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Minutes of TT WG Teleconference on 02/24/05

From: Thierry MICHEL <tmichel@w3.org>
Date: Tue, 12 Apr 2005 00:30:30 +0200
Message-ID: <425AFA86.6010208@w3.org>
To: public-tt@w3.org

Minutes of TT WG Teleconference on 02/24/05


  Glenn Adams (XFSI, Chair, Scribe) [GA]
  Geoff Freed (WGBH/NCAM) [GF]
  Sean Hayes (Microsoft) [SH]
  Erik Hodge (RealNetworks) [EH]
  David Kirby (BBC) [DK]


  Mike Dolan (invited expert) [MD]
  Thierry Michel (W3C) [TM]
  Dave Singer (Apple) [DS]

1. Status of sample texts.

[DK] Has exhausted attempts to obtain permission from Norma Farnes,
without receiving any response.

Action: [GA] Advise W3-COMM to remove 1st public WD from W3C site;
request that this removal occur when 2nd WD is posted.

[DK] BBC will not be able to provide formal permission to use
Eastender text examples; however, BBC does not believe the amount
of cited text presents any problem. Nevertheless, if a conservative
positoin is required, then recommend replacing this example text
as well.

Action: [DK] to provide substitutes for Eastender text that use
public domain text.

2. 2nd WD Status

[GA] Reviews changes in 2nd WD draft:

* addition of tts:unicodeBidi and tts:direction; these are needed
to satisfy basic I18N requirements and TT-AF-1-0-REQ R291, and, in
particular, to satisfy [1].

[1] http://www.w3.org/TR/unicode-xml/#Bidi

* change previous ttp:smpteMode to new name of ttp:markerMode;

* specify new ttp:smpteMode with values nonDrop, dropNTSC, and dropPAL;

[DK] Notes that a default is not specified.

Action: [GA] specify nonDrop as default for ttp:smpteMode.

* change body time containment to "par"

[EH] Notes this is consistent with HTML+Time.

* specify implicit duration (in 10.4) to be "indefinite" when parent
is "par" and 0 when parent is "seq";

[EH] notes that similar effect is achieved in SMIL by specifying
a default fill of "hold" which causes discrete media to retain
their display even when their implicit duration is zero.

[EH] notes that implicit duration of indefinite causes parent "par"
to be indefinite as well in case it does not have an explicit duration.

[GA] wants to avoid introducing "fill" semantics in DFXP if using
"indefinite" will suffice. Expect to discuss further at next F2F.

[GA] is planning to write a psuedo-code algorithm for generating
full time intervals in section 10.4 rather than depending on
normative reference to SMIL, which is somewhat problematic for
readers given its density and many other features which are
not present in DFXP.

* new sample images

[GA] notes problems in images for tts:overflow, tts:wrapOption, and

Action: [GF] to send updated images.

Action: [GA] to incorporate new tts:direction and tts:unicodeBidi
sample images provided by [GF].

[GA] asks if any objection to publishing 2nd WD with following changes:

* specify nonDrop as default for ttp:smpteMode
* update sample images for tts:overflow, tts:wrapOption, tts:writingMode
* add sample images for tts:direction, tts:unicodeBidi
* replace sample text/images in section 1.2 Document Example

[*] No objection.

Resolution: to send update as "Editor's Copy" to public-tt reflector
and request W3-COMM publish as 2nd WD.

Action: [GA] to send update as "Editor's Copy" to public-tt reflector
and request W3-COMM publish as 2nd WD.

3. Schedule

* telecon for next week (03/03) cancelled due to [GA] travel; next
telecon will be 03/10;

* still on schedule for LC on 03/18;

4. Open Issues

[GA] Not discussed to lack of time. Issues that remain to be

1. [DS] doesn't like example of multiple <set>s to show a fade.

2. [DS] how to express drop frame vs non drop frame counting; [GA]
suggest adopting [MD] proposal to relabel ttp:smpteMode as
ttp:markerMode, then introduce new ttp:smpteMode with values "drop"
and "nonDrop".

[GA] Note this issue is addressed in new draft with introduction
of new ttp:smpteMode.

3. [DS] whether to permit expressing durations in real or media time
while operating in discontinuous SMPTE marker mode; [GA] suggest we
(continue to) rule out durations while operating in discontinous mode;

4. [MD] wants to see buffer model characterized in streaming annex;
[GA] we could add a number of parameters that characterize certain
maximums that are relevant to buffering and processing on a user
agent, such as (where max* means the maximum of some value that
applies at a given instant in time):

* ttp:maxRegions    -- max regions at one time
* ttp:maxStyles     -- max styles that apply to content at one time
* ttp:maxCharacters -- max chars to be displayed at one time
* ttp:maxPixels     -- max pixels of regions at one time

5. [GA] should we apply lowerCamelCase rules to attribute values as
well, e.g., no-wrap vs noWrap; probably should apply in order to be

[GA] Note this issue is addressed in new draft by changing attr
values to lowerCamelCase.

6. [GA] there may be some authoring confusion around having a general
ttm:agent attribute for content, but then having a local (unqualfieid)
agent attribute for the ttm:actor element.



Resolution: to send update as "Editor's Copy" to public-tt reflector
and request W3-COMM publish as 2nd WD.


Action: [GA] Advise W3-COMM to remove 1st public WD from W3C site;
request that this removal occur when 2nd WD is posted.

Action: [DK] to provide substitutes for Eastender text that use
public domain text.

Action: [GA] specify nonDrop as default for ttp:smpteMode.

Action: [GF] to send updated images for tts:overflow, tts:wrapOption,
and tts:writingMode.

Action: [GA] to incorporate new tts:direction and tts:unicodeBidi
sample images provided by [GF].

Action: [GA] to send update as "Editor's Copy" to public-tt reflector
and request W3-COMM publish as 2nd WD.


Action: [EH] Provide use cases in TT context for priority class attr

Done. See [2].

[2] http://lists.w3.org/Archives/Member/member-tt/2004Nov/0011.html

Action: [SH] To elaborate use cases for audio embed usage.

Action: [GA] to generalize and clearly articulate [MD] feedback on XBC
with TT-AF structured timing as use case, then send to WG for review
prior to forwarding to XBC.

Action: [GA] need to document conventions regarding normative definition
of element vocabulary and syntax used therein.

Done. See Section 2.3 of current WD.

Action: [GA] need to characterize definitions of vocabulary as normative
while supplied schemas are informative.

Closed. See Annex B intro text. Schmas are now normative; however,
body of spec provides ultimate definition of conformance, not any
particular schema.

Action: [GA] review recent proposed changes regarding xml:space from
XML Core Working Group with view of changing our vocabulary definitions
as necessary.

Action: [GA] restore nested <div/> in content model.

Closed. Obviated by subsequent decision to not support nested <div/>
in DFXP.

Action: [GA] ensure that background color applies to content elements
as well as region.


Action: [GA] change language in vocab element defs that defines equiv
class of attrs in foreign namespace to not admit unqualified attrs.

Action: [GA] need to ensure that we document whether time intervals
are half-opened intervals or closed. We always use half-opened intervals
for [begin,end) = [begin,begin+dur).

Action: [GA] ensure there is language that gives precendence to
end over dur in case both are specified.

Action: [GA] remove region attribute from span element.

Closed. Obviated by new content to region mapping algorithm.

Action: [GA], prompted by [SH], need to define what is meant by begin
attribute on <body>.


Action: [KB] lookup whether default time container for SMIL body is
seq or par. Report back by tomorrow (9/16).

Done. It was "seq".

Action: [GA] add table indicating default values for timeContainer.


Action: [GA] remove nested <span> support from schema and span
element definition.


Action: [GA] Update schema to permit multiple tts:* attributes on
style element.


Action: [GA] make style attribute IDREFS instead of ID.


Action: [GA] add style attribute to <g/>.

Closed. <g/> not supported in DFXP; however, need to ensure it is
present in AFXP.

Action: [GA] change region so that it uses style attribute to
refer to styles in addition to defining them inline as children.


Action: [GA] need to establish precedence for different style
association mechanisms as follows, with priority order as follows:
(1) inline, (2) referential or chained referential, (3) region
referential. In case that referential or chained referential results
in a diamond graph, then last instance of style in pre-order depth
first traversal wins.


Action: [SH] will research issue of interaction of combination rule
#2 and region referential styling.

Action: [GA] add <p> and <span> to list of elements to which
background-color applies


Action: [GA] change initial value of color style property to
transparent. [N.B. consequence of this is that unless author
specifies a color, then content will be invisible.]


Action: [GA] restore "inherit" value for style properties.


Action: [GA] specify language about meaning of line height.

Action: [GA] formulate proposal to express coordinates in rows
and columns and to express total # of rows/cols for which content was

Partially done. Needs more work.

Action: [GA] change DFXP schema and WD to use <meta> instead of


Action: [DK] Discuss with [MD] how to express pull-down parameters to
completely characterize frame and field composition.


Action: [GA] need to add following metadata items to schema and spec:
ttm:frame-rate ttm:frame-width ttm:frame-height
ttm:pixel-aspect-ratio ttm:content-width ttm:content-height
ttm:content-x ttm:content-y ttm:horizontal-resolution

Done. [But subsequently changed to use different (TT Paramemter)
namespace and to not support frame extent or content origin; use
tts:extent on <tt/> to express content extent. Remove h/v-res.]

Action: [GA] need to specify semantics for each metadata item, need
to specify what it means if multiple items with same name are present
in some context, and if not permitted, expected behavior.


Action: [GA] add definitions of following metadata elements to schema
and spec for DFXP: ttm:agent, ttm:name, ttm:givenName,
ttm:familyName, ttm:actor. Also add ttm:agent attribute to <p> and

Done. [Note that name, giveName, and familyName are collapsed, and
use a type attr to specify type of name.]

Action: [GA] add ttm:title, ttm:description, ttm:copyright to schema
and spec for DFXP.


Action: [GA] ensure that all elements can also take ttm:* attributes,
but need to define in context of specific elements which ones have
standard semantics.

Action: [GA] define semantics of ttm:agent metadata attribute such that
inner specifications override outer specifications, e.g.,

Action: [GA] change text-shadow to text-outline with value syntax as
follows: none | <color> <thickness> <blur-radius>, where thickness and
blur-radius are expressed as <length>.

Done. Remove text-shadow, support only text-outline.

Action: [GA] add span to wrap-option "applies to".

Done. Now specified as applies to span only, but inheritable.

Action: [GA] for each AFXP style property that we don't include in DFXP,
need to specify a normative default value for DFXP, but do so in a way
that doesn't require normative use of AFXP specification.

Action: [GA] since <color>s are opaque, need to say so in verbiage.

Action: [GA] Remove misspelled "monotype" entry from <generic-family-
name>, and replace it with "default". All other entries are also to be
removed for present time.


Action: [GA] Add row/col units to <length> style value expression.

Done. Express as "c" meaning "cells".

Action: [GA] Ensure that if we define overflow="clip" on region that
we say that outermost region is expected to be clipped in all cases.

Action: [GA] change overflow attribute on region to use tts:overflow
style property, which applies only to region, and which supports values:
visible, hidden, inherit.

Done. [Note also later introduction of "dynamic" value.]

Action: [GA] Change clock-value syntax to support expressing optional
frames and subframes in order to express NPT media times. Define clock
value semantically to be NPT for TT media object. Remove optional "+"
value from offset-expression (in which case we don't need "offset-
expression" intermediate term).


Action: [GA] allow style to use style attribute to refer to other
styles, since we effectively now allow <style> to work like a group of


Action: [GA] remove "div" from display-align's applies to list. Can't
apply to div since div has no explicit height/width.


Action: [GA] Add ttm:default-time-metric metadata item. Takes
values that are one of time-count metric, e.g., "h", "m", "s",
"f", etc.

Done. See ttp:defaultTimeMetric.

Action: [GA] send John's document to WG reflector, then (at some point
in future) ask him to send to public list so it can be handled as public

Action: [GA] Add informative Annex to DFXP spec which enumerates the
requirements of TT-AF-1-0-REQ which are intentionally not intended to
be met in DFXP.

Done. See Annex E.

Action: [KB] Review the March 2002 TT Task Force requirements to see if
the current TT-AF-1-0-REQ does not include all those earlier
and if not, then make a case for including in TT-AF-1-0-REQ. [TM] will
help as required and report back to WG.

Action: [DB] to send draft intro text with example by Monday (10/04).

Closed. [GA] wrote intro text.

Action: [MD] to send normative text descriptions of SMPTE marker labels.
Will send after returning from vacation in a week's time.


Action: [DS] to send font registration I-D to IETF editors for


Action: [GA] To make necessary chanes to DFXP draft to support ttm:desc
and ttm:title in contexts where tt:meta can appear.


Action: [GA] To send minutes with attached lastest draft (in the form
of an "editor's copy") of DFXP to public TT reflector by end of day
on Oct 18 unless objection arises from some member.


Action: [GA] send email to reflector on need to distinguish between
outer media time and timebase time (based on parent relationships);
is as follows: if you have begin="00:00:01", then does this denote
1 sec in time base established by parent element, or does it denote
1 sec into the TT media object (independently of parent timebases)?
Can one mix both timebase times and outer media times?

Done. See ttp:timeBase parameter.

Action: [GA] to complete DFXP draft 6 and sent to member reflector
by noon ET on Tuesday, 10/26/04, then work with [TM] to request
publishing as Public WD.


Action: [TM] to draft request for [GA] to send to appropriate parties
to begin process of advancing DFXP to public WD.


Action: [GA] To verify that TTPRO DB is well configured to handle
DFXP comments.

Action: [DK] To help verify that TTPRO DB is populated with open
DFXP issues.

Action: [GA] Will resolve any issues about having F2F with W3T
(Philipp Hoschka) and report results.


Action: [GA] To send notice to reflector and request Thierry to post
standard meeting participation info.


Action: [MD] Will review and propose changes/additions as necessary
regarding ttm:role values.

Done. See [3] and [4].

[3] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0017.html
[4] http://lists.w3.org/Archives/Member/member-tt/2004Nov/0060.html

Action: [MD] Will review and propose changes/additions as necessary
regarding ttm:frame-rate and use of time values.

Done. See [3].

Action: [DK] to submit input from EBU/AAF adhoc on following topics:
(1) use of metadata to announce languages used in document; (2) use
of metadata to categorize subtitles, e.g., closed vs open;

Done. See [5].

[5] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0001.html

Action: [SH] to submit message to reflector on text-outline issue;

Action: [GF] to update example of background-color to include different
colors for div, p and span.


Action: [GF] to review style examples for need to add depictions of
enumerated values of styles;


Action: [GA] Remove last sentence of 3rd para of 4.1.5; see [12] -
item 11.


Action: [GA] Address typos reported by [12] - items 4-10, 12


Action: [DB] to send proposal for using root-layout element to


Action: [KB] to review metadata for content adaptation workshop
presentations [15] to see if there is relevant input to our work on

Action: [GA] to investigate and propose definition of whitespace
normalization to apply when xml:space="default".


Action: [GA] add language under namespace and/or conventions section
indicates that if an element type is used unqualified in spec then it is
in tt: namespace.

Action: [GA] need to add definition of "S" non-terminal used in 5.2.5.

Action: [GA] consider need for tts:display in context of using <set/>.

Done. Add tts:display.

Action: [GA] Change all names to camelCase form.


Action: [GA] Remove editorial note in 5.3.4; already covered by text in
2nd paragraph.


Action: [GA] Add text to 5.3.4, saying that the concrete font used to
map monospace-* and proportional-* should be monospace, proportional,

Done. Define mapping to be system dependent.

Action: [GA] further research required on quoted-string.

Action: [DK] to obtain permission and propose language for proper
attribution in acknowledgments annex.

Done. Final resolution is that permissions not obtainable in
reasonable time period. Replace all samples with public domain

Action: [DK] will elaborate examples in [*] (1), dividing into 3: (a)
showing mixed language material; (b) separate translations of same
material in different documents; (c) mixture of separate translations
in same document, where (c) is explicitly disrecommended.

[*] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0010.html

Done. See [6].

[6] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0024.html

Action: [GA] formulate proposal for metadata in head that enumerates
language usage.

Closed. Obviated by subsequent decision to use standard xml:lang
semantics without calling out any special usage or constraints.

Action: [DK] Change example in [*] (2) to use "x-open" and "x-closed"
for ttm:role values.

Done. See [6].

Action: [DK] Change "characters" to "columns" and "lines" to "rows"
in [*] (3).

Done. See [6].

Action: [DK] Change "considered" to "included" in [*] (4)

Done. See [6].

Action: [DK] Change to read "TTWG is considering"in [*] (8).

Done. See [6].

Action: [DK] Change to present tense in [*] (9).

Done. See [6].

Action: [DK] in [*] (10) cite 3rd para of 4.1.2 and use example of
ttm:agent metadata being defined in either <head/> or under a content
element, such as <p/>.

Done. See [6].

Action: [GA] Propose document level property to express how to interpret
time expressions, with values: internal-media, external-media,
and smpte-non-linear; should be extensible list.

Done. See ttp:timeBase.

Action: [GA] send email documenting counter-proposal to root-layout.


Action: [DK]|[GF] respond to query at [2].

Action: [TM] check on whether we can update charter time schedule to
reflect new schedule.

Action: [GA] to verify policty regarding need of transition request to
go to LC.

Done. No transition request required.

Action: [TM] send pointer to QA WG docs on test planning to reflector.

Action: [GA] add ttp:frame-rate-multiplier, ttp:sub-frame-rate,
ttp:smpte-mode, ttp:timebase parameters to DFXP LC draft.

Done. See ttp:frameRateMultiplier, ttp:subFrameRate,
ttp:markerMode, and ttp:timeBase.

Action: [GA] propose mechanism or language in DFXP LC draft that
permits use of ticks, which may or may not be related any way to
video frames.

Done. See ttp:tickRate.

Action: [GA] update LC draft to express all ttp:* on root element.


Action: [DS] to draft informative language regarding streaming
DFXP; [GA] as backup of [DS] fails to produce.

Done. See Annex F of latest WD.

Action: [TM] reserve slot on Feb 9 for publishing LC.


Action: [GA] to finalize and incorporate fixes, with update before
Feb 4 COB; send request to reflector on Feb 7 for agreement to publish
as LC; notify [TM] by 1200 Eastern on Feb 8 with GO/NOGO decision;


Action: [GF] To prepare alternative script examples based on text
that is in public domain, e.g., Lewis Carroll, Shakespeare.


Action: [TM] Inform tech plenary organizers that TT WG will not meet on
Mar 3-4.


Action: [GA] Announce meeting change to TT reflector.


Action: [TM] Update TTWG meeting page to reflect change from Mar 3-4 to
Apr 11-13 for next F2F.


Action: [TM] Move http://www.w3.org/TR/2005/WD-ttaf1-dfxp-20050209
to to http://www.w3.org/AudioVideo/TT/Group/Drafts/2005, replacing
schema modules with recently transmitted update.


Action: [TM] Schedule publishing slot on Feb 18 or Feb 17 for 2nd public



See Issue DB.

*** Upcoming Meetings ***

Telecon for next week (03/03) cancelled due to [GA] travel; next
telecon will be 03/10;

F2F - Apr 11-13/2005 - Mt View, CA (Apple)

*** URIs ***

[1] http://www.w3.org/TR/unicode-xml/#Bidi
[2] http://lists.w3.org/Archives/Member/member-tt/2004Nov/0011.html
[3] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0017.html
[4] http://lists.w3.org/Archives/Member/member-tt/2004Nov/0060.html
[5] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0001.html
[6] http://lists.w3.org/Archives/Member/member-tt/2004Dec/0024.html

Received on Monday, 11 April 2005 22:30:34 UTC

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