Phonon videoplayer doesn't play some files

[SepticInsect]

Hello!
I'm creating a videoplayer using phonon. If I call Phonon::BackendCapabilities::availableMimeTypes() it says it can play avi, mp4, mpeg and some more file types.
I can play all the videos on Windows Media Player but I can only play mpeg-files, and some avi-files in my phonon videoplayer. If I start a file that my player can't play, a black square is displayed and no audio is played.
I am only running the application from Qt Creator, I haven't tried installing it on another computer yet.

Do you have any ideas? I need all the help I can get!

Best regards
Erik

[Oleg]

It's Phonon backend specific. Actually AVI, MP4 is just containers, not codecs. We use libVLC backend to play all formats VLC player supports. You can choose another option.

[SepticInsect]

Thanks!
But how do I change backend? Do I have to connect the backend to my Phonon::VideoPlayer?

Erik

[Oleg]

Due to some stupidness (or maybe it's a missed feature) in Phonon it loads the first available backend, so just make sure you have the only one need in phonon_backend folder.

[SepticInsect]

Hi!
I can't get this to work. I have built my application and move it to a different folder containing the following files:
myvideoplayer.exe
libgcc_s_dw2-1.dll
mingwm20.dll
phonon4.dll
QtCore4.dll
QtGui4.dll
QtOpdenGL.dll
phonon_backend
My application doesn't seem to use the backend. It makes no difference what file i put in my phonon_backend folder. I have tried phonon_ds9d4.dll, phonon_vlc.dll and no file at all. My application can play the same files no matter what file is in the phonon_backend folder. Should I replace the phonon_backend before I build the application?

[SepticInsect]

Can anyone help me?

As I discribed above I have built my application and moved it to a folder on my desktop. In that folder i have the files listed above and the phonon_backend folder.
Can I just replace the files in the phonon_backend folder with phonon_vlc.dll?
Or should I replace the files in the phonon_backend folder in my c:/program files/qt/.../phonon_backend before I build the application?

I am greatful for all the help I can get!