Re: more profile confusion ( ISSUE-170)

On Wed, Jun 13, 2012 at 5:45 AM, Andreas Tai <tai@irt.de> wrote:

>  Thanks for taking this up. Background of the question is still, what the
> interpretation should be if no profile element or attribute was specified
> in a TTML document.
>

Currently I think the text is clear, and the answer depends upon whether
the *document interchange context* specifies (in some way unknown to the
TTML specification, i.e., in a non-standardized manner) a profile or not;
if yes, then that profile applies, if no, then the transformation profile
applies.

In any case, we have agreed to further elaborate on the meaning of *document
interchange context* via a note.


>
> It would be interesting to know if current TTML processors are conformant
> TTML transformation and/or conformant TTML presentation processors.
>

>From the perspective of the TTML spec, it depends on whether such
processors "claim" conformance or not. One could ask which processors:

   1. don't claim conformance and aren't conformant
   2. don't claim conformance, but are conformant
   3. claim conformance, but are not conformant
   4. claim conformance and are conformant

The third of these is prohibited by the spec; however, the other three are
permitted. Since we don't define a 'generic' profile (for an implementation
that satisfies only the generic processor requirements), the second and
fourth are ruled out as well. So, for such a processor, no conformance
claim could be made with respect to the currently defined profiles, and
thus, only the first above applies.


>
> Best regards,
>
> Andreas
> Am 13.06.2012 05:04, schrieb Glenn Adams:
>
>
> On Tue, Jun 12, 2012 at 9:21 AM, Andreas Tai <tai@irt.de> wrote:
>
>>  Thanks for the helpful analysis, Glenn.
>>
>> Yes, at the end it is about a conformant TTML generic processor. Is it
>> possible that a TTML generic processor does not support the profile feature
>> (and hence is not a conformant transformation nor presentation processor)?
>>
>
>  It is an open question in my mind, since, to my knowledge, we never
> considered the idea of a TTML processor that conformed only to the generic
> requirements, but not to either transformation/presentation processor
> requirements. However, I don't see anything in TTML 1.0 that rules out such
> an implementation, it's just that it could not claim to be either a
> conforming transformation or presentation processor.
>
>
>>
>> Am 11.06.2012 19:42, schrieb Glenn Adams:
>>
>>
>> On Mon, Jun 11, 2012 at 9:27 AM, Andreas Tai <tai@irt.de> wrote:
>>
>>>  From my reading the profile mechanism is a TTML feature itself and can
>>> be optional. So if the context make the profile mechanism optional it is
>>> not needed for a TTML processor to implement it. Am I correct?
>>>
>>
>>  yes, #profile is an enumerated feature [1]
>>
>>  [1] http://www.w3.org/TR/ttaf1-dfxp/#feature-profile
>>
>>  however, it is also a mandatory feature for both transformation [2] and
>> presentation [3] profiles
>>
>>  [2]
>> http://www.w3.org/TR/ttaf1-dfxp/#feature-transformation-mandatory-table
>> [3] http://www.w3.org/TR/ttaf1-dfxp/#feature-presentation-mandatory-table
>>
>>  finally, a conformant transformation processor [4] and a conformant
>> presentation processor [5] are obliged to support the transformation and
>> presentation profiles, respectively
>>
>>  [4]
>> http://www.w3.org/TR/ttaf1-dfxp/#conformance-transformation-processor
>> [5] http://www.w3.org/TR/ttaf1-dfxp/#conformance-presentation-processor
>>
>>  so, when you ask "it is not needed for a TTML processor to implement
>> it", then the answer is yes if you mean either a "conformant TTML
>> transformation processor" or a "conformant TTML presentation processor"
>>
>>
>>>
>>> Furthermore it maybe a possibility for TTML 1.1 to reflect on the
>>> profile mechanism with respect to it´s implementation by TTML
>>> users/processors.
>>>
>>
>>  what I think you may be asking here is whether a TTML processor may be
>> a "conformant TTML generic processor" [6], but neither a (conformant)
>> transformation processor nor a (conformant) presentation processor; is that
>> correct?
>>
>>  [6] http://www.w3.org/TR/ttaf1-dfxp/#conformance-generic-processor
>>
>>
>>>
>>> Best regards,
>>>
>>> Andreas
>>>
>>> Am 06.06.2012 18:28, schrieb Glenn Adams:
>>>
>>> ok, that's a reasonable clarification; i agree that "if the document
>>> interchange context does not specify a profile" is not sufficiently
>>> precise
>>>
>>> On Wed, Jun 6, 2012 at 10:07 AM, Michael A Dolan <mdolan@newtbt.com>wrote:
>>>
>>>>  I agree with the spirit of what you say.  But as drafted, the
>>>> Recommendation is using a defined term, “profile”, so I disagree that it
>>>> does not, as drafted, require a profile document.  That’s the issue.  Even
>>>> if you read it differently, the point is that others read it the same as I
>>>> do, and therefore it needs clarification.  I proposed “conforming subset or
>>>> something more generic”.  How about “…and if the document interchange
>>>> context does not specify a profile document, or other equivalent set
>>>> of feature designators,…”
>>>>
>>>>
>>>>
>>>> Whatever wording works for you is fine with me.
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>>
>>>>
>>>>                 Mike
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *From:* Glenn Adams [mailto:glenn@skynav.com]
>>>> *Sent:* Wednesday, June 06, 2012 8:49 AM
>>>> *To:* Michael A Dolan
>>>> *Cc:* public-tt@w3.org
>>>>
>>>> *Subject:* Re: more profile confusion
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Jun 6, 2012 at 8:51 AM, Michael A Dolan <mdolan@newtbt.com>
>>>> wrote:
>>>>
>>>> Another troubling profile sentence in 5.2 was called to my attention:
>>>>
>>>>
>>>>
>>>> If neitherttp:profile<http://www.w3.org/TR/ttaf1-dfxp/#parameter-attribute-profile>attribute
>>>> norttp:profile<http://www.w3.org/TR/ttaf1-dfxp/#parameter-vocabulary-profile>element
>>>> is present in a TTML document instance, and if the document interchange
>>>> context does not specify a profile, then the DFXP Transformation profile
>>>> applies.
>>>>
>>>>
>>>>
>>>> A “document interchange context” might well fully define a conforming
>>>> subset definition, but it may or may not formally define a “profile” as
>>>> defined in the recommendation.
>>>>
>>>>
>>>>
>>>> An instance document would more likely declare its conformance by some
>>>> other means, such as reference to a schema, or using xml-model, or simply
>>>> by its context (e.g. a branded MP4 file).
>>>>
>>>>
>>>>
>>>> When we get to overhauling the profile language, we should fix the
>>>> above, minimally replacing “profile” with “conforming subset” or something
>>>> more generic that does not imply a TTML Profile definition is required.
>>>>
>>>>
>>>>
>>>> Actually, I think I do not agree with this. The point of the above
>>>> cited language is to ensure that the applicable profile is well defined,
>>>> since it is necessary to know the applicable profile in order to perform
>>>> processing in a compliant manner.
>>>>
>>>>
>>>>
>>>> As reference to a profile defined/specified by a document interchange
>>>> context is intended to serve as a out-of-band protocol to allow
>>>> determination of which profile applies. It does not mean that a ttp profile
>>>> document must be available for either author or client, it means that the
>>>> information that would be included in such a document is known is some
>>>> manner, whether or not it is defined in a profile file.
>>>>
>>>>
>>>>
>>>> Finally, the phrase "conforming subset" has no formal meaning/use in
>>>> TTML at present other than indirectly through the use of profile
>>>> definitions.
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> ------------------------------------------------
>>> Andreas Tai
>>> Production Systems Television IRT - Institut fuer Rundfunktechnik GmbH
>>> R&D Institute of ARD, ZDF, DRadio, ORF and SRG/SSR
>>> Floriansmuehlstrasse 60, D-80939 Munich, Germany
>>>
>>> Phone: +49 89 32399-389 | Fax: +49 89 32399-200
>>> http: www.irt.de | Email: tai@irt.de
>>> ------------------------------------------------
>>>
>>> registration court&  managing director:
>>> Munich Commercial, RegNo. B 5191
>>> Dr. Klaus Illgner-Fehns
>>> ------------------------------------------------
>>>
>>>
>>
>>
>> --
>> ------------------------------------------------
>> Andreas Tai
>> Production Systems Television IRT - Institut fuer Rundfunktechnik GmbH
>> R&D Institute of ARD, ZDF, DRadio, ORF and SRG/SSR
>> Floriansmuehlstrasse 60, D-80939 Munich, Germany
>>
>> Phone: +49 89 32399-389 | Fax: +49 89 32399-200
>> http: www.irt.de | Email: tai@irt.de
>> ------------------------------------------------
>>
>> registration court&  managing director:
>> Munich Commercial, RegNo. B 5191
>> Dr. Klaus Illgner-Fehns
>> ------------------------------------------------
>>
>>
>
>
> --
> ------------------------------------------------
> Andreas Tai
> Production Systems Television IRT - Institut fuer Rundfunktechnik GmbH
> R&D Institute of ARD, ZDF, DRadio, ORF and SRG/SSR
> Floriansmuehlstrasse 60, D-80939 Munich, Germany
>
> Phone: +49 89 32399-389 | Fax: +49 89 32399-200
> http: www.irt.de | Email: tai@irt.de
> ------------------------------------------------
>
> registration court&  managing director:
> Munich Commercial, RegNo. B 5191
> Dr. Klaus Illgner-Fehns
> ------------------------------------------------
>
>