With a valid mp3 with no id3 tag, using the -a -sf flags will give you
an identical mp3.  However not using the -sf flag, but instead using
the -s flag will give you a much smaller mp3 (This should be fixed).


By default -sf will strip the id3 tag off, but if you want it, use the
-i tag, and a fresh one will be created for you.

