title: Creating WP8 in-app video is not generating a .jpg thumbnail
body: <p>I've been told that when I allow the user to create a video from within my app, a .jpg thumbnail image is supposed to be generated automatically.  However, using windows phone power tools, I can see that only the video is generated, no image.  Here is the code below:</p>
  
  <p><strong>EDIT: the QUESTION here, is HOW does one GET a thumbnail image from a given video that is saved in isolated storage?</strong></p>
  
  <pre><code>        ' Set recording state: start recording.
  Private Async Sub StartVideoRecording()
      Try
          App.ViewModel.IsDataLoaded = False
  
          'isoStore = Await ApplicationData.Current.LocalFolder.GetFolderAsync("IsolatedStore")
          strVideoName = GenerateVideoName()
          isoFile = Await isoVideoFolder.CreateFileAsync(strVideoName, CreationCollisionOption.ReplaceExisting)
          thisAccessStream = Await isoFile.OpenAsync(FileAccessMode.ReadWrite)
          Await avDevice.StartRecordingToStreamAsync(thisAccessStream)
  
          'save the name of the video file into the list of video files in isolated storage settings
          Dim videoList As New List(Of InfoViewModel)
  
          isoSettings = IsolatedStorageSettings.ApplicationSettings
          If isoSettings.Contains("ListOfVideos") Then
              videoList = isoSettings("ListOfVideos")
          Else
              isoSettings.Add("ListOfVideos", videoList)
          End If
          videoList.Add(New InfoViewModel With {.Name = strVideoName, .DateRecorded = Date.Now})
          isoSettings("ListOfVideos") = videoList
          isoSettings.Save()
          isoSettings = Nothing
  
  
          ' Set the button states and the message.
          UpdateUI(ButtonState.Recording, "Recording...")
      Catch e As Exception
          ' If recording fails, display an error.
          Me.Dispatcher.BeginInvoke(Sub() txtDebug.Text = "ERROR: " &amp; e.Message.ToString())
      End Try
  End Sub
  </code></pre>