declarative-camera VideoOutput frozen in record mode on iOS 7.0.4

The sample runs almost fine on an iPhone 5S (iOS 7.0.4) after you add the following plugins to the .pro:

QTPLUGIN += qavfcamera qtaudio_coreaudio qavfmediaplayer

However the VideoOutput freezes when you click the “Switch to Video” button and it remains frozen during the record. By "VideoOutput" I'm refering to this object in declarative-camera.qml:

VideoOutput {
        id: viewfinder
        visible: cameraUI.state == "PhotoCapture" || cameraUI.state == "VideoCapture"

        x: 0
        y: 0
        width: parent.width - stillControls.buttonsPanelWidth
        height: parent.height

        source: camera
        autoOrientation: true
    }

Still the replay of the record when you click the “View” button after recording is ok. So video recording works here but you're not able to see the video output during the record operation itself.
There is no error reported in the application output of QT creator during the execution.