title: How to use the setMetadata(key,value) method in QtMultimidia CameraCapture QML Type?
body: <p>I'm interested in setting GPS location metadata to captured images in QML. I noticed the setMetadata(key,value) method in several qml capture elements but I can't understand how it works, or find any examples. </p>
  
  <p>The definition in the documentation states:</p>
  
  <blockquote>
    <p>"Sets a particular metadata key to value for the subsequent image
    captures."</p>
  </blockquote>
  
  <p><a href="http://qt-project.org/doc/qt-5/qml-qtmultimedia-cameracapture.html" rel="nofollow">http://qt-project.org/doc/qt-5/qml-qtmultimedia-cameracapture.html</a></p>
  
  <p>Does the method work? if so, please place a simple example. 
  If not, is there any other way to set (or edit) image metadata (even if use of C++ is necessary) in Qt?</p>
  
  <p><strong>Update (but not solved)</strong>:
  I've tried the following code, the app runs on desktop takes the picture and saves it. After I open it up with Preview (MAC) and check the metadata... and nothing special there (no comment key).</p>
  
  <pre><code> Camera {
          id: camera
          captureMode: Camera.CaptureStillImage
          Component.onCompleted: {
              imageCapture.setMetadata("Comment","My Picture")
          }
  
          imageCapture {
              resolution: "640x480"
              onImageCaptured: {
                  console.log("Image Captured Callback : Preview : "+preview)
              }
              onImageSaved: {
                  console.log("Image Saved Callback : Save Path : "+path)
              }
              onImageMetadataAvailable: {
                  console.log("Image Metadata Callback : "+key+" = "+value)
              }
          }
      }
  </code></pre>