[ale] Changing ID3 APIC tag, anyone know...

[Ken Arromdee]

I have some MP3 files which have embedded pictures which are of type
image/jpg.  If you look at the specs at http://www.id3.org/id3v2.4.0-frames
it says that the picture should be mime type image/jpeg.  My Mp3 player seems
to take this very literally and refuses to show pictures which are jpg rather
than jpeg.

Does anyone know what tool I can use under Linux, command line, to extract
and change the mime type from the APIC field while leaving the picture itself
in place?  eyeD3 and id3v2 don't have this feature, and in general, changing
the APIC (especially just changing part of the APIC) is rarely implemented
by any programs.