I was trying to get the QMediaPlayer with audio output only to play some files attached on the network storage. It simply didn't work - either I got the "Could not open file" media player error or sometimes it resulted in an exception somewhere in QFFMpeg.

Tested on QT 5.6.0 and 5.6.2. I've found a workaround where I made things work by using QFile and QMediaPlayer::setSourceDevice instead of QMediaPlayer::setSource and QUrl::fromLocalFile.