ID3v2 comment language code (ISO-639-2)

Different programs require ID3v2 comments to be written with specific language code identifiers. Mp3tag’s default is eng, but depending on the language of your Windows installation, you might want to use the ISO-639-2 code of this language so that comments are displayed in Windows Explorer or Windows Media Player (e.g., deu for a German Windows installation).

However, if you use another language code than eng iTunes won’t read the comments of your ID3v2 tagged files anymore, since it requires them to be written with this particular language code identifier.

Always display POPULARIMETER values for ID3v2 ratings

If this option is enabled, Mp3tag displays the POPULARIMETER field for ID3v2 ratings instead of any app-specific fields. Changing this setting might require reloading of the file’s tags for the changes to be visible.

List chapters as separate files

Some file formats, e.g., MP4 or Matroska, can have chapters. If you enable this setting and reload the directory, Mp3tag lists chapters as separate files. It’s especially helpful if you’re into editing video files and want to edit the titles of the individual chapters (or the global tags of a file if disabled).

If the option to list chapter as separate files is disabled, it can be difficult to identify which files actually have chapters. You can use the following information fields to identify those files, e.g., in a File List column:

• %_subsong_count% provides the number of subsongs in a file and
• %_subsong% contains the subsong index.

Use recommended mapping for Matroska video

The Matroska file format features a complex metadata structure based on target types. These define different levels at which the same tag field can be applied. For example, PART_NUMBER can be the track number (level 30) and the disc number (level 50). To improve compatibility with other apps and to match semantics, this option enables the recommended mapping for Matroska video (MKV) files. Disable for apps that only read TITLE with target type T=30.

Use single MP4 atom for multiple values

This option enables writing of one single MP4 atom to store multiple values for one field (instead of one MP4 atom per value). Individual values are stored in multiple data atoms that are contained in the MP4 atom for the actual field.

Reuse unmodified MP4 atoms ^beta-only

This option enables reuse of existing MP4 atoms when writing tags, provided the field value has not changed. It’s useful when you want to limit the impact Mp3tag is having on your existing tag fields or if you require Mp3tag to not touch certain fields for compatibility reasons, or with legacy or non-standard implementations.

If this option is enabled, existing user-defined fields for which a mapping exists are not remapped to the target atom unless the field value changes. As a result, mapped atoms are only rewritten when their corresponding field contents are modified.

Reuse unmodified ID3v2 frames ^beta-only

This option enables reuse of existing ID3v2 frames when writing tags, provided the field value has not changed. It’s useful when you want to limit the impact Mp3tag is having on your existing tag fields or if you require Mp3tag to not touch certain fields for compatibility reasons, or with legacy or non-standard implementations.

If this option is enabled, existing user-defined fields for which a mapping exists are not remapped to the target frame unless the field value changes. As a result, mapped frames are only rewritten when their corresponding field contents are modified.