Re: ISSUE-330 (Is Presented Region a synonym for temporally active region?): Is Presented Region a synonym for temporally active region? [TTML IMSC 1.0]

No, temporally active region and presented region are not synonymous.
Further, showBackground="whenActive" does not mean "when temporally
active", rather it means "when temporally active and has content selected
into it". As such it is a bit of a misnomer, but we adopted the name from
SMIL and repurposed it to our ends.

See my additional comments in Issues 314 and 330.


On Mon, Jul 28, 2014 at 6:56 AM, Timed Text Working Group Issue Tracker <
sysbot+tracker@w3.org> wrote:

> ISSUE-330 (Is Presented Region a synonym for temporally active region?):
> Is Presented Region a synonym for temporally active region? [TTML IMSC 1.0]
>
> http://www.w3.org/AudioVideo/TT/tracker/issues/330
>
> Raised by: Nigel Megitt
> On product: TTML IMSC 1.0
>
> This issue is related to Issue-314 and was generated as part of the
> resolution to Issue-313.
>
> TTML 1 SE §9.3.2 [1] uses the term "temporally active region" to define
> regions that are included in the construction of intermediate synchronic
> documents "for the purposes of performing presentation processing".
> Issue-314 covers the point that this term is not defined.
>
> [1] http://www.w3.org/TR/ttml1/#semantics-region-layout-step-1
>
> IMSC 1 editor's draft §4.6.1 [2] defines and uses the term "presented
> region" to define regions that may be presented at any moment, and in all
> but one case references presented region with respect to an intermediate
> synchronic document.
>
> [2]
> https://dvcs.w3.org/hg/ttml/raw-file/tip/ttml-ww-profiles/ttml-ww-profiles.html#presented-region
>
> It looks as though these two terms may be synonyms, or very closely
> related to each other. If this is the case then IMSC 1 should reference the
> defined term in TTML 1 SE (if need be, after the resolution to Issue-314).
> If it is not the case then the difference should be clarified making
> reference to the similar concept.
>
> For example, if the resolution to Issue-314 is to define temporally active
> region in TTML 1 SE as any region that is either temporally active or has
> content selected into it that is temporally active, or has
> showBackground="always", then Presented Region in IMSC 1 may be defined as:
>    any temporally active region which satisfies all of the following
> conditions...,
>    where those conditions include [those currently specified] and those
> noted additionally by Glenn in response to Issue-313 [3], i.e. the values
> of the attributes tts:display, tts:visibility, tts:extent and tts:opacity
> are such that marks may be made by the region or its contents.
>
> [3] http://lists.w3.org/Archives/Public/public-tt/2014Jul/0036.html
>
> This issue created as per Action-308.
>
>
>
>