How to use a web cam in C# with .NET Framework 4.0 and Microsoft Expression Encoder 4

Download source code - 27.6 KB

Introduction

If you are interested in using your webcam from C# in an easy way, this little article is for you. In order to achieve our goal, we need Microsoft .NET 4.0 and Microsoft Expression Encoder 4. You can get the latter for free, using the 'Microsoft Web Platform Installer', that can be downloaded from here: http://www.microsoft.com/web/downloads/platform.aspx.

After that, we need to create a Windows Forms application and add the following references to the project:

Assembly Microsoft.Expression.Encoder
C:\Program Files\Microsoft Expression\Encoder 4\SDK\Microsoft.Expression.Encoder.dll

Assembly Microsoft.Expression.Encoder.Utilities
C:\Program Files\Microsoft Expression\Encoder 4\SDK\Microsoft.Expression.Encoder.Utilities.dll

Assembly Microsoft.Expression.Encoder.Types
C:\Program Files\Microsoft Expression\Encoder 4\SDK\Microsoft.Expression.Encoder.Types.dll

Using the Code

Here is the code to enumerate the video and audio devices:

foreach (EncoderDevice edv in EncoderDevices.FindDevices(EncoderDeviceType.Video))
{
     lstVideoDevices.Items.Add(edv.Name);
}
foreach (EncoderDevice eda in EncoderDevices.FindDevices(EncoderDeviceType.Audio))
{
     lstAudioDevices.Items.Add(eda.Name);
}

Here is the code to preview the video and the audio:

// Starts new job for preview window
_job = new LiveJob();

// Create a new device source. We use the first audio and video devices on the system
_deviceSource = _job.AddDeviceSource(video, audio);

// Sets preview window to winform panel hosted by xaml window
_deviceSource.PreviewWindow = new PreviewWindow(new HandleRef(panel1, panel1.Handle));

// Make this source the active one
_job.ActivateSource(_deviceSource);

Here is the code to record the video and audio to a .wmv file:

// Sets up publishing format for file archival type
FileArchivePublishFormat fileOut = new FileArchivePublishFormat();

// Sets file path and name
fileOut.OutputFileName = String.Format("C:\\WebCam{0:yyyyMMdd_hhmmss}.wmv", DateTime.Now);

// Adds the format to the job. You can add additional formats
// as well such as Publishing streams or broadcasting from a port
_job.PublishFormats.Add(fileOut);

// Start encoding
_job.StartEncoding();

Streaming the webcam over the network

Here is the code to stream the video (and audio) of your webcam over the network:

// Sets up publishing format for file archival type
_job = new LiveJob();

_deviceSource = _job.AddDeviceSource(video, audio);
_job.ActivateSource(_deviceSource);         

// Finds and applys a smooth streaming preset        
_job.ApplyPreset(LivePresets.VC1256kDSL16x9);

// Creates the publishing format for the job
PullBroadcastPublishFormat format = new PullBroadcastPublishFormat();
format.BroadcastPort = 8080;
format.MaximumNumberOfConnections = 2;

// Adds the publishing format to the job
_job.PublishFormats.Add(format);

// Starts encoding
_job.StartEncoding();

To view the broadcast, you can create a WPF application and use the MediaElement. It is just one line of code! Here is the whole code of the WPF application:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Show Broadcast" Height="350" Width="525">
    <Grid>
        <MediaElement Name="VideoControl" Source="http://localhost:8080" />
    </Grid>
</Window>

Conclusion

A piece of cake, isn't it? This is the new frontier of how to manage video and audio from C#. In the early days of C#, using a webcam was not so easy. I hope this will help those who want to play a bit with a webcam. Thanks for reading my first article :-)