IHTTPHandler on Web Api

Question

I try to use an existing IHttpHandler on an ASP.NET MVC\WEB API website, deployed on a VS IIS EXPRESS 8.0 and on a production IIS 7.5

It basically looks like

public class MP4DownloadHandler : IHttpHandler
{
    ...

    public void ProcessRequest(HttpContext context)
    {
        this.InternalRequestedFileInfo = this.GetRequestedFileInfo(context);
        this.InternalRequestedFileEntityTag = this.GetRequestedFileEntityTag(context);
        this.InternalRequestedFileMimeType = this.GetRequestedFileMimeType(context);

        ...
     }

     ...
 }

I want it to handle requests to urls ending with .mp4

I registered the MP4DownloadHandler in web.config

<system.webServer>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />

      <add name="MP4DownloadHandler" verb="*" path="*.mp4" type="MP4DownloadHandler" resourceType="Unspecified"/>


      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

    </handlers>
</system.webServer>

and also added ignore rules to the routing table for MVC and WEB API routing engines

in MVC Register():

routes.IgnoreRoute(
    "get/GetImage/{fileName}",
    new { fileName = @".*\.mp4" }
);

in WEB API RegisterRoutes()

config.Routes.IgnoreRoute(
    routeName: "Ignoremp4WebApi",
    routeTemplate: "get/GetImage/{fileName}",
    constraints: new { fileName=@".*\.mp4" }
);

When I try to make a get request with a url:

localhost:6032/get/GetImage/test.mp4

I get the following response:

Remote Address:127.0.0.1:8888
Request URL:http://localhost:6032/get/GetImage/test.mp4
Request Method:GET
Status Code:404 Not Found

<Error>
    <Message>
        No HTTP resource was found that matches the request URI 'http://localhost:6032/get/GetImage/test.mp4'.
    </Message>
    <MessageDetail>No route data was found for this request.</MessageDetail>
</Error>    

In debug I see that my ProcessRequest was not called, so I can conclude that it's not the case that the handler doesn't find the file.

Is there anything special to be done in order to make IHttpHadlers work with MVC?