ISSUE-328: ittm:altText should be in TT namespace in TTML 2.0

John Birch

ittm:altText should be in TT namespace in TTML 2.0

Raised by:
John Birch
Opened on:
NOTE: This issue assumes that smpte:backgroundImage is also promoted to a TTML 2.0 namespace element or equivalent functionality (See ISSUE 238).

At present in IMSC, the smpte:backgroundImage element is used in a document conforming to the image profile as a child element of a containing div. However the *text equivalent* supported by the ittm:altText element must be placed as a child of a metadata element that is itself a child of that div.

This position of the ittm:altText under a metadata child contradicts the 'equivalence' of the two elements and diminishes the value of the altText tag and unnecessarily increases the verbosity of the document.

Subject to ISSUE 238, it is suggested that ittm:altText should be deprecated in favour of a native ttml element that is placed at the *same document level* as any new TTML 2.0 background image element.
Related Actions Items:
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Related emails:
  1. {minutes} TTWG Meeting 24/7/2014 (from on 2014-07-24)
  2. {agenda} TTWG Meeting 24/7/2014 (from on 2014-07-23)
  3. ISSUE-328 (John Birch): ittm:altText should be in TT namespace in TTML 2.0 [TTML2] (from on 2014-07-23)

Related notes:

A better title/description for this issue would be "If images are introduced into TTML2, then there should be a way to express an alternative text representation that corresponds to the image.

Glenn Adams, 23 Jul 2014, 21:16:33

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