[Vorbis] metadata

[Ian Malone]

  Oscar Sundbom wrote:
> Paul Ellis wrote:
> 
>> Ian, I don't know much about the metadata for Ogg, but let me confirm 
>> that you most likely will regret asking this on this mailing list.  I 
>> don't know if you've read through the archives for this list, but 
>> basically it is what it is now.  You are free to do what you want, but 
>> there is nothing more that is going to change to the metadata 
>> "officially".
> 
> 
>  From what I've gathered, both when I asked about a year or two ago, and 
> from reading other threads on the subject, there is still a desire for a 
> complete ogg metadata format, but it has not been done yet basically 
> because nobody has, well, done it yet. :) From what I understand, the 
> metadata format should be able to describe most everything related to 
> media, for it to be adopted by xiph. I'm sure, though, they know their 
> standpoint than I am.
> You're correct about the comments, though. They won't change 
> "officially". Something about them being just something you scribble on 
> a CD-R... not that it makes much sense to me.
> 

Thanks for your replies.

The most recent discussion on /comments/ was to suggest making a
collection of unofficial ones.  It would be useful to see how other
people have "overloaded/abused (depending on your point of view) for
most other things."

Metadata OTOH:
I'll have to read the Ogg description.  My understanding is that
is possible to drop in a raw (preferably utf-8) XML document as a
single page of a separate stream to the Vorbis data (and check that
it doesn't break existing players).  The difficulty is not in putting
the data in, but in structuring it (ie. as always, writing the code
is the easy bit).

Rambling thoughts on metadata follow.  Don't read on unless you really
care about this.

My own aim is basically to be able to put liner notes into the meta-
data.  Example: I have two albums in front of me: a Naxos recording
of Vivaldi Bassoon concertos and the Led Zeppelin BBC sessions.

The Vivaldi has a short résumé of the work (which I probably wouldn't
want to include, but would fit in Dublin Core's description element),
the soloist, the orchestra, the conductor, recording location and
dates, engineer, Naxos catalogue number and the recording/mastering DDD.
On top of that; the publisher and copyright, author for the booklet
notes and editors.  Plus the difficulties of deciding on 'track' names
for classical music.  Oh, and Vivaldi himself.

The BBC Sessions have the recording and broadcast dates for each track
(some have a 'not broadcast' note), the show and presenter, song
writing credits (including for the covers), credits for samples, and
there's a medley track on disc 2 which includes covers.  Plus mastering
and compilation credits.

You should see how much I can scribble onto the front of a CDR.

Both also have a text on the inside.  My own view is that, if I had the
patience to type them in, they would belong in their own file (possibly
with their own metadata, but someone else can worry about that).

I realize there's unlikely to be any real standard until someone finds
a use for all this information, but that's a bit of a chicken and egg
problem.  Besides, I'll suffer less headaches trying to be consistent
if there's a logical arrangement.  Operas are particularly painful;
things like "JOSE=(Don José) Nicolai Gedda" happen.

To some degree the Dublin Core (DC) stuff looks useful, but it is
still heavily directed towards publications: there is no analogue
for the Vorbis suggested comment 'LOCATION', and in both the above
examples you would have to have a lot of qualified 'contributor'
elements and decide on the difference between creator and contributor.
The most helpful thing they have is listings of the possible
restricted vocabularies; pointers to standards for specifying
locations, dates, etc.

Any solution should probably be able to replicate the suggested tags
at <http://www.xiph.org/vorbis/doc/v-comment.html>.  Most of those
actually fit well with DC.  Exceptions: location (mentioned above),
genre (maybe format, but I don't think it sits well), album (maybe
I've missed something in DC, I expected them to be able to categorize
something as part of a series; a more general description which would
also sit better with classical works[1]).

On top of this: multiple performers, qualified so cast, conductor,
etc. can be entered easily (cast also has the requirement of listing
character).  Contributors can probably hold engineers.  Creator seems
to sit best with writing credits, but is slightly at odds with the
traditional use of ARTIST: Jimi Hendrix---All Along the Watchtower,
Eric Clapton---Little Wing are good examples of times I want to see
performer in XMMS's title bar rather the creator.  A use for genre
maybe?  (Quick, get some prior art out before MS patent it.)

Anyone survived this far and have any thoughts?

[1] Also solves the problem of how do you deal with two pieces on
     a single cd: separate series elements for piece and album.

-- 
imalone
(Maybe I should be quiet for a while now)