History:ID3v2.4.0
I wish to collect info about application/libraries that support ID3v2.4.0 tags. Docs that make up the id3v2.4.0 standard. I also would like to collect tips for people writing code to read/write 2.4.0 tags.
Libraries
I'm mostly intrested in libs that can read AND write id3v2.4.0 tags
libid3tag (C) - http://www.underbit.com/products/mad/
pyid3 in tunetagger CVS (python) - http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/tunetagger/pyid3/
MP3::Info (perl) - http://sf.net/projects/pudge/
normalize (C) - http://www1.cs.columbia.edu/~cvaill/normalize/ ( comes with a library called nid3lib, which normalize uses internally for writing RVA2 tags )
eyeD3 (python) - http://www.travisshirk.net/eyeD3/
TagLib (C++) - http://developer.kde.org/~wheeler/taglib.html (provides a high level library for ID3v1/2, Ogg Vorbis and FLAC tags - is able to read and write ID3v2.4)
Bugs
MP3::Info can't write id3v2 tags. It does a good job of reading them, though.
iTune writes some comments with a frame name of 'COM '. See http://use.perl.org/~pudge/journal/10555
Some implementation NULL terminate all strings, others only NULL terminate the last string in the frame.
MP3ext writes the string "MP3ext " in the padding area, where the specs call for only NULLs to be written.