Re: Old technical input for TTML 1.0

On Thu, May 10, 2012 at 4:21 PM, Philippe Le Hegaret <plh@w3.org> wrote:

> For the purpose of review the charter, it would help me to understand
> the position of the Group on the following input:
>
> [[
> Reference to XML 1.1 are in the text (in Normative section D.1) and not
> in the Reference section
>

should update reference section


>
> Why UAAG and WCAG are using version 1.0 instead of 2.0 ?
>

UAAG 2.0 is in WD, not REC  at time of TTML 1.0 REC

TTML does refer to WCAG 2.0 already


>
>
> Namespace 1.0 is now at 3rd Edition
>

2ed. can be updated to Namespaces in XML 1.1 (Second Edition) [1]

[1] http://www.w3.org/TR/xml-names11/


>
> How is TTML supposed to be integrated in HTML5 ?
>

not yet defined; can be informatively addressed in 2nd Ed.


>
> Content model of p is Content: Metadata.class*, Animation.class*,
> Inline.class* : I'm surprised by this content model since XML Schema and
> DTD cannot enforced it (Text is always mixed)
>

XML Schema is not used to define the normative syntax for TTML [2]

[2] http://www.w3.org/TR/ttaf1-dfxp/#schemas

"In any case where a schema specified by this appendix differs from the
normative definitions of document type, element type, or attribute type as
defined by the body of this specification, then the body of this
specification takes precedence."


> Why isn't xml:base allowed ?
>

because there are no URIs in TTML content


>
> Why all the examples are putting one attribute per style element ?


not correct, the example in 1.2 [3] under *Example Fragment - TTML
Style*uses multiple styles per element

[3] http://www.w3.org/TR/ttaf1-dfxp/#example

What are the added values ?
>

don't understand question... what is "added values"?


> <region xml:id="r3">
> <style tts:extent="128px 66px"/>
> <style tts:origin="0px 132px"/>
> <style tts:backgroundColor="black"/>
> <style tts:color="white"/>
> <style tts:displayAlign="before"/>
> <style tts:textAlign="start"/>
> </region>
>
> In 8.3.6, how are genericFamilyName defined ? in XSL 1.1 or CSS 2.0 only
> "serif", "sans-serif", "cursive", "fantasy", and "monospace" are
> defined ?
>

see [4] and specifically:

"The mapping between a generic (font) family name and an actual font is not
determined by this specification; however, the distinction of monospace
versus proportional and serif versus sans-serif should be maintained if
possible when performing presentation."

[4] http://www.w3.org/TR/ttaf1-dfxp/#style-value-genericFamilyName


> Using c for cell is a very bad idea because it is incompatible with
> existing CSS library because of "cm" for centimeter ; CSS units uses
> "gd" for grid so it might be better to sync with CSS Values
> http://www.w3.org/TR/css3-values/#lengths


at the time TTML 1.0 was published, neither XSL-FO nor CSS defined a unit
that was appropriate to a fixed grid layout; use of "gd" may be considered
for a future 1.1 or following revision of TTML, but was not defined at time
of TTML 1.0; furthermore, CSS3 values is a WD, and not close to REC


> In 8.2.12, how does tts:lineHeight work with a value with unit "c" ?
>

ttp:cellResolution [5] allows precise determination of cell size, i.e.,
divide root container extent in width and height by number of cells in
width and height; in turn, this yields precise determination of lineHeight
in pixels

[5] http://www.w3.org/TR/ttaf1-dfxp/#parameter-attribute-cellResolution


>
> In 8.3.1, <alpha> uses XML Schema "float" definition. But in XML Schema
> float allow the value "INF", "-INF", "NaN" and "10e-3" ? It is really
> worth the complexity of allowing the XML Schema definition ? It's
> probably wiser to use http://www.w3.org/TR/css3-values/#non-negative


CSS3 values is a WD, not close to REC


> In 8.3.2 Colors aren't compatible with CSS colors that are #rgb and not
> #rrggbbaa ; It should be aligned with this spec
> http://www.w3.org/TR/css3-color/#rgb-color


#rrggbbaa is an extension of CSS Color Module Level 3 [6]

[6] http://www.w3.org/TR/css3-color/#rgba-color

it was not a requirement to be syntactically limited to CSS values #rrggbb


> In 8.2.19 tts:textDecoration are inventing new values (noUnderline,
> etcc.)
>

not correct, noUnderline, etc., correspond to XSL-FO (and CSS) definitions
no-underline, etc.; TTML maps these property values to their camel case
equivalent as described in tts:textDecoration note 1 [7]

[7] http://www.w3.org/TR/ttaf1-dfxp/#attribute-vocab-derivation-table


>
> In short, many values are underdefined, redefined and misleading in many
> case and doesn't allow reuse of existing library
>

comment is not sufficiently specific to comment or respond


> This specification should better integrated other W3C specifications
>

TTML was defined and published as an independent specification. It was not
a requirement to define how to integrate with other W3C specifications. See
also Disposition of Comments for TTML Last Calls [8][9]

[8] http://www.w3.org/2005/03/21/DFXPLastCallResponses.html
[9] http://www.w3.org/2005/03/21/DFXP-2ND-LastCallResponses.html

It is possible to define how to make use of  TTML with HTML5, and such
definition may be provided in TTML 1.0 Second Edition as a result of new
work chartered in the TTWG. Note that a bug is filed against HTML5 to make
the text track mechanism more neutral to the content type of a timed text
track [10].

[10] https://www.w3.org/Bugs/Public/show_bug.cgi?id=13359