ID3 is a metadata container most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, or other information about the file to be stored in the file itself. Metadata (Greek meta after and Latin data information) are data that describe other data. ... MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format and algorithm, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Versions of ID3

There are two unrelated versions of ID3: ID3v1 and ID3v2.

ID3v1

ID3v1 was created by Eric Kemp in 1996 and quickly became the de facto standard for storing metadata in MP3s. The ID3v1 tag occupies 128 bytes, beginning with the string TAG. To maintain compatibility with older media players the tag was placed at the end of the file. Some players played a small burst of static when they read the tag, but most ignored it, and almost all modern players will correctly skip it. 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... De facto is a Latin expression that means in fact or in practice. It is commonly used as opposed to de jure (meaning by law) when referring to matters of law or governance or technique (such as standards), that are found in the common experience as created or developed without... This article refers to the unit of binary information. ... Wikipedia does not yet have an article with this exact name. ...

ID3v1 was extended by Michael Mutschler in 1997, by using the last byte of the little-used "comment" field to store the track number. Such tags are referred to as ID3v1.1. 1997 (MCMXCVII) was a common year starting on Wednesday of the Gregorian calendar. ...

Problems with ID3v1

The small tag size only allowed for 30 bytes for the title, artist, album, and a "comment", 4 bytes for the year, and a byte to identify the genre of the song from a list of 80 values (Winamp later extended this list to 148 values). Long song or album titles were simply truncated. Look up genre in Wiktionary, the free dictionary. ... Winamp is a multimedia player made by Nullsoft. ...

Many users criticized the predefined genre list, which did not contain common genres like minimalist or Baroque, but did contain entries like Christian Rap. Minimalist music is a genre of experimental music named in the 1960s which displays some or all of the following features: emphasis on consonant harmony, if not functional tonality; reiteration of musical phrases or smaller units such as figures, motifs, and cells, with subtle, gradual, and/or infrequent variation (no... Baroque music describes an era and a set of styles of European classical music which were in widespread use between approximately 1600 to 1750 (see Dates of classical music eras for a discussion of the problems inherent in defining the beginning and end points). ... Christian rap (originally gospel rap, but also known as holy hip hop, or Christian hip-hop) is a form of rap music that uses Christian-themed lyrics to express the songwriters faith. ...

ID3v1 also lacked support for internationalization. While nominally the text was supposed to be encoded in ISO-8859-1, in practice the user's local encoding was usually used, and so mojibake are common in ID3v1 tags. Internationalization and localization are means of adapting products such as publications or software for non-native environments, especially other nations and cultures. ... ISO 8859-1, more formally cited as ISO/IEC 8859-1 or less formally as Latin-1, is part 1 of ISO/IEC 8859, a standard character encoding defined by ISO. It encodes what it refers to as Latin alphabet no. ... Mojibake (文字化け, moji character + bake change, literally ghost characters or changed characters) is Japanese for broken characters: the result of trying to display text in character encodings which a piece of software is not configured to deal with. ...

ID3v2

In response to these criticisms, a new standard called ID3v2 was created. Although it bears the name ID3, it has little to no relation to the ID3v1 standard.

ID3v2 tags are of variable size, and usually occur at the start of the file, to aid streaming media. They consist of a number of frames, each of which contains a piece of metadata. For example, the TIT2 frame contains the title, and the WOAR frame contains the URL of the artist's website. Frames can be 16MB in length. Textual frames are marked with an encoding bit, though mojibake are still common. Streaming media is media that is consumed (heard or viewed) (mostly in the form of clips) while it is being delivered. ... A Uniform Resource Locator, URL (spelled out as an acronym, not pronounced as earl), or Web address, is a standardized address name layout for resources (such as documents or images) on the Internet (or elsewhere). ... Mojibake (文字化け, moji character + bake change, literally ghost characters or changed characters) is Japanese for broken characters: the result of trying to display text in character encodings which a piece of software is not configured to deal with. ...

In the latest ID3v2 standard there are 84 types of frame, and applications can also define their own types. There are standard frames for containing cover art, BPM, copyright and license, lyrics, and arbitrary text and URL data, as well as other things. Beats per minute (bpm) is a unit typically used as either a measure of tempo in music, or a measure of ones heart rate. ...

There are three versions of ID3v2, v2.2, v2.3, and v2.4.

ID3v2.2

This was the first public version of ID3v2. It used three character frame identifiers rather than four (TT2 for the title instead of TIT2). Most of the common v2.3 and v2.4 frames have direct analogues in v2.2.

ID3v2.3

ID3v2.3 expanded the frame identifier to four characters, and added a number of frames. A frame could contain multiple values, separated with a / character.

ID3v2.4

ID3v2.4 is the latest version of the standard, dated November 1, 2000. Notably, it allows textual data to be encoded in UTF-8, which was a common practice in earlier tags despite the standard. It uses a null byte to separate multiple values, and so / can appear in text data again. November 1 is the 305th day of the year (306th in leap years) in the Gregorian Calendar, with 60 days remaining. ... This article is about the year 2000. ... UTF-8 (8-bit Unicode Transformation Format) is a variable-length character encoding for Unicode created by Ken Thompson and Rob Pike. ...

ID3v2 Chapters

The ID3v2 Chapter Addendum was published in December 2005 but is not widely supported as yet. It allows users to jump easily to specific locations or chapters within an audio file and can provide a synchronized slide show of images and titles during playback. Typical applications include Enhanced podcasts and it can be used in ID3v2.3 or ID3v2.4 tags. An funhanced podcast is a podcast multimedia format that allows images to be displayed in time with audio. ...

Criticisms and problems

Although the different versions of ID3v2 are conceptually similar, implementing an algorithm to read and write them is difficult. There are subtle but critical differences between all the versions. Even within a version, the structure of frames differs greatly. For example, the TIT2 frame which contains the title, and the USLT which contains a lyrics transcription, require different algorithms to extract the data. With 84 different frames, dozens of such sub-parsers are required. Other tagging formats such as APEv2 eschew this, and use a single key/value pair for the internal structure of every frame. APEv2 tags are used to add metadata, such as the title, artist, or track number, to digital audio files. ...

ID3v2 stores many things in the tag that are more commonly left to the audio format itself. Some examples are the TLEN frame which stores the audio length, or the AENC frame which contains the encryption scheme of the audio. (However, the information provided by TLEN is often not derived trivially. In general, the duration of a variable bitrate stream can be calculated only after examining each frame of the entire stream. Thus, TLEN can be useful for streaming audio and inadequate hardware.) // In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. ...

Despite being over six years old, ID3v2.4 has not seen much adoption. This is likely because the ID3v2 reference implementation still cannot read or write it. However, this is changing, as new tagging tools such as Amarok, Quod Libet, and foobar2000 will only write v2.4 tags by default. Amarok (formerly known as amaroK) is a free software music player for GNU/Linux and other varieties of Unix. ... Quod Libet is an audio player application for gnome, similar to amaroK. External links QuodLibet Homepage Categories: | | ... foobar2000 is a freeware audio player for Windows developed by Peter Pawlowski, a former freelance contractor for Nullsoft. ...

Due to these problems, some tagging tools now use other metadata formats when tagging MP3s. Few new audio formats have adopted ID3v2 tags, opting instead for APEv2 tags or Vorbis comments. APEv2 tags are used to add metadata, such as the title, artist, or track number, to digital audio files. ... A Vorbis comment is a metadata container used in the Vorbis and FLAC audio file formats. ...

Editing ID3 tags

ID3 tags may be edited in a variety of ways. On some platforms the file's properties may be edited by viewing extended information in the file manager. Additionally most audio players allow editing single or groups of files. Editing groups of files is often referred to as "batch tagging". There are also specialized applications, called taggers, which concentrate specifically on editing the tags of and related tasks. These often offer advanced features such as advanced batch tagging or editing based on regular expressions. The following tables compare general and technical information for a number of media player programs. ... In computing, a regular expression (abbreviated as regexp or regex, with plural forms regexps, regexes, or regexen) is a string that describes or matches a set of strings, according to certain syntax rules. ...

See also

• APEv2 tag
• Vorbis comment
• Tag editor

APEv2 tags are used to add metadata, such as the title, artist, or track number, to digital audio files. ... A Vorbis comment is a metadata container used in the Vorbis and FLAC audio file formats. ... A tag editor (or tagger) is a piece of software that supports editing metadata of multimedia file formats rather than the actual file content. ...

External links

• Official site for ID3, including the format specifications
• List of genres in ID3v1
• ID3 renamer