 [nigel]
close action-333
15:08:26 [trackbot]
Closed action-333.
15:09:15 [nigel]
tmichel: The document will be published on Dec 9 and then I'll send the call for implementation announcement
15:09:26 [nigel]
... on the same day. It will also be advertised on the W3C homepage.
15:09:37 [nigel]
... The webmaster has approved the document today.
15:09:46 [nigel]
... (so it is now frozen)
15:10:24 [nigel]
nigel and pal: Thanks everyone for the work put into this document.
15:10:28 [nigel]
glenn: Congratulations.
15:11:03 [nigel]
pal: The next step is to start compiling our test suite and test material. I plan to translate the DECE
15:11:16 [nigel]
... submission into what I think is valid IMSC 1 documents - primarily a change to namespace.
15:11:38 [nigel]
... Also I'm going to reach out to implementors. Would the group also be interested in a more formal
15:11:56 [nigel]
... message or template message to send to those who are interested. How do we proceed?
15:12:24 [nigel]
tmichel: The Call for Implementations is sent out to the chairs and ac-forum and will be published on the W3C homepage.
15:12:40 [nigel]
... That will be done on the day of publication. We can take that message and send it to whomever we want.
15:12:49 [nigel]
... We need to wait until publication.
15:13:04 [nigel]
pal: Does that make it easy for people who want to contribute to know who to contact?
15:13:22 [nigel]
tmichel: I'll send a link. Basically it says the spec is now in CR and invites participation for implementation.
15:13:30 [nigel]
... It also says how to feedback to the public mailing list.
15:13:52 [nigel]
pal: Thank you. Also there are Simon's outstanding comments that have been deferred. Can we discuss that
15:13:55 [nigel]
... next week?
15:13:59 [nigel]
nigel: Okay.
15:14:14 [nigel]
Topic: Action Items
15:14:27 [nigel]
15:14:27 [trackbot]
action-356 -- Nigel Megitt to Request review of ttml2 pending review issues from group -- due 2014-12-04 -- PENDINGREVIEW
15:14:27 [trackbot]
15:14:37 [nigel]
close action-356
15:14:37 [trackbot]
Closed action-356.
15:15:46 [nigel]
nigel: I should list the issues that have been implemented since last week, for review on 18th December,
15:15:52 [nigel]
... a similar timescale.
15:16:47 [nigel]
glenn: The list is: 21, 213, 236, 237, 285, 286, 294. Those are all the new ones since last week.
15:17:28 [nigel]
15:17:28 [trackbot]
action-355 -- Glenn Adams to Resolve duplication between issue-357 and issue-229 -- due 2014-12-04 -- OPEN
15:17:28 [trackbot]
15:18:01 [nigel]
glenn: I've been focusing on the issues so I've not done work on this AI or any of the others.
15:18:15 [nigel]
15:18:15 [trackbot]
action-354 -- Mike Dolan to Investigate formal contact at arib -- due 2014-11-27 -- OPEN
15:18:15 [trackbot]
15:18:50 [nigel]
mike: Status is: I reached out to the executive director of ARIB and he's going to get back to me.
15:19:08 [nigel]
... Somewhat unrelated, a colleague from Toshiba indicated some other practical aspects of the ARIB work
15:19:32 [nigel]
... so that's interesting too. It looks like another 6 months to a year before it's out for basic UHDTV.
15:19:55 [nigel]
... Hopefully before the holidays we'll have specific logistics for how to work with them to add
15:19:59 [nigel]
... the extensions to TTML2.
15:21:31 [nigel]
Topic: Issues
15:21:51 [nigel]
15:21:51 [trackbot]
issue-21 -- window anchor points not supported? -- pending review
15:21:51 [trackbot]
15:22:22 [nigel]
glenn: This is about positioning the root container region more flexibly, or other regions relative to it.
15:22:44 [nigel]
... I'm proposing a new tts:position style attribute fairly closely related to the backgroundPosition property
15:23:06 [nigel]
... in CSS 3 image backgrounds and borders. For example you could say "position the bottom edge of the
15:23:21 [nigel]
... region 20% above the bottom edge of the container region".
15:23:44 [nigel]
... So you could say 10% bottom, or center, which would center the region in its container region.
15:23:59 [nigel]
... Take a look at that - I think it will be interesting. I've defined it so that if you have both tts:origin and
15:24:18 [nigel]
... tts:position then in a TTML2 context you'd ignore tts:origin and use tts:position, otherwise you can
15:24:32 [nigel]
... still use tts:origin as a fallback. The presentation in that case may end up different of course.
15:24:48 [pal]
15:24:53 [nigel]
ack pal
15:25:07 [mike]
15:25:23 [nigel]
pal: Do we really need this feature? Positioning has been problematic for a number of implementors in
15:25:32 [nigel]
... the past so I'm concerned about the complexity. What is the use case?
15:25:49 [nigel]
glenn: I'm responding to the issue - someone requested anchor points so I've provided a solution.
15:26:13 [nigel]
pal: This issue was opened in 2008.
15:26:37 [nigel]
glenn: We should bear in mind that there are general uses for TTML2 not just captioning and subtitling.
15:26:57 [nigel]
... There are features that need similar features. We shouldn't confuse implementation complexity with
15:27:05 [atai]
15:27:16 [nigel]
... syntax complexity. Many browsers implement the CSS feature too, so there are implementations.
15:27:32 [nigel]
ack mike
15:28:02 [nigel]
mike: How would this work? If you have overflow, extent etc what would happen? Would the anchor remain
15:28:15 [nigel]
... where it was set. That needs to be addressed.
15:28:32 [nigel]
glenn: This only addresses position of the region, not extent or overflow, which are separate.
15:28:45 [nigel]
... In order to compute the position you have to have resolved the extent already. The overflow issue
15:28:56 [nigel]
... is independent of positioning and sizing. So this is only related to position.
15:29:12 [nigel]
mike: I think the combination of the two could result in some interesting effects depending on how it is
15:29:15 [nigel]
... defined.
15:29:33 [nigel]
glenn: There are some extensions coming to the extent attribute, including the ability to say it should be
15:29:47 [nigel]
... computed so that the result is contained in the outer containing block, for example if you're sizing the
15:30:04 [nigel]
... root container region to ensure it fits in the available area of the related media object, and needs to be
15:30:23 [nigel]
... in the center, you'd specify extent="contain" and position="center" and the semantics would work
15:30:46 [nigel]
... alongside another new parameter storageAspectRatio which constrains the related media object's
15:30:57 [nigel]
... shape. Then the root container region is positioned correctly.
15:31:23 [nigel]
mike: I think the original issue (could have been me, I'm not sure!) needs to be mapped from 708 semantics
15:31:41 [nigel]
... into this, whatever we end up doing. I share some of pal's concerns re complexity.
15:32:00 [nigel]
glenn: I agree, and would point out that it's bad design in my opinion to throw out possible features early
15:32:16 [nigel]
... in the process. It's better to propose solutions that can be considered. As the process moves forward
15:32:34 [nigel]
... we can see if they will be implemented and do what is needed, rather than cutting them out too soon.
15:32:49 [nigel]
... This also establishes IPR precedent and commitment by putting them into the FPWD even if they don't
15:33:02 [nigel]
... end up in the final version. This is the wrong time to discuss complexity.
15:33:05 [nigel]
ack atai
15:33:23 [nigel]
atai: We discussed anchor points in the EBU group some years ago with Sean Hayes. We mostly discussed
15:33:44 [nigel]
... positioning of the region within the root container. We didn't talk about positioning the root container
15:34:02 [nigel]
... in relation to the media object. Just a note. I'm not sure if we have an option for simplification there.
15:34:32 [nigel]
glenn: THere are three applications: 1) positioning the root container region wrt the display or the media object.
15:34:51 [nigel]
... For example a 16:9 display showing a 2:1 media - you may want to position the subtitles in the black
15:35:01 [nigel]
... bar beneath the video.
15:35:11 [nigel]
... 2) Positioning the region within the root container region.
15:35:32 [nigel]
... 3) Positioning background images relative to content or a region. The border rectangle, padding
15:35:41 [nigel]
... rectangle and content rectangle need to be considered.
15:35:56 [nigel]
15:35:56 [trackbot]
issue-213 -- Advance notice of deprecation for textOutline -- pending review
15:35:56 [trackbot]
15:36:29 [nigel]
glenn: There's no action - I don't propose that we don't deprecate textOutline. I'll be drafting the
15:37:05 [nigel]
... orthogonal text shadow feature, but they're independent of each other.
15:37:19 [nigel]
... It's already in TTML1 so I propose to keep it.
15:37:43 [nigel]
mike: As long as we end up having the 708 features that can't be emulated with textOutline (drop shadow support).
15:38:10 [nigel]
glenn: The way we defined textOutline is that it extends perpendicular to the tangent of the outline of the
15:38:37 [nigel]
... glyph at any given point, inner or outer. textShadow is an x-y offset vector that translates the outline
15:38:45 [nigel]
... without changing its size.
15:39:17 [nigel]
mike: My concern isn't textOutline but making sure we have text shadow.
15:39:50 [nigel]
courtney: I think that means you won't be able to support all the FCC regulations in TTML.
15:40:07 [nigel]
glenn: I'm proposing not deprecating, so both are available, and I believe it will support all of the options.
15:40:17 [nigel]
... We will need to go through all of the 708 edge styles and verify that they can be achieved.
15:41:20 [nigel]
PROPOSAL: Close this issue.
15:41:31 [nigel]
close issue-213
15:41:31 [trackbot]
Closed issue-213.
15:41:42 [nigel]
15:41:42 [trackbot]
issue-236 -- Character spacing, i.e. letter-spacing -- pending review
15:41:42 [trackbot]
15:42:17 [nigel]
glenn: this allows introducing tracking in the same way as CSS letter spacing. I've introduced it.
15:42:31 [nigel]
15:42:31 [trackbot]
issue-237 -- Inline space -- pending review
15:42:31 [trackbot]
15:42:50 [nigel]
glenn: This is similar - inline space allows the width of an inline box that contains some glyphs,
15:43:07 [nigel]
... for example a span with some content in it within a paragraph. I might want to say 14% of the region
15:43:24 [nigel]
... width, etc. It turns out that in CSS and XSL-FO there are both width and height properties that apply
15:43:37 [nigel]
... to content elements however the semantics are such that for inline non-replaced elements like span,
15:43:56 [nigel]
... width and height are ignored! So, what to do? It turns out there's a nice mechanism in CSS which I'd
15:44:20 [nigel]
... overlooked for a while, called display:inline-block. While you can't say that an inline block is a
15:44:33 [nigel]
... particular width you can say that a block in an inline context is a particular width and height. So I
15:44:49 [nigel]
... introduced those concepts, and said that they magically turn spans into inline blocks to which width
15:45:07 [nigel]
... and height can apply. I've tested it in various browsers and it does exactly what you'd think it does.
15:45:40 [nigel]
15:45:40 [trackbot]
issue-285 -- Align rendered rows within a region to each other, and the set to the region -- pending review
15:45:40 [trackbot]
15:45:59 [nigel]
glenn: This is the long standing EBU request for multiRowAlign. We've played around with some options.
15:46:12 [nigel]
... We looked at flexbox, but I recently realised that the inline block mechanism I just described can
15:46:31 [nigel]
... satisfy the same requirement. E.g. A paragraph with a single span in it, the p being the whole width of
15:46:48 [nigel]
... the root container region, and you want to centre the text, but align any broken lines left or right to
15:47:06 [nigel]
... each other within that centre-aligned paragraph. The inline block mechanism allows that too.
15:47:27 [nigel]
... You can specify a separate alignment on the content of the span and that will allow two alignments,
15:47:42 [nigel]
... one to the content of the paragraph and the other to the span. My experiments on browsers show
15:48:05 [nigel]
... this works as desired. If you specify a textAlign on span, which is new, then it results in the promotion of
15:48:30 [nigel]
... the span to an inline block for display purposes. That would allow for example left justified lines in a
15:48:35 [nigel]
... center aligned paragraph.
15:48:55 [atai]
15:49:02 [nigel]
ack atai
15:49:14 [nigel]
glenn: This separates out the concepts so the existing semantics don't have to change.
15:49:28 [nigel]
atai: This is an interesting approach that the EBU group should review. I'm not sure it matches the intended
15:50:48 [nigel]
... presentation - does it align multiple lines of text with the longest line in the group? For example
15:51:04 [nigel]
... a centred first (and longest) line, with the second line right aligned to it? Would this work?
15:51:34 [nigel]
glenn: I'm not sure. I need a written down sample or example to check. My proposal does work when
15:51:58 [nigel]
... the line breaks are defined with br elements. If two lines are wrapped in a span with textAlign="right"
15:52:16 [nigel]
... and contained in a paragraph with textAlign="center" then it would first layout the block right aligned
15:52:32 [nigel]
... and then centre the whole block as the paragraph. So this would have the result you want.
15:52:39 [nigel]
atai: ok
15:52:56 [nigel]
glenn: I'd be interested in scenarios where this might not work, according to my reading of the EBU spec.
15:53:33 [nigel]
15:53:33 [trackbot]
issue-286 -- Extend the background area behind rendered text to improve readability -- pending review
15:53:33 [trackbot]
15:54:00 [nigel]
glenn: I fixed that by allowing padding to be assigned to a span, and saying if done, it must use
15:54:06 [nigel]
... box-decoration-break:clone semantics.
15:54:09 [nigel]
15:54:10 [trackbot]
issue-294 -- Style attribute to prevent overflow by shrinking text to fit on a line -- pending review
15:54:10 [trackbot]
15:54:29 [nigel]
glenn: This is one that I believe John Birch specified and I said that the proposal was about content
15:54:46 [nigel]
... fitting, e.g. automatically reducing the font size to fit the content. Nobody in CSS land or elsewhere
15:55:05 [nigel]
... is doing that, so it would be highly complex to implement. However the region can now be shrink-fit
15:55:30 [nigel]
... to the content. I've proposed a new value for tts:extent: "fit-content" that comes out of a CSS3 spec.
15:55:37 [nigel]
15:55:37 [trackbot]
issue-307 -- Conformance language and processor profile rather than content profile. -- pending review
15:55:37 [trackbot]
15:56:37 [nigel]
nigel: Since relevant changes have been made I propose to close this with no further action.
15:56:48 [nigel]
close issue-307
15:56:48 [trackbot]
Closed issue-307.
15:57:52 [nigel]
Topic: AOB
15:58:10 [nigel]
nigel: Please note the liaison from ITU-R WP 6B which came in earlier today and went to member-tt.
15:59:12 [nigel]
nigel: They would like a liaison I think, want to know about our work on WebVTT and IMSC 1 and how
15:59:25 [nigel]
... they relate to each other. They also have some detail questions on IMSC 1.
15:59:36 [nigel]
pal: I'm happy to draft a first response on those IMSC 1 questions.
15:59:54 [nigel]
Action: pal Draft response to ITU-R liaison re IMSC 1 questions.
15:59:55 [trackbot]
Created ACTION-358 - Draft response to itu-r liaison re imsc 1 questions. [on Pierre-Anthony Lemieux - due 2014-12-11].
16:00:07 [nigel]
glenn: I notice the liaison also mentions the ARIB-TT development.
16:00:23 [nigel]
nigel: Yes, I encourage everyone to have a look at the liaison document.
16:01:52 [Zakim]
16:01:53 [Zakim]
16:01:53 [Zakim]
16:01:56 [Zakim]
16:01:57 [Zakim]
16:01:59 [Zakim]
16:02:22 [nigel]
nigel: For next week we have 1 hour set aside and a lot of issues to close on TTML2, hopefully, so in the
16:02:41 [nigel]
... interests of time please could everyone discuss them offline on the reflector as much as possible, so
16:03:16 [nigel]
... we only have to discuss the minimum number of questions?
16:03:23 [nigel]
[adjourns meeting]
16:03:32 [nigel]
rrsagent, make logs public
16:03:36 [nigel]
rrsagent, generate minutes
16:03:36 [RRSAgent]
I have made the request to generate nigel
16:06:43 [nigel]
ScribeOptions: -final -noEmbedDiagnostics
16:06:46 [nigel]
rrsagent, generate minutes
16:06:46 [RRSAgent]
I have made the request to generate nigel
16:22:40 [Zakim]
16:34:52 [Zakim]
16:34:53 [Zakim]
SYMM_TTWG()10:00AM has ended
16:34:53 [Zakim]
Attendees were +1.858.882.aaaa, glenn, mike, pal, Thierry, Andreas, nigel, jdsmith, +1.408.771.aabb, courtney
16:57:54 [glenn_]
glenn_ has joined #tt
17:49:47 [Zakim]
Zakim has left #tt