Re: Is the same video but in different encodings the owl:sameAs?

Hello,

On Wed, Dec 4, 2013 at 3:13 PM, Thomas Steiner <tomac@google.com> wrote:
> Dear Public-LOD,
>
> As different Web browsers support different video codecs, with Web
> video it is not uncommon to see things like the below (simplified for
> legibility reasons)…
>
>   <video>
>     <source src="./video.ogv" type="…">
>     <source src="./video.mp4" type="…">
>   </video>
>
> When I want to make statements about the video in question, I have the
> problem that the "same" video has two different URIs ([…].mp4,
> […].ogv). So I have to say ("ma:" from the Ontology for Media
> Resources [0])…
>
>   <http://ex.org/video.ogv> a ma:MediaResource .
>   <http://ex.org/video.ogv> ma:title "Sample Video" .
>   <http://ex.org/video.ogv> ma:description "Sample Description" .
>
> …and also…
>
>   <http://ex.org/video.mp4> a ma:MediaResource .
>   <http://ex.org/video.mp4> ma:title "Sample Video" .
>   <http://ex.org/video.mp4> ma:description "Sample Description" .
>
> Essentially (unless I wanted to introduce something more complex) I am
> forced to duplicate all statements I make about both video resources,
> where actually I would like to make statements about the video no
> matter its encoding.
>
> Long story short, is it too much of a stretch to just say…
>
>  <http://ex.org/video.mp4> owl:sameAs <http://ex.org/video.ogv>

It is too much of a stretch, imho. These videos are different encoding
of the same underlying content, so you need to introduce another
resource capturing that, i.e.

:content
  :encoding <video.mp4> , <video.ogv> .

So that you can state things about these various files, e.g.

<video.mp4> :format :mp4 .
<video.ogv> :format :ogg .

And things about the content, i.e.

:content ma:description "sample description" .

(That's one of the main issue I have with mediaont - it is too flat,
so doesn't enable this sort of things to be expressed)

Best,
Yves

>
> …as to avoid the problem? One issue I see is that, e.g., ma:format
> (which makes statements about the MIME type) obviously does not hold
> true for both media resources as their MIME types are different.
>
> The implicit (as I read the spec at least) semantics of <video> are
> that the given alternatives in the various <source>-s should be the
> "same" video, just in different encodings. What I actually wanted
> would be something like a canonical URI [1] for a video like
> <http://ex.org/video>, so that one could make statements based on its
> canonical URI that would hold true for all representations in
> different encodings…
>
>   <http://ex.org/video> a ma:MediaResource .
>   <http://ex.org/video> ma:title "Sample Video" .
>   <http://ex.org/video> ma:description "Sample Description" .
>
> …which would hold true for   <http://ex.org/video.ogv> and
> <http://ex.org/video.mp4>.
>
> Thanks for your thoughts.
>
> Best,
> Tom
>
> --
> [0] http://www.w3.org/TR/mediaont-10/
> [1] https://support.google.com/webmasters/answer/139394?hl=en
>
> --
> Thomas Steiner, Employee, Google Inc.
> http://blog.tomayac.com, http://twitter.com/tomayac
>
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Received on Thursday, 5 December 2013 11:01:05 UTC