Qt 5 Qcamera CaptureVideo

[Fahrenheit]

Hello! I use a qt 5 and class qcamera to capture video from your screen and its subsequent record. OC Windows 7

1. receiving device camera:

QByteArray cameraDevice;
foreach(const QByteArray &deviceName, QCamera::availableDevices()) {
QString description = camera->deviceDescription(deviceName);
if (cameraDevice.isEmpty()) {
cameraDevice = deviceName;
}
(after the first step, I get a : device == uscreencapture)

2. after I check:
   camera = new QCamera(cameraDevice);
   bool check = true;
   check = camera->isCaptureModeSupported(QCamera::CaptureVideo);
   and check == false

Tell me how do I correct this situation?