See also: IRC log
<trackbot> Date: 16 January 2014
<scribe> scribeNick: nigel
nigel: will be taking part in chairs training next week, choices are to proceed next week without me or to cancel and reconvene on 30th.
glenn: suggests cancelling on 23rd
nigel: okay let's do that.
<scribe> agenda: Charter
nigel: some licence drafting has been going on in the background, barring adverse comments expect to take new charter to AC following edits by plh, towards the end of this week.
issue-162?
<trackbot> issue-162 -- update standalone profile documents -- open
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/162
glenn: think we can close the
issues.
... There was a question about backward compatibility. My
analysis showed that the previous versions were not up to date.
If anyone used them then those implementations need to change
anyway.
... They were not compatible with what was published in the
Rec. I'm happy with the new docs, which have been
published.
nigel: Moved to Pending Review.
action-141?
<trackbot> action-141 -- Nigel Megitt to Call for Action to identify discrepancies in TTML 1.0 on different profiles. -- due 2013-02-14 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/141
close action-141
<trackbot> Closed action-141.
action-225?
<trackbot> action-225 -- Glenn Adams to Work with plh to update standalone profile docs for ttml1se -- due 2013-10-31 -- OPEN
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/225
close action-225
<trackbot> Closed action-225.
issue-231?
<trackbot> issue-231 -- Individual character rotation -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/231
pal: The solution only affects horizontal glyphs with vertical layout. Are there any other circumstances in which characters may need to be rotated?
glenn: from the standpoint of
normal writing, no, but for arbitrary graphics it might be
wanted of coure, for artistic reasons.
... It's not supported now by CSS though it is supported by SVG
because SVG supports arbitrary angular rotation.
pal: it's possible to create
custom fonts with rotated glyphs so this is okay.
... I'm happy to close this.
close issue-231
<trackbot> Closed issue-231.
close action-255
<trackbot> Closed action-255.
issue-259?
<trackbot> issue-259 -- Define "closest" -- pending review
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/259
pal: See comments on issue. Wording would be better to define in terms of distance from zero.
glenn: origin doesn't involve
enclosure so rounding towards zero seemed more appropriate than
for other attributes where making further from zero allows for
more conservative spacing.
... We don't want to make a discrepancy between TTML2 and TTML1
by changing the way this could work.
pal: Reference to euclidean
distance may mean that this never gets implemented
correctly.
... CFF-TT has specific wording for rounding from percentages
to pixels using 'round half up' terminology. So there's prior
implementation that does it differently, independently of
TTML1.
nigel: is this about the wording or the mathematics?
pal: no problem with the wording - it's about the mathematics.
glenn: there are 2 options in the issue, a and b. Is there any difference in b between the proposal and the existing solution?
pal: I think so. Take tts:fontSize for example.
http://www.w3.org/TR/ttml1/#style-attribute-fontSize
pal: Euclidean distance requires
square root of the sum of the squares. If two have the same
computational result then choose the one furthest from
zero.
... My suggestion is to round each dimension separately.
glenn: this is a corner case. Prefer to think about, say, padding.
http://www.w3.org/TR/ttml1/#style-attribute-padding
glenn: the difference between the two things? For padding they are the same, however distance is not otherwise defined. So I used Euclidean distance specifically.
pal: Imagine there's a computed value for padding that consists of 4 lengths - how would you compute the Euclidean distance between this value and the next closest - what would be the computation?
glenn: it would be on a component by component basis.
pal: I agree, so there's no difference.
glenn: the key is that this is already implied by the use of the term "computed" which is already resolved to the component level.
pal: Can we be clear about where "computed" means this?
glenn: The definition of CSS that we refer to defines this. We presume that you include the CSS etc definitions.
pal: I think we need to be clear about how many components are included in this Euclidean computation.
nigel: which values have multiple
dimensions that are managed together?
... is it only color?
pal: Euclidean distance can be applied to vector values as well as scalar values.
glenn: In the case of padding it is not a vector. For fontSize it would be considered a vector.
nigel: Aren't they two scalars?
glenn: In the case of scaling of bitmap fonts I definitely meant to do a vector comparison.
nigel: That could be inferred from the notation used but do we need to add wording to make it explicit?
glenn: As we've tried to become
more precise it's become more complicated. Do we change TTML2
to be different from TTML1, or add an errata to TTML1? These
are all informative notes at the moment.
... We need to consider testing too.
pal: At least one reader did not have the same interpretation as the editor.
glenn: 2 issues - one is using Euclidean distance; the other is about origin in which you're suggesting changing the direction of rounding.
pal: yes.
glenn: It may be worth separating these into different issues. I'm more concerned about one than the other.
action pal to create a new issue to split these out for tracking.
<trackbot> Created ACTION-257 - Create a new issue to split these out for tracking. [on Pierre-Anthony Lemieux - due 2014-01-23].
glenn: if we put aside the issue of how distance is defined linguistically then on this issue of origin, what are our thoughts?
pal: I suggest deferring this
issue until later and putting higher priority on bigger
issues.
... I can dig deeper into this and try to get some hard data
regarding the implementations prior to TTML1SE.
nigel: Okay we can take this offline, but in the absence of further agreement we'll make no edits in TTML2
glenn: I'm happy to define what
is meant by Euclidean distance a bit, i.e. in terms of
component-wise or vector-wise comparison.
... In terms of rounding of origin I think it's early enough to
make a change now without impacting implementations now. We can
add an errata and a note.
... So we can solve both issues in a way that's not too complex
to implement.
<pal> sounds good
<glenn> ACTION: glenn to work with pal to resolve edits needed for issue-259 comments [recorded in http://www.w3.org/2014/01/16-tt-minutes.html#action01]
<trackbot> Created ACTION-258 - Work with pal to resolve edits needed for issue-259 comments [on Glenn Adams - due 2014-01-23].
action-238
<trackbot> action-238 -- Pierre-Anthony Lemieux to Follow up on issue-295 -- due 2013-12-19 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/238
issue-295?
<trackbot> issue-295 -- Remove code point restrictions from IMSC -- open
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/issues/295
pal: I have made the edits
nigel: Glenn are you happy with the updated wording?
pal: Annex B has been removed
entirely and Annex A has been refactored to take into account
CLDR. The wording has been changed to emphasise that this is a
set of characters from which
... authors are encouraged to choose depending on the language
of the element.
glenn: I still have some issues with table 2 because of its non-inclusive nature. It is a somewhat Euro-centric subset of languages.
pal: Remember this is a union of the CLDR sets, which still apply - it's an addition to them only.
glenn: The scope is worldwide.
plh: I did my action item on ATSC
- please review. We can also close the action on the document
licence.
... I have updated the charter for the document licence, which
only applies to WebVTT. I wanted to know where we are on
action-88 on the media type.
... If we don't conclude by Jan 30 there will be another long
cycle.
glenn: I haven't added the errata yet but given this info on priority I'll pick it up this week.
plh: I did contact IANA to say we'll get back to them.
nigel: did you do the EBU wording?
<plh> ACTION: plh to add EBU wording in charter [recorded in http://www.w3.org/2014/01/16-tt-minutes.html#action02]
<trackbot> Created ACTION-259 - Add ebu wording in charter [on Philippe Le Hégaret - due 2014-01-23].
plh: not yet.
pal: what's the process? Do we review it in the group before it goes to AC?
<plh> http://www.w3.org/2013/10/timed-text-charter.html
plh: yes.
... I can do a diff too if that's helpful.
... I will send diffs to the public group
nigel: what's the review process?
plh: I would say a week for this
group.
... regrets from me for the 30th though I'll be on IRC if
needed.
pal: Am happy to follow up with Glenn and understand the concerns.
glenn: My preference is to remove
table 2 but otherwise to put a paragraph in showing that it's a
subset of example character sets that are believed to apply to
the specified set of languages.
... To be exhaustive there would need to be citations for every
language but right now there are no references to normative
works.
... That paragraph should also say that others may be added in
the future.
pal: That sounds excellent.
glenn: I've noticed some issues
elsewhere.
... for example lineHeight.
nigel: proposes to close actions 238 and 243 and leave 244 pending
close action-238
<trackbot> Closed action-238.
close action-243
<trackbot> Closed action-243.
pal: needs to leave soon. any more for me?
nigel: action-252 overdue
action-252
<trackbot> action-252 -- Pierre-Anthony Lemieux to Add an issue for tracking purposes to refactor imsc to conform to the content profile specification of ttml2 dependent on ttml2 profile updates. -- due 2013-12-19 -- OPEN
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/252
pal: this is dependent on ttml2 work. I'll do it when I can.
nigel: will extend the due date
so it's not overdue, to 7th March.
... have done that.
action-203?
<trackbot> action-203 -- Glenn Adams to Investigate 708 border style mapping issues with mike's help -- due 2013-09-26 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/203
glenn: can't make progress with this as it stands due to lack of definition.
action-214?
<trackbot> action-214 -- Glenn Adams to Review cp008 and consider reformulating the recently added <animate> support to better align -- due 2013-10-10 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/214
<jdsmith> I've just marked https://www.w3.org/AudioVideo/TT/tracker/actions/164 pending review as well.
glenn: we discussed this in detail in the f2f and I've implemented it. It has has a long review period.
<glenn> http://www.w3.org/wiki/TTML/changeProposal008
close action-214
<trackbot> Closed action-214.
action-219?
<trackbot> action-219 -- Glenn Adams to Change to rec in ttml2, and add note to authors indicating that if author wants specific value, then they should specify specific value -- due 2013-10-24 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/219
https://dvcs.w3.org/hg/ttml/raw-file/default/ttml2/spec/ttml2.html#style-attribute-lineHeight
glenn: the action as stated has been done.
nigel: there's still a question
of whether it's possible to state a value as an alternative to
the normal keyword's default 125% behaviour.
... The lineHeight algorithm is now more explicit.
glenn: I haven't described that
algorithm previously on this call.
... [takes a couple of minutes to describe the algorithm to
turn "normal" into a single computed parameter]
... I reviewed blink, webkit and mozilla as to how they resolve
"normal". They take the paragraph's nominal font, then look at
Ascent, Descent and line Gap, then take the font size that
applies and scale
... the metrics accordingly. They add the three values together
to give a computed lineHeight property when the original
specified value is "normal". If those metrics are not
available
... then they use 125% of the fontSize that applied to that
paragraph.
... So at this level descendent spans with different font sizes
would not apply.
... and the 125% is only used if A, D and G are not
available.
... There's a separate process for inline elements than for
block elements.
... The lineHeight becomes a minimum value for the line box
that will be used if there's nothing else in the line box that
has a greater height.
... However if there's an inline box that's a child of the
linebox that has larger non-replaced text then the A and D will
be used to increase the overall inline box's height.
... And there's separate processing for padding and
margin.
... Note that when we introduce images we'll have replaced
content that comes into effect in this algorithm.
jdsmith: are the new steps consistent with those browsers?
glenn: yes, this is based on my
analysis of those three. I didn't analyse IE because I didn't
have access to the source code.
... Does MS use this algorithm?
jdsmith: Was there a different algorithm before?
glenn: We referred to CSS but
that is ambiguous and defers to implementations without
documenting properly.
... Mozilla confirmed that this is what we meant but didn't
write down in CSS.
nigel: do we need to formally communicate this to CSSWG?
glenn: yes we do. In the past
we've had comments at Last Calls but should call this out
specifically.
... The formal time to do it is during LC. I can raise it there
when we have consensus here on this language.
... I'd like to make sure that at least pal has an input
because he's written something different in IMSC.
action nigel to email group notifying of this change and initiating formal approval
<trackbot> Created ACTION-260 - Email group notifying of this change and initiating formal approval [on Nigel Megitt - due 2014-01-23].
action-221?
<trackbot> action-221 -- Glenn Adams to Double check spec language on css and xsl-fo around line height stacking strategy -- due 2013-10-24 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/221
nigel: this seems to be related to the similar edits.
action-260: reference changes in both action-219 and action-221
<trackbot> Notes added to action-260 Email group notifying of this change and initiating formal approval.
close action-219
<trackbot> Closed action-219.
close action-221
<trackbot> Closed action-221.
action-233?
<trackbot> action-233 -- Glenn Adams to Reach out to CSS WG to understand potential mapping of multi-row-align to CSS -- due 2013-11-18 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/233
glenn: I queried this, got the
answer to use flexbox and discovered that this is possible. I
tested it on Chrome, Firefox and Opera and Safari - it only
worked on more recent versions on Safari.
... I assume IE will work too because it supports flexbox
too.
<glenn> http://lists.w3.org/Archives/Public/public-tt/2013Nov/0027.html
glenn: Jerry you might want to
have a look at the attachments on this message including
examples to try.
... I will also send a screenshot of what it should look
like.
close action-233
<trackbot> Closed action-233.
action jerry and glenn to verify flexbox solution to multi row align using IE
<trackbot> Created ACTION-261 - And glenn to verify flexbox solution to multi row align using ie [on Jerry Smith - due 2014-01-23].
action-261: this is a follow-up to action-233
<trackbot> Notes added to action-261 And glenn to verify flexbox solution to multi row align using ie.
glenn: There's still an open
question as to how we specify this in TTML2 - do we expose
flexbox features directly or add some specific line alignment
syntax
... A new property is a shorthand for the use of the flexbox
solution.
action nigel to update relevant change proposal to include row alignment requirement and potential CSS solution based on action-233 findings
<trackbot> Created ACTION-262 - Update relevant change proposal to include row alignment requirement and potential css solution based on action-233 findings [on Nigel Megitt - due 2014-01-23].
action-164?
<trackbot> action-164 -- Jerry Smith to Investigate interop issues using CSS familyName constructs -- due 2013-12-05 -- PENDINGREVIEW
<trackbot> http://www.w3.org/AudioVideo/TT/tracker/actions/164
jdsmith: actually this is pending
review
... The view was that we should be aligning TTML with CSS.
There's a short term convenience for tools if we don't put the
CSS escape mechanism into the XML but it's cleaner to be
aligned and to
... use the CSS escapes.
... On another call we said to use XML escapes?
glenn: whatever tool we use the
XML escapes to apply, because we use XML. We don't use the
stylesheets as syntactically defined by CSS, just the value
syntax.
... So the original use of these escapes came about because
when you express a CSS stylesheet as a separate resource then
you can use a backslash U notation.
... Since we don't reference external stylesheets that was not
an issue.
... In TTML2 we're using something closer to XSL-FO and SVG for
attribute value syntax in XML. If we introduce the escape
mechanism in tokens based on CSS's escaping mechanism then we
will end up
... with 2 mechanisms: the XML one and the CSS one. There's
redundancy there.
jdsmith: Yes, I prefer both.
glenn: This optimisation is in
TTML1 as a constraint. In a future version of TTML1 we could
widen that out to re-include the Unicode escapes.
... We can certainly include in TTML2 because strict backward
compatibility isn't required for this.
jdsmith: I will probably follow this up with a proposal for a change.
glenn: Spec-ready text is
preferred. The Change Proposal should address interoperability
with TTML1 re this issue as well, and discuss the co-concurrent
features of XML numeric character references
... Should maybe define this in terms of where in the process
this happens.
http://www.w3.org/wiki/TTML/ChangeProposalIndex
glenn: the 'index' doesn't actually have an index - it would be good to edit this to make a true index.
action nigel to tidy change proposal index page to include an index
<trackbot> Created ACTION-263 - Tidy change proposal index page to include an index [on Nigel Megitt - due 2014-01-23].
action-263: glenn suggests listing a table with each change proposal by number with different columns, with status, package etc.
<trackbot> Notes added to action-263 Tidy change proposal index page to include an index.
action nigel ensure all P1 and P2 issues not closed belong in a change proposal
<trackbot> Created ACTION-264 - Ensure all p1 and p2 issues not closed belong in a change proposal [on Nigel Megitt - due 2014-01-23].
This is scribe.perl Revision: 1.138 of Date: 2013-04-25 13:59:11 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Succeeded: s/authors/... authors/ Succeeded: s/gerry/glenn/ Found ScribeNick: nigel Inferring Scribes: nigel Default Present: nigel, +41.22.749.aaaa, tmichel, +1.720.897.aabb, glenn, pal, [Microsoft], Plh Present: nigel glenn tmichel plh pal jdsmith frans_ebu Regrets: Michael_Dolan_for_first_30-60_minutes Frans_de_Jong_after_first_30_minutes Pierre-Anthony_Lemieux_after_first_60_minutes Found Date: 16 Jan 2014 Guessing minutes URL: http://www.w3.org/2014/01/16-tt-minutes.html People with action items: glenn plh[End of scribe.perl diagnostic output]