Using Media in XNA Game Studio : Video

Rendering a Video

Create a new Windows Game project and add the samplevideo.wmv file from the downloadable examples to the content project. Add a couple variables to your project to hold and control the video:

Video video;
VideoPlayer player;

Of course, you have to instantiate them in your LoadContent method:

video = Content.Load<Video>("SampleVideo");
player = new VideoPlayer();

Before getting into the details of these classes, let’s get your video rendering. Add the following lines directly after creating the player in the LoadContent method:

player.IsLooped = true;
player.Play(video);

Finally, replace the Draw method with the following:

protected override void Draw(GameTime gameTime)
{
    GraphicsDevice.Clear(Color.Black);
    spriteBatch.Begin();
    spriteBatch.Draw(player.GetTexture(), GraphicsDevice.Viewport.Bounds, Color.White);
    spriteBatch.End();
    base.Draw(gameTime);
}

					  

That’s it. Running the project now renders your video to the full window and repeats the video until the project is closed as in Figure 1.

Figure 1. Rendered video

The Video object is a repository for the data about a video. It includes the Duration of the video and the FramesPerSecond (the number of frames of video in each second, if the name wasn’t obvious). The native Width and Height of the video are stored here, too, along with the VideoSoundtrackType. The sound track type can be Dialog, Music, or MusicAndDialog, and these are used to determine how the system should interact with the audio from the video. If the sound track type is Music, and the system controls the music, the audio from your video does not play. If the setting is Dialog, and the system controls the music (and music is playing), the audio from the video mixes with this music. If the setting is MusicAndDialog, system sounds stop and the video’s audio plays.

The VideoPlayer object is similar to the MediaPlayer object from earlier. It has IsMuted and IsLooped properties (where looped is similar to repeating, except it loops only the current video). It has the Play, Pause, Stop, and Resume methods, along with the State property, which mirrors what you saw earlier. It also has the PlayPosition property you saw previously. The last method, which you used in the Draw method previously, is GetTexture. This method returns the current frame of video as a texture. So long as the video is playing (via the Play method), you don’t need to do anything special to make it continue to update.

Because this is a Texture2D, it can be used in any place a texture is used. You can use it to render in a sprite batch, but you could just as easily use it to render onto a 3D model. Add a new model variable to your content project:

Model model;

To get the content, add the box.fbx model to your content project and then update LoadContent:

model = Content.Load<Model>("Box");

Finally, replace your Draw method with the following and notice your video rendering onto each face of the cube spinning around as in Figure 2:

protected override void Draw(GameTime gameTime)
{
    GraphicsDevice.Clear(Color.CornflowerBlue);
    BasicEffect effect = model.Meshes[0].Effects[0] as BasicEffect;
    effect.Texture = player.GetTexture();
    effect.TextureEnabled = true;
    model.Draw(Matrix.CreateRotationX((float)gameTime.TotalGameTime.TotalSeconds) *
        Matrix.CreateRotationY((float)gameTime.TotalGameTime.TotalSeconds /2) *
        Matrix.CreateScale(3.0f),
        Matrix.CreateLookAt(new Vector3(5,0,-5),
        Vector3.Zero, Vector3.Up),
        Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4,
        GraphicsDevice.Viewport.AspectRatio, 1.0f, 100.0f));
    base.Draw(gameTime);
}

					  

Figure 2. Rendered video onto a 3d cube

There shouldn’t be anything surprising in this section of code. All you do is render a model with a slight rotation and scale, and update its texture every frame. Even though the most common use of videos is for cut scenes where they are rendered over the entire viewable area, this snippet shows it is possible to render them onto 3D objects, too.