Streaming TTML content can contain links to external resources

[palemieux]

The third bullet under Streaming TTML Content (Non-Normative) is not correct: a TTML document appropriate for streaming can reference external resources, e.g. images, as long as these images are contained within the same segment/access unit/sample as the TTML document.

[nigelmegitt]

@palemieux doesn't the parenthetical text "if it does not reference any external data resources" deal with this?

[palemieux]

@nigelmegitt In what situations does the third bullet apply?

[edited to refer to the third bullet]

[palemieux]

See also w3c/imsc#281 (review)

[nigelmegitt]

[does a double take] you asked about the third bullet, and then switched it to the second one @palemieux ? I think the second one is about in-document references, e.g. not having something like:

<styling>
<style xml:id="s1" style="s2" .../>
<style xml:id="s2" .../>
</styling>

which would require the first style to reference the second style defined later in the document, and therefore would be slightly unfriendly when parsing with a SAX parser, in the sense that the reference might have to be resolved based on a promise of some kind rather than immediately.

[palemieux]

@nigelmegitt I meant the third bullet. It is not clear how it ever applies given the exclusion "if it does not reference any external data resources"

[nigelmegitt]

@palemieux I agree, it's hard to parse. I think there's a missing "i.e." at the beginning of the parenthetical clause, as in the first bullet.

But to address your point, I think bringing in external packaging constructs like segment/access unit/sample seems odd here. How about this proposal:

• does not require dereferencing (and subsequent loading) of any resources other than TTML Content that are not already available (i.e. if it does not reference any external data resources that have not yet been fetched)

?

[palemieux]

@nigelmegitt I would simply remove the hanging paragraph at Annex R since subclauses R.x contain the actual information.

[nigelmegitt]

Sorry I don't follow, which paragraph do you want to remove @palemieux?

[palemieux]

@nigelmegitt TTML Content can be authored to meet the following characteristics [....] content that follows temporal presentation order;_

[nigelmegitt]

@palemieux You mean remove the whole paragraph and all the bullets? I don't think the subclauses contain that same information, but one could argue that its not actually especially useful information at all. I'm neutral about it - I could live with it remaining (edited for clarity) or being removed.