ID3v2: Difference between revisions

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ID3v2 is a new tagging system that lets you put enriching and relevant information about your audio files within them. In more down to earth terms, ID3v2 is a chunk of data prepended to the binary audio data. Each ID3v2 tag holds one or more smaller chunks of information, called frames. These frames can contain any kind of information and data you could think of such as title, album, performer, website, lyrics, equalizer presets, pictures etc.
[[Image:id3v2_blocks.png|thumb|Example ID3v2 Tag, image copyright © [https://id3.org/Copyright Martin Nilsson]]]
'''ID3v2''' is a tagging format for MP3 files, designed to provide a much greater deal of functionality and flexibility over its predecessor, [[ID3v1]]. ID3v2 allows for a much greater amount of [[metadata]] to be embedded within MP3 files over ID3v1, allowing each frame (metadata field) to contain practically any conceivable type of information, including title, album, performer, lyrics, equalizer presets, album art and other images, and much, much more.


<center>[[Image:id3v2_blocks.png|frame|center|Example ID3v2 Tag]]</center>
One of the design goals of ID3v2 was flexibility and extensibility. To acheive this, the ID3v2 format was modelled as a container format, allowing the creation of new frames within ID3v2 tags without worrying whether they will break other programs, as all ID3v2 parsers will simply ignore any frames they don't recognize.
Each frame can be as large as 16MB, and the entire tag can be as large as 256MB, so there are practically no space constraints when writing ID3v2 tags.


One of the design goals were that the ID3v2 should be very flexible and expandable. It is very easy to add new functions to the ID3v2 tag, because, just like in HTML, all parsers will ignore any information they don't recognize. Since each frame can be 16MB and the entire tag can be 256MB you'll probably never again be in the same situation as when you tried to write a useful comment in the old ID3 being limited to 30 characters.
Also, ID3v2 supports Unicode as standard, allowing metadata to be created in any language.


Speaking of characters, the ID3v2 supports Unicode so even if you use the Bopomofo character set you'll be able to write in your native language. You can also include in which language you're writing so that one file might contain e.g. the same lyrics but in different languages.
ID3v2 tags are generally added to the beginning of MP3 files, allowing audio players to display tag metadata before the end of the file is read (useful for streaming MP3 files). However, as of ID3v2.4, they can be appended to the end as well, meaning that a change in length in any ID3 frame will not necessarily provoke a rewrite of the entire file.


Even though the tag supports a lot of byte consuming capabilities like inline pictures and even the possibility to include any other file, ID3v2 still tries to use the bytes as efficient as possibly. If you convert an [[ID3v1]] tag to an ID3v2 tag it is even likely that the new tag will be smaller. If you convert an [[ID3v1]] tag where all fields are full (that is, all 30 characters are used in every field) to an ID3v2 tag it will be 56 bytes bigger. This is the worst case scenario for [[ID3v1]] to ID3v2 conversion.
ID3v2-tagged files are also generally safe to be played on players that weren't designed to support them. They are sync-safe, allowing MPEG audio decoders to determine the tags contain no audio data and can be safely skipped.


Since it's so easy to implement new functionality into ID3v2, one can hope that we'll see a lot of creative uses for ID3v2 in the future. E.g. there is a built-in system for rating the music and counting how often you listen to a file, just to mention some brainstorm results that are included. This feature can be used to build playlists that play your favourite songs more often than others.
Even though ID3v2 is designed to support a lot of space-heavy features, such as inline pictures and file inclusion, ironically, ID3v2 still tries to use bytes as efficiently as possible, and allows for compression of each frame. If you convert an ID3v1 tag to an ID3v2 tag, it is likely that the ID3v2 tag will be smaller. If you convert an ID3v1 tag with full fields (that is, all 30 bytes are used in every field) to an ID3v2 tag, it will be 56 bytes larger. Note that this is the worst case scenario with regards to tag size for ID3v1 to ID3v2 conversion.


 
==See also==
==Additional Reading==
* [[ID3v1]]
* [[ID3v1]]
* [[ID3v1.1]]
* [[ID3v1.1]]


==External links==
* [https://id3.org/ID3v2Easy What is ID3v2?]
===Standards===
* [https://id3.org/id3v2-00 ID3v2.2.0 Informal Standard]
* [https://id3.org/id3v2.3.0 ID3v2.3.0 Informal Standard]
* [https://id3.org/id3v2.4.0-structure ID3v2.4.0 Informal Standard]


==Copyright==
[[Category:Metadata]]
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:MP3]]
[[Category:Technical]]

Latest revision as of 09:11, 11 June 2022

Example ID3v2 Tag, image copyright © Martin Nilsson

ID3v2 is a tagging format for MP3 files, designed to provide a much greater deal of functionality and flexibility over its predecessor, ID3v1. ID3v2 allows for a much greater amount of metadata to be embedded within MP3 files over ID3v1, allowing each frame (metadata field) to contain practically any conceivable type of information, including title, album, performer, lyrics, equalizer presets, album art and other images, and much, much more.

One of the design goals of ID3v2 was flexibility and extensibility. To acheive this, the ID3v2 format was modelled as a container format, allowing the creation of new frames within ID3v2 tags without worrying whether they will break other programs, as all ID3v2 parsers will simply ignore any frames they don't recognize. Each frame can be as large as 16MB, and the entire tag can be as large as 256MB, so there are practically no space constraints when writing ID3v2 tags.

Also, ID3v2 supports Unicode as standard, allowing metadata to be created in any language.

ID3v2 tags are generally added to the beginning of MP3 files, allowing audio players to display tag metadata before the end of the file is read (useful for streaming MP3 files). However, as of ID3v2.4, they can be appended to the end as well, meaning that a change in length in any ID3 frame will not necessarily provoke a rewrite of the entire file.

ID3v2-tagged files are also generally safe to be played on players that weren't designed to support them. They are sync-safe, allowing MPEG audio decoders to determine the tags contain no audio data and can be safely skipped.

Even though ID3v2 is designed to support a lot of space-heavy features, such as inline pictures and file inclusion, ironically, ID3v2 still tries to use bytes as efficiently as possible, and allows for compression of each frame. If you convert an ID3v1 tag to an ID3v2 tag, it is likely that the ID3v2 tag will be smaller. If you convert an ID3v1 tag with full fields (that is, all 30 bytes are used in every field) to an ID3v2 tag, it will be 56 bytes larger. Note that this is the worst case scenario with regards to tag size for ID3v1 to ID3v2 conversion.

See also

External links

Standards

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