[Tracker] [RFC] Adding CUE sheet support

[Sam Thursfield <ssssam gmail com>]

Hi!

A lot of people these days have CDs stored as one big .FLAC file, with
a .CUE sheet listing the offset of each actual track. To get Tracker
to recognise these requires some sort of ontology addition to express
the track offsets. As far as I can see, the best solution is the
following: each logical track is a nmm:MusicPiece resource with its
nie:uri pointing to the one .FLAC file, and a new
nfo:audioContainerOffset property that specifies the offset in samples
of the track into its file.

Is this the best approach? The name of the property and its unit also
need nailing down - samples are the most accurate unit, and they apply
to basically all types of audio other than .mod files, but of course
that makes the property audio-specific (hence the suggested name
nfo:audioContainerOffset).

In terms of implementation, I'm going to have to add it to the libflac
based extractor, because there's a whole lot of work to be finished up
before gstreamer can handle this sort of thing[1].

Also, does anyone know the best way to contact nepomuk upstream these
days? the only committer to the shared-desktop-ontologies[2] seems to
be Sebastian Trueg (of KDE), they don't seem to have their own mailing
list so I think I'm going to ask him where is best to get their
opinion.

Thanks!
Sam

[1] https://bugzilla.gnome.org/show_bug.cgi?id=540890
[2] http://oscaf.git.sourceforge.net/git/gitweb.cgi?p=oscaf/shared-desktop-ontologies;a=summary