# class MediaObject

###

Module | phonon
Namespace | Phonon
Class | MediaObject
Inherits | QObject,Phonon::MediaNode

\class MediaObject mediaobject.h Phonon/MediaObject Interface for media playback of a given URL.

This class is the most important class in %Phonon. Use it to open a media file at an arbitrary location, a CD or DVD or to stream media data from the application to the backend.

This class controls the state (play, pause, stop, seek) and you can use it to get a lot of information about the media data.

Notice that most functions of this class are asynchronous. That means if you call play() the object only starts playing when the stateChanged() signal tells you that the object changed into PlayingState. The states you can expect are documented for those methods.

A common usage example is the following:

    media = new MediaObject(this);
    connect(media, SIGNAL(finished()), SLOT(slotFinished());
    media->setCurrentSource("/home/username/music/filename.ogg");
    media->play();

If you want to play more that one media file (one after another) you can either tell MediaObject about all those files

    media->setCurrentSource(":/sounds/startsound.ogg");
    media->enqueue("/home/username/music/song.mp3");
    media->enqueue(":/sounds/endsound.ogg");

or provide the next file just in time:

    media->setCurrentSource(":/sounds/startsound.ogg");
    connect(media, SIGNAL(aboutToFinish()), SLOT(enqueueNextSource()));
    }

    void enqueueNextSource()
    {
    media->enqueue("/home/username/music/song.mp3");
    }

Author Matthias Kretz <kretz@kde.org>

### methods

- aboutToFinish ( )

  returns Nothing
  SIGNAL ("aboutToFinish ()")

  Emitted before the playback of the whole queue stops. When this signal is emitted you still have time to provide the next MediaSource (using enqueue) so that playback continues.

  This signal can be used to provide the next MediaSource just in time for the transition still to work.

  See also enqueue

- bufferStatus (percentFilled)

  returns Nothing
  SIGNAL ("bufferStatus (int)")

  Argument | Type | Default
  --- | --- | ---
  percentFilled | int |

  Tells about the status of the buffer.

  You can use this signal to show a progress bar to the user when in BufferingState:

      progressBar->setRange(0, 100); // this is the default
      connect(media, SIGNAL(bufferStatus(int)), progressBar, SLOT(setValue(int)));

  percentFilled - A number between 0 and 100 telling you how much the buffer is filled.

- clearQueue ( )

  returns Nothing

  Clears the queue of sources.

- currentSource ( )

  returns Phonon.MediaSource

  Returns the current media source.

  See also setCurrentSource

- currentSourceChanged (newSource)

  returns Nothing
  SIGNAL ("currentSourceChanged (const MediaSource&)")

  Argument | Type | Default
  --- | --- | ---
  newSource | Phonon.MediaSource |

  Emitted when the MediaObject makes a transition to the next MediaSource in the queue.

  In other words, it is emitted when an individual MediaSource is finished.

  newSource - The source that starts to play at the time the signal is emitted.

- currentTime ( )

  returns qint64

  Get the current time (in milliseconds) of the file currently being played.

  Returns The current time in milliseconds.

  See also tick

- enqueue (source)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  source | Phonon.MediaSource |

  Appends one source to the queue. Use this function to provide the next source just in time after the aboutToFinish signal was emitted.

  See also aboutToFinish

  See also setQueue

  See also clearQueue

- enqueue (sources)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  sources | QList<Phonon::MediaSource> |

  Appends multiple sources to the queue.

  See also setQueue

  See also clearQueue

- enqueue (urls)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  urls | QList<QUrl> |

  Appends multiple sources to the queue.

  See also setQueue

  See also clearQueue

- errorString ( )

  returns QString

  Returns a human-readable description of the last error that occurred.

- errorType ( )

  returns ErrorType

  Tells your program what to do about the error.

  See also Phonon.ErrorType

- finished ( )

  returns Nothing
  SIGNAL ("finished ()")

  Emitted when the object has finished playback. It is not emitted if you call stop(), pause() or load(), but only on end-of-queue or a critical error.

  This signal is not emitted when the current source has finished and there's another source in the queue. It is only emitted when the queue is empty.

  See also currentSourceChanged

  See also aboutToFinish

  See also prefinishMarkReached

- hasVideo ( )

  returns bool

  Check whether the media data includes a video stream.

  This information cannot be known immediately. It is best to also listen to the hasVideoChanged signal.

      connect(media, SIGNAL(hasVideoChanged(bool)), hasVideoChanged(bool));
      media->setCurrentSource("somevideo.avi");
      media->hasVideo(); // returns false;
      }

      void hasVideoChanged(bool b)
      {
      // b == true
      media->hasVideo(); // returns true;
      }

  Returns true if the media contains video data. false otherwise.

  See also hasVideoChanged

- hasVideoChanged (hasVideo)

  returns Nothing
  SIGNAL ("hasVideoChanged (bool)")

  Argument | Type | Default
  --- | --- | ---
  hasVideo | bool |

  Emitted whenever the return value of hasVideo() changes.

  Normally you'll check hasVideo() first and then let this signal tell you whether video is available now or not. That way you don't have to poll hasVideo().

  hasVideo - true The stream contains video and adding a VideoWidget will show a video. false There is no video data in the stream and adding a VideoWidget will show an empty (black) VideoWidget.

- isSeekable ( )

  returns bool

  Check whether the current media may be seeked.

  This information cannot be known immediately. It is best to also listen to the hasVideoChanged signal.

      connect(media, SIGNAL(hasVideoChanged(bool)), hasVideoChanged(bool));
      media->setCurrentSource("somevideo.avi");
      media->hasVideo(); // returns false;
      }

      void hasVideoChanged(bool b)
      {
      // b == true
      media->hasVideo(); // returns true;
      }

  Returns true when the current media may be seeked. false otherwise.

  See also seekableChanged()

- metaData (key)

  returns QStringList

  Argument | Type | Default
  --- | --- | ---
  key | QString |

  Returns the strings associated with the given key.

  Backends should use the keys specified in the Ogg Vorbis documentation: http://xiph.org/vorbis/doc/v-comment.html

  Therefore the following should work with every backend:

  A typical usage looks like this:

      setMetaArtist (media->metaData("ARTIST" ));
      setMetaAlbum (media->metaData("ALBUM" ));
      setMetaTitle (media->metaData("TITLE" ));
      setMetaDate (media->metaData("DATE" ));
      setMetaGenre (media->metaData("GENRE" ));
      setMetaTrack (media->metaData("TRACKNUMBER"));
      setMetaComment(media->metaData("DESCRIPTION"));

  For Audio CDs you can query

      metaData("MUSICBRAINZ_DISCID");

  to get a DiscID hash that you can use with the MusicBrainz service: http://musicbrainz.org/doc/ClientHOWTO

- metaData (key)

  returns QStringList

  Argument | Type | Default
  --- | --- | ---
  key | Phonon.MetaData |

  Returns the strings associated with the given key.

  Same as above except that the keys are defined in the Phonon.MetaData enum.

- metaData ( )

  returns QMultiMap<QString,QString>

  Returns all meta data.

- metaDataChanged ( )

  returns Nothing
  SIGNAL ("metaDataChanged ()")

  This signal is emitted whenever the audio/video data that is being played is associated with new meta data. E.g. for radio streams this happens when the next song is played.

  You can get the new meta data with the metaData methods.

- pause ( )

  returns Nothing

  Requests playback to pause. If it was paused before nothing changes.

  Possible states right after this call:

- PlayingState
- PausedState
- (\ref ErrorState)

- play ( )

  returns Nothing

  Requests playback of the media data to start. Playback only starts when stateChanged() signals that it goes into PlayingState, though.

  Possible states right after this call:

- BufferingState
- PlayingState
- (\ref ErrorState)

- prefinishMark ( )

  returns qint32

- prefinishMarkReached (msecToEnd)

  returns Nothing
  SIGNAL ("prefinishMarkReached (qint32)")

  Argument | Type | Default
  --- | --- | ---
  msecToEnd | qint32 |

  Emitted when there are only msecToEnd milliseconds left for playback.

  msecToEnd - The remaining time until the playback queue finishes.

  This signal is not emitted when there is another source in the queue. It is only emitted when the queue is empty.

  See also setPrefinishMark

  See also prefinishMark

  See also aboutToFinish

  See also finished

- queue ( )

  returns QList<Phonon::MediaSource>

  Returns the queued media sources. This does list does not include the current source (returned by currentSource).

- remainingTime ( )

  returns qint64

  Get the remaining time (in milliseconds) of the file currently being played.

  Returns The remaining time in milliseconds.

- seek (time)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  time | qint64 |

  Requests a seek to the time indicated.

  You can only seek if state() == PlayingState, BufferingState or PausedState.

  The call is asynchronous, so currentTime can still be the old value right after this method was called. If all you need is a slider that shows the current position and allows the user to seek use the class SeekSlider.

  time - The time in milliseconds where to continue playing.

  Possible states right after this call:

- BufferingState
- PlayingState
- (\ref ErrorState)

See also SeekSlider

- seekableChanged (isSeekable)

  returns Nothing
  SIGNAL ("seekableChanged (bool)")

  Argument | Type | Default
  --- | --- | ---
  isSeekable | bool |

  Emitted whenever the return value of isSeekable() changes.

  Normally you'll check isSeekable() first and then let this signal tell you whether seeking is possible now or not. That way you don't have to poll isSeekable().

  isSeekable - true if the stream is seekable (i.e. calling seek() works) false if the stream is not seekable (i.e. all calls to seek() will be ignored)

- setCurrentSource (source)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  source | Phonon.MediaSource |

  Set the media source the MediaObject should use.

  source - The MediaSource object to the media data. You can just as well use a QUrl or QString (for a local file) here.

      QUrl url("http://www.example.com/music.ogg");
      media->setCurrentSource(url);

  See also currentSource

- setPrefinishMark (msecToEnd)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  msecToEnd | qint32 |

- setQueue (sources)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  sources | QList<Phonon::MediaSource> |

  Set the MediaSources to play when the current media has finished.

  This function will overwrite the current queue.

  See also clearQueue

  See also enqueue

- setQueue (urls)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  urls | QList<QUrl> |

  Set the MediaSources to play when the current media has finished.

  This function overwrites the current queue.

  See also clearQueue

  See also enqueue

- setTickInterval (newTickInterval)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  newTickInterval | qint32 |

- setTransitionTime (msec)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  msec | qint32 |

- state ( )

  returns State

  Get the current state.

  Returns The state of the object.

  See also State

  See also stateChanged

- stateChanged (newstate, oldstate)

  returns Nothing
  SIGNAL ("stateChanged (State, State)")

  Argument | Type | Default
  --- | --- | ---
  newstate | Phonon.State |
  oldstate | Phonon.State |

  Emitted when the state of the MediaObject has changed. In case you're not interested in the old state you can also connect to a slot that only has one State argument.

  newstate - The state the Player is in now.

  oldstate - The state the Player was in before.

- stop ( )

  returns Nothing

  Requests playback to stop. If it was stopped before nothing changes.

  Possible states right after this call:

- the state it was in before (e.g. PlayingState)
- StoppedState
- (\ref ErrorState)

- tick (time)

  returns Nothing
  SIGNAL ("tick (qint64)")

  Argument | Type | Default
  --- | --- | ---
  time | qint64 |

  This signal gets emitted every tickInterval milliseconds.

  time - The position of the media file in milliseconds.

  See also setTickInterval, tickInterval

- tickInterval ( )

  returns qint32

- totalTime ( )

  returns qint64

  Get the total time (in milliseconds) of the file currently being played.

  Returns The total time in milliseconds.

  See also totalTimeChanged

- totalTimeChanged (newTotalTime)

  returns Nothing
  SIGNAL ("totalTimeChanged (qint64)")

  Argument | Type | Default
  --- | --- | ---
  newTotalTime | qint64 |

  This signal is emitted as soon as the total time of the media file is known or has changed. For most non-local media data the total time of the media can only be known after some time. At that time the totalTime function can not return useful information. You have to wait for this signal to know the real total time.

  newTotalTime - The length of the media file in milliseconds.

  See also totalTime

- transitionTime ( )

  returns qint32