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Re: Intro and 'use cases'

From: Felix Sasaki <fsasaki@w3.org>
Date: Tue, 23 Sep 2008 16:15:31 +0900
Message-ID: <48D89793.1040406@w3.org>
To: Dave Singer <singer@apple.com>
CC: public-media-annotation@w3.org

Hi Dave,


Dave Singer さんは書きました:
>
> Hi
>
> I'm David Singer, multimedia standards guy at Apple; I attend various 
> standards bodies and track a few more (Blu-ray, MPEG, IETF multimedia, 
> 3GPP multimedia, and so on, as well as the W3C). I'm the editor and 
> chair of the MP4 file format spec/group.
>
> At MPEG I socialize(d) with the MPEG-7 and MPEG-21 people, but I 
> wasn't involved in those standards directly (apart from file format 
> issues).
>
> Considerations for media annotation:
>
> I'd like to draw a distinction between material that is needed for the 
> web to function properly -- attributes, and so on -- and annotation 
> which is there to help explain or connect at a semantic level. I know 
> that this distinction is not hard and fast, but nonetheless I think 
> it's useful. For example, 'what codec(s) are used in the content' is 
> really a key characteristic of the content and directly affects 
> interop. 'what is the title of the media file?' is really an 
> annotative question. I am not convinced that expressing accessibility 
> aspects is an annotation question, as it directly affects the choice 
> and configuration of the file presented to a user. I posted a 
> suggestion recently to public-html 
> <http://lists.w3.org/Archives/Public/public-html/2008Sep/0118.html>.

A comment on what you wrote at
http://lists.w3.org/Archives/Public/public-html/2008Sep/att-0118/html5-media-accedssibility.html#

"Sign language has a number of variants, not easily identified; not only 
does American sign language differ from British, but the dialects that 
form around schools that use sign language also diverge significantly. 
This problem of identifying what sign language is present or desired is 
exacerbated by ISO 639-2, which has only one code for sign-language 
('sgn'). The user preference for which kind of sign language is needed 
may need storing, as well as their need for sign language in general. 
We're hoping that the user's general language preferences can be used, 
for a first pass."

ISO-639-3 offers codes for individual sign languages, e.g. "ase" for 
"american sign language". See for tagging guidelines (should I use "sgn" 
or "ase"?) from http://tools.ietf.org/html/draft-ietf-ltru-4646bis-17

 Sign languages share a mode of communication rather than a linguistic
   heritage.  There are many sign languages which have developed
   independently and the subtag 'sgn' indicates only the presence of a
   sign language.  A number of sign languages also had grandfathered
   tags registered for them during the RFC 3066 <http://tools.ietf.org/html/rfc3066> era.  For example, the
   grandfathered tag "sgn-US" was registered to represent 'American Sign
   Language' specifically, without reference to the United States.  This
   is still valid, but deprecated: a document in American Sign Language
   can be labeled either "ase" or "sgn-ase" (the 'ase' subtag is for the
   language called 'American Sign Language').


ISO-639-3 will also be incorporated in the upcoming update of RFC 4646 
(which is applied e.g. in xml:lang).

>
> There has recently been work in the image space on settling on a 
> select few tags that have well-defined meanings that it is recommended 
> images support -- even though the group does *not* mandate the way the 
> way they are stored in any given format. This means that any image can 
> be queried for (for example) its copyright string and this has a 
> well-defined common meaning.
>
> Common meaning is a useful term here. Metadata (annotations) are not 
> easily convertible between annotation systems or vocabularies, 
> usually. "Is what this system calls the 'name' of the work the same as 
> what that system calls the 'title'?". This is sometimes (often) 
> answered by something soft like "well, usually, except...". This 
> causes problems in two areas:
> a) converting from one format to another;
> b) making uniform queries of a disparate set of resources ('please 
> catalog by title all the works in this collection').
>
> The latter is very much a W3C problem, as an embedded media element 
> may be in a variety of formats, or even (in HTML5) have different 
> alternative forms. We nonetheless want to be able to do uniform queries.

agree. See also issue 6083 at 
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6083 which should cover 
the requirement. to do uniform queries, across formats.

>
> There are two solutions, perhaps, to this problem: (a) relate all 
> media annotation systems by means of a firm semantic background, so 
> that a machine translator can do the best it can ('the tag called 
> title is the formal_name of the work', 'the tag called author is the 
> formal_name of the person who created the words of the work'); (b) 
> have a small set of tags which we encourage should be implemented in 
> any standard.
>
> We prefer (b) now; (a) is a research project, not a standards 
> activity. As a basis here, we'd like to consider the 
> very-commonly-used ID3 tags (to the extent that they are defined).

Our charter
http://www.w3.org/2008/01/media-annotations-wg.html
says that we ought to develop a "simple lingua franca" between existing 
standards. I translate "simple" into "also useable *as is*", that is 
into what you describe as (b). I also agree that we should concentrate 
on (b), and I think there is a some agreement in this group about that. 
What do others think?

>
> There are cross-site security concerns that we should consider here; 
> IMG has limited media annotation because of this. [The issue comes up 
> when you construct a public web page that I load that also loads a 
> multimedia resource from within my security envelope -- e.g. internal 
> to Apple -- and then use scripts to interrogate that resource and send 
> the results outside the envelope.]

Do you think this should be a separate use case / requirement on the 
ontology. I understand that it is an issue, but I am not sure how (we, 
with our work items) should take it into account.

>
> Internationalization needs to be considered; we may want to be able to 
> tag the name of the movie as presented in spanish, or as presented in 
> spain, as well as its normal mongolian name. But care needs to be 
> taken; 'what is the mongolian copyright' should not get the answer 
> 'none' if there is an established copyright in a jurisdiction which 
> mongolian copyright recognizes.

I think this relates to issue 6066
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6066

>
> We may need intrinsic annotation ('within the media file') and also 
> extrinsic ('associated with the media file'). Again considering that 
> HTML5 allows for codec-variants of the same resource, it may be easier 
> to say
> <video...>
> <source src=".../x.ogg" annotations=".../x.w3c_annot"/>
> <source src=".../x.mp4" annotations=".../x.w3c_annot"/>
> </video>
> ie. associate the same set of annotations with multiple disparate 
> media files.

I created a requirement "Allow users for intrinsic and extrinsic usage 
of the ontology", see http://www.w3.org/Bugs/Public/show_bug.cgi?id=6109

Felix
Received on Tuesday, 23 September 2008 07:16:09 GMT

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