There are different versions of mp3 tags
Mp3 tags reside at the end of an mp3 file
, after the actual music
. Tags hold meta information
about the mp3 song itself such as author
. This information
from the actual recording
At the beginning
of the mp3 file lies information regarding the structure
of the file such as bitrate
outlines the structure
of an id3v1 tag.
However, id3v2 tags are becoming increasingly popular
An id3v1 tag is a static
size of 128 byte
s. All bytes are stored as type char
except for genre
which is an 8-bit
The first three bytes of a tag are always the same. They are the chars 'T','A','G'.
The 'T' is 128 bytes before the end of the file. A tagger module
can look in these three bytes offset
from the end of the file to ensure that an mp3 tag is valid.
The following 30 bytes store the title
of the song
If all 30 bytes are not used, the end of the string should be padded with '/0' or the string terminator char.
The next 30 bytes store the artist
The next 30 bytes store the album title
The next 4 bytes comprise the year of the recording. This is not stored as a number. It holds the literal
charecters corresponding to the year. '1','9','9','4' for example.
The next 30 bytes are reserved for any comments
The last 1 byte is stored as a number.
There are 128 possible values, and they each correspond to a differend genre