The problem is that when I first start the app with my usb camera, the light will flash for a bit then turn solid like it should be on, but there is no image displayed on the widget. However, if I stop and restart the app quickly then the light on the camera behave the same way, but the image is displayed correctly. It feels like the camera has to "warm up" and if it's allowed to get "cold" it won't work anymore. I don't know how else to describe it and I have no errors to go on. The state changes of the camera are identical either way. Can anyone help with this?

I'm on ubuntu 20, qt 5.12.8.

    QActionGroup *videoDevicesGroup = new QActionGroup(this);
    videoDevicesGroup->setExclusive(true);
    const QList<QCameraInfo> availableCameras = QCameraInfo::availableCameras();
    qDebug() << availableCameras;
    for (const QCameraInfo &cameraInfo : availableCameras) {
        QAction *videoDeviceAction = new QAction(cameraInfo.description(), videoDevicesGroup);
        videoDeviceAction->setCheckable(true);
        qDebug() << cameraInfo;

        videoDeviceAction->setData(QVariant("/dev/video0"));
        if (cameraInfo == QCameraInfo::defaultCamera())
            videoDeviceAction->setChecked(true);
            qDebug() << videoDeviceAction;

        //ui->menuDevices->addAction(videoDeviceAction);
    }

    //connect(videoDevicesGroup, &QActionGroup::triggered, this, &Camera::updateCameraDevice);
    //connect(ui->captureWidget, &QTabWidget::currentChanged, this, &Camera::updateCaptureMode);

    setCamera(QCameraInfo::defaultCamera());
}

void MainWindow::setCamera(const QCameraInfo &cameraInfo)
{
    m_camera.reset(new QCamera(cameraInfo));

    connect(m_camera.data(), &QCamera::stateChanged, this, &MainWindow::updateCameraState);
    connect(m_camera.data(), QOverload<QCamera::Error>::of(&QCamera::error), this, &MainWindow::displayCameraError);

//    m_mediaRecorder.reset(new QMediaRecorder(m_camera.data()));
//    connect(m_mediaRecorder.data(), &QMediaRecorder::stateChanged, this, &MainWindow::updateRecorderState);

//    m_imageCapture.reset(new QCameraImageCapture(m_camera.data()));

//    connect(m_mediaRecorder.data(), &QMediaRecorder::durationChanged, this, &MainWindow::updateRecordTime);
//    connect(m_mediaRecorder.data(), QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
//            this, &MainWindow::displayRecorderError);

//    m_mediaRecorder->setMetaData(QMediaMetaData::Title, QVariant(QLatin1String("Test Title")));

//    connect(ui->exposureCompensation, &QAbstractSlider::valueChanged, this, &MainWindow::setExposureCompensation);
    updateCameraState(m_camera->state());
//    updateLockStatus(m_camera->lockStatus(), QCamera::UserRequest);
    qDebug() << m_camera->lockStatus();
//    updateRecorderState(m_mediaRecorder->state());

//    connect(m_imageCapture.data(), &QCameraImageCapture::readyForCaptureChanged, this, &MainWindow::readyForCapture);
//    connect(m_imageCapture.data(), &QCameraImageCapture::imageCaptured, this, &MainWindow::processCapturedImage);
//    connect(m_imageCapture.data(), &QCameraImageCapture::imageSaved, this, &MainWindow::imageSaved);
//    connect(m_imageCapture.data(), QOverload<int, QCameraImageCapture::Error, const QString &>::of(&QCameraImageCapture::error),
//            this, &MainWindow::displayCaptureError);

//    connect(m_camera.data(), QOverload<QCamera::LockStatus, QCamera::LockChangeReason>::of(&QCamera::lockStatusChanged),
//            this, &MainWindow::updateLockStatus);

//    ui->captureWidget->setTabEnabled(0, (m_camera->isCaptureModeSupported(QCamera::CaptureStillImage)));
//    ui->captureWidget->setTabEnabled(1, (m_camera->isCaptureModeSupported(QCamera::CaptureVideo)));

    qDebug() << m_camera->isCaptureModeSupported(QCamera::CaptureStillImage);
    qDebug() << m_camera->isCaptureModeSupported(QCamera::CaptureVideo);
//    updateCaptureMode();
    m_camera->setCaptureMode(QCamera::CaptureStillImage);

    //QCameraViewfinder* viewfinder = new QCameraViewfinder();
    QVideoWidget *videoWidget = new QVideoWidget;
    m_camera->setViewfinder(videoWidget);

    //m_camera->setViewfinder(viewfinder);

    //viewfinder->show();
    videoWidget->show();
    m_camera->start();
}