Comment 5 for bug 1485522

Actually, this seems to already be fixed... https://github.com/qtproject/qtmultimedia/commit/5f33d7bea3fd3dd441aff499576826a02e8e5be2 ...which is in 5.4.1, so should be on touch too. So forget about the previous comment; that said, I do see a message in PulseAudio saying that the stream volume is explicitly changed, so it's somewhere up the stack...