ID3v1.1

2018-03-10T14:24:29Z

XP1:

Although [[ID3v1]] may well be easy to implement for programmers, it sure is frustrating for those with their own creative ideas. Since the [[ID3v1]] tag had a fixed size and no space marked "Reserved for future use", there isn't really room for that much improvement, if you want to maintain compatibility with existing software.

{|align=center border="0" cellpadding="5" cellspacing="5"
|[[Image:id3v1.1_blocks.png|frame|center|Example ID3v1.1 Tag]]
|
{|border="1" cellpadding="2" cellspacing="0"
| Song title || 30 characters
|-
| Artist || 30 characters
|-
| Album || 30 characters
|-
| Year || 4 characters
|-
| Comment || 28 characters
|-
| Album track || 2 characters
|-
| Genre || 1 byte
|}
|}

A person who discovered a way was Michael Mutschler, who made a quite clever improvement on [[ID3v1]]. Since all non-filled fields must be padded with zeroed bytes, it is a good assumption that all [[ID3v1]] readers will stop reading the field when they encounter a zeroed byte. If the second last byte of a field is zeroed and the last one isn't, we have an extra byte to fill with information. As the comments field is too short to write anything useful, the ID3v1.1 standard declares that this field should be 28 characters, that the next byte always should be zero and that the last byte before the genre byte should contain which track on the CD this music comes from.

==Additional Reading==
* [[ID3v1]]
* [[ID3v2]]

==Copyright==
This material is copyrighted by [http://id3.org/Copyright Martin Nilsson], taken from [http://id3.org/ID3v1 ID3 made easy ].

[[Category:Metadata]]
[[Category:MP3]]
[[Category:Technical]]

ID3v1

2018-03-10T14:14:45Z

XP1:

The audio formats MPEG layer I, layer II, and layer III (MP3) have no native way of saving information about the contents, except for some simple yes/no parameters like "private", "copyrighted", and "original home" (meaning this is the original file and not a copy). A solution to this problem was introduced with the program "Studio3" by Eric Kemp, alias NamkraD, in 1996. By adding a small chunk of extra data at the end of the file, one could get the MP3 file to carry information about the audio and not just the audio itself.

The placement of the tag, as the data was called, was probably chosen as there was little chance that it would disturb decoders. In order to make it easy to detect, a fixed size of 128 bytes was chosen. The tag has the following layout:

{|align=center border="0" cellpadding="5"
|[[Image:id3v1_blocks.png|frame|left|Example Id3v1 Tag]]
|
{| align=right border="1" cellpadding="2" cellspacing="0"
| Song title || 30 characters
|-
| Artist || 30 characters
|-
| Album || 30 characters
|-
| Year || 4 characters
|-
| Comment || 30 characters
|-
| Genre || 1 byte
|}
|}

If we sum the size of all these fields, we see that 30+30+30+4+30+1 equals 125 bytes and not 128 bytes. The missing three bytes can be found at the very beginning of the tag, before the song title. These three bytes are always "TAG", which is the identification that this is indeed a ID3 tag. The easiest way to find a ID3v1/1.1 tag is to look for the word "TAG" 128 bytes from the end of a file.

As not all artists have a 30-character name, it is said that if there are some bytes left after the information is entered in the field, those bytes should be filled with the binary value 0. You might also think that you cannot write that much in the genre field, being one byte big, but it is clever than that. The byte value you enter in the genre field corresponds to a value in a predefined list. The list that Eric Kemp created had 80 entries, ranging from 0 to 79.

==Additional Reading==
* [[ID3v1.1]]
* [[ID3v2]]

==Copyright==
This material is copyrighted by [http://www.id3.org/copy.html Martin Nilsson], taken from [http://www.id3.org/id3v1.html ID3 made easy ].

[[Category:Metadata]]
[[Category:MP3]]

Hydrogenaudio Knowledgebase - User contributions [en]

ID3v1.1

ID3v1