W3C home > Mailing lists > Public > public-tt@w3.org > October 2007

RE: Timed Text roles

From: Glenn A. Adams <gadams@xfsi.com>
Date: Thu, 11 Oct 2007 09:49:34 -0400
Message-ID: <C0A7A8BF0F28BA4B9C6C8816309E1D07202D1C@ES1.xfsi.com>
To: "Benjamin Hawkes-Lewis" <bhawkeslewis@googlemail.com>
Cc: <public-tt@w3.org>, <w3c-wai-ig@w3.org>

The roles are, at present, intended to be "standard" only in the sense
that there is a "stsandard" set of keywords. What those keywords mean is
up to the author(s). I agree that this does not permit interoperable
interchange of semantics, but it does permit interoperable interchange
of symbols as such. Just think about what the <strong/> or <em/> tags
mean in HTML. How would you define them in a meaningful way?

It would be going overboard to recommend that authors NOT use these
keywords if they can find a meaningful use for them. If some group of
authors and some group of recipients should wish to define a profile
that provides further semantics or context, then there is nothing to
prevent doing this. Many standards define facilities that for effective
interchange requires profiling.

However, if you would like to propose a set of definitions for
standardization, then please feel free to do so, and I will make sure
that the TTWG considers them. But even then, how would you enforce
consistent use with such definitions?


> -----Original Message-----
> From: Benjamin Hawkes-Lewis [mailto:bhawkeslewis@googlemail.com]
> Sent: Thursday, October 11, 2007 8:32 PM
> To: Glenn A. Adams
> Cc: public-tt@w3.org; w3c-wai-ig@w3.org
> Subject: Re: Timed Text roles
> Glenn A. Adams wrote:
> > The TTWG discussed this need, and concluded it would be exceedingly
> > difficult or impossible to define them in a way that would retain
> > utility while not overly constraining such use.
> Thanks kindly for the response, but I don't understand at all. :(
> you please explain the WG's reasoning a bit more? Given that authors
> always create a new role in the x- prefixed space, how would defining
> the standard roles constrain authoring? What is the real-world utility
> of a standardised set of roles that aren't defined in any way? It
> to me that not defining "transcription", for example, means that TT
> fails to provide "clear indications in the format of what text
> corresponds to speech in some corresponding audio segment" as
> by Alfred S. Gilman:
> http://lists.w3.org/Archives/Public/public-tt/2005Apr/0043.html
> > It was recognized that
> > some existing standards, such as the US Digital Television Closed
> > Captioning (DTVCC) standard, CEA-708, similarly enumerated such a
> > but without providing any further definition.
> Are the standard roles precisely the same as CEA-708? If they are, why
> doesn't the TT spec say they are? And if they aren't, then what is the
> relevance of this apparent anti-pattern in CEA-708?
> Might it not be better to specify cea- prefixed roles for mapping
> CEA-708 roles to Timed Text?
> > Notwithstanding the above, we may consider adding informative
> > to the text of DFXP during the process of transitioning from CR to
> > If you would like to submit such examples, possibly with
> > then that would be most welcome.
> Well, I'd be happy to do that, but I can't submit examples or
> descriptions when I can't tell what the roles are for! If existing
> in CEA-708 form is to be mapped to such roles, then we need to know
> such labels are currently used by people who use CEA-708: I can't just
> make things up. And if they use them in utterly incoherent ways, then
> shouldn't a new format provide a set of coherent roles?
> As things stand, I would have to recommend that authors don't make any
> use of these ambiguous standard roles, but instead publish some sort
> microformat using the x- space. At least then one could find out what
> the author intended.
> Has the WG considered allowing people to specify a URI that defines
> the roles they are using so that there is no possibility of confusion?
> Compare the approaches of HTML 4.01, the draft XHTML 2.0 Role
> Module, and GRDDL:
> http://www.w3.org/TR/html401/struct/global.html#profiles
> http://www.w3.org/TR/grddl/
> (PS Apologies to w3c-wai-ig for the noise. I mistook public-tt latest
> for the whole public-tt archives: turns out that thankfully there are
> people on this list.)
> --
> Benjamin Hawkes-Lewis
Received on Thursday, 11 October 2007 13:51:21 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 5 October 2017 18:24:02 UTC