Streaming video using WCF service

This post will show you how to stream video on asp.net using the WCF rest service. The techniques used here are as we don’t know the exact content length of the data, so we used Content-Encoding transfer encoding to maintain an HTTP persistent connection for dynamically generated content. In this case, the HTTP Content-Length header cannot be used to delimit the content and the next HTTP request/response, as the content size is unknown. Chunked encoding has the benefit of generating the full content before writing the header, as it allows streaming of content as chunks and explicitly signalling the end of the content, making the connection available for the next HTTP request/response…

• Open visual studio and create a simple WCF service.
• Add a new class and add the following code to it.

---

public class ContentTypeMessageFormatter : IDispatchMessageFormatter
{
    private IDispatchMessageFormatter formatter;
    private String contentType;
    public ContentTypeMessageFormatter(IDispatchMessageFormatter formatter, String contentType)
    {
        this.formatter = formatter;
        this.contentType = contentType;
    }

    public void DeserializeRequest(Message message, object[] parameters)
    {
        formatter.DeserializeRequest(message, parameters);
    }

    public Message SerializeReply(MessageVersion messageVersion, Object[] parameters, Object result)
    {
        if (!String.IsNullOrEmpty(contentType))
        {
            WebOperationContext.Current.OutgoingResponse.ContentType = contentType;
        }
        return formatter.SerializeReply(messageVersion, parameters, result);
    }
}

• Create another class and add the following code

public class ContentTypeAttribute : Attribute, IOperationBehavior
{
  public ContentTypeAttribute(String contentType)
  {
      this.ContentType = contentType;
  }

  public String ContentType
  {
      get;
      set;
  }

  public void AddBindingParameters(OperationDescription operationDescription, BindingParameterCollection bindingParameters)
  {
  }

  public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation)
  {
  }

  public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
  {
      dispatchOperation.Formatter = new ContentTypeMessageFormatter(dispatchOperation.Formatter, ContentType);
  }

  public void Validate(OperationDescription operationDescription)
  {
  }
}

• Add a new Interface named IMediaService and add the following code to it

using System;  

using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

[ServiceContract]
public interface IMediaService
{
    [OperationContract]
    [ContentType("audio/x-ms-wmv")]
    [WebGet(UriTemplate = "media/{name}")]
    Stream GetMedia(String name);
}

• Implement the service as below

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;
using System.Text;
using System.Web;

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
[ServiceBehavior]
public class MediaService : IMediaService
{
    [OperationBehavior]
    public Stream GetMedia(String name)
    {
        var dir = HttpContext.Current.Server.MapPath("~"); 
        var file = String.Format("{0}.mp4", "x");
        var filePath = Path.Combine(dir, file);
        return File.OpenRead(filePath);
    }
}

• Configure the service.

<?xml version="1.0"?>
<configuration>

  <appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true"/>
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5"/>
    <httpRuntime targetFramework="4.5"/>
  </system.web>
  <system.serviceModel>

    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
    <services>
      <service behaviorConfiguration="serviceBehav" name="MediaService">
        <endpoint behaviorConfiguration="RestBehaviorConfig" binding="webHttpBinding"
          bindingConfiguration="HttpStreaming" contract="IMediaService" />
      </service>
    </services>
    <bindings>
      <webHttpBinding>
        <binding name="HttpStreaming" maxReceivedMessageSize="67108864" transferMode="Streamed"/>
      </webHttpBinding>
    </bindings>
    <behaviors>
      <endpointBehaviors>
        <behavior name="RestBehaviorConfig">
          <webHttp />
        </behavior>
      </endpointBehaviors>
      <serviceBehaviors>
        <behavior name="serviceBehav">
          <serviceMetadata httpGetEnabled="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <!--
 To browse web app root directory during debugging, set the value below to true.
 Set to false before deployment to avoid disclosing web app folder information.
 -->
    <directoryBrowse enabled="true"/>
  </system.webServer>
</configuration>

Now our streaming service is ready. Let’s test it. Create a html5 web page in visual studio and add the following tag to the page.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <video src="http://localhost/MediaWCF/Service.svc/media/x" autoplay="autoplay"></video>
    </div>
    </form>
</body>
</html>