Included MDPs

Different MDPs support different file types and metadata fields. When requesting metadata fields, you must state the metadata categories and the individual attributes that you want to retrieve; see mmmd_get() for more details.

The libmd library combines a category (the prefix) with each of the listed attributes (the suffixes) to form the full names of the metadata fields. You can state as many categories and attributes as you need but you should be aware of which fields are supported by which MDPs.

The MDPs shipped with libmd and the file types and metadata that they support are as follows:

MDP Files Metadata categories Attributes
CDDA CD audio tracks md_title album, artist, genre, name, composer, track, bitrate, samplerate, duration, format
Exif POSIX files on mass storage devices (e.g., USB sticks) md_title width, height, date_time_original, shutter_speed, fnumber, iso_speed_ratings, focal_length, orientation, description, latitude, longitude, keywords
Extart External artwork such as cover images for albums and thumbnail graphics for tracks md_title art (see 1)
md_artwork image (see 2), count, size, urls
IMG Image files md_title width, height, color_depth
iPod iPod media files md_title art (see 1)
md_artwork image (see 2), mimetype, width, height, size, count
MediaFS Files on MTP devices md_title name, artist, album, composer, genre, year, duration, comment, protected, track, art (see 1)
md_artwork image (see 2), width, height, size, mimetype, count
MMF MMF files accessible from either a network source (e.g., an HTTP server) or a POSIX device md_title name, artist, album, albumartist, composer, genre, comment, duration, track, disc, year, seekable, pausable, samplerate, bitrate, protected, mediatype (see 3), width, height, art (see 1), compilation, rating
md_video width, height, pixel_width, pixel_height, frame, fourcc
md_audio fourcc
md_artwork image (see 2), description, type, mimetype, count, size
1 This field is an alias for md_artwork::image, which is the preferred way of requesting image data.
2 The image field must include a file option that names the path to write the image data. This can be a POSIX path in the local filesystem or a special value to request an image file reference instead of the image data (for more information, see "Metadata provider constants"). The field can also specify an index to select one image from many within the given path (for details, see "Extracting artwork").
3 The value returned for the md_title::mediatype field is in decimal but should be converted to hexadecimal for readability. For the mapping of hexadecimal values to media types, see the MediaFormat_t data structure in the Addon Interface Library Reference.