The man pages of the file command/libmagic are talking about a datatype called "ID3 length".
The only explanation i found was:
A 32-bit ID3 length

So what is this for a type ? Is it related to the ID3-Tag in mp3s ?


The magic(5) manual page says only (referring to this as a datatype):

  beid3   A 32-bit ID3 length in big-endian byte order.

  leid3   A 32-bit ID3 length in little-endian byte order.

and libmagic's associating the ID3 tags with mp3 has been noticed, e.g., Discussion: libmagic for MP3 can go horribly wrong, since the feature was added in 2008:

2008-11-06 18:18  Christos Zoulas <christos@zoulas.com>

    * Handle ID3 format files.

The ID3 format stores the tag length as a special 32-bit integer (which is the length you are asking about):

The ID3v2 tag size is stored as a 32 bit synchsafe integer (section 6.2), making a total of 28 effective bits (representing up to 256MB).

Further reading:

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.