It is recommended that xesam metadata fields (prefixed by "xesam:") are used wherever possible. This allows for natural extension of the specification in a standard way.
There are also a few MPRIS-specific fields that are intended for interaction with other methods in the specification. These are prefixed with "mpris:".
Any metadata fields that are not part of a xesam ontology or defined in this document should be prefixed with a different tag, such as "totem:" or "kde:".
- Common Xesam properties
Note that some types that you might expect to be strings are, in fact, "lists of strings". These should be sent using the "as" D-Bus type (array of string).
Date/time fields should be sent as strings in ISO 8601 extended format. If the timezone is known (eg: for xesam:lastPlayed), the internet profile format of ISO 8601, as specified in RFC 3339, should be used.
For example: "2007-04-29T13:56+01:00" for 29th April 2007, four minutes to 2pm, in a time zone 1 hour ahead of UTC.
URIs should be sent as (UTF-8) strings. Local files should use the "file://" schema.
D-Bus path: A unique identity for this track within the context of an MPRIS object (eg: tracklist).
64-bit integer: The duration of the track in microseconds.
URI: The location of an image representing the track or album. Clients should not assume this will continue to exist when the media player stops giving out the URL.
Common audio properties from the Xesam specification:
String: The album name.
List of Strings: The album artist(s).
List of Strings: The track artist(s).
String: The track lyrics.
Integer: The speed of the music, in beats per minute.
Float: An automatically-generated rating, based on things such as how often it has been played. This should be in the range 0.0 to 1.0.
List of Strings: A (list of) freeform comment(s).
List of Strings: The composer(s) of the track.
Date/Time: When the track was created. Usually only the year component will be useful.
Integer: The disc number on the album that this track is from.
Date/Time: When the track was first played.
List of Strings: The genre(s) of the track.
Date/Time: When the track was last played.
List of Strings: The lyricist(s) of the track.
String: The track title.
Integer: The track number on the album disc.
URI: The location of the media file.
Integer: The number of times the track has been played.
Float: A user-specified rating. This should be in the range 0.0 to 1.0.