VisualBrush using MediaElement in a Style
<p>I have a UserControl that converts a text to a shape. I can then Stroke it or Fill it with a Brush. When I try to use a Visual Brush with a MediaElement (video) as the Source I am running into problems. When I do it directly in the XAML as below:</p>

<pre><code>                    &lt;custom:ExtendedTextBlock Text="Video Filled Text" FontFamily="Arial Black" FontSize="60"&gt;
                &lt;custom:ExtendedTextBlock.Fill&gt;
                    &lt;VisualBrush&gt;
                        &lt;VisualBrush.Visual&gt;
                            &lt;MediaElement Source="assets\1267066.mp4" Width="596" Height="366" LoadedBehavior="Play" Stretch="UniformToFill" MediaEnded="MediaElement_MediaEnded" MediaFailed="MediaElement_MediaFailed" MediaOpened="MediaElement_MediaOpened" /&gt;
                        &lt;/VisualBrush.Visual&gt;
                    &lt;/VisualBrush&gt;
                &lt;/custom:ExtendedTextBlock.Fill&gt;
            &lt;/custom:ExtendedTextBlock&gt;
</code></pre>

<p>It works great. The problem appears when I try to create a Style using the same information:</p>

<pre><code>           &lt;Style x:Key="VideoFill" TargetType="{x:Type custom:ExtendedTextBlock}"&gt;
        &lt;Setter Property="StrokeThickness" Value="2" /&gt;
        &lt;Setter Property="Stroke" Value="Black" /&gt;
        &lt;Setter Property="Fill"&gt;
            &lt;Setter.Value&gt;
                &lt;VisualBrush&gt;
                    &lt;VisualBrush.Visual&gt;
                        &lt;MediaElement Source="assets/1267066.mp4" Width="596" Height="366" LoadedBehavior="Play" LoadedBehavior="Play" Stretch="UniformToFill" MediaEnded="MediaElement_MediaEnded" MediaFailed="MediaElement_MediaFailed" MediaOpened="MediaElement_MediaOpened" /&gt;
                    &lt;/VisualBrush.Visual&gt;
                &lt;/VisualBrush&gt;
            &lt;/Setter.Value&gt;
        &lt;/Setter&gt;
    &lt;/Style&gt;
</code></pre>

<p>I get no fill. No MediaOpened is thrown, no MediaFailed is thrown. It just doesn't render the fill. Using this same method with a SolidColorBrush, LinearGradientBrush, ImageBrush all works perfectly. Can anyone tell me what is going on here?</p>