update external subs

Emby.Drawing/ImageProcessor.cs

@@ -227,6 +227,9 @@ namespace Emby.Drawing
                     imageProcessingLockTaken = true;
 
                     _imageEncoder.EncodeImage(originalImagePath, cacheFilePath, newWidth, newHeight, quality, options);
+
+                    // ImageMagick doesn't seem to always release it right away
+                    await Task.Delay(100).ConfigureAwait(false);
                 }
             }
             finally

MediaBrowser.Model/Dlna/StreamBuilder.cs

@@ -759,15 +759,13 @@ namespace MediaBrowser.Model.Dlna
 
                 if (profile.Method == SubtitleDeliveryMethod.External && subtitleStream.IsTextSubtitleStream == MediaStream.IsTextFormat(profile.Format))
                 {
-                    if (!requiresConversion)
+                    if (subtitleStream.IsTextSubtitleStream || !requiresConversion)
                     {
-                        return profile;
-                    }
-
                         if (subtitleStream.SupportsExternalStream)
                         {
                             return profile;
                         }
+                    }
 
                     // For sync we can handle the longer extraction times
                     if (context == EncodingContext.Static && subtitleStream.IsTextSubtitleStream)

MediaBrowser.Server.Implementations/Library/MediaSourceManager.cs

@@ -127,10 +127,13 @@ namespace MediaBrowser.Server.Implementations.Library
                 {
                     var supportsExternalStream = StreamSupportsExternalStream(subStream);
 
+                    if (!subStream.IsExternal)
+                    {
                         if (supportsExternalStream && videoBitrate >= maxAllowedBitrateForExternalSubtitleStream)
                         {
                             supportsExternalStream = false;
                         }
+                    }
 
                     subStream.SupportsExternalStream = supportsExternalStream;
                 }

MediaBrowser.Server.Implementations/Sync/SyncManager.cs

@@ -539,11 +539,6 @@ namespace MediaBrowser.Server.Implementations.Sync
                         return false;
                     }
 
-                    if (video.IsStacked)
-                    {
-                        return false;
-                    }
-
                     if (video.IsShortcut)
                     {
                         return false;