phonon app work on Qt4.5.0 but does not work on Qt4.5.3?

i have a problem with a Qt application which uses phonon library. i built the app on a linux ubuntu with Qt 4.5.0 and the app works fine and the sound plays successfully.
but when i take my app to a device having Qt4.5.3 the app work but the sound does not
and i get the following warning
[CODE]
WARNING: Phonon needs QCoreApplication::applicationName to be set to export audio output names through the DBUS interface
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::AudioOutput ( no objectName ).
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded
WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded[/CODE]
and i deployed my app on N900 device but also the sound does not work.
what is the problem?
thanks alot.

Try this phonon demo
[URL="http://www.mediafire.com/file/dj41mnyz1od/mediaplayer.tar.gz"]http://www.mediafire.com/file/dj41mnyz1od/mediaplayer.tar.gz[/URL]
It works fine both in Ubuntu 9.04 and on Maemo 5.

If it doesn't work for you then there is something with your configuration. Try to provide output of dpkg -l "*qt4*" then.

I tried to execute the example but i get the same warning so i searched on the Internet about a solution. i found that i must install the package
phonon-backend-gstreamer
so i installed it and tried to run the example again, i get the following
message when i am trying to operate mp3 file.
(<unknown>:3830): GStreamer-CRITICAL **: gst_element_make_from_uri: assertion `gst_uri_is_valid (uri)' failed
can you help me plz?

Hi,
Hard to say where issue is.. if it's a GStreamer problem or something wrong in Phonon.

Maemo Qt 4.5.3 with Maemo5 GStreamer should work fine.. if you want to understand what is
broken in your linux box,I suggest you to enable debug messages.
Phonon debug messages can be enabled setting PHONON_GST_DEBUG to 3
and then launching your application.
You can enable GStreamer debug messages setting GST_DEBUG var.

Antonio

[QUOTE=mismael;686674]I tried to execute the example but i get the same warning so i searched on the Internet about a solution. i found that i must install the package
phonon-backend-gstreamer
so i installed it and tried to run the example again, i get the following
message when i am trying to operate mp3 file.
(<unknown>:3830): GStreamer-CRITICAL **: gst_element_make_from_uri: assertion `gst_uri_is_valid (uri)' failed
can you help me plz?[/QUOTE]

It's enough to re-flash device with 42-11 release and then install Qt packages from here: [url]http://repository.maemo.org/pool/fremantle/free/q/qt4-x11/[/url]