.NET code to record a specific form activity + audio to avi

Question

I am looking for some C# code .. or .NET component to record the activity of a form on my screen (not the whole desktop) along with audio, similar to what programs like Camtasia allow to do.

Answer 1

The video part is actually pretty easy. All you need to have is a timer running 20 times a second that will save form's canvas to a image files as frames. Then create an animation out of these pictures.

To capture image:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        tVideo.Start();
    }

    int i = 0;

    private void tVideo_Tick(object sender, EventArgs e)
    {
        String lFile = String.Format("c:\\{0}.bmp", i);
        SaveAsBitmap(this, lFile);

        i++;
    }

    public void SaveAsBitmap(Control aCtrl, string aFileName)
    {
        if (File.Exists(aFileName))
            File.Delete(aFileName);

        Graphics lGraphics = aCtrl.CreateGraphics();

        Bitmap lImage = new Bitmap(aCtrl.Width, aCtrl.Height);

        aCtrl.DrawToBitmap(lImage, new Rectangle(0, 0, aCtrl.Width, aCtrl.Height));

        lImage.Save(aFileName);
        lImage.Dispose();
    }
}

This is just a light sample, of course you would have to add some compression and try to avoid saving the same image twice. Knowing how many images are the same + knowing about the framerate, you know how long to display the same frame.

To add a cursor you would have to keep some variables with mouse x,y and an event on mouse click. And then just add it to pictures.

Of course, this won't work for 3d games inspite of overlay which is drawn after the win32 paints.

For that you would have to go with DirectX/OpenGl/XNA. I think the idea is the same. For audio, DirectX also.

My complete source: http://deathsquad.pl/archiwum/Inne/so/answer-1934452.rar

Some DirectX audio samples: http://www.codeproject.com/KB/directx/audiosav.aspx

Answer 2

Check out Gallio: It is a great testing framework, and it has built in screen recording API.

This post shows a few examples: http://blog.bits-in-motion.com/2009/09/announcing-gallio-and-mbunit-v31.html