Nepomuk MultiMedia (NMM): Tracker Ontology Reference Manual

Nepomuk MultiMedia (NMM)

Nepomuk MultiMedia (NMM) — Description of multimedia objects like Music, Video and Images

Synopsis

@prefix nmm: <http://tracker.api.gnome.org/ontology/v3/nmm#>

Additional Properties

alternativeMedia, artwork, dlnaMime, dlnaProfile, genre, skipCounter, uPnPShared

Overview

Introduction

This ontology extends NIE (Nepomuk Information Element ontology) and NFO (Nepomuk File Ontology) into the domains of multimedia, including Images, Videos, Music and Radio, and includes a couple of properties to support uPnP sharing.

This ontology replaces/complements NID3 and NEXIF. Those ontologies are a direct map of the respective metadata standards, which makes very difficult to map cleanly other standards (like gstreamer metadata, mp4, ogg, and so on). Besides, those ontologies contain a lot of very low level technical information that is useless to the average user of the desktop.

Our approach in NMM is to keep the minimum properties that make sense for the user, and are present in all (or almost all) specific metadata formats. A profesional photographer (or musician) who needs more fine-grained details for its documents, is free to add also nID3 information or other extensions to the ontology.

Images domain

The core of images in NMM ontology is the class nmm:Photo. It is (through a long hierarchy) a nie:InformationElement, an interpretation of some bytes. It has properties to store the basic information (camera, metering mode, white balance, flash), and inherits from nfo:Image orientation (nfo:orientation) and resolution (nfo:verticalResolution and nfo:horizontalResolution).

Note that for tags, nie:keywords (from nie:InformationElement) can be used, or the NAO ontology.

Radio domain

NMM includes classes and properties to represent analog and digital radio stations. There is a class nmm:RadioStation on the nie:InformationElement side of the ontology, representing what the user sees about that station (genre via PTY codes, icon, plus title inherited from nie:InformationElement)

A nmm:RadioStation can have one or more nmm:carrier properties representing the different frequencies (or links when it is digitial) it can be tuned. This property links the station with nfo:MediaStream, but usually it will point to one of the subclasses: nmm:DigitalRadio (if digital) or nmm:AnalogRadio (if analog). An analog station has properties as modulation and frequency, while the digial station has streaming bitrate, encoding or protocol.

Note that nfo:MediaStream refers to a flux of bytes/data, and it is on the nie:DataObject side of the ontology

Class Details

AnalogRadio

Description

FM Radio carrier signal data. Basically the frequency

Class hierarchy

    nfo:MediaStream 
        nmm:AnalogRadio

Properties

Name	Type	Notes	Description
`frequency`	integer		Frequency in the Radio spectrum in Khz (note that usually FM frequencies are in MHz)
`modulation`	RadioModulation		Modulation used in the frequency (AM or FM)

Artist

Description

An artist.

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement ──┐
    nco:Role ────────────────┤
                             └── nmm:Artist

Properties

Name	Type	Notes	Description
`artistName`	string		Name of the artist

DigitalRadio

Description

Online Radio Stream data object (i.e. as a raw flow of bytes)

Class hierarchy

    nfo:MediaStream 
        nmm:DigitalRadio

Properties

Name	Type	Description
`encoding`	string	Encoding of the radio. It is a property of the streaming, that it is known before hand, so the applications can choose the encoding they understand.
`protocol`	string	Protocol used for the streaming (HTTP, RTSP)
`streamingBitrate`	integer	Bitrate indicating the quality of the stream in Kbits (usual values 32, 64, 128...)

Flash

Description

Enumeration of the possible values of flash property

Class hierarchy

    rdfs:Resource 
        nmm:Flash

Predefined instances

nmm:Flash has the following predefined instances:

nmm:flash-off
nmm:flash-on

ImageList

Description

An album of images

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:MediaList 
        nmm:ImageList

MeteringMode

Description

Enumeration of different ways a camera determines exposure.

Class hierarchy

    rdfs:Resource 
        nmm:MeteringMode

Predefined instances

nmm:MeteringMode has the following predefined instances:

nmm:metering-mode-other
nmm:metering-mode-partial
nmm:metering-mode-pattern
nmm:metering-mode-multispot
nmm:metering-mode-spot
nmm:metering-mode-center-weighted-average
nmm:metering-mode-average

Movie

Description

A Movie

Class hierarchy

    nie:InformationElement ──┐
    nfo:Media ───────────────┤
    nfo:Video ───────────────┤
    nfo:Visual ──────────────┤
                             └── nmm:Movie

MusicAlbum

Description

The music album as provided by the publisher. Not to be confused with media lists or collections

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:MediaList 
        nmm:MusicAlbum

Properties

Name	Type	Description
`albumArtist`	Artist	main artists of the album
`albumDuration`	integer	Duration of the album
`albumGain`	integer	Gain of album
`albumPeakGain`	integer	Peak Gain of album
`albumTrackCount`	integer	Track count of album

MusicAlbumDisc

Class hierarchy

    nie:InformationElement 
        nmm:MusicAlbumDisc

Properties

Name	Type	Description
`albumDiscAlbum`	MusicAlbum	Album of the disc
`musicCDIdentifier`	string	Music CD identifier to for databases like FreeDB.org. This frame is intended for music that comes from a CD, so that the CD can be identified in databases such as the CDDB. The frame consists of a binary dump of the Table Of Contents, TOC, from the CD, which is a header of 4 bytes and then 8 bytes/track on the CD plus 8 bytes for the 'lead out' making a maximum of 804 bytes. The offset to the beginning of every track on the CD should be described with a four bytes absolute CD-frame address per track, and not with absolute time.
`setNumber`	integer	Disc number of album disc

MusicPiece

Description

Used to assign music-specific properties such as BPM to video and audio

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:Media 
        nmm:MusicPiece

Properties

Name	Type	Description
`artist`	Artist	main artist of the MusicPiece
`beatsPerMinute`	integer	beats per minute
`composer`	Artist	Composer
`internationalStandardRecordingCode`	string	ISRC ID. Format: 'CC-XXX-YY-NNNNN'
`lyricist`	Artist	Lyricist
`lyrics`	SynchronizedText
`musicAlbum`	MusicAlbum	album the music belongs to
`musicAlbumDisc`	MusicAlbumDisc	album disc the music belongs to
`performer`	Artist	Performer
`trackNumber`	integer	Track number of the music in its album

Photo

Description

A photo

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:Image 
        nmm:Photo

Properties

Name	Type	Description
`exposureTime`	double	Exposure time of the photo
`flash`	Flash	Specifies whether flash was used
`fnumber`	double	The diameter of the entrance pupil in terms of the focal length of the lens
`focalLength`	double	A measure of how strongly the lens converges light
`isColorCorrected`	boolean
`isCropped`	boolean
`isoSpeed`	double	Measure of a photographic film's sensitivity to light as ISO value
`meteringMode`	MeteringMode	Metering mode refers to the way in which a camera determines the exposure.
`whiteBalance`	WhiteBalance

Playlist

Description

Specific class to split MediaList in Albums and playlists.

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:MediaList 
        nmm:Playlist

RadioModulation

Description

Set of instances for analog radio modulation

Class hierarchy

    rdfs:Resource 
        nmm:RadioModulation

Predefined instances

nmm:RadioModulation has the following predefined instances:

nmm:radio-modulation-fm
nmm:radio-modulation-am

RadioStation

Description

The Radio station in user terms: BBC3, Radio5, YLEX, ... It is linked with 1 or more carriers (different FM frenquencies, online sources in different qualities, etc.). Some RDS information is represented with nie properties, nie:identifier for PI, nie:title for PS

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:Audio 
        nmm:RadioStation

Properties

Name	Type	Description
`carrier`	MediaStream	Signal where a radio can be tuned in. There can be more than one.
`radioIcon`	Image	Image used as logo for a radio station
`radioPTY`	integer	PTY Code (content description) as integer. RDS specs define the translations into human readable descriptions for various languages

SynchronizedText

Class hierarchy

    nfo:PlainTextDocument 
        nmm:SynchronizedText

Properties

Name	Type	Notes	Description
`isForHearingImpaired`	boolean		Does text stream contain helper tags for hearing-impaired such as <steps in hallway>

TVSeason

Description

A season of a TV show

Class hierarchy

    nie:InformationElement 
        nmm:TVSeason

Properties

Name	Type	Description
`hasSeasonEpisode`	TVShow	Relates a TV Show season to its episodes
`seasonNumber`	integer	The number of a season
`seasonOf`	TVSeries	Relates a TV Season to its series

TVSeries

Description

A TV Series has multiple seasons and episodes

Class hierarchy

    nie:InformationElement 
        nmm:TVSeries

Properties

Name	Type	Notes	Description
`hasEpisode`	TVShow		A TVSeries has many episodes
`hasSeason`	TVSeason		Relates a TV Series to its seasons

TVShow

Description

A TV show

Class hierarchy

    nie:InformationElement ──┐
    nfo:Media ───────────────┤
    nfo:Video ───────────────┤
    nfo:Visual ──────────────┤
                             └── nmm:TVShow

Properties

Name	Type	Description
`episodeNumber`	integer	Episode number of a TV show
`isPartOfSeason`	TVSeason	Relates a TV Show to its season
`series`	TVSeries	Relates a TV Show to its TV series

Video

Description

This class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nfo:Video ──┐
    nfo:Audio ──┤
                └── nmm:Video

Properties

Name	Type	Description
`MPAARating`	string
`category`	string
`director`	Artist
`hasSubtitle`	boolean
`isContentEncrypted`	boolean
`leadActor`	Artist
`producedBy`	Artist
`runTime`	integer
`subtitle`	SynchronizedText
`synopsis`	string	Long form description of video content (plot, premise, etc.)

WhiteBalance

Description

Camera's white balance setting

Class hierarchy

    rdfs:Resource 
        nmm:WhiteBalance

Predefined instances

nmm:WhiteBalance has the following predefined instances:

nmm:white-balance-manual
nmm:white-balance-auto

Property Details

Additional properties for nfo:Media

Description

Properties this ontology defines which can describe nfo:Media resources.

Properties

Name	Type	Description
`alternativeMedia`	Media	Link between to different version of the same media. This is used for instances in uPnp where the server can provide the same video in different resolutions and codecs
`artwork`	Image	Associated Artwork
`dlnaMime`	string	Mimetypes as defined for DLNA (occasional differences compared to xdg-mime)
`dlnaProfile`	string	DLNA profile of the content, like MP3, MPEG_TS_HD_US, LPCM etc
`genre`	string
`skipCounter`	integer
`uPnPShared`	boolean	Tells the uPnP MediaServer (e.g. Rygel) whether to export/share the resource or not

Credits and Copyright

Authors:

Urho Konttori <urho.konttori@nokia.com>

Editors:

Ivan Frade <ivan.frade@nokia.com>
Urho Konttori <urho.konttori@nokia.com>

Upstream:

Not available

ChangeLog:

Tracker changes