Why does QCameraInfo/QCamera require an instance of QApplication?

[FiddlerJoe]

Hello,

I'd like to write a library that uses Qt's capabilites to control cameras. The lib is to be used in both console and gui applications. However, a QApplication object seems to be necessary for QCameraInfo to work properly. Why is this the case? Is it possible to use QCameraInfo and QCamera without a graphical user interace? Consider the following example. If no QApplication is constructed, QCameraInfo::availableCameras() always returns an empty list:

#include <iostream>
#include <QtMultimedia/QCamera>
#include <QtMultimedia/QCameraInfo>
#include <QApplication>
 
using namespace std;
 
int main(int argn, char** argv)
{
	QApplication app(argn, argv);
	QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
	cout << cameras.size() << endl;
 
	return 0;
}

#include <iostream>
#include <QtMultimedia/QCamera>
#include <QtMultimedia/QCameraInfo>
#include <QApplication>

using namespace std;

int main(int argn, char** argv)
{
	QApplication app(argn, argv);
	QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
	cout << cameras.size() << endl;

	return 0;
}

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I'm using windows 10 and Qt 5.5.1. Thank you for your help!