ISSUE-313: Presented Region section is informative only

Presented Region is informative only

Presented Region section is informative only

State:
CLOSED
Product:
TTML IMSC 1.0
Raised by:
Nigel Megitt
Opened on:
2014-05-21
Description:
The definition of Presented Region [1] appears intended to add no information relative to what is in TTML1SE. I suggest making it informative rather than normative.

However it does differ in that in TTML1SE temporally active regions with opacity=0 will be included in the intermediate synchronic document construction. Note that TTML1SE does not actually define "temporally active" directly as used in §9.3.2 Intermediate Synchronic Document Construction (though it may be implied by reference to SMIL semantics). Another solution to this issue would therefore be to rephrase in terms of a localised definition of "temporally active" as applied to regions.

For example:

A region, as defined in [TTML1], is considered temporally active if all of the following conditions are true:
...

Arguably this should be captured in an errata to TTML1SE and not needed in IMSC 1.0 at all.

[1] http://www.w3.org/TR/ttml-imsc1/#presented-region
[2] http://www.w3.org/TR/ttml1/#semantics-region-layout-step-1
Related Actions Items:
Related emails:
  1. 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] (from nigel.megitt@bbc.co.uk on 2014-08-13)
  2. 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] (from nigel.megitt@bbc.co.uk on 2014-08-13)
  3. 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] (from pal@sandflow.com on 2014-08-12)
  4. {agenda} TTWG Meeting 31/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-30)
  5. 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] (from nigel.megitt@bbc.co.uk on 2014-07-28)
  6. 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] (from nigel.megitt@bbc.co.uk on 2014-07-28)
  7. 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] (from glenn@skynav.com on 2014-07-28)
  8. ISSUE-330 (Is Presented Region a synonym for temporally active region?): Is Presented Region a synonym for temporally active region? [TTML IMSC 1.0] (from sysbot+tracker@w3.org on 2014-07-28)
  9. {minutes} TTWG Meeting 24/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-24)
  10. {agenda} TTWG Meeting 24/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-23)
  11. Re: Revised ED of IMSC (from pal@sandflow.com on 2014-07-22)
  12. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from pal@sandflow.com on 2014-07-22)
  13. RE: Revised ED of IMSC (from John.Birch@screensystems.tv on 2014-07-22)
  14. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from glenn@skynav.com on 2014-07-21)
  15. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from nigel.megitt@bbc.co.uk on 2014-07-21)
  16. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from glenn@skynav.com on 2014-07-21)
  17. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from nigel.megitt@bbc.co.uk on 2014-07-21)
  18. Re: ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from pal@sandflow.com on 2014-07-20)
  19. Revised ED of IMSC (from pal@sandflow.com on 2014-07-17)
  20. {minutes} TTWG Meeting 17/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-17)
  21. {agenda} TTWG Meeting 17/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-16)
  22. {agenda} TTWG Meeting 10/7/2014 (from nigel.megitt@bbc.co.uk on 2014-07-09)
  23. Re: ACTION-302: Re-review issue-313 (Timed Text Working Group) (from nigel.megitt@bbc.co.uk on 2014-06-20)
  24. {minutes} TTWG Meeting 19/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-19)
  25. RE: {agenda} TTWG Meeting 19/6/2014 (from mdolan@newtbt.com on 2014-06-18)
  26. {agenda} TTWG Meeting 19/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-18)
  27. RE: {agenda} TTWG Meeting 12/6/2014 (from mdolan@newtbt.com on 2014-06-12)
  28. Re: {agenda} TTWG Meeting 12/6/2014 (from pal@sandflow.com on 2014-06-11)
  29. Re: {agenda} TTWG Meeting 12/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-11)
  30. Re: {agenda} TTWG Meeting 12/6/2014 (from pal@sandflow.com on 2014-06-11)
  31. Re: {agenda} TTWG Meeting 12/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-11)
  32. {agenda} TTWG Meeting 12/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-11)
  33. RE: {agenda} TTWG Meeting 5/6/2014 (from mdolan@newtbt.com on 2014-06-04)
  34. {agenda} TTWG Meeting 5/6/2014 (from nigel.megitt@bbc.co.uk on 2014-06-04)
  35. {agenda} TTWG Meeting 29/5/2014 (from nigel.megitt@bbc.co.uk on 2014-05-28)
  36. {agenda} TTWG Meeting 22/5/2014 (from nigel.megitt@bbc.co.uk on 2014-05-21)
  37. ISSUE-313 (Presented Region is informative only): Presented Region section is informative only [TTML IMSC 1.0] (from sysbot+tracker@w3.org on 2014-05-21)

Related notes:

This is also related to Issue-314 [1] which I've raised on TTML1.

[1] https://www.w3.org/AudioVideo/TT/tracker/issues/314

Nigel Megitt, 21 May 2014, 13:18:31

Right. The section contains no conformance language, so it is informative. It is intended as a definition since the concept is used multiple times in IMSC and TTML 1 does not define an equivalent concept. Are you suggesting moving the section to a Definition section?

Pierre-Anthony Lemieux, 21 May 2014, 22:46:44

No, definitions are normative too. It should just be marked as informative.

Nigel Megitt, 22 May 2014, 13:36:53

If "Presented Region" is used in normative provisions throughout the document, why shouldn't it be a definition? Can you point us to an equivalent term in TTML 1?

Pierre-Anthony Lemieux, 22 May 2014, 23:45:02

I've re-reviewed this as per Action-302. There seem to be a few questions to resolve:

1. Is §4.6.1 where Presented Region is defined normative?

According to the text in §2 Conformance, it does not fall under any of the exceptions so it is normative. However the text neither describes processing behaviour nor syntax nor semantics, so logically removing it (in its current state) would have zero effect - I guess this is what Pierre meant in his comment of 21st May.

2. Is Presented Region a term used in normative sections?

Yes, clearly it is, a simple search reveals the uses of the term.

3. Is Presented Region a defined term?

No, there's no Definitions section and the prose in §4.6.1 describes when a region is presented not explicitly the term 'Presented Region' - to my mind merely making Presented Region the title of the section doesn't by itself qualify the section as a definition of that term.

4. Is there already an equivalent concept to Presented Region defined in TTML1SE?

Yes - this is "temporally active region" as used in §9.3.2 of TTML1SE. However the same problem of definition arises there, i.e. this term is not defined. I have raised this as ISSUE-314.


So the question is what action to take to resolve this issue: If we resolve ISSUE-314 with an erratum on TTML1SE then we can reference it from IMSC1 and use the common term "temporally active region". I would prefer this to creating a duplicate term "Presented Region" unless there is a difference between the two concepts. If the two concepts are different then I would propose to resolve this by the addition of a Definitions section and defining within it "Presented Region" as "a region that is temporally active and is presented in a given Intermediate Synchronic Document, as defined in §4.6.1".

If we can not resolve ISSUE-314 with an erratum then we must define both concepts in IMSC1.

Nigel Megitt, 20 Jun 2014, 16:18:50

[nigel]: An acceptable proposal would be to change the wording in §4.6.1 specifically to define the term "Presented region".

17 Jul 2014, 14:20:57

Changelog:

Created issue 'Presented Region section is informative only' nickname Presented Region is informative only owned by Nigel Megitt on product TTML IMSC 1.0, description 'The definition of Presented Region [1] appears intended to add no information relative to what is in TTML1SE. I suggest making it informative rather than normative.

However it does differ in that in TTML1SE temporally active regions with opacity=0 will be included in the intermediate synchronic document construction. Note that TTML1SE does not actually define "temporally active" directly as used in §9.3.2 Intermediate Synchronic Document Construction (though it may be implied by reference to SMIL semantics). Therefore another solution to this issue would therefore be to rephrase in terms of a localised definition of "temporally active" as applied to regions.

For example:

A region, as defined in [TTML1], is considered temporally active if all of the following conditions are true:
...

Arguably this should be captured in an errata to TTML1SE and not needed in IMSC 1.0 at all.

[1] http://www.w3.org/TR/ttml-imsc1/#presented-region
[2] http://www.w3.org/TR/ttml1/#semantics-region-layout-step-1' non-public

Nigel Megitt, 21 May 2014, 13:03:36

Description changed to 'The definition of Presented Region [1] appears intended to add no information relative to what is in TTML1SE. I suggest making it informative rather than normative.

However it does differ in that in TTML1SE temporally active regions with opacity=0 will be included in the intermediate synchronic document construction. Note that TTML1SE does not actually define "temporally active" directly as used in §9.3.2 Intermediate Synchronic Document Construction (though it may be implied by reference to SMIL semantics). Another solution to this issue would therefore be to rephrase in terms of a localised definition of "temporally active" as applied to regions.

For example:

A region, as defined in [TTML1], is considered temporally active if all of the following conditions are true:
...

Arguably this should be captured in an errata to TTML1SE and not needed in IMSC 1.0 at all.

[1] http://www.w3.org/TR/ttml-imsc1/#presented-region
[2] http://www.w3.org/TR/ttml1/#semantics-region-layout-step-1'

Nigel Megitt, 22 May 2014, 13:33:43

Status changed to 'pending review'

Pierre-Anthony Lemieux, 6 Jun 2014, 23:33:08

Status changed to 'open'

Nigel Megitt, 9 Jul 2014, 15:06:03

Status changed to 'closed'

24 Jul 2014, 14:40:38


David Singer <singer@apple.com>, Nigel Megitt <nigel.megitt@bbc.co.uk>, Chairs, Thierry Michel <tmichel@w3.org>, Philippe Le Hégaret <plh@w3.org>, Atsushi Shimono <atsushi@w3.org>, Staff Contacts
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