[Webkit-unassigned] [Bug 110479] [Meta] Implement support for TTML

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=110479





--- Comment #25 from Glenn Adams <glenn at skynav.com>  2013-02-25 14:57:33 PST ---
(In reply to comment #24)
> (In reply to comment #23)
> > (In reply to comment #21)
> > > TTML's spec says: "It is intended to be used for the purpose of transcoding or exchanging timed text information among legacy distribution content formats presently in use for subtitling and captioning functions."
> > 
> > Just so there's no misunderstanding, TTML as published is definitely intended to be used as a distribution format. Indeed, it was previously named DFXP (Distribution Format Exchange Profile) to distinguish it from a more ambitious, but never fully specified AFXP (Authoring Format Exchange Profile).
> 
> 
> I have no issues with this statement. TTML was built with two aims:
> * as a distribution format ("distribution" in contrast to "rendering")
> * with a focus on captioning and subtitling
> 
> That's all I wanted to point out.

TTML defines two types of content processors, a transformation processor and a presentation processor. TTML authors indicate (within the document) which of these must be supported and used by the receiving entity. Therefore, the only two documented use cases for TTML upon distributing a document is to transform it or to render it. Most of the profiles in use today, such as SMPTE-TT, EBU-TT, and SDP-US, mandate support for presentation processing.

So it would be incorrect to imply that Distribution of TTML does not include rendering as a potential use case. Indeed, most existing uses of TTML today specify the use of a presentation processor.

-- 
Configure bugmail: https://bugs.webkit.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.