Downloading big files on iOS ... WWW will give "out of memory" error.

 // Based on this:
 // http://stackoverflow.com/questions/4768443/downloading-file-via-tcpclient-from-http-server
 
 public class main : MonoBehaviour 
 {
     string host = "www.server.com";
     string uri = "/path/to/file/1920x1080.mp4";
     uint contentLength;
     int n = 0;
     int read = 0;
     
     NetworkStream networkStream; 
     FileStream fileStream;
     Socket client;
 
     // Use this for initialization
     void Start () 
     {
         string query = "GET " + uri.Replace(" ", "%20") + " HTTP/1.1\r\n" +
                          "Host: " + host + "\r\n" +
                          "User-Agent: undefined\r\n" +
                          "Connection: close\r\n"+
                          "\r\n";
 
         
         Debug.Log (query);
         
         client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
         client.Connect(host, 80);   
         
         networkStream = new NetworkStream(client);
         
         var bytes = Encoding.Default.GetBytes(query);
         networkStream.Write(bytes, 0, bytes.Length);
         
         var bReader = new BinaryReader(networkStream, Encoding.Default);
         
         string response = "";
         string line;
         char c;
         
         do 
         {
             line = "";
             c = '\u0000';
             while (true) 
             {
                  c = bReader.ReadChar();
                   if (c == '\r')
                        break;
                   line += c;
             }
             c = bReader.ReadChar();
             response += line + "\r\n";
         } 
         while (line.Length > 0);  
         
         Debug.Log ( response );
         
         Regex reContentLength = new Regex(@"(?<=Content-Length:\s)\d+", RegexOptions.IgnoreCase);
         contentLength = uint.Parse(reContentLength.Match(response).Value);
         
         fileStream = new FileStream( Application.persistentDataPath + "/download.mp4", FileMode.Create);
     }
 
     
     void Update()
     {
         byte[] buffer = new byte[4 * 1024];
         
         if (n < contentLength) 
         {
                 if (networkStream.DataAvailable) 
                 {
                   read = networkStream.Read(buffer, 0, buffer.Length);
                   n += read;
                   fileStream.Write(buffer, 0, read);
                 }
                 Debug.Log ( "Downloaded: " + n + " of " + contentLength + " bytes ..." );
          }
         else
         {
               fileStream.Flush();
               fileStream.Close();
             
               client.Close();
         }
     }
     
 }