[mb-devel] Picard & tag mapping

[Lukáš Lalinský]

On Ne, 2007-08-19 at 00:45 +0200, Vidar Wahlberg wrote:
> what's the reason for having one "key" for id3v2/mp4 and another "key"
> for ogg vorbis/apev2?
> eg. "MusicBrainz Album Id" for id3v2/mp4 and "MUSICBRAINZ_ALBUMID" for
> ogg vorbis/apev2.
> wouldn't it be more intuitive & consistent to use the same key for all 4?
> eg: TXXX:MUSICBRAINZ_ALBUMID  | MUSICBRAINZ_ALBUMID
> or: TXXX:MusicBrainz Album Id | MusicBrainz Album Id
> there are certain TXXX fields which are set all in upper case
> (TXXX:CATALOGNUMBER, TXXX:ALBUMARTISTSORT) and that just makes it a bit
> more unclear why it's not done like this in other fields.

Because it's an existing standard, which applications already do
support. I don't know the original reason for defining it this way in
the standard, though.

> and speaking of ALBUMARTISTSORT (and other ".*SORT"), wasn't this
> ALBUMARTISTSORTNAME earlier (possibly pre-picard, i've been dormant for
> some time)?
> why did the "NAME" disappear?

In pre-Picard times it wasn't at all, in Picard 0.7.2 it's
"MUSICBRAINZ_ALBUMARTISTSORTNAME" and "TXXX:MusicBrainz Album Artist
Sortname" and "----:com.apple.iTunes:MusicBrainz Album Artist Sortname".

"ALBUMARTISTSORT" is used by non-MB applications and as this wasn't in
the original MB tag reference, I changed it in PicardQt.

> and finally:
> "MusicBrainz Track Id" is saved as a UFID frame in id3v2, and a "----"
> frame in mp4. now i know the UFID frame is made especially for "unique
> file identification" and that the track id fits fair here, but in my
> opinion this should just be in a TXXX frame to group it with the other
> ids.

No, it should be an UFID frame as it is. The other MB IDs should be in
PRIV frames, but it's too late to change that.

> if i got it right the UFID data supposedly should be binary as well.

Yes, ASCII text is binary. :)

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