i\'m currently porting an application from Qt4(.8.4) to Qt5(.2.0). I\'m nearly done with all the known changes like deprecated toAscii()-function, missing QtGui and so on. N
Just came to this page. There the available/chosen audio-backends for each platform are listed:

As you can see the DirectShow-Plugin (Windows) does support stream sources whereas AVM Foundation/Quicktime 7 (OSX) don't have streaming support. So I guess the only solution seems to ship a custom backend with the application (gstreamer, vlc).