added live channel playback

MediaBrowser.Api/Playback/EndlessStreamCopy.cs

@@ -0,0 +1,32 @@
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Api.Playback
+{
+    public class EndlessStreamCopy
+    {
+        public async Task CopyStream(Stream source, Stream target, CancellationToken cancellationToken)
+        {
+            long position = 0;
+            
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                await source.CopyToAsync(target, 81920, cancellationToken).ConfigureAwait(false);
+
+                var fsPosition = source.Position;
+
+                var bytesRead = fsPosition - position;
+
+                //Logger.Debug("Streamed {0} bytes from file {1}", bytesRead, path);
+
+                if (bytesRead == 0)
+                {
+                    await Task.Delay(100, cancellationToken).ConfigureAwait(false);
+                }
+
+                position = fsPosition;
+            }
+        }
+    }
+}