Phonon's VolumeSlider doesn't change the volume

Question

I'm trying to create a VolumeSlider widget that changes the volume of my audio output.

log.debug("Starting audio player (%s)..." % url)
mediaSource = Phonon.MediaSource(url)
mediaSource.setAutoDelete(True)

self.player = Phonon.createPlayer(Phonon.VideoCategory, mediaSource)
self.player.setTickInterval(100)
self.player.tick.connect(self.updatePlayerLength)
self.mediaSlider.setMediaObject(self.player)

audioOutput = Phonon.AudioOutput(Phonon.MusicCategory)
Phonon.createPath(self.player, audioOutput)
self.mediaVolumeSlider.setAudioOutput(audioOutput)

self.player.play()

However even though I can move the volume slider, the actual volume doesn't change. What did I miss?

Answer 1

I have never used Phonon.createPlayer, because the API seems totally baffling. Apparently, it is supposed to be a "convenience" function that creates a path between an media object and an audio output. But it only gives a reference to the media object. There appears to be no access to the audio output object, which would seem to make it completely useless (but I may well be missing something).

Anyway, I think it is much more convenient to create the paths explicitly, so that it is clear how all the parts are connected together.

The following code works for me on Linux and WinXP:

self.media = Phonon.MediaObject(self)
self.video = Phonon.VideoWidget(self)
self.audio = Phonon.AudioOutput(Phonon.VideoCategory, self)
Phonon.createPath(self.media, self.audio)
Phonon.createPath(self.media, self.video)
self.slider = Phonon.VolumeSlider(self)
self.slider.setAudioOutput(self.audio)