Wcf byte array + HTML 5 Video + Custombinding

Again, this article looks at different ways to load byte array from WCF representing video data to web clients, this approach will return a byte array and use a CustomBinding in WCF. You can start by cloning the repository I have prepared from here:
git clone https://toreaurstad@bitbucket.org/toreaurstad/wcfaudiostreamdemo.git git fetch && git checkout VideBase64String_05082018
The following method is added to our WCF service contract, note that now we leave the webHttpBinding and use a CustomBinding.

     [OperationContract]
     byte[] GetVideoBytes(string videofile);

There is no [WebGet] attribute this time, as noted we will not use WCF REST but SOAP instead. The web.config of the host website for the WCF services exposes this CustomBinding:

<system.serviceModel>

    <services>
      
      <service name="WcfStreamAudioDemo.Host.AudioService">
        <endpoint behaviorConfiguration="RestBehaviorConfig" binding="webHttpBinding" bindingConfiguration="HttpStreaming" contract="WcfStreamAudioDemo.Common.IAudioServiceContract" />
      </service>
      
      <service name="WcfStreamAudioDemo.Host.VideoService">
        <endpoint behaviorConfiguration="RestBehaviorConfig" binding="webHttpBinding" bindingConfiguration="HttpStreaming" contract="WcfStreamAudioDemo.Common.IVideoServiceContract" />
        <endpoint address="custom" binding="customBinding" bindingConfiguration="CustomBinding" contract="WcfStreamAudioDemo.Common.IVideoServiceContract" />
      </service> 

    </services>
    

    <bindings>
      
     <customBinding>
        <binding name="CustomBinding">
          <binaryMessageEncoding>
            <readerQuotas maxArrayLength="100000000" maxStringContentLength="100000000"/>
          </binaryMessageEncoding>
          <httpTransport />
        </binding>
      </customBinding>

      <webHttpBinding>
        <binding name="HttpStreaming" transferMode="Streamed" maxReceivedMessageSize="1000000000" maxBufferPoolSize="100000000">
          <readerQuotas maxArrayLength="100000000" maxStringContentLength="100000000"/>
        </binding>
      </webHttpBinding>
    </bindings>
    
    <behaviors>

      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
     
      <endpointBehaviors>
        <behavior name="RestBehaviorConfig">
          <webHttp />
        </behavior>
      </endpointBehaviors>

    </behaviors>
    <protocolMapping>
        <add binding="basicHttpsBinding" scheme="https" />
    </protocolMapping>    
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
  </system.serviceModel>

Note that the custom binding allows us to set up a binaryMessageEncoding. The next step is to go to the client project and add a service reference to the host project containing the WCF service. The app.config file is then updated, relevant parts shown here:

 <system.webServer>
    <directoryBrowse enabled="true" />
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="1073741824" />
      </requestFiltering>
    </security>
        <staticContent>
            <mimeMap fileExtension=".mp4" mimeType="video/mp4" />
        </staticContent>
  </system.webServer>


  <system.serviceModel>
    <bindings>
      
      <customBinding>
        <binding name="CustomBinding">
          <binaryMessageEncoding>
            <readerQuotas maxArrayLength="100000000" maxStringContentLength="100000000" />
          </binaryMessageEncoding>
          <httpTransport maxReceivedMessageSize="100000000" />
        </binding>
      </customBinding>

    </bindings>
    <client>
      <endpoint address="http://he139920.helsemn.no/WcfStreamAudioDemo.Host/VideoService.svc/custom" contract="VideoService.IVideoServiceContract" binding="customBinding" bindingConfiguration="CustomBinding" />
    </client>
    
  </system.serviceModel>

Note the changes of setting up a MIME map for .mp4 files and setting up requestlimits. I will explain this soon. The client script now actually consists both of a server side script run in ASP.NET that sets up the video control in two ways. One way is to construct a HTML5 Data Url. This clearly was demanding for the browser to cope with and is not recommended. The video is actually embed on the page as a base64 encoded string! For a small video such as our video, it is actually possible still. It is of course fascinating that we can embed an entire video on our ASPX web page just as a Base64 encoded string, like it or not. The way to do this anyways is like this:

<script runat="server">

    private void btnInvokeWcfService_OnClick(object sender, EventArgs e)
    {

        using (var proxy = new VideoServiceContractClient())
        {
            byte[] payload = proxy.GetVideoBytes("sintel_trailer-480p");

            SetVideoSourceToHtmlDataUri(payload);

        }
    }


    private void SetVideoSourceToHtmlDataUri(byte[] payload)
    {
        //Set a base64 Html data uri

        videoCtrlFedByByteArrayThroughProxy.Attributes["type"] = "video/mp4";

        string base64String = Convert.ToBase64String(payload);

        videoCtrlFedByByteArrayThroughProxy.Attributes["src"] = "data:video/mp4;base64," + base64String;
    }

</script>

The following image shows how this actually works! Of course, this gives rendering and performance issues, as the web page now got very large content - the entire video is embedded into the page! Another way is to write the byte array to a temporary file on the server, and set the src attribute to this temporary file.

<script runat="server">

    private void btnInvokeWcfService_OnClick(object sender, EventArgs e)
    {

        using (var proxy = new VideoServiceContractClient())
        {
            byte[] payload = proxy.GetVideoBytes("sintel_trailer-480p");

            SetVideoSourceToTempFile(payload);

        }
    }

    private void SetVideoSourceToTempFile(byte[] payload)
    {
        //write to a temp file 
        string tempfile = Path.GetRandomFileName() + ".mp4";
        string tempfilePathForWebServer = HttpContext.Current.Server.MapPath("media/") + tempfile;
        File.WriteAllBytes(tempfilePathForWebServer, payload);

        videoCtrlFedByByteArrayThroughProxy.Attributes["src"] = "media/" + tempfile;
    }

</script>

Note that in these two samples, I have adjusted the HTML5 video control to be accessible to ASP.NET like this:

   <asp:Button runat="server" ID="btnInvokeWcfService" Text="Load Video" OnClick="btnInvokeWcfService_OnClick"/>
        
        <video id="videoCtrlFedByByteArrayThroughProxy" type="video/mp4"  runat="server"  controls width="320" height="240">         
            <p>Your browser doesn't support HTML5 video. Here is a <a href="http://wcfaudiodemohost.azurewebsites.net/VideoService.svc/mediabytes/sintel_trailer-480p">link to the video</a> instead.</p> 
        </video>

This method of retrieving video from WCF is the quickest way, it only fetches the original byte array data and it loads quickly. An adjusted version would not write to a file directly accessible on the web server, but use for example IsolatedStorage instead. I will look into that in the future. Hope you found this article interesting. CustomBindings in WCF gives you a lot of flexibility!

Share this article on LinkedIn.