Get Webcam stream using Aforge.NET in C# and WPF

I want to capture a webcam feed using my camera. For that I am using the 2 references: AForge.Video.dll and AFo开发者_如何转开发rge.Video.DirectShow.dll.

Here's a snippet I found:

public FilterInfoCollection CamsCollection;
public VideoCaptureDevice Cam = null;

void Cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{   
  frameholder.Source = (Bitmap)eventArgs.Frame.Clone(); 
  /* ^
   * Here it cannot convert implicitly from System.Drawing.Bitmap to
   * System.Windows.Media.ImageSource
   */

}

private void startcam_Click(object sender, RoutedEventArgs e)
{
  CamsCollection = new FilterInfoCollection(FilterCategory.VideoInputDevice);

  Cam = new VideoCaptureDevice(CamsCollection[1].MonikerString);
  Cam.NewFrame += new NewFrameEventHandler(Cam_NewFrame);
  Cam.Start();
}

private void stopcam_Click(object sender, RoutedEventArgs e)
{
  Cam.Stop();
}

}

They use a PictureBox to display the frames. As I am working in WPF, I used this

To sum up here's what my code looks like currently.

public FilterInfoCollection CamsCollection;
public VideoCaptureDevice Cam = null;


void Cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{

    System.Drawing.Image imgforms = (Bitmap)eventArgs.Frame.Clone();


    BitmapImage bi = new BitmapImage();
    bi.BeginInit ();

    MemoryStream ms = new MemoryStream ();

    imgforms.Save(ms, ImageFormat.Bmp);

    ms.Seek(0, SeekOrigin.Begin);
    bi.StreamSource  = ms;
    frameholder.Source = bi; 
   /* ^ runtime error here because `bi` is occupied by another thread.
    */
    bi.EndInit();
}

private void startcam_Click(object sender, RoutedEventArgs e)
{

    CamsCollection = new FilterInfoCollection(FilterCategory.VideoInputDevice);

    Cam = new VideoCaptureDevice(CamsCollection[1].MonikerString);
    Cam.NewFrame += new NewFrameEventHandler(Cam_NewFrame);
    Cam.Start();
}

private void stopcam_Click(object sender, RoutedEventArgs e)
{
    Cam.Stop();
}

Edit1: for a detailed explanation view my blogpost on the same topic.

I fixed the error using the Dispatcher class as a mutex:

void Cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
    {

        System.Drawing.Image imgforms = (Bitmap)eventArgs.Frame.Clone(); 

        BitmapImage bi = new BitmapImage(); 
        bi.BeginInit(); 

        MemoryStream ms = new MemoryStream(); 
        imgforms.Save(ms, ImageFormat.Bmp); 
        ms.Seek(0, SeekOrigin.Begin); 

        bi.StreamSource = ms; 
        bi.EndInit();

        //Using the freeze function to avoid cross thread operations 
        bi.Freeze();

        //Calling the UI thread using the Dispatcher to update the 'Image' WPF control         
        Dispatcher.BeginInvoke(new ThreadStart(delegate
        {
            frameholder.Source = bi; /*frameholder is the name of the 'Image' WPF control*/
        }));     

    }

Now it runs as expected and I get good performance without any drop in the fps.

If you want to support Silverlight, be it for web or standalone or WP7, you shouldn't start with WPF, as many features from WPF are lacking in Silverlight.

Here is a Silverlight 4+ tutorial:

http://www.silverlightshow.net/items/Capturing-the-Webcam-in-Silverlight-4.aspx