I have some questions about tagging possibilities. I'm using mpc & APEv2 for long time, but I never created other fields than standard one (artist-title-date...). Simply because Winamp and other players don't show other ones.

Now that foobar benefits by the tagging window of Peter Pawlowski, and include a nice title formatting/Album List/Masstagger, I decided to think about better fields than standard ones. With them, I can create the powerful jukebox/organizer I always dreamt about (with performer sorting, label grouping...).
I actually need additional fields in order to store extra- but essential informations as performer and conductor. And I'm thinking about others one, in order to skip the useless (for me) « album » field, and replace it with something like « title / subtitle » or « maintitle / title ».

But I have some questions : are there some risks to do it ? Will I break some compatibilities ? And what kind of name can I create : are space allowed by the APE standard [main title or main_title], how many characters for one field, are redundancies allowed (i.e. PERFORMER, and PERFORMER again in the same file) ?
I can of course answer myself by simple tests in foobar2000 ; nevertheless, I prefer theoretical informations. I don't want to put a lot of work and time in retagging 10.000 files for losing the benefits few month later with an hypothetical SV7->SV8 transcoder that doesn't allow exotic/non-standard tagging informations...

Last one : are there defined (officially, I mean) fields ? I found two interesting leads in these links :
http://www.private.uni-jena.de/~pfk/mpp/sv...sv8/apekey.html
http://membres.lycos.fr/guruboolez/img/tagger.png

Are the names official ? Are they stopped ? Must we follow them, or are they only suggestions ?

Thank you for answering

I don't think there are any compatibility issues with using your own custom fields. I have been doing it for quite awhile myself with no problems. You may run into a situation where a player assumes that there are certain fields by default (like ALBUM, TRACKNUMBER, etc), but I think any application that properly supports ApeV2 tags (or Vorbis comments) should be designed well enough to allow configuration for these kinds of things.

I think you can use tags with spaces in the name, but I don't remember for sure. I'm not sure I've ever tried actually.

I also think that you can use multiple tags with the same name (like multiple PERFORMER tags), but again, I don't remember for sure. I could imagine that this might cause more of a problem for certain poorly designed players too, even if it is actually supported by the ApeV2 spec.

Also, the fields listed on the ApeV2 page are not really standardized in any universal sense, they are just recommendations I think.

Thank you Dibrom for your comments.
You're right : there are no problems with multiple tags using the same name. Foobar show them in the playlist, separated by a « , » ; Winamp 2 introduce a separation with an « ; ».

Only problem : sorting.
If a file has two string TITLE :
- ACT I
- Overture
Foobar will show : ACT I, Overture (good point)
However, if I add a new TITLE string :
-Fidelio
Foobar will show : ACT I, Overture, Fidelio
Pity : I want Fidelio, ACT I, Overture
And I can't reverse this order... (maybe should I ask to Peter a new feature).


With Winamp, I can change the order. In the file box, all strings, in TITLE informations are present, separated by a semicolon :
ACT I; Overture; Fidelio
If I manually change the order : Fidelio; ACT I; Overture, then foobar will take this modification in count :
Fidelio, ACT I, Overture.
It's fastidious to change the order, but possible...


Therefore, the semicolon « ; » is a splitting character. I noticed it with some of my own comment tags, splitted in 3 or 4 parts (though I didn't understand why).
If I enter, in fb2k, a title as :
Fidelio; Act I; Overture
I will have ONE field, filled with : Fidelio; Act I; Overture.
The semicolon, introduce by foobar, will not split anything in foobar2000.
But if I changed after that something else in the tag with winamp or another soft (tag, qcd...), then I will have in foobar THREE fields, one with Fidelio, another with Act I, and the last with Overture.
This is a bit confusing... Should I split this message and post this part in fb2k forum ;-)



(P.S) : space seemed to be allowed for the field name. Long name are allowed too (more than 64 characters, for sure).

I chose to use semicolon as multi field separator in Winamp's MPC plugin while waiting for better tag editing interface, the behavior there isn't optimal but I thought it's good enough for time being. Foobar's tag editor is flexible enough to give access to all tag fields without any such hacks.


Space is allowed, only control codes and characters with ascii value over 127 are not allowed. There are also no artificial length limits in fields, only the practical caused by using 32 bit numbers to store lengths.