Red Recondite

I have been working on a WPF (Windows Presentation Framework) application using Visual C# 2008 Express. Even though I am at the Initial Optimism phase of Software Development, and my imagination is running wild, I know that nothing will probably become of this work.

The basic goal is to play videos encoded with a number of different codecs (i.e. h.264, Xvid, and DivX). So, I thought, before I went into all of the other features that this application will do, I’ll keep things simple and just play a video with the filename hard-coded.

It’s the year 2008. I have the latest Microsoft tools available. Playing a video can’t be that difficult, can it?

1) WPF has a native MediaElement… that only supports wmv files.

2) Microsoft provides a Windows Media Player ActiveX Control (AxWMPLib), that does not seem to be able to use any codecs. The status displays “Locating codec”… “Error downloading codec”, and only plays the audio for the video file. Using the example from the Windows SDK has the same result.

3) DirectX 9.0 includes a Video class in Microsoft.DirectX.AudioVideoPlayback… that throws an exception “Error in the application” whenever you try to play a video. I even downloaded an example and built it in Visual Studio 2003, and that doesn’t work either.

4) VideoLAN has a .NET Interface… stored in a wiki. I guess the concept of a .zip file to download is too much for some developers. After copying-and-pasting the interface file-by-file, I built it, and got it to play video in the WPF application (by way of the WindowsFormsHost control).

    VLanControl.VlcUserControl lVideo = new VLanControl.VlcUserControl();

    windowsFormsHost1.Child = lVideo;

    lVideo.AddToPlayList( "W:/tv/Curb Your Enthusiasm/curb.3x01 - Chet's Shirt.avi", "Curb", null );

    lVideo.Play();

Hooray! The video played! I closed the application, ready to finish this off for good, when I experienced a blue screen of death.

As it turns out, you need to stop the video (and maybe clear the playlist) before you exit.

    protected override void OnClosing( CancelEventArgs e )
    {
        if ( lVideo != null )
        {
            lVideo.Stop();
            System.Threading.Thread.Sleep( 1000 );
            lVideo.ClearPlayList();
            System.Threading.Thread.Sleep( 1000 );
        }
        base.OnClosing( e );
    }

Be careful… in WPF, Microsoft decided to remove support for ‘OnClosing’-type events. You can add an event handler for Closed, but not Closing. At first, I had tried to add an event for Closed that would stop the video, but because this happened after the window had closed, I still experienced a blue screen.

Also note that the Sleep statements are absolutely necessary. I tried to get rid of them once, and tried to wait until the VlcUserControl state was no longer ‘Playing’, but the BSOD decided to appear anyway.

This entry was posted on Saturday, February 16th, 2008 at 3:41 pm and is filed under C#, Development, WPF. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.