ogg dev - Sep 2007 - The use for an XML based metadata format

On Mon, Sep 10, 2007 at 01:19:05PM +0100, Ian Malone wrote:
> as artist=(composer) Beethoven), I think cast lists for films present
> a similar problem.  There is consistency and indexability to be
> addressed (Ludvig van Beethoven; Beethoven, Ludvig van;
> Beethoven).
ID3 has a concept of "sort" tags, which provide a string for sorting 
purposes which is different from the (presumedly full name) of the usal 
tag. TSOP="Beethoven", TCOM="Ludwig van Beethoven".

If you want something more precise, you have to link to unique 
identifiers for a particular artist, like a musicbrainz id. I
gather that's not what you're interested in here?
> Finally complex relationships are even harder to
> handle such as specifying a resource's relationship to the rest
> of a collection.
Stepping back a bit, there are three levels of metadata models.

1) The first is just untyped attributes. This includes folksonomy[1]
   tag systems like flickr tags, as well as older systems like 
   "keywords" or "PACS numbers"[2] used for subject indexing
by
   some scientific communities.

   "Beethoven", "Moonlight", "Piano"

2) The second level adds typing to the attributes. This covers all 
   (key, value) pair schemes, including Vorbis comments, EXIF and 
   PNG metadata, and XML attributes.

   Composer="Beethoven", Title="Moonlight Sonata"

3) The third level is what is usually called the RDF model, where
   the metadata is described by a graph. The nodes are items that
   and the labelled edges describe a relationship between nodes.

   Audio title is Moonlight Sonata.
   Moonlight Sonata composed by Ludwig van Beethoven.
   Ludwig van Beethoven has a short name Beethoven
   Moonlight Sonata was composed in 1801.
   Audio performed by Arthur Rubinstein.
   Arthur Rubinstein born in 1887.

I think we need to decide which of these models are implied by our
requirements. Once we know what we have to encode, it will be easier
to setting the encoding issues.

There are other axes, such as whether the categories are ad-hoc, like in 
flickr tags, or reference an absolute collection like musicbrainz ids.

 -r

Ralph Giles wrote:
> On Mon, Sep 10, 2007 at 01:19:05PM +0100, Ian Malone wrote:
> 
>> as artist=(composer) Beethoven), I think cast lists for films present
>> a similar problem.  There is consistency and indexability to be
>> addressed (Ludvig van Beethoven; Beethoven, Ludvig van;
>> Beethoven).
> 
> ID3 has a concept of "sort" tags, which provide a string for
sorting
> purposes which is different from the (presumedly full name) of the usal 
> tag. TSOP="Beethoven", TCOM="Ludwig van Beethoven".
> 
> If you want something more precise, you have to link to unique 
> identifiers for a particular artist, like a musicbrainz id. I
> gather that's not what you're interested in here?
> 
Well, musicbrainz is great, but it won't identify actors
(for example).  More generally for organisation internal
metadata where you might want to say 'Bob recorded this'
musicbrainz is never going to give you an ID unless Bob
also happens to be a successful recording artist.  You
could use an organisation internal ID scheme of course;
a new band releasing a track online still faces a problem
though.

Actually it might be instructive to bring up (some of!)
the tags from a file that I have on my hd:
title=Bad Penny
artist=Rory Gallagher
MUSICBRAINZ_ALBUMID=ca0d3987-5d30-4f29-8863-599cc71b36d0
MUSICBRAINZ_ALBUMSTATUS=official
MUSICBRAINZ_ALBUMTYPE=compilation
MUSICBRAINZ_ARTISTID=933fdeae-ec68-48e9-a752-8bcfd44bc429
MUSICBRAINZ_NONALBUM=0
MUSICBRAINZ_SORTNAME=Gallagher, Rory
MUSICBRAINZ_TRACKID=e7c53164-8d74-4306-87be-e78fac6fb1a8
MUSICBRAINZ_VARIOUSARTISTS=0
RELEASECOUNTRY=GB

All capitalised tags are the result of an MB automatic
tagging tool.  The MB one includes all the uuids, but
also pulls in a 'sortname'. (Incidentally the album name
had been added when encoding, I suspect that's why it was
unmodified.)  Despite UUIDs there's an acknowledgement
here that you don't want to have to query the MB database
every time you want to search your music collection, the
UUID's main feature as far as I can see is to help tie
the database together at their end.

What I think would be useful would be a way of specifying
names which makes it easier to do structured sort.
Having separate first name(s) and last name fields would
work for most cases, but a vCard-like sortname field is
probably more realistic.  Make the sort name a mandatory
part of the name description and suggest to application
developers how it should be used.

-- 
imalone

On Wed, Sep 12, 2007 at 11:55:04PM +0100, Ian Malone wrote:
> All capitalised tags are the result of an MB automatic
> tagging tool.  The MB one includes all the uuids, but
> also pulls in a 'sortname'. (Incidentally the album name
> had been added when encoding, I suspect that's why it was
> unmodified.)  
> Despite UUIDs there's an acknowledgement
> here that you don't want to have to query the MB database
> every time you want to search your music collection, the
> UUID's main feature as far as I can see is to help tie
> the database together at their end.
*nod*
> What I think would be useful would be a way of specifying
> names which makes it easier to do structured sort.
> Having separate first name(s) and last name fields would
> work for most cases, but a vCard-like sortname field is
> probably more realistic.  Make the sort name a mandatory
> part of the name description and suggest to application
> developers how it should be used.
I agree a sort name makes more sense. Separate name fields
also don't internationalize well. But I don't think we can
make any of this mandatory. Falling back to sorting on the
full name is reasonable.

 -r