纵向视频录制在Windows Phone 8中旋转90度

Question

我在我的应用程序中使用此xaml来录制视频和播放。除了视频以90度旋转形式播放外，一切正常。 ：

<phone:PhoneApplicationPage

    x:Class="RecoedVedio.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="PortraitOrLandscape" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True" x:Name="PhoneAppBar" Opacity="0.0">

            <shell:ApplicationBarIconButton IconUri="/Assets/AppBar/feature.video.png" Text="record"  x:Name="StartRecording" Click="StartRecording_Click" />

 <shell:ApplicationBarIconButton IconUri="/Assets/AppBar/stop.png" Text="stop" x:Name="StopPlaybackRecording" Click="StopPlaybackRecording_Click"/>

<shell:ApplicationBarIconButton IconUri="/Assets/AppBar/transport.play.png" Text="play" x:Name="StartPlayback" Click="StartPlayback_Click"  />

 <shell:ApplicationBarIconButton IconUri="/Assets/AppBar/transport.pause.png" Text="pause" x:Name="PausePlayback" Click="PausePlayback_Click"/>

</shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Canvas x:Name="LayoutRoot" Background="Transparent">

        <!--Camera viewfinder >-->
        <Rectangle x:Name="viewfinderRectangle" Width="460" Height="661" HorizontalAlignment="Left" Canvas.Left="10" Canvas.Top="10"/>

    <MediaElement x:Name="VideoPlayer"  AutoPlay="True" RenderTransformOrigin="0.5, 0.5" VerticalAlignment="Center" HorizontalAlignment="Center" Stretch="UniformToFill"  Canvas.Left="10" Canvas.Top="10"/>

        <!--Used for debugging >-->
        <TextBlock 
            Height="40" 
            HorizontalAlignment="Left"
            Name="txtDebug" 
            VerticalAlignment="Top"
            Width="414"
            FontSize="24" 
            FontWeight="ExtraBold" Canvas.Left="42" Canvas.Top="616"/>

  </Canvas> 
</phone:PhoneApplicationPage>

但是当我以纵向录制视频时，屏幕上显示的视频会旋转90度。 任何人都可以告诉我我在哪里做错了吗？ 帮助赞赏。