add date content added comparer

MediaBrowser.Server.Implementations/Library/MediaSourceManager.cs

@@ -1,6 +1,7 @@
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Persistence;
 using MediaBrowser.Model.Entities;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -47,5 +48,59 @@ namespace MediaBrowser.Server.Implementations.Library
         {
             return true;
         }
+
+        public IEnumerable<MediaStream> GetMediaStreams(string mediaSourceId)
+        {
+            var list = GetMediaStreams(new MediaStreamQuery
+            {
+                ItemId = new Guid(mediaSourceId)
+            });
+
+            return GetMediaStreamsForItem(list);
+        }
+
+        public IEnumerable<MediaStream> GetMediaStreams(Guid itemId)
+        {
+            var list = GetMediaStreams(new MediaStreamQuery
+            {
+                ItemId = itemId
+            });
+
+            return GetMediaStreamsForItem(list);
+        }
+
+        private IEnumerable<MediaStream> GetMediaStreamsForItem(IEnumerable<MediaStream> streams)
+        {
+            var list = streams.ToList();
+
+            var subtitleStreams = list
+                .Where(i => i.Type == MediaStreamType.Subtitle)
+                .ToList();
+
+            if (subtitleStreams.Count > 0)
+            {
+                var videoStream = list.FirstOrDefault(i => i.Type == MediaStreamType.Video);
+
+                // This is abitrary but at some point it becomes too slow to extract subtitles on the fly
+                // We need to learn more about when this is the case vs. when it isn't
+                const int maxAllowedBitrateForExternalSubtitleStream = 10000000;
+
+                var videoBitrate = videoStream == null ? maxAllowedBitrateForExternalSubtitleStream : videoStream.BitRate ?? maxAllowedBitrateForExternalSubtitleStream;
+
+                foreach (var subStream in subtitleStreams)
+                {
+                    var supportsExternalStream = StreamSupportsExternalStream(subStream);
+
+                    if (supportsExternalStream && videoBitrate >= maxAllowedBitrateForExternalSubtitleStream)
+                    {
+                        supportsExternalStream = false;
+                    }
+
+                    subStream.SupportsExternalStream = supportsExternalStream;
+                }
+            }
+
+            return list;
+        }
     }
 }