Re: Difference between url and contentUrl?

I'm willing to take a stab at an answer (and thus willing to be wrong!). It
probably works better with VideoObject or AudioObject examples which are
more likely to have embeddable players.

* url: is for a URL that offers additional info _about_ the given
MediaObject (example:
https://archive.org/details/WhatIsLinkedDataAndWhatDoesItMeanForLibraries)
* contentUrl: is for URL that provides a directly retrievable instance of
the MediaObject (example:
https://archive.org/download/WhatIsLinkedDataAndWhatDoesItMeanForLibraries/2010.10.15Nla2010LinkedData.ogv
)

... and to add in a suggested answer to Martin's related question around
embedUrl:

* embedUrl: is for a URL that can be used to embed the media on a web page
via a specific media player (example:
http://archive.org/embed/WhatIsLinkedDataAndWhatDoesItMeanForLibraries --
often embedded in an iframe element like <iframe src="
https://archive.org/embed/WhatIsLinkedDataAndWhatDoesItMeanForLibraries"
width="640" height="480" frameborder="0" webkitallowfullscreen="true"
mozallowfullscreen="true" allowfullscreen></iframe>). And of course this
URL will often be used in the page referenced by schema:url about the
VideoObject :)

So ultimately you could have a object with meaningfully distinct properties
like:

<script type="application/ld+json">
{
  "@context": "http://schema.org",
  "@type": "VideoObject",
  "contentUrl": "
https://archive.org/download/WhatIsLinkedDataAndWhatDoesItMeanForLibraries/2010.10.15Nla2010LinkedData.ogv
",
  "embedUrl": "
http://archive.org/embed/WhatIsLinkedDataAndWhatDoesItMeanForLibraries",
  "url": "
https://archive.org/details/WhatIsLinkedDataAndWhatDoesItMeanForLibraries",
  "name": "What is Linked Data and What Does it Mean for Libraries?"
}
</script>

To summarize:

* I think all three properties have a reason to exist, if you look at them
in context with one another
* The properties probably make much more sense if used with a more
conventionally streamable example such as AudioObject or VideoObject
* We probably need to add more examples in this area, and ensure that we
have some in which all of contentUrl, embedUrl, and url appear (and hang
those examples off the properties, too) :)

Dan


On Wed, Apr 29, 2015 at 7:47 PM, Aaron Bradley <aaranged@gmail.com> wrote:

> For MediaObject, what's the difference between using the "url" and
> contentUrl" property?
>
> For example, if I want to declare the URL of an ImageObject can I use
> either the "url" property ("URL of the item") or the "contentUrl" property
> ("Actual bytes of the media object, for example the image file or video
> file")?
>
> Looking at the MediaObject examples this is clearly okay:
> <script type="application/ld+json">
> {
>   "@context": "http://schema.org",
>   "@type": "ImageObject",
>   "contentUrl": "http://www.airshock.com/images/acme-logo.png",
>   "name": "Acme Logo"
> }
> </script>
>
> But what about this - is it also correct, and how might it materially
> differ from the code above?
> <script type="application/ld+json">
> {
>   "@context": "http://schema.org",
>   "@type": "ImageObject",
>   "url": "http://www.airshock.com/images/acme-logo.png",
>   "name": "Acme Logo"
> }
> </script>
>
> Put another way, in what circumstance would or could the "url" of a
> MediaObject be different than the "contentUrl" of a MediaObject?  And what
> meaning exactly is "actual bytes" supposed to convey?
>
> Thanks for any insights.
>