To my knowledge ID3 is an extension and not an original part of mp3 either. I think these are just two different standards of tagging which could be both used for mp3-files. I'm to unexperienced to tell what's the superior plan here. From what I have read APE is the more modern format, it is more simple and flexible, it is better in the department of unicode support (languages) and some people say they would love to use APE if it would be more common and interchangable.
I'm unsure to judge which is the best format for my needs. From a practical point of view it is ID3 - cause simply my portable player does not speak APE. But within MB and for communication with other sources and being prepared best for the future etc. it could be an other choice.
That's why I like to argue from a higher level of abstraction: why not let them both live in the same file. I don't see that they would interfere technically: ID3 writes its information to the beginning of the file - APE to the end.
Though it is a problem of the players like MB who reads all standards to implement some additional logic of interpretation when i.e. in the title tags of the different formats different values of information are written (which shouldn't - but can happen, when the file comes from other sources). I think this could be solved and MB already does a good job on it. But it is not flexible as it strictly rules ID3 over APE and does not let the user decide about the preference. And it removes APE information when it writes ID3 tags - and vice versa.
So let me play a bit with that thought: I think MB could act in two ways (options):
* smart tagging (name corresponding to 'smart gain'):
1) ALL formats which are 'already in' the file will be written back with the best pool of information found in all of them (see below for the latter)
2) the format choice set in preferences will be written additionally, if not already done by 1)
* fix tagging:
1) all formats which are defined in the tag format setting under preferences will be written, again with the best pool of information found in all of the tags found
2) the options of formats in preference will be enlarged in that ID3V2.x and APE could be written both alltogether - not solely exclusive; and ID3v1 could be ticked additionally as is already realized
* Best pool of information:
MB already reads all formats in the file, merges the informations which are exclusively existent in one format and picks infomations by priority rule in case of informations are existent in more than one format for the same field.
I.e. I stumbled into this tagging issue as I noticed different replaygain settings in my files after doing a re-analysis for replaygain with the new algorithm. Other cases could be different informations of artist in the respective artist-tag of ID3 and APE; could be it is only a matter of case in writing a typo or whatsoever. To deal with this there must be a priority rule which information to trust - or to prefer.
But a program cannot tell which is the 'true' information having only the two values at hand and no mean to proof the one or other, looking into the internet for help is totally overkill here. So it could only be a 'stupid' rule of priority - as done by MB already. MB strictly rules ID3 over AVE. But it could be the case that the user 'trusts' its AVE tags more than its ID3 tags. Than the actual rule of MB is not the optimum.
Thus I can think of an option to let the user choose between the priority rules (for mp3-files):
1) ID3 over APE
2) APE over ID3
and within ID3:
1) ID3v1 over ID3v2
2) ID3v2 over ID3v1
Well, at the end let me say, its all thinking. MB does a good job here already (with some oddities I will post in another thread in the next days) - but may be the one or other hooks on here an my thoughts could be a starter to make MB even better.
Ralf