With the code I have right now I CAN play .mp3 data from files succesfully. However I need to play the same data using a QtCore.QBuffer (NOT from a file). When I use the example of the docs it errors an unexpected type of QBuffer! However...... that is what it SHOULD see, according to the docs. But............... it throws: TypeError: Phonon.MediaObject.setCurrentSource(Phonon.MediaSource): argument 1 has unexpected type 'QBuffer' The code I use is (1): someBuffer = QtCore.QBuffer() someBuffer.writeData(TrackData) mediaObject.setCurrentSource(someBuffer) I also tried (2): someBuffer = QtCore.QBuffer() mediaObject.setCurrentSource(someBuffer) someBuffer.writeData(TrackData) and (3): someBuffer = QtCore.QBuffer() someBuffer.writeData(TrackData) mediaObject.setCurrentSource(Phonon.MediaSource(someBuffer)) The last example (3) throws an different ERROR and wipes my Gui off screen ;-) ASSERT: "d-connected" in file /builddir/build/BUILD/phonon-4.5.1/phonon/streaminterface.cpp, line xxxx Notes: TrackData contains the mp3 data and IS PLAYING OK when I write it to a File and use that as a resource to mediaObject.setCurrentSource(Phonon.MediaSource())I also experimented with a QByteArray but that leads to the same "unexpected QBuffer" error. To be more precise everything I feed setCurrentSource is not accepted. Tried a string (errors an unexpected type of String), tried a QBuffer (errors an unexpected type of QBuffer), tried a QByteArray (errors an unexpected type of QByteArray). BTW: I run Qt, PyQt on Linux. Any ideas??