passing object and stream to rest wcf - wcf

Question

Here, when I am trying to pass both object and stream to wcf operation. I am getting "bad request 400" exception. If I pass only stream it is working fine with no issues and I am able to get output as stream. Any suggestions are greatly appreciated.
Client side code:
testclass tcls = new testclass();
tcls.name = "myclass";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(string.Format(#"http://localhost:225141/RestService.svc/getobject/tc/{0}",tcls));
string svcCredentials = Convert.ToBase64String(ASCIIEncoding.ASCII.GetBytes("bda11d91-7ade-4da1-855d-24adfe39d154"));
req.Headers.Add("Authorization", "Basic " + svcCredentials);
req.MaximumResponseHeadersLength = 2147483647;
req.Method = "POST";
req.ContentType = "application/octet-stream";
FileStream fs = new FileStream("file1.txt", FileMode.Open, FileAccess.Read);
MemoryStream ms = new MemoryStream();
fs.CopyTo(ms);
ms.Position = 0;
byte[] dd = ms.ToArray();
Stream strw = req.GetRequestStream();
strw.Write(dd.ToArray(), 0, dd.Length);
strw.Close();
// here i am getting "bad request error"
using (WebResponse svcResponse = (HttpWebResponse)req.GetResponse())
{
MemoryStream msm = new MemoryStream();
svcResponse.GetResponseStream().CopyTo(msm);
msm.Position = 0;
byte[] data = msm.ToArray();
}
...
Service side code:
//IRestService.cs
[ServiceContract]
public interface IRestService
{
[OperationContract]
[WebInvoke(UriTemplate="getobject/tc/{tc}",Method="POST",
BodyStyle=WebMessageBodyStyle.Wrapped,ResponseFormat=WebMessageFormat.Json)]
Stream getobjectl(testclass obj,Stream tc);
}
[DataContract]
[KnownType(typeof(testclass))]
public class testclass
{
[DataMember]
public string name { get; set; }
}
//RestService.cs
public Stream getobject(testclass tc, Stream st)
{
//code;
}