Phonon on Windows

Right now I have Phonon working on windows with a DS backend. However, it will not play certain mp3 files and although it appears to be playing m4a files (the song progress bar keeps moving) no sound comes out. The application is built using PyQt4 on Windows and is aim开发者_高级运维ed at Windows users.

I know that this is not the fault of my program as when I replaced a file with one that did not play normally with one that did, the song played perfectly. I have downloaded phonon vlc, and tried to build it, but I cannot get CMake to create a makefile. Whenever I try, it tells me that the dev-cpp gcc is not able to make a simple test file.

I also tried downloading clementine and amorak to see if I could get that to work, but I have had the same problems there as well. Has anyone run into this sort of problem before?

I've run into the same problem recently. It seems to be that Phonon has a bit of a hissy fit about ID3 tags, particularly compressed ones. I've taken to creating a temporary copy of every mp3 that I open and using mutagen to delete the tags from that copy. I then open the de-tagged temporary file using PyQt/Phonon, and everything works as I expect. BTW, mutagen is awesome.

Phonon does have a bit of a habit of failing reasonably silently. This is what I do: check if your MediaObject is in a Phonon.ErrorState; if so check its errorString(), usually some incomprehensible message. Google this message and try to work from there.

Edit: Hmm, interesting. It's not Phonon having the problem, it's the DirectShow backend not being able to play the file with the compressed ID3 headers. While the "fix" I outline above does work, I found I was still having problems playing other types of files, e.g. .m4a, despite having the right codecs installed.

The solution was to install the K-Lite Codec Pack, and use the Win7DSFilterTweaker tool that comes with it to change the default decoder for the various codec types from "Microsoft" to "ffdshow". You might also need to run the ffdshow audio decoder configuration tool and tick the box marked Show dialog when an unknown application tries to load ffshow in the DirectShow control tab.