MPRIS is only partially implemented

[Alfonso Sanchez-Beato]

* Metadata property from org.mpris.MediaPlayer2.Player is not exported (see service_skeleton.cpp)

* Some DBus calls to object /org/mpris/MediaPlayer2 do not return anything, like:

dbus-send --print-reply --type=method_call --dest=core.ubuntu.media.Service /org/mpris/MediaPlayer2 org.freedesktop.DBus.Properties.GetAll string:org.mpris.MediaPlayer2.TrackList

Others are not answered, like:

dbus-send --print-reply --type=method_call --dest=core.ubuntu.media.Service /org/mpris/MediaPlayer2 org.freedesktop.DBus.Properties.Get string:org.mpris.MediaPlayer2.TrackList string:Tracks

Note that MPRIS specification [1] says that the implementations *must* use "/org/mpris/MediaPlayer2" as object path. However, we are using "/core/ubuntu/media/Service/sessions/<number>" and "/core/ubuntu/media/Service/sessions/<number>/TrackList" for most signals and methods.

* The track list is emptied when the non-standard call org.mpris.MediaPlayer2.TrackList.Reset is performed or when music-app is terminated, but no signal is generated, and indicator-sound still thinks there is something to play.

* Also, we do not return an error in the DBus call if DBus calls Next or Previous fail due to an empty track list (see media::TrackListSkeleton::next() and media::TrackListSkeleton::previous())

[1] http://specifications.freedesktop.org/mpris-spec/latest/

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Pat McGowan (pat-mcgowan)]

If this is required to support metadata in the sound indicator it needs higher priority

[pedaliero2012 (patrik-simon)]

The bug #1559012 is also a duplicate

[Jim Hodapp (jhodapp)]

The attached branch fixes the metadata part of this bug. I'm going to separate this bug into multiple ones so that each can be addressed in smaller bits.

[Łukasz Zemczak (sil2100)]

This bug was fixed in the package media-hub 4.2.0+15.04.20160609-0ubuntu1 in https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/stable-phone-overlay

---------------

media-hub (4.2.0+15.04.20160609-0ubuntu1) vivid; urgency=medium

  * Enable exporting of metadata via MPRIS over dbus. This does not
    export everything yet and focused solely on track title, track album
    name and artist name. (LP: #1498962)

 -- Jim Hodapp <email address hidden> Thu, 09 Jun 2016 16:56:41 +0000

[Launchpad Janitor (janitor)]

This bug was fixed in the package media-hub - 4.2.0+16.10.20160609-0ubuntu1

---------------
media-hub (4.2.0+16.10.20160609-0ubuntu1) yakkety; urgency=medium

  * Enable exporting of metadata via MPRIS over dbus. This does not
    export everything yet and focused solely on track title, track album
    name and artist name. (LP: #1498962)

 -- Jim Hodapp <email address hidden> Thu, 09 Jun 2016 16:56:41 +0000

[cm-t 🦄🏂🌈🎵 (cm-t)]

Newbie question/note here:

Does MPRIS is just for actions, or for metadata too? If it take in charge the metadatas too, then thumbnail is currently missing.

[Jim Hodapp (jhodapp)]

MPRIS covers both general info like song title but also covers album artwork. Album artwork is coming in a separate landing which is on schedule to arrive with OTA 12.