ISSUE-367: Clarify initial value override for tts:textAlign
#textAlign clarification
Clarify initial value override for tts:textAlign
- State:
- CLOSED
- Product:
- TTML IMSC 1.0
- Raised by:
- Nigel Megitt
- Opened on:
- 2015-01-27
- Description:
- The feature list in §7.4 of the IMSC 1 CR specifies for #textAlign:
> MAY be used. The initial value of tts:textAlign shall be "center" for the default region. NOTE: This is consistent with [ST2052-1].
This is somewhat subtle, and doesn't indicate that it's a variation from TTML1SE. I propose the following edited version:
> MAY be used. The initial value of tts:textAlign shall be "center" for the default region only. NOTE: This is consistent with [ST2052-1] but differs from TTML1SE. Document authors are recommended not to rely on the initial value for text alignment in the default region but to specify the tts:textAlign attribute explicitly to generate the expected presentation by both generic TTML1SE and IMSC 1 presentation processors.
I also propose appending this wording to the #layout feature in §6.10:
> NOTE: Authors are recommended to define and reference a region rather than relying on the default region, to avoid inconsistent presentation between generic TTML1SE and IMSC 1 presentation processors resulting from the different initial value of tts:textAlign for the default region. See also #textAlign.
This is an editorial clarification rather than a substantive change. - Related Actions Items:
- No related actions
- Related emails:
- Second CR for IMSC1 (from pal@sandflow.com on 2015-05-04)
- {minutes} TTWG Meeting 2015-04-02 (from nigel.megitt@bbc.co.uk on 2015-04-02)
- Re: List of changes since the IMSC1 CR (from pal@sandflow.com on 2015-04-02)
- {agenda} TTWG Meeting 2015-04-02 (from nigel.megitt@bbc.co.uk on 2015-04-01)
- List of changes since the IMSC1 CR (from pal@sandflow.com on 2015-03-30)
- {minutes} TTWG Meeting 2015-03-26 (from nigel.megitt@bbc.co.uk on 2015-03-26)
- {agenda} TTWG Meeting 2015-03-26 (from nigel.megitt@bbc.co.uk on 2015-03-25)
- {minutes} TTWG Meeting 2015-01-29 (from nigel.megitt@bbc.co.uk on 2015-01-29)
- {agenda} TTWG Meeting 2015-01-29 (from nigel.megitt@bbc.co.uk on 2015-01-28)
- Re: ISSUE-367 (#textAlign clarification): Clarify initial value override for tts:textAlign [TTML IMSC 1.0] (from glenn@skynav.com on 2015-01-27)
- ISSUE-367 (#textAlign clarification): Clarify initial value override for tts:textAlign [TTML IMSC 1.0] (from sysbot+tracker@w3.org on 2015-01-27)
Related notes:
I have no problem with this if there is added to the note the following:
"TTML1 requires the initial value of tts:textAlign to be interpreted as start. An IMSC1 processor that interprets the initial value of tts:textAlign as center is not compliant with TTML1; specifically, it is not compliant with Section 3.2.1, item (5)."
Per 20150319 telecon: remove constraints on displayAlign and textAlign initial values.
Pierre-Anthony Lemieux, 20 Mar 2015, 03:18:22Addressed at https://dvcs.w3.org/hg/ttml/rev/50e39c06d413
Pierre-Anthony Lemieux, 20 Mar 2015, 03:30:45Display change log