W3C home > Mailing lists > Public > public-tt@w3.org > May 2009

feature review

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Fri, 15 May 2009 14:05:36 +0100
To: Timed Text Working Group WG <public-tt@w3.org>
Message-ID: <AB3FC8E280628440B366A29DABB6B6E8075D4F5397@EA-EXMSG-C334.europe.corp.microsoft.com>
I have been reviewing the features set, and while I mostly agree with Glenn's formulation, I have a few suggested changes. These are based on the principles that:

any transformation processor should be required to understand timed text completely at the syntactic level,

and that any presentation processor should be able to perform all of the timing, and all of the styling mechanics, (but not any specific styling properties) necessary in creating a synchronic XSL:FO document.

for clarity in the features themselves:

I propose #content be added to #structure, as well as the syntactic aspects of #layout and #styling and thus required in the transformation and presentation profile
I propose #nested-div and #nested-span also be required in transformation and presentation profile, (and actually considered part of #content)
I propose #styling-inheritance-region be required in the presentation profile (In fact I propose that all the styling mechanics be rolled up as indivisible #styling and required in presentation profile.)

I propose that #attribute be defined to generically replace all of the lines of the form:
     A TT AF transformation processor supports the #X feature if it recognizes and is capable of transforming all defined values of X attribute.

With wording:
A TT AF transformation processor supports the #attribute feature if it recognizes and is capable of transforming all attribute vocabulary of this specification.
A TT AF presentation processor supports the #attribute feature if it implements all semantic support for attribute value resolution for all attribute vocabulary of this specification.

I propose we merge #time-clock into #time-offset and  #time-clock-with-frames into #time-offset-with-frames; these don't have an independent semantics based on SMIL2.1 (http://www.w3.org/TR/2005/REC-SMIL2-20051213/smil-timing.html#Timing-OffsetValueSyntax ), except when markerMode is specified in which case #markerMode is the option.

All specific style property features should be optional, with only# fontSize-isomorphic requiring special handling (it would be mandatory for visual  presentation, and optional for audible or tactile presentation).

I think there may need to be some consolidation in the #dynamicFlow features too, but I haven't analysed that yet.

At some point I think we need to develop a caption profile which builds on the minimal presentation profile but is actually useful for web captioning (this is work for post Rec.) In order to facilitate that discussion though, I'd like to separate out at this stage the feature tables into the following:

Core: (required in any profile (#)= to be eliminated by rolling into other buckets in this table)
#attribute
#content

#core

#metadata

#nested-div (#)

#nested-span (#)

#profile

#structure

The following are required by any presentation profile

#layout
#styling

#styling-chained (#)

#styling-inheritance-content (#)

#styling-inheritance-region (#)

#styling-inline (#)

#styling-nested (#)

#styling-referential( #)



Aspects of timing that can be independently selected
Timing - (PP)= should be mandatory in any presentation profile.

#animation
#clockMode

#frameRate

#frameRateMultiplier
#markerMode

#smpteMode

#subFrameRate

#tickRate

#timeBase-clock

#timeBase-media (PP)

#timeBase-smpte

#time-clock (PP)

#time-clock-with-frames

#timeContainer

#time-offset (PP)

#time-offset-with-frames

#time-offset-with-ticks

#timing (PP)


Style - all of these are optional except #fontSize-isomorphic which is required for visual presentation, but which may be ignored by aural or Braille display.

#backgroundColor

#backgroundColor-block

#backgroundColor-inline

#backgroundColor-region

#bidi

#cellResolution

#color

#direction

#display

#displayAlign

#display-block

#display-inline

#display-region

#dynamicFlow

#dynamicFlow-block

#dynamicFlow-character

#dynamicFlow-glyph

#dynamicFlow-in

#dynamicFlow-inline

#dynamicFlow-inter

#dynamicFlow-intra

#dynamicFlow-jump

#dynamicFlow-line

#dynamicFlow-out

#dynamicFlow-smooth

#dynamicFlow-teletext

#dynamicFlow-word

#extent

#fontFamily

#fontFamily-generic

#fontFamily-non-generic

#fontSize

#fontSize-anisomorphic

#fontSize-isomorphic

#fontStyle

#fontStyle-italic

#fontWeight

#fontWeight-bold

#length

#length-cell

#length-em

#length-integer

#length-negative

#length-percentage

#length-pixel

#length-positive

#length-real

#lineHeight

#opacity

#origin

#overflow

#overflow-dynamic

#padding

#padding-1

#padding-2

#padding-3

#padding-4

#pixelAspectRatio

#rollup

#showBackground

#textAlign

#textAlign-absolute

#textAlign-relative

#textDecoration

#textDecoration-over

#textDecoration-through

#textDecoration-under

#textOutline

#textOutline-blur

#unicodeBidi

#visibility

#visibility-block

#visibility-inline

#visibility-region

#wrapOption

#writingMode

#writingMode-horizontal

#writingMode-horizontal-lr

#writingMode-horizontal-rl

#writingMode-vertical

#zIndex


Sean Hayes
Media Accessibility Strategist
Accessibility Business Unit
Microsoft

Office:  +44 118 909 5867,
Mobile: +44 7875 091385
Received on Friday, 15 May 2009 13:06:28 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 2 November 2009 22:41:42 GMT