Re: Track kinds

Hello, All:

It has been proposed that we take the second half of our Media telecon
this week to discuss this question further. Philippe and Judy are able
to join the call at that time, and I have asked Paul to join us as well,
hoping he's able to do so.

I suspect we can readily agree on our goal here, but perhaps the
appropriate mechanisms may prove somewhat more troublesone. As I
understand the goal, it is to have a single, consistent naming
convention for the various media representations, consistent naming for
users, and consistent machine identifiable designations. In my mind this
needs to be consistent across text and binary types, but we can perhaps
start our discussion on just this question of the goal.

Which brings up the question of mechanism. As a confirmed optimist, I'm
expecting we'll work out a mechanism that will allow W3C, WHAT, 3GPP,
MPEG Dash, and anyone else to support users with consistent language
about the various media kinds we all need to support.

For reference, our previous discussion on this topic took place at the
11 May Media teleconference which is logged at:


Mark Watson writes:
> Hi Silvia,
> I like your proposed reply, except this last part.
> On Jun 5, 2011, at 10:34 PM, Silvia Pfeiffer wrote:
> There will be no URN to specify these names.
> Specifying a URN is no more than giving a permanent machine-readable name to the list of values (not, it's not a URN for each individual value). It has not cost (URNs are an infinite resource) and has value in that it enables the kinds we specify to be referred to in other protocols, specifically DASH.
> We recommend that the 3GPP define their own names, since they may
> require more than what HTML5 requires. We therefore further recommend
> that 3GPP create a URN scheme for their own names themselves.
> 3GPP certainly can and will do the above if they have requirements not met by the W3C kinds. But it would be better to avoid the situation were we have duplicate definitions in HTML and container formats and the consequent maintenance problem ...
> There
> will be no URN for the W3C names, since they are listed in the HTML5
> specification and will be maintained there.
> I didn't follow the logic of that last sentence.
> I think that container specifications are absolutely the wrong place for these definitions as there is nothing container-specific about the concept of track kinds. The right place is somewhere that abstracts the services offered by multiple different containers and offers them to the higher application layers in a container-independent language - which is what HTML does.
> 3GPP and MPEG are offering to support that container-independent language directly. It would be a great benefit if we took them on that offer and gave them a way to refer to our list. (That doesn't mean there won't be other lists defined in other places for particular applications).
> ...Mark


Janina Sajka,	Phone:	+1.443.300.2200

Chair, Open Accessibility	
Linux Foundation

Chair, Protocols & Formats
Web Accessibility Initiative
World Wide Web Consortium (W3C)

Received on Tuesday, 7 June 2011 22:19:48 UTC