- From: Felix Sasaki <fsasaki@w3.org>
- Date: Tue, 25 Nov 2008 21:07:41 +0900
- To: Pierre-Antoine Champin <swlists-040405@champin.net>
- CC: public-media-annotation@w3.org
Pierre-Antoine Champin さんは書きました: > Felix Sasaki a écrit : > >> Hi Pierre-Antoine again (btw. ,do you mind to forward this to the >> mailing list?), >> > > absolutely not! I just missed the "reply all" button in my last reply :-( > Sorry everybody... However, the last exchange with Felix in enclosed below. > > >> I think we don't disagree - we just stress different points. >> > > It is also my opinion :) > Great :) > And by the way, I am perfectly ok with the bottom-up approach, having > the conceptual model emerge from use cases, which is indeed a good way > of keeping it (the conceptual model) simple enough. > > Thinking about it, I realized that external metadata is indeed an > important feature for me, Could you give an example why? I.e., a practical "application scenario" In the sense of http://lists.w3.org/Archives/Public/public-media-annotation/2008Nov/0100.html (if we go for that structuring proposal) Allowing for external metadata would be a use case IMO, based on an application scenario. The requirement would be to provide the external format. > hence my bias in favor of a specific format > for our ontology. > > External metadata allows people to exchange it separately from the > (potentially copyrighted) video. It is indeed a key feature of the > Advene application (on which I am working), as well as popular social > applications focused on video (like youtube). > > Wouldn't that deserve a use-case, by the way? > Yes please, see above. We also have a "mini" issue about this already: http://www.w3.org/Bugs/Public/show_bug.cgi?id=6109 Felix > pa > > >> Pierre-Antoine Champin さんは書きました: >> >>> Felix, >>> >>> Felix Sasaki a écrit : >>> >>> >>>> Pierre-Antoine Champin さんは書きました: >>>> >>>> >>>>> Hi Felix, thank you for your feedback. >>>>> >>>>> First, the term "data structure" was a bad choice. I should have >>>>> written >>>>> "conceptual model", which describes better what I am interested in. I >>>>> think once we agree on a conceptual model, we can chose the best syntax >>>>> to represent it -- if we want to... >>>>> >>>>> As a matter of fact, I took for granted that we would have to define >>>>> our >>>>> own format. But once again, the most important thing is the conceptual >>>>> model. >>>>> >>>>> >>>> I'm sorry, I have to disagree again. Take again a statement like >>>> "Mapping for getDate" from >>>> http://dev.w3.org/2008/video/mediaann/mediaont-api-1.0/mediaont-api-1.0.html#property-createDate >>>> >>>> >>>> "exif:DateTimeDigitized (based on [MWG Guidelines Image]). This is taken >>>> only into account if both xmp:createDate and exif:DateTimeOriginal are >>>> missing." >>>> I think this fulfils our task without a conceptual model: to provide >>>> interoperability between heterogenous metadata formats for video. >>>> >>>> >>> how do you (or the MWG Guidelines) end up with such a recommendation, if >>> not by building (even if only mentally) a conceptual model of the >>> metadata, beyond a simple attribute-value model? >>> >>> >> You hit the point with "even mentally". I'm fine with a conceptual >> model. However, I am worried that we spend too much time thinking about >> a conceptual, without working on our main task of describing >> interoperability between properties of existing formats. IMO a >> conceptual model, more ore less explicit, will come naturally along if >> we concentrate on that task. >> >> If we concentrate on the model we might end up with lots of abstraction >> layers, which are good for some use cases, but bad for others: I see us >> as a competitor to approaches like Blinx, see >> http://www.w3.org/2008/10/24-mediaann-minutes.html#item01 >> who have just 5 categories for searching across *a lot* of videos. >> >> >>> Take the rationale about dates, in the MWG Guidlines (p.16). It >>> introduces different *processes* in the lifetime of a digital image, >>> such as *photo taken*, *image digitized* and *file modified*. Only after >>> that can you discuss about the various date and argument that "date/time >>> original" should be prefered over the other ones. >>> >>> >> A good example: the description is very specific to metadata fields >> specific to date / time, and does not argue with an overall conceptual >> model. I think you can end up with a section like that by looking into >> existing formats and their fields related to date / time, and >> classifying these fields. Again: I don't think we disagree, but put a >> different focus. >> >> >> >>> My point is that, since this effort is necessary, it is better to make >>> it explicit >>> >> Agree if we make it explicit *after* analyzing properties, or if we at >> least start with the analysis, and not with thinking about the model. >> >> >> >>> -- even if only as prose, rather than emerging only through >>> its consequences in each property mapping. >>> >> I see "only throughits consequences in each property mapping" as a >> benefit. AFAIK the metadata WG deliverable was also written in such a >> "bottom-up" approach, and the conceptul model you see is a result or >> something emerging "on the way", and not the start of that work. >> >> >>> I see the following >>> advantages to this: >>> >>> - making the ontology/API easier to understand >>> - enabling implementors of the API to extend it in a consisten way >>> - to properties that we would have considered out of scope >>> - to format that we would not have considered >>> >>> >> I agree with all these advantages. >> >> >>> >>> >>>>> [example of "album title", "original album title"] >>>>> >>>>> >>>> Good example. My opinion is exaclty that mapping these properties to >>>> Dublin Core *does not* require finding these equivalences. From our >>>> charter: >>>> http://www.w3.org/2008/01/media-annotations-wg.html >>>> Success criteria: "Abilitity to convert core metadata information from >>>> one metadata standard to an other". This does not talk about >>>> roundtripping, so information loss is OK. >>>> Out of scope: "Full coverage of all metadata elements in EXIF, IPTC, >>>> XMP, MPEG-7, and similar broad vocabularies, is out of scope". >>>> I interpret this as "it's OK to loose the structure of ID3 tags is lost >>>> in the mapping to ID3.". >>>> >>>> >>> Information loss is OK indeed, but we should be aware of the information >>> we are losing. >>> >>> >> I agree. >> >> Felix >> >> > > >
Received on Tuesday, 25 November 2008 12:14:59 UTC