title: recording video to file with QML
body: <p>I am using the Qt Multimedia framework and I can display video on my window just fine using QML and the Camera module as follows:</p>
  
  <pre><code>ControlView {
      id: recorderWindow
      color: "#000000"
      border.width: 5
  
      Camera {
          id: camera
          captureMode: Camera.CaptureVideo
          videoRecorder.mediaContainer: "mp4"
      }
      VideoOutput {
          source: camera
          focus: visible
          anchors.fill: parent
          MouseArea {
              anchors.fill: parent;
              onClicked: {
                  camera.videoRecorder.record();
              }
          }
      }
  }
  </code></pre>
  
  <p>I am running this on an ARM based processor running Ubuntu 14.04 (nvidia Jetson).</p>
  
  <p>Now, my problem is that when I record videos, the preview in the UI comes to a complete halt. Additionally, the recorded video drops a lot of frames. One thing I noticed is that it always uses the <code>ogg</code> container rather than the <code>mp4</code> container as specified.</p>
  
  <p>Using gstreamer, I can run the following with display and recording at the same time without any issues:</p>
  
  <pre><code>gst-launch-1.0 -v autovideosrc ! tee name = t ! queue ! omxh264enc ! 
  'video/x-h264, stream-format=(string)byte-stream' ! h264parse ! qtmux 
  ! filesink location=test.mp4 t. ! queue ! videoscale ! video/x-raw, 
  width=480,height=270 ! xvimagesink -e sync=false
  </code></pre>
  
  <p>Would it be possible to have a similar pipeline using the Camera module and QML (I think these are based on gstreamer).</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>I tried setting <code>videoRecorder.videoCodec: "video/x-h264"</code> but this does not seem to have any effect. The encoding is still done with <code>Theora</code>.</p>