[Wasabi] Kicking of the Metadata spec - brainstorm

[Jon Phillips]

On Tue, 2007-02-20 at 15:10 +0100, Jos van den Oever wrote:
> 2007/2/20, Mikkel Kamstrup Erlandsen <mikkel.kamstrup at gmail.com>:
> > 2007/2/20, Jos van den Oever <jvdoever at gmail.com>:
> >
> > > 2007/2/19, Mikkel Kamstrup Erlandsen <mikkel.kamstrup at gmail.com>:
> > > > Let's get the ball rolling on the metadata spec. This first period will
> > just
> > > > be *brainstorming*, so let's try and avoid the nitty gritty details for
> > now.
> > > >
> > > >  ** What we need:
> > > >
> > > >   Fields)  Metadata field names and descriptions for *desktop* objects
> > > >
> > > >   Types) A type grouping of metadata fields to be used in user search
> > > > language. Example types could be "Email", "Image", "Audio", etc.
> > > >
> > > >   API) A dbus api to get/set metadata
> > > >
> > > >   ?Tag/Emblem) Tagging/Keywords/Emblems
> > > >
> > > >  ** Starting points/References:
> > > >  - Adobe XMP:
> > > >
> > http://partners.adobe.com/public/developer/en/xmp/sdk/XMPspecification.pdf
> > > >
> > > >  - Shared Metadata Spec:
> > > >
> > http://freedesktop.org/wiki/Standards_2fshared_2dfilemetadata_2dspec
> >
> > > >  - Tracker metadata api:
> > > >
> > http://svn.gnome.org/viewcvs/tracker/trunk/data/tracker-introspect.xml?view=markup
> >
> > > >
> > > >  - Spotlight Metadata Spec:
> > > >
> > http://developer.apple.com/documentation/Carbon/Reference/MetadataAttributesRef/Reference/CommonAttrs.html
> >
> > > >
> > > >  - Shared Emblem Spec:
> > > >
> > http://freedesktop.org/wiki/Standards_2fdesktop_2demblem_2dspec
> > > >  - Others ideas? Nepomuk-specs? Beagle-specs?
> > > >
> > > >  ** My thoughts:
> > > > Regarding Fields): To prevent death-by-1000-page-spec I suggest we keep
> > the
> > > > field names to a core set of commonly used attributes. Ie not like
> > Apples
> > > > spotlight spec (see above) which defines every known property in the
> > > > universe. When things move on, teams with expert knowledge can refine
> > > > extensions to this spec. Fx a Wasabi Photography Metadata spec could be
> > > > hashed out by people in the know (which could just be EXIF, but I'm not
> > the
> > > > photography expert).
> > > >
> > > > Regarding Types): There are some suggestions in the top of the Tracker
> > api
> > > > link above. Regarding these I think we should leave the VFS* types out,
> > and
> > > > only use single-word type names (Ie no spaces).
> > > >
> > > > On the API): Obviously we getters and setters. They probably need to
> > operate
> > > > on uris. There probably needs to be some search functionality in here
> > too
> > > > since we probably shouldn't assume that the indexer and metadata server
> > are
> > > > the same.
> > > >
> > > > Tagging/Emblems: If you ask me they should be "just another type of
> > > > metadata". When the metadata spec matures a bit we can evaluate if it
> > needs
> > > > it's own api to make things easier (and allow for dedicated tagging
> > > > services).
> > >
> > > Hi All,
> > >
> > > First I'd like to point to the original mail I sent on this subject.
> > > It already contained a relatively simple spec framework. That is, not
> > > attribute names, but a way to define them, type them and check them.
> > > There was also some code attached to do allow testsets to check the
> > > correctness of metadata extraction from files. Hence the title of the
> > > mail: 'mimetype standardization by testsets'. I still stand by this
> > > idea.
> >
> >
> > Sorry Jos, how could I miss this out. For reference - here's the original
> > thread:
> > http://lists.freedesktop.org/archives/xdg/2006-October/008682.html
> Ah yes, thanks for adding the link, I forgot it.

Yes, excellent.

> >
> > > Here is an idea for a simple proposal.
> > >
> > > - Each metadata type is identified by a URI. E.g.
> > >
> > http://www.freedesktop.org/metadata/xhtml1/title.
> > > - For each URI there will be human readable descriptions in every
> > > language and keywords in every language. I will use the keyword in the
> > > further description mixed with the URI.
> >
> >
> > I like this idea as such. I can't readily see how it intermixes with known
> > widespread standards such as DC though..?

Yes, I think this approach is good as well. My main interest is in
getting proper licensing fields into this spec (I work for creative
commons ;) Maybe now is not the time to throw my 2 cents into this, but
this URI approach meshes well with other standards...

> DC also uses URIs to identify metadata types. It does not define much
> more than that though. This is too little for our needs. Within RDF
> Schema it is also customary to use URIs for type identification.

Agree, but how would you propose to mend this gap?

Is there spec on a wiki somewhere to help hammer this out?

Jon



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Jon Phillips

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