As its name suggests, mp3Tag Pro was initially created to handle MP3 tags. Later, support for other popular formats was added, and now the program also works with OGG, WMA, APE, FLAC, AAC, MPC, WV, M4A, MP4, WAV files. All supported tag formats are processed in the same way, so you can easily rename or tag a mixed group of files.
The MP3 format was made publicly available in 1993. It is part of the MPEG (Moving Picture Experts Group) standard.
Soon after its release, a problem was discovered. Although technically the MP3 format was quite perfect, there could be a difficulty identifying particular MP3 files. No textual information could be stored inside MP3 files themselves, which meant no artist, no title, no album, and so on.
One can think of saving some basic details (at least title and artist) as filenames. However, filenames in MS-DOS and early versions of Windows could have only 8 characters.
In 1996, an enhancement was suggested by Eric Kemp. A small (128 bytes) chunk of data was appended at the end of an existing MP3 file. This allowed saving 128 characters of text inside the audio file, which was way better than just 8 characters in filenames.
This enhancement was later called ID3 tag and became a de facto standard for saving meta-information in MP3 files.
The original ID3 tag version (ID3v1) included the following fields:
- Title – 30 characters.
- Artist – 30 characters.
- Album – 30 characters.
- Year – 4 characters.
- Comment – 30 characters.
- Genre – 1 character.
3 more characters were used for the header of the ID3 data block.
This layout was quite rigid, so you could not save 20 characters of a title and use the remaining 10 characters for the artist field.
A year later, in 1997, Michael Mutschler decided to take 2 bytes from the comment field and store the track number. This improvement is known as ID3v1.1.
In 1998, several contributors created a new specification of ID3 tags, now known as ID3v2. While the same name suggests a further improvement of ID3v1, the format is completely different.
ID3v1 was added at the end of an MP3 file to ensure compatibility with older players. ID3v2 was appended at the beginning of an MP3 file. This made it suitable for streaming media.
Length of fields (frames) in ID3v2 became variable. Now a field could contain up to 16 MB of data, so a big novel would easily fit. There were more predefined fields, including fields for lyrics and album art. Furthermore, new types of fields could be easily defined without changing the existing specification.
In general, there are 3 versions of ID3v2:
- ID3v2.2 – the first version of ID3v2, now obsolete.
- ID3v2.3 – an improved version of ID3v2, uses 4 characters for frame identifiers (the original version used 3 characters) and has more predefined frames. This version is most widely used.
- ID3v2.4 – the latest version of ID3v2 released in 2000, allows using the UTF-8 character encoding and includes some other features. ID3v2.4 is not as popular as ID3v2.3. In particular, all versions of Windows (including Windows 8) and Windows Media Player do not support this version.
For maximum compatibility, the ID3v2.3 version is recommended.
ID3v2 allows using different encodings. Most frequently, the usual “Windows text” (ANSI) and Unicode (UTF-16) are used.
Most players and programs that work with MP3 files understand both ID3v1 and ID3v2. As a rule, ID3v2 is preferred. Nevertheless, it is recommended to keep ID3v1 and ID3v2 synchronized.
mp3Tag Pro supports the following additional fields of ID3v2 (basic fields, including track number, are the same as in ID3v1, although without the limit on length):
- Disc number.
- Album artist.
- Original artist.
- Encoded by.
- Album art.
- BPM (beats per minute).
By default, the program saves both ID3v1 and ID3v2, but you can change this. Additionally, there is an option to delete all tags, which deletes ID3v1 and ID3v2.