1 files changed, 16 insertions, 11 deletions
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index eba1e466a..8809f155c 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -12,6 +12,7 @@ using System.Runtime.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
 using CommonIO;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Channels;
 
 namespace MediaBrowser.Controller.Entities
@@ -44,24 +45,23 @@ namespace MediaBrowser.Controller.Entities
             }
         }
 
-        [IgnoreDataMember]
-        public override string PresentationUniqueKey
+        public override string CreatePresentationUniqueKey()
         {
-            get
+            if (!string.IsNullOrWhiteSpace(PrimaryVersionId))
             {
-                if (!string.IsNullOrWhiteSpace(PrimaryVersionId))
-                {
-                    return PrimaryVersionId;
-                }
-
-                return base.PresentationUniqueKey;
+                return PrimaryVersionId;
             }
+
+            return base.CreatePresentationUniqueKey();
         }
 
         [IgnoreDataMember]
-        public override bool EnableForceSaveOnDateModifiedChange
+        public override bool EnableRefreshOnDateModifiedChange
         {
-            get { return true; }
+            get
+            {
+                return VideoType == VideoType.VideoFile || VideoType == VideoType.Iso;
+            }
         }
 
         public int? TotalBitrate { get; set; }
@@ -612,6 +612,11 @@ namespace MediaBrowser.Controller.Entities
                 SupportsDirectStream = i.VideoType == VideoType.VideoFile
             };
 
+            if (info.Protocol == MediaProtocol.File)
+            {
+                info.ETag = i.DateModified.Ticks.ToString(CultureInfo.InvariantCulture).GetMD5().ToString("N");
+            }
+
             if (i.IsShortcut)
             {
                 info.Path = i.ShortcutPath;