update live stream buffer

MediaBrowser.Controller/IO/StreamHelper.cs

@@ -0,0 +1,20 @@
+using System.IO;
+using System.Threading;
+
+namespace MediaBrowser.Controller.IO
+{
+    public static class StreamHelper
+    {
+        public static void CopyTo(Stream source, Stream destination, int bufferSize, CancellationToken cancellationToken)
+        {
+            byte[] buffer = new byte[bufferSize];
+            int read;
+            while ((read = source.Read(buffer, 0, buffer.Length)) != 0)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+
+                destination.Write(buffer, 0, read);
+            }
+        }
+    }
+}