Re: ISSUE-261: signaling docoument profile conformance is separate from decoder presentation requirements [TTML.next]

Is there a use case for having a document include inline the definition of
a content profile it claims to conform to? Or is it sufficient to allow a
document to refer to a URI which is feasibly resolvable to a definition of
a content profile?


On Fri, Jul 12, 2013 at 2:08 PM, Pierre-Anthony Lemieux <pal@sandflow.com>wrote:

> > > Some means must be defined to separately signal these different
> semantics.
> > For example, we could create a new element and attribute -
> <ContentProfile> and contentProfile.
>
> Sounds good. I also see value in exploring means for (a) defining a
> content profile and (b) signaling conformance of a document to one or
> more content profile.
>
> > <ContentProfile>
>
> What about following the <ttp:profile> template with the following tweaks:
>
> - adding a @designator attribute allowing the content profile
> designator to be specified
> - @use can contain one or more URIs, each identifying a content
> profile to be included in its entirety by reference, thereby avoiding
> having to repeat all features already defined in another profile.
> Perhaps @use can reference "profile" even when defining
> "contentProfile" so that existing content designator can be used.
> - allowing constraints over a base content profile to be specified
> using value="prohibited"
>
> <contentprofile designator="http://example.noname/profile1"
> use="http://example.noname/profile4 http://example.noname/profile3"
> xmlns="http://www.w3.org/ns/ttml#parameter">
>      <features xml:base="http://www.w3.org/ns/ttml/feature/">
>        <feature value="prohibited">#fontStyle-italic</feature>
>        <feature value="use">#fontStyle-bold</feature>
>      </features>
>     <extensions xml:base="http://example.noname/profile1">
>         <ttp:extension
> value="required">#prefilter-by-language</ttp:extension>
>     </ttp:extensions>
> </contentprofile>
>
> > @contentProfile
>
> What about a list of one or more content profile designator URIs, each
> indicating conformance to a content profile, e.g.
>
> <tt ttp:contentProfile="http://example.noname/profile1
> http://example.noname/profile2">
>
> Best,
>
> -- Pierre
>
> On Thu, Jul 11, 2013 at 9:16 AM, Timed Text Working Group Issue
> Tracker <sysbot+tracker@w3.org> wrote:
> > ISSUE-261: signaling docoument profile conformance is separate from
> decoder presentation requirements [TTML.next]
> >
> > http://www.w3.org/AudioVideo/TT/tracker/issues/261
> >
> > Raised by: Mike Dolan
> > On product: TTML.next
> >
> > The profile element and attribute currently signal a feature set that a
> decoder must implement in order to reasonably present the document.
> Although it also hints at what features the document instance may include,
> it does not signal document instance conformance today.
> >
> > There is currently no mechanism to signal what profile a document
> instance conforms to (e.g. sdp-us).
> >
> > It is desirable to add this capability to TTML. However, simply adding
> this semantic to the existing profile element and attribute overly
> constrains the existing (decoder) and desired (document) semantics. It is
> unreasonable to require that the single element and attribute
> simultaneously signal both. For example, the fact that a document instance
> conforms to dfxp-full does and should not automatically infer that an
> sdp-us decoder could not properly present it. That is instance dependent.
> This situation is aggravated when multiple profiles are involved.
> >
> > Some means must be defined to separately signal these different
> semantics. For example, we could create a new element and attribute -
> <ContentProfile> and contentProfile.
> >
> >
> >
> >
>
>