[vorbis] The metadata problem

[Segher Boessenkool]

Maybe this will help, maybe it's fuel on the fire.  Who knows.

<p>I think we should first of all recognize there's different kinds
of metadata;  they most of all differ in _what you use it for_.

<p>Kind (1) is what the Vorbis comment header is: human readable comments.
It's just the same as if you're sitting in a bar and tell a friend
"hey, have you heard the new song XXX by YYY already?"  It's just some
textual comments about a track, nothing more, nothing less.  And most of
all, there are no requirements to it.  No mandatory tags, no nothing.

Of course, *some* consistency in this might be nice, just as in the bar
you say "the song XXX by the band YYY" and not "the cow XXX by the table YYY".

<p>Kind (2) is the data that a "media player" (like winamp) uses.  It's
used for
display, and more importantly, for searching and sorting.  But this *really*
isn't our problem; it's the media players problem.  It itself should
store a
database that contains the "tags", "columns", whatever you want to call it
that it wants to use.

<p>Kind (3) is the end-to-all data that you can store about a recording.  By
nature, this is hierarchical data.  This is the kind of data that is stored
in the internet music databases (although no one of them is anywhere near
thorough enough, at the moment).

A good way to *transport* this data within an Ogg stream would be an xml
metadata substream.

<p>Of course, if you've got (3), you can use it to automatically fill out
(2) and (1);
and if you've got (2), you can use it to fill out (1).  But it _will
not_ work
the other way around.

<p>Cheers,

Segher

<p>--- >8 ----
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