problems with http file upload to wcf-rest service - wcf

Question

I would like to upload a file using a form like this:
<form action="http://127.0.0.1:8090/MyService/"
method="post" enctype="multipart/form-data">
<p>Select File<br>
<input name="Datei" type="file" size="50">
<input type="submit" value="Submit">
</p>
</form>
And have a wcf service like this:
[ServiceContract]
public interface IDocumentConverter
{
[OperationContract, WebInvoke(UriTemplate = "/", Method = "POST")]
void UploadFile(Stream fileContents);
}
I have two problems with this. When I write the stream back into a file it does not only contain the file data but also some http stuff. This seems odd. Is there nice way to get the raw file data?:
-----------------------------67832811011758
Content-Disposition: form-data; name="Datei"; filename="haha.jpg"
Content-Type: image/jpeg
ÿØÿà...
The original file looks like this:
ÿØÿà...
Secondly I would like to have the filename in wcf. Ideally like this:
[ServiceContract]
public interface IDocumentConverter
{
[OperationContract, WebInvoke(UriTemplate = "/{filename}", Method = "POST")]
void UploadFile(string filename, Stream fileContents);
}
But this is not working, because I don't know how to integrate the filename into the url using the form/input stuff.