Default QAudioDevice (or null)?

Audetto

I find the documentation and the behaviour of the code for QAudioDevice confusing.

The doc says that the default constructor of QAudioDevice creates a null device

https://doc.qt.io/qt-6/qaudiodevice.html#QAudioDevice

The doc, of QAudioSink says that this constructor will use the default audio device: https://doc.qt.io/qt-6/qaudiosink.html#QAudioSink

The corresponding code is: https://github.com/qt/qtmultimedia/blob/a81ad78773995fb840f0cc3d22329be9e73ae3a2/src/multimedia/audio/qaudiosink.cpp#L78

The 2 statements are in contradiction, since {} creates a null device, not the default?

Does it matter? Sometimes yes. On my PC default or null seems to be the same, but on some of my users, null (i.e. {}) produces no sound, while if I use

QMediaDevices::defaultAudioOutput() I get the real default device which plays audio.

Since QAudioSink lacks the ability to tell which audio device it is exactly using, a lot of the above is reverse engineered.

What I am saying is that

QAudioSink(QMediaDevices::defaultAudioOutput(), format);

and

QAudioSink(format);

are not the same, contrary to what the doc says.

Regards

SGaist

Hi,

Your analysis looks correct. The default QAudioOutput constructor does indeed use the default output but in this case, it's the QAudioDevice constructor that is called.

You should check the bug report system to see if there's already something about and if not, please open a new ticket.