Merge branch 'master' into comparisons

119 files changed, 1090 insertions, 1057 deletions

diff --git a/MediaBrowser.Controller/BaseItemManager/BaseItemManager.cs b/MediaBrowser.Controller/BaseItemManager/BaseItemManager.cs
index 68119cfed..ffc274c5d 100644
--- a/MediaBrowser.Controller/BaseItemManager/BaseItemManager.cs
+++ b/MediaBrowser.Controller/BaseItemManager/BaseItemManager.cs
@@ -3,6 +3,7 @@
 using System;
 using System.Linq;
 using System.Threading;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Channels;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
@@ -52,7 +53,7 @@ namespace MediaBrowser.Controller.BaseItemManager
             var typeOptions = libraryOptions.GetTypeOptions(baseItem.GetType().Name);
             if (typeOptions != null)
             {
-                return typeOptions.MetadataFetchers.Contains(name, StringComparer.OrdinalIgnoreCase);
+                return typeOptions.MetadataFetchers.Contains(name.AsSpan(), StringComparison.OrdinalIgnoreCase);
             }
 
             if (!libraryOptions.EnableInternetProviders)
@@ -62,7 +63,7 @@ namespace MediaBrowser.Controller.BaseItemManager
 
             var itemConfig = _serverConfigurationManager.Configuration.MetadataOptions.FirstOrDefault(i => string.Equals(i.ItemType, GetType().Name, StringComparison.OrdinalIgnoreCase));
 
-            return itemConfig == null || !itemConfig.DisabledMetadataFetchers.Contains(name, StringComparer.OrdinalIgnoreCase);
+            return itemConfig == null || !itemConfig.DisabledMetadataFetchers.Contains(name.AsSpan(), StringComparison.OrdinalIgnoreCase);
         }
 
         /// <inheritdoc />
@@ -83,7 +84,7 @@ namespace MediaBrowser.Controller.BaseItemManager
             var typeOptions = libraryOptions.GetTypeOptions(baseItem.GetType().Name);
             if (typeOptions != null)
             {
-                return typeOptions.ImageFetchers.Contains(name, StringComparer.OrdinalIgnoreCase);
+                return typeOptions.ImageFetchers.Contains(name.AsSpan(), StringComparison.OrdinalIgnoreCase);
             }
 
             if (!libraryOptions.EnableInternetProviders)
@@ -93,7 +94,7 @@ namespace MediaBrowser.Controller.BaseItemManager
 
             var itemConfig = _serverConfigurationManager.Configuration.MetadataOptions.FirstOrDefault(i => string.Equals(i.ItemType, GetType().Name, StringComparison.OrdinalIgnoreCase));
 
-            return itemConfig == null || !itemConfig.DisabledImageFetchers.Contains(name, StringComparer.OrdinalIgnoreCase);
+            return itemConfig == null || !itemConfig.DisabledImageFetchers.Contains(name.AsSpan(), StringComparison.OrdinalIgnoreCase);
         }
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Channels/Channel.cs b/MediaBrowser.Controller/Channels/Channel.cs
index 26c64e0da..26a936be0 100644
--- a/MediaBrowser.Controller/Channels/Channel.cs
+++ b/MediaBrowser.Controller/Channels/Channel.cs
@@ -84,7 +84,7 @@ namespace MediaBrowser.Controller.Channels
 
         internal static bool IsChannelVisible(BaseItem channelItem, User user)
         {
-            var channel = ChannelManager.GetChannel(channelItem.ChannelId.ToString(""));
+            var channel = ChannelManager.GetChannel(channelItem.ChannelId.ToString(string.Empty));
 
             return channel.IsVisible(user);
         }
diff --git a/MediaBrowser.Controller/Channels/ChannelItemInfo.cs b/MediaBrowser.Controller/Channels/ChannelItemInfo.cs
index fa7aff647..4d1e35f9e 100644
--- a/MediaBrowser.Controller/Channels/ChannelItemInfo.cs
+++ b/MediaBrowser.Controller/Channels/ChannelItemInfo.cs
@@ -13,6 +13,19 @@ namespace MediaBrowser.Controller.Channels
 {
     public class ChannelItemInfo : IHasProviderIds
     {
+        public ChannelItemInfo()
+        {
+            MediaSources = new List<MediaSourceInfo>();
+            TrailerTypes = new List<TrailerType>();
+            Genres = new List<string>();
+            Studios = new List<string>();
+            People = new List<PersonInfo>();
+            Tags = new List<string>();
+            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            Artists = new List<string>();
+            AlbumArtists = new List<string>();
+        }
+
         public string Name { get; set; }
 
         public string SeriesName { get; set; }
@@ -80,18 +93,5 @@ namespace MediaBrowser.Controller.Channels
         public bool IsLiveStream { get; set; }
 
         public string Etag { get; set; }
-
-        public ChannelItemInfo()
-        {
-            MediaSources = new List<MediaSourceInfo>();
-            TrailerTypes = new List<TrailerType>();
-            Genres = new List<string>();
-            Studios = new List<string>();
-            People = new List<PersonInfo>();
-            Tags = new List<string>();
-            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-            Artists = new List<string>();
-            AlbumArtists = new List<string>();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Channels/ChannelItemResult.cs b/MediaBrowser.Controller/Channels/ChannelItemResult.cs
index 8e937852f..6b2077662 100644
--- a/MediaBrowser.Controller/Channels/ChannelItemResult.cs
+++ b/MediaBrowser.Controller/Channels/ChannelItemResult.cs
@@ -8,13 +8,13 @@ namespace MediaBrowser.Controller.Channels
 {
     public class ChannelItemResult
     {
-        public List<ChannelItemInfo> Items { get; set; }
-
-        public int? TotalRecordCount { get; set; }
-
         public ChannelItemResult()
         {
             Items = new List<ChannelItemInfo>();
         }
+
+        public List<ChannelItemInfo> Items { get; set; }
+
+        public int? TotalRecordCount { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Channels/ChannelLatestMediaSearch.cs b/MediaBrowser.Controller/Channels/ChannelLatestMediaSearch.cs
new file mode 100644
index 000000000..6f0761e64
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/ChannelLatestMediaSearch.cs
@@ -0,0 +1,11 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+namespace MediaBrowser.Controller.Channels
+{
+    public class ChannelLatestMediaSearch
+    {
+        public string UserId { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Channels/ChannelSearchInfo.cs b/MediaBrowser.Controller/Channels/ChannelSearchInfo.cs
index 53a73d62a..990b025bc 100644
--- a/MediaBrowser.Controller/Channels/ChannelSearchInfo.cs
+++ b/MediaBrowser.Controller/Channels/ChannelSearchInfo.cs
@@ -10,9 +10,4 @@ namespace MediaBrowser.Controller.Channels
 
         public string UserId { get; set; }
     }
-
-    public class ChannelLatestMediaSearch
-    {
-        public string UserId { get; set; }
-    }
 }
diff --git a/MediaBrowser.Controller/Channels/IChannelManager.cs b/MediaBrowser.Controller/Channels/IChannelManager.cs
index 4c5626338..49be897ef 100644
--- a/MediaBrowser.Controller/Channels/IChannelManager.cs
+++ b/MediaBrowser.Controller/Channels/IChannelManager.cs
@@ -51,32 +51,47 @@ namespace MediaBrowser.Controller.Channels
         /// Gets the channels internal.
         /// </summary>
         /// <param name="query">The query.</param>
+        /// <returns>The channels.</returns>
         QueryResult<Channel> GetChannelsInternal(ChannelQuery query);
 
         /// <summary>
         /// Gets the channels.
         /// </summary>
         /// <param name="query">The query.</param>
+        /// <returns>The channels.</returns>
         QueryResult<BaseItemDto> GetChannels(ChannelQuery query);
 
         /// <summary>
-        /// Gets the latest media.
+        /// Gets the latest channel items.
         /// </summary>
+        /// <param name="query">The item query.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The latest channels.</returns>
         Task<QueryResult<BaseItemDto>> GetLatestChannelItems(InternalItemsQuery query, CancellationToken cancellationToken);
 
         /// <summary>
-        /// Gets the latest media.
+        /// Gets the latest channel items.
         /// </summary>
+        /// <param name="query">The item query.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The latest channels.</returns>
         Task<QueryResult<BaseItem>> GetLatestChannelItemsInternal(InternalItemsQuery query, CancellationToken cancellationToken);
 
         /// <summary>
         /// Gets the channel items.
         /// </summary>
+        /// <param name="query">The query.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The channel items.</returns>
         Task<QueryResult<BaseItemDto>> GetChannelItems(InternalItemsQuery query, CancellationToken cancellationToken);
 
         /// <summary>
-        /// Gets the channel items internal.
+        /// Gets the channel items.
         /// </summary>
+        /// <param name="query">The query.</param>
+        /// <param name="progress">The progress to report to.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The channel items.</returns>
         Task<QueryResult<BaseItem>> GetChannelItemsInternal(InternalItemsQuery query, IProgress<double> progress, CancellationToken cancellationToken);
 
         /// <summary>
@@ -84,9 +99,14 @@ namespace MediaBrowser.Controller.Channels
         /// </summary>
         /// <param name="item">The item.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task{IEnumerable{MediaSourceInfo}}.</returns>
+        /// <returns>The item media sources.</returns>
         IEnumerable<MediaSourceInfo> GetStaticMediaSources(BaseItem item, CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Whether the item supports media probe.
+        /// </summary>
+        /// <param name="item">The item.</param>
+        /// <returns>Whether media probe should be enabled.</returns>
         bool EnableMediaProbe(BaseItem item);
     }
 }
diff --git a/MediaBrowser.Controller/Channels/IDisableMediaSourceDisplay.cs b/MediaBrowser.Controller/Channels/IDisableMediaSourceDisplay.cs
new file mode 100644
index 000000000..0539b9048
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/IDisableMediaSourceDisplay.cs
@@ -0,0 +1,12 @@
+namespace MediaBrowser.Controller.Channels
+{
+    /// <summary>
+    /// Disable media source display.
+    /// </summary>
+    /// <remarks>
+    /// <see cref="Channel"/> can inherit this interface to disable being displayed.
+    /// </remarks>
+    public interface IDisableMediaSourceDisplay
+    {
+    }
+}
diff --git a/MediaBrowser.Controller/Channels/IHasFolderAttributes.cs b/MediaBrowser.Controller/Channels/IHasFolderAttributes.cs
new file mode 100644
index 000000000..47277a8cc
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/IHasFolderAttributes.cs
@@ -0,0 +1,9 @@
+#pragma warning disable CS1591
+
+namespace MediaBrowser.Controller.Channels
+{
+    public interface IHasFolderAttributes
+    {
+        string[] Attributes { get; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Channels/IRequiresMediaInfoCallback.cs b/MediaBrowser.Controller/Channels/IRequiresMediaInfoCallback.cs
index 589295543..eeaa6b622 100644
--- a/MediaBrowser.Controller/Channels/IRequiresMediaInfoCallback.cs
+++ b/MediaBrowser.Controller/Channels/IRequiresMediaInfoCallback.cs
@@ -1,5 +1,3 @@
-#pragma warning disable CS1591
-
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -7,11 +5,17 @@ using MediaBrowser.Model.Dto;
 
 namespace MediaBrowser.Controller.Channels
 {
+    /// <summary>
+    /// The channel requires a media info callback.
+    /// </summary>
     public interface IRequiresMediaInfoCallback
     {
         /// <summary>
         /// Gets the channel item media information.
         /// </summary>
+        /// <param name="id">The channel item id.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The enumerable of media source info.</returns>
         Task<IEnumerable<MediaSourceInfo>> GetChannelItemMediaInfo(string id, CancellationToken cancellationToken);
     }
 }
diff --git a/MediaBrowser.Controller/Channels/ISearchableChannel.cs b/MediaBrowser.Controller/Channels/ISearchableChannel.cs
index b58446fc4..b87943a6e 100644
--- a/MediaBrowser.Controller/Channels/ISearchableChannel.cs
+++ b/MediaBrowser.Controller/Channels/ISearchableChannel.cs
@@ -5,7 +5,6 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using MediaBrowser.Controller.Entities;
 
 namespace MediaBrowser.Controller.Channels
 {
@@ -19,35 +18,4 @@ namespace MediaBrowser.Controller.Channels
         /// <returns>Task{IEnumerable{ChannelItemInfo}}.</returns>
         Task<IEnumerable<ChannelItemInfo>> Search(ChannelSearchInfo searchInfo, CancellationToken cancellationToken);
     }
-
-    public interface ISupportsLatestMedia
-    {
-        /// <summary>
-        /// Gets the latest media.
-        /// </summary>
-        /// <param name="request">The request.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task{IEnumerable{ChannelItemInfo}}.</returns>
-        Task<IEnumerable<ChannelItemInfo>> GetLatestMedia(ChannelLatestMediaSearch request, CancellationToken cancellationToken);
-    }
-
-    public interface ISupportsDelete
-    {
-        bool CanDelete(BaseItem item);
-
-        Task DeleteItem(string id, CancellationToken cancellationToken);
-    }
-
-    public interface IDisableMediaSourceDisplay
-    {
-    }
-
-    public interface ISupportsMediaProbe
-    {
-    }
-
-    public interface IHasFolderAttributes
-    {
-        string[] Attributes { get; }
-    }
 }
diff --git a/MediaBrowser.Controller/Channels/ISupportsDelete.cs b/MediaBrowser.Controller/Channels/ISupportsDelete.cs
new file mode 100644
index 000000000..204054374
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/ISupportsDelete.cs
@@ -0,0 +1,15 @@
+#pragma warning disable CS1591
+
+using System.Threading;
+using System.Threading.Tasks;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Channels
+{
+    public interface ISupportsDelete
+    {
+        bool CanDelete(BaseItem item);
+
+        Task DeleteItem(string id, CancellationToken cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Channels/ISupportsLatestMedia.cs b/MediaBrowser.Controller/Channels/ISupportsLatestMedia.cs
new file mode 100644
index 000000000..dbba7cba2
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/ISupportsLatestMedia.cs
@@ -0,0 +1,21 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Controller.Channels
+{
+    public interface ISupportsLatestMedia
+    {
+        /// <summary>
+        /// Gets the latest media.
+        /// </summary>
+        /// <param name="request">The request.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>The latest media.</returns>
+        Task<IEnumerable<ChannelItemInfo>> GetLatestMedia(ChannelLatestMediaSearch request, CancellationToken cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Channels/ISupportsMediaProbe.cs b/MediaBrowser.Controller/Channels/ISupportsMediaProbe.cs
new file mode 100644
index 000000000..bc7683125
--- /dev/null
+++ b/MediaBrowser.Controller/Channels/ISupportsMediaProbe.cs
@@ -0,0 +1,9 @@
+namespace MediaBrowser.Controller.Channels
+{
+    /// <summary>
+    /// Channel supports media probe.
+    /// </summary>
+    public interface ISupportsMediaProbe
+    {
+    }
+}
diff --git a/MediaBrowser.Controller/Channels/InternalChannelFeatures.cs b/MediaBrowser.Controller/Channels/InternalChannelFeatures.cs
index 152c653dc..45cd08173 100644
--- a/MediaBrowser.Controller/Channels/InternalChannelFeatures.cs
+++ b/MediaBrowser.Controller/Channels/InternalChannelFeatures.cs
@@ -30,7 +30,7 @@ namespace MediaBrowser.Controller.Channels
         public List<ChannelMediaContentType> ContentTypes { get; set; }
 
         /// <summary>
-        /// Represents the maximum number of records the channel allows retrieving at a time.
+        /// Gets or sets the maximum number of records the channel allows retrieving at a time.
         /// </summary>
         public int? MaxPageSize { get; set; }
 
@@ -41,7 +41,7 @@ namespace MediaBrowser.Controller.Channels
         public List<ChannelItemSortField> DefaultSortFields { get; set; }
 
         /// <summary>
-        /// Indicates if a sort ascending/descending toggle is supported or not.
+        /// Gets or sets a value indicating whether a sort ascending/descending toggle is supported or not.
         /// </summary>
         public bool SupportsSortOrderToggle { get; set; }
 
diff --git a/MediaBrowser.Controller/Collections/CollectionCreatedEventArgs.cs b/MediaBrowser.Controller/Collections/CollectionCreatedEventArgs.cs
new file mode 100644
index 000000000..82b3a4977
--- /dev/null
+++ b/MediaBrowser.Controller/Collections/CollectionCreatedEventArgs.cs
@@ -0,0 +1,24 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System;
+using MediaBrowser.Controller.Entities.Movies;
+
+namespace MediaBrowser.Controller.Collections
+{
+    public class CollectionCreatedEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Gets or sets the collection.
+        /// </summary>
+        /// <value>The collection.</value>
+        public BoxSet Collection { get; set; }
+
+        /// <summary>
+        /// Gets or sets the options.
+        /// </summary>
+        /// <value>The options.</value>
+        public CollectionCreationOptions Options { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Collections/CollectionCreationOptions.cs b/MediaBrowser.Controller/Collections/CollectionCreationOptions.cs
index 94e7541f8..30f5f4efa 100644
--- a/MediaBrowser.Controller/Collections/CollectionCreationOptions.cs
+++ b/MediaBrowser.Controller/Collections/CollectionCreationOptions.cs
@@ -25,8 +25,8 @@ namespace MediaBrowser.Controller.Collections
 
         public Dictionary<string, string> ProviderIds { get; set; }
 
-        public string[] ItemIdList { get; set; }
+        public IReadOnlyList<string> ItemIdList { get; set; }
 
-        public Guid[] UserIds { get; set; }
+        public IReadOnlyList<Guid> UserIds { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Collections/CollectionEvents.cs b/MediaBrowser.Controller/Collections/CollectionModifiedEventArgs.cs
index 821318ffc..8155cf3db 100644
--- a/MediaBrowser.Controller/Collections/CollectionEvents.cs
+++ b/MediaBrowser.Controller/Collections/CollectionModifiedEventArgs.cs
@@ -9,23 +9,14 @@ using MediaBrowser.Controller.Entities.Movies;
 
 namespace MediaBrowser.Controller.Collections
 {
-    public class CollectionCreatedEventArgs : EventArgs
-    {
-        /// <summary>
-        /// Gets or sets the collection.
-        /// </summary>
-        /// <value>The collection.</value>
-        public BoxSet Collection { get; set; }
-
-        /// <summary>
-        /// Gets or sets the options.
-        /// </summary>
-        /// <value>The options.</value>
-        public CollectionCreationOptions Options { get; set; }
-    }
-
     public class CollectionModifiedEventArgs : EventArgs
     {
+        public CollectionModifiedEventArgs(BoxSet collection, IReadOnlyCollection<BaseItem> itemsChanged)
+        {
+            Collection = collection;
+            ItemsChanged = itemsChanged;
+        }
+
         /// <summary>
         /// Gets or sets the collection.
         /// </summary>
@@ -36,6 +27,6 @@ namespace MediaBrowser.Controller.Collections
         /// Gets or sets the items changed.
         /// </summary>
         /// <value>The items changed.</value>
-        public List<BaseItem> ItemsChanged { get; set; }
+        public IReadOnlyCollection<BaseItem> ItemsChanged { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Devices/IDeviceManager.cs b/MediaBrowser.Controller/Devices/IDeviceManager.cs
index ef17c8fb3..8096be1bd 100644
--- a/MediaBrowser.Controller/Devices/IDeviceManager.cs
+++ b/MediaBrowser.Controller/Devices/IDeviceManager.cs
@@ -20,7 +20,6 @@ namespace MediaBrowser.Controller.Devices
         /// </summary>
         /// <param name="reportedId">The reported identifier.</param>
         /// <param name="capabilities">The capabilities.</param>
-        /// <returns>Task.</returns>
         void SaveCapabilities(string reportedId, ClientCapabilities capabilities);
 
         /// <summary>
@@ -47,6 +46,9 @@ namespace MediaBrowser.Controller.Devices
         /// <summary>
         /// Determines whether this instance [can access device] the specified user identifier.
         /// </summary>
+        /// <param name="user">The user to test.</param>
+        /// <param name="deviceId">The device id to test.</param>
+        /// <returns>Whether the user can access the device.</returns>
         bool CanAccessDevice(User user, string deviceId);
 
         void UpdateDeviceOptions(string deviceId, DeviceOptions options);
diff --git a/MediaBrowser.Controller/Drawing/IImageEncoder.cs b/MediaBrowser.Controller/Drawing/IImageEncoder.cs
index 800f7a8bb..4e640d421 100644
--- a/MediaBrowser.Controller/Drawing/IImageEncoder.cs
+++ b/MediaBrowser.Controller/Drawing/IImageEncoder.cs
@@ -1,7 +1,4 @@
-#nullable disable
-
 #pragma warning disable CS1591
-#nullable enable
 
 using System;
 using System.Collections.Generic;
diff --git a/MediaBrowser.Controller/Drawing/IImageProcessor.cs b/MediaBrowser.Controller/Drawing/IImageProcessor.cs
index 9bfead8b3..c7f61a90b 100644
--- a/MediaBrowser.Controller/Drawing/IImageProcessor.cs
+++ b/MediaBrowser.Controller/Drawing/IImageProcessor.cs
@@ -1,7 +1,4 @@
-#nullable disable
-
 #pragma warning disable CS1591
-#nullable enable
 
 using System;
 using System.Collections.Generic;
diff --git a/MediaBrowser.Controller/Drawing/ImageCollageOptions.cs b/MediaBrowser.Controller/Drawing/ImageCollageOptions.cs
index f06bbe4d0..e9c88ffb5 100644
--- a/MediaBrowser.Controller/Drawing/ImageCollageOptions.cs
+++ b/MediaBrowser.Controller/Drawing/ImageCollageOptions.cs
@@ -1,5 +1,7 @@
 #nullable disable
 
+using System.Collections.Generic;
+
 #pragma warning disable CS1591
 
 namespace MediaBrowser.Controller.Drawing
@@ -10,7 +12,7 @@ namespace MediaBrowser.Controller.Drawing
         /// Gets or sets the input paths.
         /// </summary>
         /// <value>The input paths.</value>
-        public string[] InputPaths { get; set; }
+        public IReadOnlyList<string> InputPaths { get; set; }
 
         /// <summary>
         /// Gets or sets the output path.
diff --git a/MediaBrowser.Controller/Drawing/ImageHelper.cs b/MediaBrowser.Controller/Drawing/ImageHelper.cs
index 204175ed5..9ef92bc98 100644
--- a/MediaBrowser.Controller/Drawing/ImageHelper.cs
+++ b/MediaBrowser.Controller/Drawing/ImageHelper.cs
@@ -1,7 +1,4 @@
-#nullable disable
-
 #pragma warning disable CS1591
-#nullable enable
 
 using MediaBrowser.Model.Drawing;
 
diff --git a/MediaBrowser.Controller/Drawing/ImageStream.cs b/MediaBrowser.Controller/Drawing/ImageStream.cs
index 591cc53d1..5ee781ffa 100644
--- a/MediaBrowser.Controller/Drawing/ImageStream.cs
+++ b/MediaBrowser.Controller/Drawing/ImageStream.cs
@@ -22,9 +22,15 @@ namespace MediaBrowser.Controller.Drawing
 
         public void Dispose()
         {
-            if (Stream != null)
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
             {
-                Stream.Dispose();
+                Stream?.Dispose();
             }
         }
     }
diff --git a/MediaBrowser.Controller/Dto/DtoOptions.cs b/MediaBrowser.Controller/Dto/DtoOptions.cs
index 758e841a7..ecc833154 100644
--- a/MediaBrowser.Controller/Dto/DtoOptions.cs
+++ b/MediaBrowser.Controller/Dto/DtoOptions.cs
@@ -18,37 +18,17 @@ namespace MediaBrowser.Controller.Dto
             ItemFields.RefreshState
         };
 
-        public IReadOnlyList<ItemFields> Fields { get; set; }
-
-        public IReadOnlyList<ImageType> ImageTypes { get; set; }
-
-        public int ImageTypeLimit { get; set; }
-
-        public bool EnableImages { get; set; }
-
-        public bool AddProgramRecordingInfo { get; set; }
-
-        public bool EnableUserData { get; set; }
+        private static readonly ImageType[] AllImageTypes = Enum.GetValues<ImageType>();
 
-        public bool AddCurrentProgram { get; set; }
+        private static readonly ItemFields[] AllItemFields = Enum.GetValues<ItemFields>()
+            .Except(DefaultExcludedFields)
+            .ToArray();
 
         public DtoOptions()
             : this(true)
         {
         }
 
-        private static readonly ImageType[] AllImageTypes = Enum.GetNames(typeof(ImageType))
-            .Select(i => (ImageType)Enum.Parse(typeof(ImageType), i, true))
-            .ToArray();
-
-        private static readonly ItemFields[] AllItemFields = Enum.GetNames(typeof(ItemFields))
-            .Select(i => (ItemFields)Enum.Parse(typeof(ItemFields), i, true))
-            .Except(DefaultExcludedFields)
-            .ToArray();
-
-        public bool ContainsField(ItemFields field)
-            => Fields.Contains(field);
-
         public DtoOptions(bool allFields)
         {
             ImageTypeLimit = int.MaxValue;
@@ -60,6 +40,23 @@ namespace MediaBrowser.Controller.Dto
             ImageTypes = AllImageTypes;
         }
 
+        public IReadOnlyList<ItemFields> Fields { get; set; }
+
+        public IReadOnlyList<ImageType> ImageTypes { get; set; }
+
+        public int ImageTypeLimit { get; set; }
+
+        public bool EnableImages { get; set; }
+
+        public bool AddProgramRecordingInfo { get; set; }
+
+        public bool EnableUserData { get; set; }
+
+        public bool AddCurrentProgram { get; set; }
+
+        public bool ContainsField(ItemFields field)
+            => Fields.Contains(field);
+
         public int GetImageLimit(ImageType type)
         {
             if (EnableImages && ImageTypes.Contains(type))
diff --git a/MediaBrowser.Controller/Dto/IDtoService.cs b/MediaBrowser.Controller/Dto/IDtoService.cs
index 7f4bbead0..61d796235 100644
--- a/MediaBrowser.Controller/Dto/IDtoService.cs
+++ b/MediaBrowser.Controller/Dto/IDtoService.cs
@@ -36,11 +36,17 @@ namespace MediaBrowser.Controller.Dto
         /// <param name="options">The options.</param>
         /// <param name="user">The user.</param>
         /// <param name="owner">The owner.</param>
+        /// <returns>The <see cref="IReadOnlyList{T}"/> of <see cref="BaseItemDto"/>.</returns>
         IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User user = null, BaseItem owner = null);
 
         /// <summary>
         /// Gets the item by name dto.
         /// </summary>
+        /// <param name="item">The item.</param>
+        /// <param name="options">The dto options.</param>
+        /// <param name="taggedItems">The list of tagged items.</param>
+        /// <param name="user">The user.</param>
+        /// <returns>The item dto.</returns>
         BaseItemDto GetItemByNameDto(BaseItem item, DtoOptions options, List<BaseItem> taggedItems, User user = null);
     }
 }
diff --git a/MediaBrowser.Controller/Entities/AggregateFolder.cs b/MediaBrowser.Controller/Entities/AggregateFolder.cs
index f1944a7d3..fe1bc62ab 100644
--- a/MediaBrowser.Controller/Entities/AggregateFolder.cs
+++ b/MediaBrowser.Controller/Entities/AggregateFolder.cs
@@ -22,6 +22,8 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class AggregateFolder : Folder
     {
+        private bool _requiresRefresh;
+
         public AggregateFolder()
         {
             PhysicalLocationsList = Array.Empty<string>();
@@ -85,7 +87,6 @@ namespace MediaBrowser.Controller.Entities
             }
         }
 
-        private bool _requiresRefresh;
         public override bool RequiresRefresh()
         {
             var changed = base.RequiresRefresh() || _requiresRefresh;
@@ -105,11 +106,11 @@ namespace MediaBrowser.Controller.Entities
             return changed;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             ClearCache();
 
-            var changed = base.BeforeMetadataRefresh(replaceAllMetdata) || _requiresRefresh;
+            var changed = base.BeforeMetadataRefresh(replaceAllMetadata) || _requiresRefresh;
             _requiresRefresh = false;
             return changed;
         }
@@ -154,11 +155,11 @@ namespace MediaBrowser.Controller.Entities
             return base.GetNonCachedChildren(directoryService).Concat(_virtualChildren);
         }
 
-        protected override async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             ClearCache();
 
-            await base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService)
+            await base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken)
                 .ConfigureAwait(false);
 
             ClearCache();
@@ -184,7 +185,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="id">The id.</param>
         /// <returns>BaseItem.</returns>
-        /// <exception cref="ArgumentNullException">id</exception>
+        /// <exception cref="ArgumentNullException">The id is empty.</exception>
         public BaseItem FindVirtualChild(Guid id)
         {
             if (id.Equals(Guid.Empty))
diff --git a/MediaBrowser.Controller/Entities/Audio/Audio.cs b/MediaBrowser.Controller/Entities/Audio/Audio.cs
index 4c2b7cb7c..576ab67a2 100644
--- a/MediaBrowser.Controller/Entities/Audio/Audio.cs
+++ b/MediaBrowser.Controller/Entities/Audio/Audio.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text.Json.Serialization;
 using Jellyfin.Data.Enums;
@@ -82,19 +83,19 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("0000 - ") : "")
-                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ") : "") + Name;
+            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty)
+                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty) + Name;
         }
 
         public override List<string> GetUserDataKeys()
         {
             var list = base.GetUserDataKeys();
 
-            var songKey = IndexNumber.HasValue ? IndexNumber.Value.ToString("0000") : string.Empty;
+            var songKey = IndexNumber.HasValue ? IndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) : string.Empty;
 
             if (ParentIndexNumber.HasValue)
             {
-                songKey = ParentIndexNumber.Value.ToString("0000") + "-" + songKey;
+                songKey = ParentIndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) + "-" + songKey;
             }
 
             songKey += Name;
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
index 6101d3016..c0cd81110 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
@@ -94,7 +94,7 @@ namespace MediaBrowser.Controller.Entities.Audio
             return base.IsSaveLocalMetadataEnabled();
         }
 
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             if (IsAccessedByName)
             {
@@ -102,7 +102,7 @@ namespace MediaBrowser.Controller.Entities.Audio
                 return Task.CompletedTask;
             }
 
-            return base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService);
+            return base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken);
         }
 
         public override List<string> GetUserDataKeys()
@@ -114,7 +114,7 @@ namespace MediaBrowser.Controller.Entities.Audio
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -208,9 +208,9 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (IsAccessedByName)
             {
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
index b07d47ffd..a682a2e58 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
@@ -38,7 +38,7 @@ namespace MediaBrowser.Controller.Entities.Audio
         public override bool IsDisplayedAsFolder => true;
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -106,9 +106,9 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index ca5213273..6137ddbf7 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -92,7 +92,8 @@ namespace MediaBrowser.Controller.Entities
         public const string ShortsFolderName = "shorts";
         public const string FeaturettesFolderName = "featurettes";
 
-        public static readonly string[] AllExtrasTypesFolderNames = {
+        public static readonly string[] AllExtrasTypesFolderNames =
+        {
             ExtrasFolderName,
             BehindTheScenesFolderName,
             DeletedScenesFolderName,
@@ -177,7 +178,7 @@ namespace MediaBrowser.Controller.Entities
         public virtual bool AlwaysScanInternalMetadataPath => false;
 
         /// <summary>
-        /// Gets a value indicating whether this instance is in mixed folder.
+        /// Gets or sets a value indicating whether this instance is in mixed folder.
         /// </summary>
         /// <value><c>true</c> if this instance is in mixed folder; otherwise, <c>false</c>.</value>
         [JsonIgnore]
@@ -244,7 +245,7 @@ namespace MediaBrowser.Controller.Entities
         public ProgramAudio? Audio { get; set; }
 
         /// <summary>
-        /// Return the id that should be used to key display prefs for this item.
+        /// Gets the id that should be used to key display prefs for this item.
         /// Default is based on the type for everything except actual generic folders.
         /// </summary>
         /// <value>The display prefs id.</value>
@@ -280,7 +281,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         [JsonIgnore]
@@ -305,8 +306,11 @@ namespace MediaBrowser.Controller.Entities
         public string ServiceName { get; set; }
 
         /// <summary>
-        /// If this content came from an external service, the id of the content on that service.
+        /// Gets or sets the external id.
         /// </summary>
+        /// <remarks>
+        /// If this content came from an external service, the id of the content on that service.
+        /// </remarks>
         [JsonIgnore]
         public string ExternalId { get; set; }
 
@@ -330,7 +334,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Gets or sets the type of the location.
+        /// Gets the type of the location.
         /// </summary>
         /// <value>The type of the location.</value>
         [JsonIgnore]
@@ -339,9 +343,9 @@ namespace MediaBrowser.Controller.Entities
             get
             {
                 // if (IsOffline)
-                //{
+                // {
                 //    return LocationType.Offline;
-                //}
+                // }
 
                 var path = Path;
                 if (string.IsNullOrEmpty(path))
@@ -449,8 +453,11 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is just a helper for convenience.
+        /// Gets the primary image path.
         /// </summary>
+        /// <remarks>
+        /// This is just a helper for convenience.
+        /// </remarks>
         /// <value>The primary image path.</value>
         [JsonIgnore]
         public string PrimaryImagePath => this.GetImagePath(ImageType.Primary);
@@ -541,7 +548,7 @@ namespace MediaBrowser.Controller.Entities
         public DateTime DateLastRefreshed { get; set; }
 
         /// <summary>
-        /// The logger.
+        /// Gets or sets the logger.
         /// </summary>
         public static ILogger<BaseItem> Logger { get; set; }
 
@@ -613,7 +620,11 @@ namespace MediaBrowser.Controller.Entities
         public string ForcedSortName
         {
             get => _forcedSortName;
-            set { _forcedSortName = value; _sortName = null; }
+            set
+            {
+                _forcedSortName = value;
+                _sortName = null;
+            }
         }
 
         private string _sortName;
@@ -621,7 +632,7 @@ namespace MediaBrowser.Controller.Entities
         private Guid[] _themeVideoIds;
 
         /// <summary>
-        /// Gets the name of the sort.
+        /// Gets or sets the name of the sort.
         /// </summary>
         /// <value>The name of the sort.</value>
         [JsonIgnore]
@@ -659,14 +670,12 @@ namespace MediaBrowser.Controller.Entities
         {
             if (SourceType == SourceType.Channel)
             {
-                return System.IO.Path.Combine(basePath, "channels", ChannelId.ToString("N", CultureInfo.InvariantCulture), Id.ToString("N", CultureInfo.InvariantCulture));
+                return System.IO.Path.Join(basePath, "channels", ChannelId.ToString("N", CultureInfo.InvariantCulture), Id.ToString("N", CultureInfo.InvariantCulture));
             }
 
             ReadOnlySpan<char> idString = Id.ToString("N", CultureInfo.InvariantCulture);
 
-            basePath = System.IO.Path.Combine(basePath, "library");
-
-            return System.IO.Path.Join(basePath, idString.Slice(0, 2), idString);
+            return System.IO.Path.Join(basePath, "library", idString.Slice(0, 2), idString);
         }
 
         /// <summary>
@@ -848,7 +857,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// When the item first debuted. For movies this could be premiere date, episodes would be first aired
+        /// Gets or sets the date that the item first debuted. For movies this could be premiere date, episodes would be first aired.
         /// </summary>
         /// <value>The premiere date.</value>
         [JsonIgnore]
@@ -945,7 +954,7 @@ namespace MediaBrowser.Controller.Entities
         public int? ProductionYear { get; set; }
 
         /// <summary>
-        /// If the item is part of a series, this is it's number in the series.
+        /// Gets or sets the index number. If the item is part of a series, this is it's number in the series.
         /// This could be episode number, album track number, etc.
         /// </summary>
         /// <value>The index number.</value>
@@ -953,7 +962,7 @@ namespace MediaBrowser.Controller.Entities
         public int? IndexNumber { get; set; }
 
         /// <summary>
-        /// For an episode this could be the season number, or for a song this could be the disc number.
+        /// Gets or sets the parent index number. For an episode this could be the season number, or for a song this could be the disc number.
         /// </summary>
         /// <value>The parent index number.</value>
         [JsonIgnore]
@@ -1017,9 +1026,9 @@ namespace MediaBrowser.Controller.Entities
             }
 
             // if (!user.IsParentalScheduleAllowed())
-            //{
+            // {
             //    return PlayAccess.None;
-            //}
+            // }
 
             return PlayAccess.Full;
         }
@@ -1251,7 +1260,7 @@ namespace MediaBrowser.Controller.Entities
 
             // Support plex/xbmc convention
             files.AddRange(fileSystemChildren
-                .Where(i => !i.IsDirectory && string.Equals(FileSystem.GetFileNameWithoutExtension(i), ThemeSongFilename, StringComparison.OrdinalIgnoreCase)));
+                .Where(i => !i.IsDirectory && System.IO.Path.GetFileNameWithoutExtension(i.FullName.AsSpan()).Equals(ThemeSongFilename, StringComparison.OrdinalIgnoreCase)));
 
             return LibraryManager.ResolvePaths(files, directoryService, null, new LibraryOptions())
                 .OfType<Audio.Audio>()
@@ -1312,14 +1321,16 @@ namespace MediaBrowser.Controller.Entities
         {
             var extras = new List<Video>();
 
-            var folders = fileSystemChildren.Where(i => i.IsDirectory).ToArray();
+            var libraryOptions = new LibraryOptions();
+            var folders = fileSystemChildren.Where(i => i.IsDirectory).ToList();
             foreach (var extraFolderName in AllExtrasTypesFolderNames)
             {
                 var files = folders
                     .Where(i => string.Equals(i.Name, extraFolderName, StringComparison.OrdinalIgnoreCase))
                     .SelectMany(i => FileSystem.GetFiles(i.FullName));
 
-                extras.AddRange(LibraryManager.ResolvePaths(files, directoryService, null, new LibraryOptions())
+                // Re-using the same instance of LibraryOptions since it looks like it's never being altered.
+                extras.AddRange(LibraryManager.ResolvePaths(files, directoryService, null, libraryOptions)
                     .OfType<Video>()
                     .Select(item =>
                     {
@@ -1330,7 +1341,7 @@ namespace MediaBrowser.Controller.Entities
                         }
 
                         // Use some hackery to get the extra type based on foldername
-                        item.ExtraType = Enum.TryParse(extraFolderName.Replace(" ", string.Empty), true, out ExtraType extraType)
+                        item.ExtraType = Enum.TryParse(extraFolderName.Replace(" ", string.Empty, StringComparison.Ordinal), true, out ExtraType extraType)
                             ? extraType
                             : Model.Entities.ExtraType.Unknown;
 
@@ -1420,10 +1431,10 @@ namespace MediaBrowser.Controller.Entities
         /// Refreshes owned items such as trailers, theme videos, special features, etc.
         /// Returns true or false indicating if changes were found.
         /// </summary>
-        /// <param name="options"></param>
-        /// <param name="fileSystemChildren"></param>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
+        /// <param name="options">The metadata refresh options.</param>
+        /// <param name="fileSystemChildren">The list of filesystem children.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns><c>true</c> if any items have changed, else <c>false</c>.</returns>
         protected virtual async Task<bool> RefreshedOwnedItems(MetadataRefreshOptions options, List<FileSystemMetadata> fileSystemChildren, CancellationToken cancellationToken)
         {
             var themeSongsChanged = false;
@@ -1765,7 +1776,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="user">The user.</param>
         /// <returns><c>true</c> if [is parental allowed] [the specified user]; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentNullException">user</exception>
+        /// <exception cref="ArgumentNullException">If user is null.</exception>
         public bool IsParentalAllowed(User user)
         {
             if (user == null)
@@ -1910,7 +1921,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="user">The user.</param>
         /// <returns><c>true</c> if the specified user is visible; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentNullException">user</exception>
+        /// <exception cref="ArgumentNullException"><paramref name="user" /> is <c>null</c>.</exception>
         public virtual bool IsVisible(User user)
         {
             if (user == null)
@@ -2208,7 +2219,7 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="type">The type.</param>
         /// <param name="imageIndex">Index of the image.</param>
         /// <returns><c>true</c> if the specified type has image; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentException">Backdrops should be accessed using Item.Backdrops</exception>
+        /// <exception cref="ArgumentException">Backdrops should be accessed using Item.Backdrops.</exception>
         public bool HasImage(ImageType type, int imageIndex)
         {
             return GetImageInfo(type, imageIndex) != null;
@@ -2316,7 +2327,7 @@ namespace MediaBrowser.Controller.Entities
                 .Where(i => i.IsLocalFile)
                 .Select(i => System.IO.Path.GetDirectoryName(i.Path))
                 .Distinct(StringComparer.OrdinalIgnoreCase)
-                .SelectMany(directoryService.GetFilePaths)
+                .SelectMany(path => directoryService.GetFilePaths(path))
                 .ToList();
 
             var deletedImages = ImageInfos
@@ -2337,9 +2348,8 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="imageType">Type of the image.</param>
         /// <param name="imageIndex">Index of the image.</param>
         /// <returns>System.String.</returns>
-        /// <exception cref="InvalidOperationException">
-        /// </exception>
-        /// <exception cref="ArgumentNullException">item</exception>
+        /// <exception cref="InvalidOperationException"> </exception>
+        /// <exception cref="ArgumentNullException">Item is null.</exception>
         public string GetImagePath(ImageType imageType, int imageIndex)
             => GetImageInfo(imageType, imageIndex)?.Path;
 
@@ -2426,7 +2436,15 @@ namespace MediaBrowser.Controller.Entities
                 throw new ArgumentException("No image info for chapter images");
             }
 
-            return ImageInfos.Where(i => i.Type == imageType);
+            // Yield return is more performant than LINQ Where on an Array
+            for (var i = 0; i < ImageInfos.Length; i++)
+            {
+                var imageInfo = ImageInfos[i];
+                if (imageInfo.Type == imageType)
+                {
+                    yield return imageInfo;
+                }
+            }
         }
 
         /// <summary>
@@ -2435,7 +2453,7 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="imageType">Type of the image.</param>
         /// <param name="images">The images.</param>
         /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns>
-        /// <exception cref="ArgumentException">Cannot call AddImages with chapter images</exception>
+        /// <exception cref="ArgumentException">Cannot call AddImages with chapter images.</exception>
         public bool AddImages(ImageType imageType, List<FileSystemMetadata> images)
         {
             if (imageType == ImageType.Chapter)
@@ -2458,7 +2476,7 @@ namespace MediaBrowser.Controller.Entities
                 }
 
                 var existing = existingImages
-                    .FirstOrDefault(i => string.Equals(i.Path, newImage.FullName, StringComparison.OrdinalIgnoreCase));
+                    .Find(i => string.Equals(i.Path, newImage.FullName, StringComparison.OrdinalIgnoreCase));
 
                 if (existing == null)
                 {
@@ -2489,8 +2507,7 @@ namespace MediaBrowser.Controller.Entities
                 var newImagePaths = images.Select(i => i.FullName).ToList();
 
                 var deleted = existingImages
-                    .Where(i => i.IsLocalFile && !newImagePaths.Contains(i.Path, StringComparer.OrdinalIgnoreCase) && !File.Exists(i.Path))
-                    .ToList();
+                    .FindAll(i => i.IsLocalFile && !newImagePaths.Contains(i.Path.AsSpan(), StringComparison.OrdinalIgnoreCase) && !File.Exists(i.Path));
 
                 if (deleted.Count > 0)
                 {
@@ -2519,10 +2536,11 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Gets the file system path to delete when the item is to be deleted.
         /// </summary>
-        /// <returns></returns>
+        /// <returns>The metadata for the deleted paths.</returns>
         public virtual IEnumerable<FileSystemMetadata> GetDeletePaths()
         {
-            return new[] {
+            return new[]
+            {
                 new FileSystemMetadata
                 {
                     FullName = Path,
@@ -2629,6 +2647,7 @@ namespace MediaBrowser.Controller.Entities
                 MetadataCountryCode = GetPreferredMetadataCountryCode(),
                 MetadataLanguage = GetPreferredMetadataLanguage(),
                 Name = GetNameForMetadataLookup(),
+                OriginalTitle = OriginalTitle,
                 ProviderIds = ProviderIds,
                 IndexNumber = IndexNumber,
                 ParentIndexNumber = ParentIndexNumber,
@@ -2645,7 +2664,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public virtual bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public virtual bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             _sortName = null;
 
@@ -2769,11 +2790,11 @@ namespace MediaBrowser.Controller.Entities
 
             // var parentId = Id;
             // if (!video.IsOwnedItem || video.ParentId != parentId)
-            //{
+            // {
             //    video.IsOwnedItem = true;
             //    video.ParentId = parentId;
             //    newOptions.ForceSave = true;
-            //}
+            // }
 
             if (video == null)
             {
@@ -2880,7 +2901,7 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Updates the official rating based on content and returns true or false indicating if it changed.
         /// </summary>
-        /// <returns></returns>
+        /// <returns><c>true</c> if the rating was updated; otherwise <c>false</c>.</returns>
         public bool UpdateRatingToItems(IList<BaseItem> children)
         {
             var currentOfficialRating = OfficialRating;
@@ -2896,7 +2917,9 @@ namespace MediaBrowser.Controller.Entities
 
             OfficialRating = ratings.FirstOrDefault() ?? currentOfficialRating;
 
-            return !string.Equals(currentOfficialRating ?? string.Empty, OfficialRating ?? string.Empty,
+            return !string.Equals(
+                currentOfficialRating ?? string.Empty,
+                OfficialRating ?? string.Empty,
                 StringComparison.OrdinalIgnoreCase);
         }
 
@@ -2993,7 +3016,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <inheritdoc />
-        public bool Equals(BaseItem item) => Object.Equals(Id, item?.Id);
+        public bool Equals(BaseItem other) => object.Equals(Id, other?.Id);
 
         /// <inheritdoc />
         public override int GetHashCode() => HashCode.Combine(Id);
diff --git a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
index c39b18891..89ad392a4 100644
--- a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
+++ b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
@@ -1,6 +1,3 @@
-#nullable disable
-
-#nullable enable
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Book.cs b/MediaBrowser.Controller/Entities/Book.cs
index 3d0370248..d75beb06d 100644
--- a/MediaBrowser.Controller/Entities/Book.cs
+++ b/MediaBrowser.Controller/Entities/Book.cs
@@ -12,6 +12,11 @@ namespace MediaBrowser.Controller.Entities
 {
     public class Book : BaseItem, IHasLookupInfo<BookInfo>, IHasSeries
     {
+        public Book()
+        {
+            this.RunTimeTicks = TimeSpan.TicksPerSecond;
+        }
+
         [JsonIgnore]
         public override string MediaType => Model.Entities.MediaType.Book;
 
@@ -28,11 +33,6 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public Guid SeriesId { get; set; }
 
-        public Book()
-        {
-            this.RunTimeTicks = TimeSpan.TicksPerSecond;
-        }
-
         public string FindSeriesSortName()
         {
             return SeriesName;
diff --git a/MediaBrowser.Controller/Entities/CollectionFolder.cs b/MediaBrowser.Controller/Entities/CollectionFolder.cs
index a86da29ce..4a721ca44 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -29,30 +29,45 @@ namespace MediaBrowser.Controller.Entities
     public class CollectionFolder : Folder, ICollectionFolder
     {
         private static readonly JsonSerializerOptions _jsonOptions = JsonDefaults.Options;
-        public static IXmlSerializer XmlSerializer { get; set; }
-
-        public static IServerApplicationHost ApplicationHost { get; set; }
+        private static readonly Dictionary<string, LibraryOptions> _libraryOptions = new Dictionary<string, LibraryOptions>();
+        private bool _requiresRefresh;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CollectionFolder"/> class.
+        /// </summary>
         public CollectionFolder()
         {
             PhysicalLocationsList = Array.Empty<string>();
             PhysicalFolderIds = Array.Empty<Guid>();
         }
 
+        public static IXmlSerializer XmlSerializer { get; set; }
+
+        public static IServerApplicationHost ApplicationHost { get; set; }
+
         [JsonIgnore]
         public override bool SupportsPlayedStatus => false;
 
         [JsonIgnore]
         public override bool SupportsInheritedParentImages => false;
 
+        public string CollectionType { get; set; }
+
+        /// <summary>
+        /// Gets the item's children.
+        /// </summary>
+        /// <remarks>
+        /// Our children are actually just references to the ones in the physical root...
+        /// </remarks>
+        /// <value>The actual children.</value>
+        [JsonIgnore]
+        public override IEnumerable<BaseItem> Children => GetActualChildren();
+
         public override bool CanDelete()
         {
             return false;
         }
 
-        public string CollectionType { get; set; }
-
-        private static readonly Dictionary<string, LibraryOptions> LibraryOptions = new Dictionary<string, LibraryOptions>();
         public LibraryOptions GetLibraryOptions()
         {
             return GetLibraryOptions(Path);
@@ -106,12 +121,12 @@ namespace MediaBrowser.Controller.Entities
 
         public static LibraryOptions GetLibraryOptions(string path)
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                if (!LibraryOptions.TryGetValue(path, out var options))
+                if (!_libraryOptions.TryGetValue(path, out var options))
                 {
                     options = LoadLibraryOptions(path);
-                    LibraryOptions[path] = options;
+                    _libraryOptions[path] = options;
                 }
 
                 return options;
@@ -120,9 +135,9 @@ namespace MediaBrowser.Controller.Entities
 
         public static void SaveLibraryOptions(string path, LibraryOptions options)
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                LibraryOptions[path] = options;
+                _libraryOptions[path] = options;
 
                 var clone = JsonSerializer.Deserialize<LibraryOptions>(JsonSerializer.SerializeToUtf8Bytes(options, _jsonOptions), _jsonOptions);
                 foreach (var mediaPath in clone.PathInfos)
@@ -139,15 +154,18 @@ namespace MediaBrowser.Controller.Entities
 
         public static void OnCollectionFolderChange()
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                LibraryOptions.Clear();
+                _libraryOptions.Clear();
             }
         }
 
         /// <summary>
-        /// Allow different display preferences for each collection folder.
+        /// Gets the display preferences id.
         /// </summary>
+        /// <remarks>
+        /// Allow different display preferences for each collection folder.
+        /// </remarks>
         /// <value>The display prefs id.</value>
         [JsonIgnore]
         public override Guid DisplayPreferencesId => Id;
@@ -155,21 +173,20 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public override string[] PhysicalLocations => PhysicalLocationsList;
 
+        public string[] PhysicalLocationsList { get; set; }
+
+        public Guid[] PhysicalFolderIds { get; set; }
+
         public override bool IsSaveLocalMetadataEnabled()
         {
             return true;
         }
 
-        public string[] PhysicalLocationsList { get; set; }
-
-        public Guid[] PhysicalFolderIds { get; set; }
-
         protected override FileSystemMetadata[] GetFileSystemChildren(IDirectoryService directoryService)
         {
             return CreateResolveArgs(directoryService, true).FileSystemChildren;
         }
 
-        private bool _requiresRefresh;
         public override bool RequiresRefresh()
         {
             var changed = base.RequiresRefresh() || _requiresRefresh;
@@ -201,9 +218,9 @@ namespace MediaBrowser.Controller.Entities
             return changed;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var changed = base.BeforeMetadataRefresh(replaceAllMetdata) || _requiresRefresh;
+            var changed = base.BeforeMetadataRefresh(replaceAllMetadata) || _requiresRefresh;
             _requiresRefresh = false;
             return changed;
         }
@@ -298,27 +315,20 @@ namespace MediaBrowser.Controller.Entities
 
         /// <summary>
         /// Compare our current children (presumably just read from the repo) with the current state of the file system and adjust for any changes
-        /// ***Currently does not contain logic to maintain items that are unavailable in the file system***
+        /// ***Currently does not contain logic to maintain items that are unavailable in the file system***.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
         /// <param name="refreshChildMetadata">if set to <c>true</c> [refresh child metadata].</param>
         /// <param name="refreshOptions">The refresh options.</param>
         /// <param name="directoryService">The directory service.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             return Task.CompletedTask;
         }
 
-        /// <summary>
-        /// Our children are actually just references to the ones in the physical root...
-        /// </summary>
-        /// <value>The actual children.</value>
-        [JsonIgnore]
-        public override IEnumerable<BaseItem> Children => GetActualChildren();
-
         public IEnumerable<BaseItem> GetActualChildren()
         {
             return GetPhysicalFolders(true).SelectMany(c => c.Children);
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index a59f5c6e4..541747422 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -37,6 +37,11 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class Folder : BaseItem
     {
+        public Folder()
+        {
+            LinkedChildren = Array.Empty<LinkedChild>();
+        }
+
         public static IUserViewManager UserViewManager { get; set; }
 
         /// <summary>
@@ -50,11 +55,6 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public DateTime? DateLastMediaAdded { get; set; }
 
-        public Folder()
-        {
-            LinkedChildren = Array.Empty<LinkedChild>();
-        }
-
         [JsonIgnore]
         public override bool SupportsThemeMedia => true;
 
@@ -86,6 +86,85 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public virtual bool SupportsDateLastMediaAdded => false;
 
+        [JsonIgnore]
+        public override string FileNameWithoutExtension
+        {
+            get
+            {
+                if (IsFileProtocol)
+                {
+                    return System.IO.Path.GetFileName(Path);
+                }
+
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Gets the actual children.
+        /// </summary>
+        /// <value>The actual children.</value>
+        [JsonIgnore]
+        public virtual IEnumerable<BaseItem> Children => LoadChildren();
+
+        /// <summary>
+        /// Gets thread-safe access to all recursive children of this folder - without regard to user.
+        /// </summary>
+        /// <value>The recursive children.</value>
+        [JsonIgnore]
+        public IEnumerable<BaseItem> RecursiveChildren => GetRecursiveChildren();
+
+        [JsonIgnore]
+        protected virtual bool SupportsShortcutChildren => false;
+
+        protected virtual bool FilterLinkedChildrenPerUser => false;
+
+        [JsonIgnore]
+        protected override bool SupportsOwnedItems => base.SupportsOwnedItems || SupportsShortcutChildren;
+
+        [JsonIgnore]
+        public virtual bool SupportsUserDataFromChildren
+        {
+            get
+            {
+                // These are just far too slow.
+                if (this is ICollectionFolder)
+                {
+                    return false;
+                }
+
+                if (this is UserView)
+                {
+                    return false;
+                }
+
+                if (this is UserRootFolder)
+                {
+                    return false;
+                }
+
+                if (this is Channel)
+                {
+                    return false;
+                }
+
+                if (SourceType != SourceType.Library)
+                {
+                    return false;
+                }
+
+                if (this is IItemByName)
+                {
+                    if (this is not IHasDualAccess hasDualAccess || hasDualAccess.IsAccessedByName)
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
+        }
+
         public override bool CanDelete()
         {
             if (IsRoot)
@@ -108,20 +187,6 @@ namespace MediaBrowser.Controller.Entities
             return baseResult;
         }
 
-        [JsonIgnore]
-        public override string FileNameWithoutExtension
-        {
-            get
-            {
-                if (IsFileProtocol)
-                {
-                    return System.IO.Path.GetFileName(Path);
-                }
-
-                return null;
-            }
-        }
-
         protected override bool IsAllowTagFilterEnforced()
         {
             if (this is ICollectionFolder)
@@ -137,16 +202,12 @@ namespace MediaBrowser.Controller.Entities
             return true;
         }
 
-        [JsonIgnore]
-        protected virtual bool SupportsShortcutChildren => false;
-
         /// <summary>
         /// Adds the child.
         /// </summary>
         /// <param name="item">The item.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task.</returns>
-        /// <exception cref="InvalidOperationException">Unable to add  + item.Name</exception>
+        /// <exception cref="InvalidOperationException">Unable to add  + item.Name.</exception>
         public void AddChild(BaseItem item, CancellationToken cancellationToken)
         {
             item.SetParent(this);
@@ -169,20 +230,6 @@ namespace MediaBrowser.Controller.Entities
             LibraryManager.CreateItem(item, this);
         }
 
-        /// <summary>
-        /// Gets the actual children.
-        /// </summary>
-        /// <value>The actual children.</value>
-        [JsonIgnore]
-        public virtual IEnumerable<BaseItem> Children => LoadChildren();
-
-        /// <summary>
-        /// thread-safe access to all recursive children of this folder - without regard to user.
-        /// </summary>
-        /// <value>The recursive children.</value>
-        [JsonIgnore]
-        public IEnumerable<BaseItem> RecursiveChildren => GetRecursiveChildren();
-
         public override bool IsVisible(User user)
         {
             if (this is ICollectionFolder && !(this is BasePluginFolder))
@@ -226,20 +273,20 @@ namespace MediaBrowser.Controller.Entities
 
         public Task ValidateChildren(IProgress<double> progress, CancellationToken cancellationToken)
         {
-            return ValidateChildren(progress, cancellationToken, new MetadataRefreshOptions(new DirectoryService(FileSystem)));
+            return ValidateChildren(progress, new MetadataRefreshOptions(new DirectoryService(FileSystem)), cancellationToken: cancellationToken);
         }
 
         /// <summary>
         /// Validates that the children of the folder still exist.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="metadataRefreshOptions">The metadata refresh options.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        public Task ValidateChildren(IProgress<double> progress, CancellationToken cancellationToken, MetadataRefreshOptions metadataRefreshOptions, bool recursive = true)
+        public Task ValidateChildren(IProgress<double> progress, MetadataRefreshOptions metadataRefreshOptions, bool recursive = true,  CancellationToken cancellationToken = default)
         {
-            return ValidateChildrenInternal(progress, cancellationToken, recursive, true, metadataRefreshOptions, metadataRefreshOptions.DirectoryService);
+            return ValidateChildrenInternal(progress, recursive, true, metadataRefreshOptions, metadataRefreshOptions.DirectoryService, cancellationToken);
         }
 
         private Dictionary<Guid, BaseItem> GetActualChildrenDictionary()
@@ -279,13 +326,13 @@ namespace MediaBrowser.Controller.Entities
         /// Validates the children internal.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
         /// <param name="refreshChildMetadata">if set to <c>true</c> [refresh child metadata].</param>
         /// <param name="refreshOptions">The refresh options.</param>
         /// <param name="directoryService">The directory service.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        protected virtual async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected virtual async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             if (recursive)
             {
@@ -294,7 +341,7 @@ namespace MediaBrowser.Controller.Entities
 
             try
             {
-                await ValidateChildrenInternal2(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService).ConfigureAwait(false);
+                await ValidateChildrenInternal2(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken).ConfigureAwait(false);
             }
             finally
             {
@@ -305,7 +352,7 @@ namespace MediaBrowser.Controller.Entities
             }
         }
 
-        private async Task ValidateChildrenInternal2(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        private async Task ValidateChildrenInternal2(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             cancellationToken.ThrowIfCancellationRequested();
 
@@ -527,7 +574,7 @@ namespace MediaBrowser.Controller.Entities
         private Task ValidateSubFolders(IList<Folder> children, IDirectoryService directoryService, IProgress<double> progress, CancellationToken cancellationToken)
         {
             return RunTasks(
-                (folder, innerProgress) => folder.ValidateChildrenInternal(innerProgress, cancellationToken, true, false, null, directoryService),
+                (folder, innerProgress) => folder.ValidateChildrenInternal(innerProgress, true, false, null, directoryService, cancellationToken),
                 children,
                 progress,
                 cancellationToken);
@@ -940,7 +987,13 @@ namespace MediaBrowser.Controller.Entities
             }
             else
             {
-                items = GetChildren(user, true).Where(filter);
+                // need to pass this param to the children.
+                var childQuery = new InternalItemsQuery
+                {
+                    DisplayAlbumFolders = query.DisplayAlbumFolders
+                };
+
+                items = GetChildren(user, true, childQuery).Where(filter);
             }
 
             return PostFilterAndSort(items, query, true);
@@ -965,7 +1018,7 @@ namespace MediaBrowser.Controller.Entities
 
             if (!string.IsNullOrEmpty(query.NameStartsWith))
             {
-                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.OrdinalIgnoreCase));
+                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.CurrentCultureIgnoreCase));
             }
 
             if (!string.IsNullOrEmpty(query.NameLessThan))
@@ -1276,10 +1329,23 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Adds the children to list.
         /// </summary>
-        /// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
         private void AddChildren(User user, bool includeLinkedChildren, Dictionary<Guid, BaseItem> result, bool recursive, InternalItemsQuery query)
         {
-            foreach (var child in GetEligibleChildrenForRecursiveChildren(user))
+            // If Query.AlbumFolders is set, then enforce the format as per the db in that it permits sub-folders in music albums.
+            IEnumerable<BaseItem> children = null;
+            if ((query?.DisplayAlbumFolders ?? false) && (this is MusicAlbum))
+            {
+                children = Children;
+                query = null;
+            }
+
+            // If there are not sub-folders, proceed as normal.
+            if (children == null)
+            {
+                children = GetEligibleChildrenForRecursiveChildren(user);
+            }
+
+            foreach (var child in children)
             {
                 bool? isVisibleToUser = null;
 
@@ -1428,8 +1494,6 @@ namespace MediaBrowser.Controller.Entities
             return list;
         }
 
-        protected virtual bool FilterLinkedChildrenPerUser => false;
-
         public bool ContainsLinkedChildByItemId(Guid itemId)
         {
             var linkedChildren = LinkedChildren;
@@ -1530,9 +1594,6 @@ namespace MediaBrowser.Controller.Entities
                 .Where(i => i.Item2 != null);
         }
 
-        [JsonIgnore]
-        protected override bool SupportsOwnedItems => base.SupportsOwnedItems || SupportsShortcutChildren;
-
         protected override async Task<bool> RefreshedOwnedItems(MetadataRefreshOptions options, List<FileSystemMetadata> fileSystemChildren, CancellationToken cancellationToken)
         {
             var changesFound = false;
@@ -1553,7 +1614,8 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Refreshes the linked children.
         /// </summary>
-        /// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
+        /// <param name="fileSystemChildren">The enumerable of file system metadata.</param>
+        /// <returns><c>true</c> if the linked children were updated, <c>false</c> otherwise.</returns>
         protected virtual bool RefreshLinkedChildren(IEnumerable<FileSystemMetadata> fileSystemChildren)
         {
             if (SupportsShortcutChildren)
@@ -1696,51 +1758,6 @@ namespace MediaBrowser.Controller.Entities
             return !IsPlayed(user);
         }
 
-        [JsonIgnore]
-        public virtual bool SupportsUserDataFromChildren
-        {
-            get
-            {
-                // These are just far too slow.
-                if (this is ICollectionFolder)
-                {
-                    return false;
-                }
-
-                if (this is UserView)
-                {
-                    return false;
-                }
-
-                if (this is UserRootFolder)
-                {
-                    return false;
-                }
-
-                if (this is Channel)
-                {
-                    return false;
-                }
-
-                if (SourceType != SourceType.Library)
-                {
-                    return false;
-                }
-
-                var iItemByName = this as IItemByName;
-                if (iItemByName != null)
-                {
-                    var hasDualAccess = this as IHasDualAccess;
-                    if (hasDualAccess == null || hasDualAccess.IsAccessedByName)
-                    {
-                        return false;
-                    }
-                }
-
-                return true;
-            }
-        }
-
         public override void FillUserDataDtoValues(UserItemDataDto dto, UserItemData userData, BaseItemDto itemDto, User user, DtoOptions fields)
         {
             if (!SupportsUserDataFromChildren)
diff --git a/MediaBrowser.Controller/Entities/Genre.cs b/MediaBrowser.Controller/Entities/Genre.cs
index 7987f38a0..b80a5be3b 100644
--- a/MediaBrowser.Controller/Entities/Genre.cs
+++ b/MediaBrowser.Controller/Entities/Genre.cs
@@ -16,6 +16,23 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class Genre : BaseItem, IItemByName
     {
+        /// <summary>
+        /// Gets the folder containing the item.
+        /// If the item is a folder, it returns the folder itself.
+        /// </summary>
+        /// <value>The containing folder path.</value>
+        [JsonIgnore]
+        public override string ContainingFolderPath => Path;
+
+        [JsonIgnore]
+        public override bool IsDisplayedAsFolder => true;
+
+        [JsonIgnore]
+        public override bool SupportsAncestors => false;
+
+        [JsonIgnore]
+        public override bool SupportsPeople => false;
+
         public override List<string> GetUserDataKeys()
         {
             var list = base.GetUserDataKeys();
@@ -34,20 +51,6 @@ namespace MediaBrowser.Controller.Entities
             return 1;
         }
 
-        /// <summary>
-        /// Returns the folder containing the item.
-        /// If the item is a folder, it returns the folder itself.
-        /// </summary>
-        /// <value>The containing folder path.</value>
-        [JsonIgnore]
-        public override string ContainingFolderPath => Path;
-
-        [JsonIgnore]
-        public override bool IsDisplayedAsFolder => true;
-
-        [JsonIgnore]
-        public override bool SupportsAncestors => false;
-
         public override bool IsSaveLocalMetadataEnabled()
         {
             return true;
@@ -72,9 +75,6 @@ namespace MediaBrowser.Controller.Entities
             return LibraryManager.GetItemList(query);
         }
 
-        [JsonIgnore]
-        public override bool SupportsPeople => false;
-
         public static string GetPath(string name)
         {
             return GetPath(name, true);
@@ -108,11 +108,13 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is called before any metadata refresh and returns true or false indicating if changes were made.
+        /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/IHasScreenshots.cs b/MediaBrowser.Controller/Entities/IHasScreenshots.cs
index b027a0cb1..ae01c223e 100644
--- a/MediaBrowser.Controller/Entities/IHasScreenshots.cs
+++ b/MediaBrowser.Controller/Entities/IHasScreenshots.cs
@@ -1,7 +1,7 @@
 namespace MediaBrowser.Controller.Entities
 {
     /// <summary>
-    /// Interface IHasScreenshots.
+    /// The item has screenshots.
     /// </summary>
     public interface IHasScreenshots
     {
diff --git a/MediaBrowser.Controller/Entities/IHasSeries.cs b/MediaBrowser.Controller/Entities/IHasSeries.cs
index 64d769d5b..5f774bbde 100644
--- a/MediaBrowser.Controller/Entities/IHasSeries.cs
+++ b/MediaBrowser.Controller/Entities/IHasSeries.cs
@@ -9,7 +9,7 @@ namespace MediaBrowser.Controller.Entities
     public interface IHasSeries
     {
         /// <summary>
-        /// Gets the name of the series.
+        /// Gets or sets the name of the series.
         /// </summary>
         /// <value>The name of the series.</value>
         string SeriesName { get; set; }
diff --git a/MediaBrowser.Controller/Entities/IHasShares.cs b/MediaBrowser.Controller/Entities/IHasShares.cs
new file mode 100644
index 000000000..bdde744a3
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/IHasShares.cs
@@ -0,0 +1,11 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+namespace MediaBrowser.Controller.Entities
+{
+    public interface IHasShares
+    {
+        Share[] Shares { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
index c06021029..ebaf5506d 100644
--- a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;
@@ -20,9 +18,9 @@ namespace MediaBrowser.Controller.Entities
 
         public int? Limit { get; set; }
 
-        public User User { get; set; }
+        public User? User { get; set; }
 
-        public BaseItem SimilarTo { get; set; }
+        public BaseItem? SimilarTo { get; set; }
 
         public bool? IsFolder { get; set; }
 
@@ -58,23 +56,23 @@ namespace MediaBrowser.Controller.Entities
 
         public bool? CollapseBoxSetItems { get; set; }
 
-        public string NameStartsWithOrGreater { get; set; }
+        public string? NameStartsWithOrGreater { get; set; }
 
-        public string NameStartsWith { get; set; }
+        public string? NameStartsWith { get; set; }
 
-        public string NameLessThan { get; set; }
+        public string? NameLessThan { get; set; }
 
-        public string NameContains { get; set; }
+        public string? NameContains { get; set; }
 
-        public string MinSortName { get; set; }
+        public string? MinSortName { get; set; }
 
-        public string PresentationUniqueKey { get; set; }
+        public string? PresentationUniqueKey { get; set; }
 
-        public string Path { get; set; }
+        public string? Path { get; set; }
 
-        public string Name { get; set; }
+        public string? Name { get; set; }
 
-        public string Person { get; set; }
+        public string? Person { get; set; }
 
         public Guid[] PersonIds { get; set; }
 
@@ -82,7 +80,7 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid[] ExcludeItemIds { get; set; }
 
-        public string AdjacentTo { get; set; }
+        public string? AdjacentTo { get; set; }
 
         public string[] PersonTypes { get; set; }
 
@@ -182,13 +180,13 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid ParentId { get; set; }
 
-        public string ParentType { get; set; }
+        public string? ParentType { get; set; }
 
         public Guid[] AncestorIds { get; set; }
 
         public Guid[] TopParentIds { get; set; }
 
-        public BaseItem Parent
+        public BaseItem? Parent
         {
             set
             {
@@ -213,9 +211,9 @@ namespace MediaBrowser.Controller.Entities
 
         public SeriesStatus[] SeriesStatuses { get; set; }
 
-        public string ExternalSeriesId { get; set; }
+        public string? ExternalSeriesId { get; set; }
 
-        public string ExternalId { get; set; }
+        public string? ExternalId { get; set; }
 
         public Guid[] AlbumIds { get; set; }
 
@@ -223,9 +221,9 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid[] ExcludeArtistIds { get; set; }
 
-        public string AncestorWithPresentationUniqueKey { get; set; }
+        public string? AncestorWithPresentationUniqueKey { get; set; }
 
-        public string SeriesPresentationUniqueKey { get; set; }
+        public string? SeriesPresentationUniqueKey { get; set; }
 
         public bool GroupByPresentationUniqueKey { get; set; }
 
@@ -235,7 +233,7 @@ namespace MediaBrowser.Controller.Entities
 
         public bool ForceDirect { get; set; }
 
-        public Dictionary<string, string> ExcludeProviderIds { get; set; }
+        public Dictionary<string, string>? ExcludeProviderIds { get; set; }
 
         public bool EnableGroupByMetadataKey { get; set; }
 
@@ -253,13 +251,13 @@ namespace MediaBrowser.Controller.Entities
 
         public int MinSimilarityScore { get; set; }
 
-        public string HasNoAudioTrackWithLanguage { get; set; }
+        public string? HasNoAudioTrackWithLanguage { get; set; }
 
-        public string HasNoInternalSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoInternalSubtitleTrackWithLanguage { get; set; }
 
-        public string HasNoExternalSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoExternalSubtitleTrackWithLanguage { get; set; }
 
-        public string HasNoSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoSubtitleTrackWithLanguage { get; set; }
 
         public bool? IsDeadArtist { get; set; }
 
@@ -267,6 +265,11 @@ namespace MediaBrowser.Controller.Entities
 
         public bool? IsDeadPerson { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether album sub-folders should be returned if they exist.
+        /// </summary>
+        public bool? DisplayAlbumFolders { get; set; }
+
         public InternalItemsQuery()
         {
             AlbumArtistIds = Array.Empty<Guid>();
@@ -283,12 +286,10 @@ namespace MediaBrowser.Controller.Entities
             ExcludeInheritedTags = Array.Empty<string>();
             ExcludeItemIds = Array.Empty<Guid>();
             ExcludeItemTypes = Array.Empty<string>();
-            ExcludeProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             ExcludeTags = Array.Empty<string>();
             GenreIds = Array.Empty<Guid>();
             Genres = Array.Empty<string>();
             GroupByPresentationUniqueKey = true;
-            HasAnyProviderId = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             ImageTypes = Array.Empty<ImageType>();
             IncludeItemTypes = Array.Empty<string>();
             ItemIds = Array.Empty<Guid>();
@@ -309,32 +310,33 @@ namespace MediaBrowser.Controller.Entities
             Years = Array.Empty<int>();
         }
 
-        public InternalItemsQuery(User user)
+        public InternalItemsQuery(User? user)
             : this()
         {
-            SetUser(user);
+            if (user != null)
+            {
+                SetUser(user);
+            }
         }
 
         public void SetUser(User user)
         {
-            if (user != null)
-            {
-                MaxParentalRating = user.MaxParentalAgeRating;
+            MaxParentalRating = user.MaxParentalAgeRating;
 
-                if (MaxParentalRating.HasValue)
-                {
-                    BlockUnratedItems = user.GetPreference(PreferenceKind.BlockUnratedItems)
-                        .Where(i => i != UnratedItem.Other.ToString())
-                        .Select(e => Enum.Parse<UnratedItem>(e, true)).ToArray();
-                }
+            if (MaxParentalRating.HasValue)
+            {
+                string other = UnratedItem.Other.ToString();
+                BlockUnratedItems = user.GetPreference(PreferenceKind.BlockUnratedItems)
+                    .Where(i => i != other)
+                    .Select(e => Enum.Parse<UnratedItem>(e, true)).ToArray();
+            }
 
-                ExcludeInheritedTags = user.GetPreference(PreferenceKind.BlockedTags);
+            ExcludeInheritedTags = user.GetPreference(PreferenceKind.BlockedTags);
 
-                User = user;
-            }
+            User = user;
         }
 
-        public Dictionary<string, string> HasAnyProviderId { get; set; }
+        public Dictionary<string, string>? HasAnyProviderId { get; set; }
 
         public Guid[] AlbumArtistIds { get; set; }
 
@@ -356,8 +358,8 @@ namespace MediaBrowser.Controller.Entities
 
         public int? MinWidth { get; set; }
 
-        public string SearchTerm { get; set; }
+        public string? SearchTerm { get; set; }
 
-        public string SeriesTimerId { get; set; }
+        public string? SeriesTimerId { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
index b2d6a4609..3e1d89274 100644
--- a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
@@ -3,12 +3,24 @@
 #pragma warning disable CS1591
 
 using System;
+using System.Collections.Generic;
 using Jellyfin.Data.Entities;
 
 namespace MediaBrowser.Controller.Entities
 {
     public class InternalPeopleQuery
     {
+        public InternalPeopleQuery()
+         : this(Array.Empty<string>(), Array.Empty<string>())
+        {
+        }
+
+        public InternalPeopleQuery(IReadOnlyList<string> personTypes, IReadOnlyList<string> excludePersonTypes)
+        {
+            PersonTypes = personTypes;
+            ExcludePersonTypes = excludePersonTypes;
+        }
+
         /// <summary>
         /// Gets or sets the maximum number of items the query should return.
         /// </summary>
@@ -16,9 +28,9 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid ItemId { get; set; }
 
-        public string[] PersonTypes { get; set; }
+        public IReadOnlyList<string> PersonTypes { get; }
 
-        public string[] ExcludePersonTypes { get; set; }
+        public IReadOnlyList<string> ExcludePersonTypes { get; }
 
         public int? MaxListOrder { get; set; }
 
@@ -29,11 +41,5 @@ namespace MediaBrowser.Controller.Entities
         public User User { get; set; }
 
         public bool? IsFavorite { get; set; }
-
-        public InternalPeopleQuery()
-        {
-            PersonTypes = Array.Empty<string>();
-            ExcludePersonTypes = Array.Empty<string>();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChild.cs b/MediaBrowser.Controller/Entities/LinkedChild.cs
index 01c0a9339..fd5fef3dc 100644
--- a/MediaBrowser.Controller/Entities/LinkedChild.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChild.cs
@@ -3,15 +3,18 @@
 #pragma warning disable CS1591
 
 using System;
-using System.Collections.Generic;
 using System.Globalization;
 using System.Text.Json.Serialization;
-using MediaBrowser.Model.IO;
 
 namespace MediaBrowser.Controller.Entities
 {
     public class LinkedChild
     {
+        public LinkedChild()
+        {
+            Id = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
+        }
+
         public string Path { get; set; }
 
         public LinkedChildType Type { get; set; }
@@ -22,7 +25,7 @@ namespace MediaBrowser.Controller.Entities
         public string Id { get; set; }
 
         /// <summary>
-        /// Serves as a cache.
+        /// Gets or sets the linked item id.
         /// </summary>
         public Guid? ItemId { get; set; }
 
@@ -41,41 +44,5 @@ namespace MediaBrowser.Controller.Entities
 
             return child;
         }
-
-        public LinkedChild()
-        {
-            Id = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
-        }
-    }
-
-    public enum LinkedChildType
-    {
-        Manual = 0,
-        Shortcut = 1
-    }
-
-    public class LinkedChildComparer : IEqualityComparer<LinkedChild>
-    {
-        private readonly IFileSystem _fileSystem;
-
-        public LinkedChildComparer(IFileSystem fileSystem)
-        {
-            _fileSystem = fileSystem;
-        }
-
-        public bool Equals(LinkedChild x, LinkedChild y)
-        {
-            if (x.Type == y.Type)
-            {
-                return _fileSystem.AreEqual(x.Path, y.Path);
-            }
-
-            return false;
-        }
-
-        public int GetHashCode(LinkedChild obj)
-        {
-            return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
new file mode 100644
index 000000000..4e58e2942
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
@@ -0,0 +1,35 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System;
+using System.Collections.Generic;
+using MediaBrowser.Model.IO;
+
+namespace MediaBrowser.Controller.Entities
+{
+    public class LinkedChildComparer : IEqualityComparer<LinkedChild>
+    {
+        private readonly IFileSystem _fileSystem;
+
+        public LinkedChildComparer(IFileSystem fileSystem)
+        {
+            _fileSystem = fileSystem;
+        }
+
+        public bool Equals(LinkedChild x, LinkedChild y)
+        {
+            if (x.Type == y.Type)
+            {
+                return _fileSystem.AreEqual(x.Path, y.Path);
+            }
+
+            return false;
+        }
+
+        public int GetHashCode(LinkedChild obj)
+        {
+            return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode(StringComparison.Ordinal);
+        }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/LinkedChildType.cs b/MediaBrowser.Controller/Entities/LinkedChildType.cs
new file mode 100644
index 000000000..9ddb7b620
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/LinkedChildType.cs
@@ -0,0 +1,18 @@
+namespace MediaBrowser.Controller.Entities
+{
+    /// <summary>
+    /// The linked child type.
+    /// </summary>
+    public enum LinkedChildType
+    {
+        /// <summary>
+        /// Manually linked child.
+        /// </summary>
+        Manual = 0,
+
+        /// <summary>
+        /// Shortcut linked child.
+        /// </summary>
+        Shortcut = 1
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/Movies/Movie.cs b/MediaBrowser.Controller/Entities/Movies/Movie.cs
index 64d60c2e9..b54bbf5eb 100644
--- a/MediaBrowser.Controller/Entities/Movies/Movie.cs
+++ b/MediaBrowser.Controller/Entities/Movies/Movie.cs
@@ -144,9 +144,9 @@ namespace MediaBrowser.Controller.Entities.Movies
         }
 
         /// <inheritdoc />
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/MusicVideo.cs b/MediaBrowser.Controller/Entities/MusicVideo.cs
index f42e7723c..237ad5198 100644
--- a/MediaBrowser.Controller/Entities/MusicVideo.cs
+++ b/MediaBrowser.Controller/Entities/MusicVideo.cs
@@ -13,15 +13,15 @@ namespace MediaBrowser.Controller.Entities
 {
     public class MusicVideo : Video, IHasArtist, IHasMusicGenres, IHasLookupInfo<MusicVideoInfo>
     {
-        /// <inheritdoc />
-        [JsonIgnore]
-        public IReadOnlyList<string> Artists { get; set; }
-
         public MusicVideo()
         {
             Artists = Array.Empty<string>();
         }
 
+        /// <inheritdoc />
+        [JsonIgnore]
+        public IReadOnlyList<string> Artists { get; set; }
+
         public override UnratedItem GetBlockUnratedType()
         {
             return UnratedItem.Music;
@@ -36,9 +36,9 @@ namespace MediaBrowser.Controller.Entities
             return info;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/Person.cs b/MediaBrowser.Controller/Entities/Person.cs
index d9ff55362..913f76d3b 100644
--- a/MediaBrowser.Controller/Entities/Person.cs
+++ b/MediaBrowser.Controller/Entities/Person.cs
@@ -50,7 +50,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -67,6 +67,9 @@ namespace MediaBrowser.Controller.Entities
             return true;
         }
 
+        /// <summary>
+        /// Gets a value indicating whether to enable alpha numeric sorting.
+        /// </summary>
         [JsonIgnore]
         public override bool EnableAlphaNumericSorting => false;
 
@@ -126,9 +129,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/Share.cs b/MediaBrowser.Controller/Entities/Share.cs
index 7e4ec1830..64f446eef 100644
--- a/MediaBrowser.Controller/Entities/Share.cs
+++ b/MediaBrowser.Controller/Entities/Share.cs
@@ -4,11 +4,6 @@
 
 namespace MediaBrowser.Controller.Entities
 {
-    public interface IHasShares
-    {
-        Share[] Shares { get; set; }
-    }
-
     public class Share
     {
         public string UserId { get; set; }
diff --git a/MediaBrowser.Controller/Entities/Studio.cs b/MediaBrowser.Controller/Entities/Studio.cs
index ae1d10447..6fd0a6c6c 100644
--- a/MediaBrowser.Controller/Entities/Studio.cs
+++ b/MediaBrowser.Controller/Entities/Studio.cs
@@ -29,7 +29,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -105,9 +105,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/TV/Episode.cs b/MediaBrowser.Controller/Entities/TV/Episode.cs
index 2724bd9b3..31c179bca 100644
--- a/MediaBrowser.Controller/Entities/TV/Episode.cs
+++ b/MediaBrowser.Controller/Entities/TV/Episode.cs
@@ -34,7 +34,7 @@ namespace MediaBrowser.Controller.Entities.TV
         public IReadOnlyList<Guid> RemoteTrailerIds { get; set; }
 
         /// <summary>
-        /// Gets the season in which it aired.
+        /// Gets or sets the season in which it aired.
         /// </summary>
         /// <value>The aired season.</value>
         public int? AirsBeforeSeasonNumber { get; set; }
@@ -44,7 +44,7 @@ namespace MediaBrowser.Controller.Entities.TV
         public int? AirsBeforeEpisodeNumber { get; set; }
 
         /// <summary>
-        /// This is the ending episode number for double episodes.
+        /// Gets or sets the ending episode number for double episodes.
         /// </summary>
         /// <value>The index number.</value>
         public int? IndexNumberEnd { get; set; }
@@ -116,7 +116,7 @@ namespace MediaBrowser.Controller.Entities.TV
         }
 
         /// <summary>
-        /// This Episode's Series Instance.
+        /// Gets the Episode's Series Instance.
         /// </summary>
         /// <value>The series.</value>
         [JsonIgnore]
@@ -218,8 +218,8 @@ namespace MediaBrowser.Controller.Entities.TV
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("000 - ") : "")
-                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ") : "") + Name;
+            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("000 - ", CultureInfo.InvariantCulture) : string.Empty)
+                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty) + Name;
         }
 
         /// <summary>
@@ -261,6 +261,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         [JsonIgnore]
         public Guid SeasonId { get; set; }
+
         [JsonIgnore]
         public Guid SeriesId { get; set; }
 
@@ -286,7 +287,8 @@ namespace MediaBrowser.Controller.Entities.TV
 
         public override IEnumerable<FileSystemMetadata> GetDeletePaths()
         {
-            return new[] {
+            return new[]
+            {
                 new FileSystemMetadata
                 {
                     FullName = Path,
@@ -318,9 +320,9 @@ namespace MediaBrowser.Controller.Entities.TV
             return id;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!IsLocked)
             {
@@ -328,7 +330,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 {
                     try
                     {
-                        if (LibraryManager.FillMissingEpisodeNumbersFromPath(this, replaceAllMetdata))
+                        if (LibraryManager.FillMissingEpisodeNumbersFromPath(this, replaceAllMetadata))
                         {
                             hasChanges = true;
                         }
diff --git a/MediaBrowser.Controller/Entities/TV/Season.cs b/MediaBrowser.Controller/Entities/TV/Season.cs
index ad3e0fe8d..aa62bb35b 100644
--- a/MediaBrowser.Controller/Entities/TV/Season.cs
+++ b/MediaBrowser.Controller/Entities/TV/Season.cs
@@ -81,7 +81,7 @@ namespace MediaBrowser.Controller.Entities.TV
         }
 
         /// <summary>
-        /// This Episode's Series Instance.
+        /// Gets this Episode's Series Instance.
         /// </summary>
         /// <value>The series.</value>
         [JsonIgnore]
@@ -122,7 +122,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 var series = Series;
                 if (series != null)
                 {
-                    return series.PresentationUniqueKey + "-" + (IndexNumber ?? 0).ToString("000");
+                    return series.PresentationUniqueKey + "-" + (IndexNumber ?? 0).ToString("000", CultureInfo.InvariantCulture);
                 }
             }
 
@@ -135,7 +135,7 @@ namespace MediaBrowser.Controller.Entities.TV
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return IndexNumber != null ? IndexNumber.Value.ToString("0000") : Name;
+            return IndexNumber != null ? IndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) : Name;
         }
 
         protected override QueryResult<BaseItem> GetItemsInternal(InternalItemsQuery query)
@@ -242,9 +242,9 @@ namespace MediaBrowser.Controller.Entities.TV
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
         /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!IndexNumber.HasValue && !string.IsNullOrEmpty(Path))
             {
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index ded825abc..44d07b4a4 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -59,8 +59,11 @@ namespace MediaBrowser.Controller.Entities.TV
         public IReadOnlyList<Guid> RemoteTrailerIds { get; set; }
 
         /// <summary>
-        /// airdate, dvd or absolute.
+        /// Gets or sets the display order.
         /// </summary>
+        /// <remarks>
+        /// Valid options are airdate, dvd or absolute.
+        /// </remarks>
         public string DisplayOrder { get; set; }
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Entities/Trailer.cs b/MediaBrowser.Controller/Entities/Trailer.cs
index b086b5906..732b45521 100644
--- a/MediaBrowser.Controller/Entities/Trailer.cs
+++ b/MediaBrowser.Controller/Entities/Trailer.cs
@@ -45,9 +45,9 @@ namespace MediaBrowser.Controller.Entities
             return info;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/UserItemData.cs b/MediaBrowser.Controller/Entities/UserItemData.cs
index f60359c01..6ab2116d7 100644
--- a/MediaBrowser.Controller/Entities/UserItemData.cs
+++ b/MediaBrowser.Controller/Entities/UserItemData.cs
@@ -96,7 +96,7 @@ namespace MediaBrowser.Controller.Entities
         public const double MinLikeValue = 6.5;
 
         /// <summary>
-        /// This is an interpreted property to indicate likes or dislikes
+        /// Gets or sets a value indicating whether the item is liked or not.
         /// This should never be serialized.
         /// </summary>
         /// <value><c>null</c> if [likes] contains no value, <c>true</c> if [likes]; otherwise, <c>false</c>.</value>
diff --git a/MediaBrowser.Controller/Entities/UserRootFolder.cs b/MediaBrowser.Controller/Entities/UserRootFolder.cs
index e492740ed..2b15a52f0 100644
--- a/MediaBrowser.Controller/Entities/UserRootFolder.cs
+++ b/MediaBrowser.Controller/Entities/UserRootFolder.cs
@@ -23,6 +23,7 @@ namespace MediaBrowser.Controller.Entities
     {
         private List<Guid> _childrenIds = null;
         private readonly object _childIdsLock = new object();
+
         protected override List<BaseItem> LoadChildren()
         {
             lock (_childIdsLock)
@@ -87,10 +88,10 @@ namespace MediaBrowser.Controller.Entities
             return list;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             ClearCache();
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (string.Equals("default", Name, StringComparison.OrdinalIgnoreCase))
             {
@@ -108,11 +109,11 @@ namespace MediaBrowser.Controller.Entities
             return base.GetNonCachedChildren(directoryService);
         }
 
-        protected override async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             ClearCache();
 
-            await base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService)
+            await base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken)
                 .ConfigureAwait(false);
 
             ClearCache();
diff --git a/MediaBrowser.Controller/Entities/UserView.cs b/MediaBrowser.Controller/Entities/UserView.cs
index 0dfde2766..57dc9b59b 100644
--- a/MediaBrowser.Controller/Entities/UserView.cs
+++ b/MediaBrowser.Controller/Entities/UserView.cs
@@ -15,13 +15,19 @@ namespace MediaBrowser.Controller.Entities
 {
     public class UserView : Folder, IHasCollectionType
     {
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the view type.
+        /// </summary>
         public string ViewType { get; set; }
 
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the display parent id.
+        /// </summary>
         public new Guid DisplayParentId { get; set; }
 
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the user id.
+        /// </summary>
         public Guid? UserId { get; set; }
 
         public static ITVSeriesManager TVSeriesManager;
@@ -110,10 +116,10 @@ namespace MediaBrowser.Controller.Entities
             return GetChildren(user, false);
         }
 
-        private static string[] UserSpecificViewTypes = new string[]
-            {
-                Model.Entities.CollectionType.Playlists
-            };
+        private static readonly string[] UserSpecificViewTypes = new string[]
+        {
+            Model.Entities.CollectionType.Playlists
+        };
 
         public static bool IsUserSpecific(Folder folder)
         {
@@ -166,7 +172,7 @@ namespace MediaBrowser.Controller.Entities
             return OriginalFolderViewTypes.Contains(viewType ?? string.Empty, StringComparer.OrdinalIgnoreCase);
         }
 
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, System.Threading.CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, Providers.MetadataRefreshOptions refreshOptions, Providers.IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, Providers.MetadataRefreshOptions refreshOptions, Providers.IDirectoryService directoryService, System.Threading.CancellationToken cancellationToken)
         {
             return Task.CompletedTask;
         }
diff --git a/MediaBrowser.Controller/Entities/UserViewBuilder.cs b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
index 15a4573c2..add734f62 100644
--- a/MediaBrowser.Controller/Entities/UserViewBuilder.cs
+++ b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
@@ -55,12 +55,12 @@ namespace MediaBrowser.Controller.Entities
             // if (query.IncludeItemTypes != null &&
             //    query.IncludeItemTypes.Length == 1 &&
             //    string.Equals(query.IncludeItemTypes[0], "Playlist", StringComparison.OrdinalIgnoreCase))
-            //{
+            // {
             //    if (!string.Equals(viewType, CollectionType.Playlists, StringComparison.OrdinalIgnoreCase))
             //    {
             //        return await FindPlaylists(queryParent, user, query).ConfigureAwait(false);
             //    }
-            //}
+            // }
 
             switch (viewType)
             {
@@ -344,12 +344,14 @@ namespace MediaBrowser.Controller.Entities
             var parentFolders = GetMediaFolders(parent, query.User, new[] { CollectionType.TvShows, string.Empty });
 
             var result = _tvSeriesManager.GetNextUp(
-            new NextUpQuery
-            {
-                Limit = query.Limit,
-                StartIndex = query.StartIndex,
-                UserId = query.User.Id
-            }, parentFolders, query.DtoOptions);
+                new NextUpQuery
+                {
+                    Limit = query.Limit,
+                    StartIndex = query.StartIndex,
+                    UserId = query.User.Id
+                },
+                parentFolders,
+                query.DtoOptions);
 
             return result;
         }
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index 723027a88..d05b5df2f 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -482,7 +482,8 @@ namespace MediaBrowser.Controller.Entities
         {
             if (!IsInMixedFolder)
             {
-                return new[] {
+                return new[]
+                {
                     new FileSystemMetadata
                     {
                         FullName = ContainingFolderPath,
diff --git a/MediaBrowser.Controller/Entities/Year.cs b/MediaBrowser.Controller/Entities/Year.cs
index 4d84a151a..f268bc939 100644
--- a/MediaBrowser.Controller/Entities/Year.cs
+++ b/MediaBrowser.Controller/Entities/Year.cs
@@ -24,7 +24,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -112,11 +112,13 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is called before any metadata refresh and returns true or false indicating if changes were made.
+        /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Extensions/StringExtensions.cs b/MediaBrowser.Controller/Extensions/StringExtensions.cs
index 8441a3171..f1af01345 100644
--- a/MediaBrowser.Controller/Extensions/StringExtensions.cs
+++ b/MediaBrowser.Controller/Extensions/StringExtensions.cs
@@ -21,6 +21,27 @@ namespace MediaBrowser.Controller.Extensions
             return Normalize(string.Concat(chars), NormalizationForm.FormC);
         }
 
+        /// <summary>
+        /// Counts the number of occurrences of [needle] in the string.
+        /// </summary>
+        /// <param name="value">The haystack to search in.</param>
+        /// <param name="needle">The character to search for.</param>
+        /// <returns>The number of occurrences of the [needle] character.</returns>
+        public static int Count(this ReadOnlySpan<char> value, char needle)
+        {
+            var count = 0;
+            var length = value.Length;
+            for (var i = 0; i < length; i++)
+            {
+                if (value[i] == needle)
+                {
+                    count++;
+                }
+            }
+
+            return count;
+        }
+
         private static string Normalize(string text, NormalizationForm form, bool stripStringOnFailure = true)
         {
             if (stripStringOnFailure)
@@ -33,7 +54,7 @@ namespace MediaBrowser.Controller.Extensions
                 {
                     // will throw if input contains invalid unicode chars
                     // https://mnaoumov.wordpress.com/2014/06/14/stripping-invalid-characters-from-utf-16-strings/
-                    text = Regex.Replace(text, "([\ud800-\udbff](?![\udc00-\udfff]))|((?<![\ud800-\udbff])[\udc00-\udfff])", "");
+                    text = Regex.Replace(text, "([\ud800-\udbff](?![\udc00-\udfff]))|((?<![\ud800-\udbff])[\udc00-\udfff])", string.Empty);
                     return Normalize(text, form, false);
                 }
             }
diff --git a/MediaBrowser.Controller/IO/FileData.cs b/MediaBrowser.Controller/IO/FileData.cs
index 3db60ae0b..b8a0bf331 100644
--- a/MediaBrowser.Controller/IO/FileData.cs
+++ b/MediaBrowser.Controller/IO/FileData.cs
@@ -24,7 +24,7 @@ namespace MediaBrowser.Controller.IO
         /// <param name="flattenFolderDepth">The flatten folder depth.</param>
         /// <param name="resolveShortcuts">if set to <c>true</c> [resolve shortcuts].</param>
         /// <returns>Dictionary{System.StringFileSystemInfo}.</returns>
-        /// <exception cref="ArgumentNullException">path</exception>
+        /// <exception cref="ArgumentNullException"><paramref name="path" /> is <c>null</c> or empty.</exception>
         public static FileSystemMetadata[] GetFilteredFileSystemEntries(
             IDirectoryService directoryService,
             string path,
diff --git a/MediaBrowser.Controller/Library/DeleteOptions.cs b/MediaBrowser.Controller/Library/DeleteOptions.cs
index b7417efcb..408e70284 100644
--- a/MediaBrowser.Controller/Library/DeleteOptions.cs
+++ b/MediaBrowser.Controller/Library/DeleteOptions.cs
@@ -4,13 +4,13 @@ namespace MediaBrowser.Controller.Library
 {
     public class DeleteOptions
     {
-        public bool DeleteFileLocation { get; set; }
-
-        public bool DeleteFromExternalProvider { get; set; }
-
         public DeleteOptions()
         {
             DeleteFromExternalProvider = true;
         }
+
+        public bool DeleteFileLocation { get; set; }
+
+        public bool DeleteFromExternalProvider { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Library/IIntroProvider.cs b/MediaBrowser.Controller/Library/IIntroProvider.cs
index 3bb1bd9a0..a74d1b9f0 100644
--- a/MediaBrowser.Controller/Library/IIntroProvider.cs
+++ b/MediaBrowser.Controller/Library/IIntroProvider.cs
@@ -12,6 +12,12 @@ namespace MediaBrowser.Controller.Library
     public interface IIntroProvider
     {
         /// <summary>
+        /// Gets the name.
+        /// </summary>
+        /// <value>The name.</value>
+        string Name { get; }
+
+        /// <summary>
         /// Gets the intros.
         /// </summary>
         /// <param name="item">The item.</param>
@@ -24,11 +30,5 @@ namespace MediaBrowser.Controller.Library
         /// </summary>
         /// <returns>IEnumerable{System.String}.</returns>
         IEnumerable<string> GetAllIntroFiles();
-
-        /// <summary>
-        /// Gets the name.
-        /// </summary>
-        /// <value>The name.</value>
-        string Name { get; }
     }
 }
diff --git a/MediaBrowser.Controller/Library/ILibraryManager.cs b/MediaBrowser.Controller/Library/ILibraryManager.cs
index 782e15398..7a4ba6a24 100644
--- a/MediaBrowser.Controller/Library/ILibraryManager.cs
+++ b/MediaBrowser.Controller/Library/ILibraryManager.cs
@@ -6,6 +6,7 @@ using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using Emby.Naming.Common;
 using Jellyfin.Data.Entities;
 using Jellyfin.Data.Enums;
 using MediaBrowser.Controller.Dto;
@@ -43,6 +44,12 @@ namespace MediaBrowser.Controller.Library
         /// <summary>
         /// Resolves a set of files into a list of BaseItem.
         /// </summary>
+        /// <param name="files">The list of tiles.</param>
+        /// <param name="directoryService">Instance of the <see cref="IDirectoryService"/> interface.</param>
+        /// <param name="parent">The parent folder.</param>
+        /// <param name="libraryOptions">The library options.</param>
+        /// <param name="collectionType">The collection type.</param>
+        /// <returns>The items resolved from the paths.</returns>
         IEnumerable<BaseItem> ResolvePaths(
             IEnumerable<FileSystemMetadata> files,
             IDirectoryService directoryService,
@@ -346,6 +353,7 @@ namespace MediaBrowser.Controller.Library
         /// <param name="viewType">Type of the view.</param>
         /// <param name="sortName">Name of the sort.</param>
         /// <param name="uniqueId">The unique identifier.</param>
+        /// <returns>The named view.</returns>
         UserView GetNamedView(
             string name,
             Guid parentId,
@@ -359,10 +367,11 @@ namespace MediaBrowser.Controller.Library
         /// <param name="parent">The parent.</param>
         /// <param name="viewType">Type of the view.</param>
         /// <param name="sortName">Name of the sort.</param>
+        /// <returns>The shadow view.</returns>
         UserView GetShadowView(
             BaseItem parent,
-          string viewType,
-          string sortName);
+            string viewType,
+            string sortName);
 
         /// <summary>
         /// Determines whether [is video file] [the specified path].
@@ -587,5 +596,11 @@ namespace MediaBrowser.Controller.Library
         BaseItem GetParentItem(string parentId, Guid? userId);
 
         BaseItem GetParentItem(Guid? parentId, Guid? userId);
+
+        /// <summary>
+        /// Gets or creates a static instance of <see cref="NamingOptions"/>.
+        /// </summary>
+        /// <returns>An instance of the <see cref="NamingOptions"/> class.</returns>
+        NamingOptions GetNamingOptions();
     }
 }
diff --git a/MediaBrowser.Controller/Library/IUserDataManager.cs b/MediaBrowser.Controller/Library/IUserDataManager.cs
index 58499e853..e5dcfcff0 100644
--- a/MediaBrowser.Controller/Library/IUserDataManager.cs
+++ b/MediaBrowser.Controller/Library/IUserDataManager.cs
@@ -49,17 +49,16 @@ namespace MediaBrowser.Controller.Library
         /// <summary>
         /// Get all user data for the given user.
         /// </summary>
-        /// <param name="userId"></param>
-        /// <returns></returns>
+        /// <param name="userId">The user id.</param>
+        /// <returns>The user item data.</returns>
         List<UserItemData> GetAllUserData(Guid userId);
 
         /// <summary>
         /// Save the all provided user data for the given user.
         /// </summary>
-        /// <param name="userId"></param>
-        /// <param name="userData"></param>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
+        /// <param name="userId">The user id.</param>
+        /// <param name="userData">The array of user data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         void SaveAllUserData(Guid userId, UserItemData[] userData, CancellationToken cancellationToken);
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Library/IUserManager.cs b/MediaBrowser.Controller/Library/IUserManager.cs
index c95b0ea32..1801b1c41 100644
--- a/MediaBrowser.Controller/Library/IUserManager.cs
+++ b/MediaBrowser.Controller/Library/IUserManager.cs
@@ -61,16 +61,16 @@ namespace MediaBrowser.Controller.Library
         /// <param name="user">The user.</param>
         /// <param name="newName">The new name.</param>
         /// <returns>Task.</returns>
-        /// <exception cref="ArgumentNullException">user</exception>
-        /// <exception cref="ArgumentException"></exception>
+        /// <exception cref="ArgumentNullException">If user is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">If the provided user doesn't exist.</exception>
         Task RenameUser(User user, string newName);
 
         /// <summary>
         /// Updates the user.
         /// </summary>
         /// <param name="user">The user.</param>
-        /// <exception cref="ArgumentNullException">user</exception>
-        /// <exception cref="ArgumentException"></exception>
+        /// <exception cref="ArgumentNullException">If user is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">If the provided user doesn't exist.</exception>
         void UpdateUser(User user);
 
         /// <summary>
@@ -87,8 +87,8 @@ namespace MediaBrowser.Controller.Library
         /// </summary>
         /// <param name="name">The name of the new user.</param>
         /// <returns>The created user.</returns>
-        /// <exception cref="ArgumentNullException">name</exception>
-        /// <exception cref="ArgumentException"></exception>
+        /// <exception cref="ArgumentNullException"><paramref name="name"/> is <c>null</c> or empty.</exception>
+        /// <exception cref="ArgumentException"><paramref name="name"/> already exists.</exception>
         Task<User> CreateUserAsync(string name);
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Library/ItemResolveArgs.cs b/MediaBrowser.Controller/Library/ItemResolveArgs.cs
index 0e2d8fb02..521e37274 100644
--- a/MediaBrowser.Controller/Library/ItemResolveArgs.cs
+++ b/MediaBrowser.Controller/Library/ItemResolveArgs.cs
@@ -39,7 +39,7 @@ namespace MediaBrowser.Controller.Library
         public IDirectoryService DirectoryService { get; }
 
         /// <summary>
-        /// Gets the file system children.
+        /// Gets or sets the file system children.
         /// </summary>
         /// <value>The file system children.</value>
         public FileSystemMetadata[] FileSystemChildren { get; set; }
@@ -242,14 +242,14 @@ namespace MediaBrowser.Controller.Library
         /// <returns>A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.</returns>
         public override int GetHashCode()
         {
-            return Path.GetHashCode();
+            return Path.GetHashCode(StringComparison.Ordinal);
         }
 
         /// <summary>
         /// Equals the specified args.
         /// </summary>
         /// <param name="args">The args.</param>
-        /// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
+        /// <returns><c>true</c> if the arguments are the same, <c>false</c> otherwise.</returns>
         protected bool Equals(ItemResolveArgs args)
         {
             if (args != null)
diff --git a/MediaBrowser.Controller/Library/Profiler.cs b/MediaBrowser.Controller/Library/Profiler.cs
deleted file mode 100644
index 8f42d3706..000000000
--- a/MediaBrowser.Controller/Library/Profiler.cs
+++ /dev/null
@@ -1,85 +0,0 @@
-#nullable disable
-
-using System;
-using System.Diagnostics;
-using System.Globalization;
-using Microsoft.Extensions.Logging;
-
-namespace MediaBrowser.Controller.Library
-{
-    /// <summary>
-    /// Class Profiler.
-    /// </summary>
-    public class Profiler : IDisposable
-    {
-        /// <summary>
-        /// The name.
-        /// </summary>
-        readonly string _name;
-
-        /// <summary>
-        /// The stopwatch.
-        /// </summary>
-        readonly Stopwatch _stopwatch;
-
-        /// <summary>
-        /// The _logger.
-        /// </summary>
-        private readonly ILogger<Profiler> _logger;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="Profiler" /> class.
-        /// </summary>
-        /// <param name="name">The name.</param>
-        /// <param name="logger">The logger.</param>
-        public Profiler(string name, ILogger<Profiler> logger)
-        {
-            this._name = name;
-
-            _logger = logger;
-
-            _stopwatch = new Stopwatch();
-            _stopwatch.Start();
-        }
-
-        /// <summary>
-        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
-        /// </summary>
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
-        }
-
-        /// <summary>
-        /// Releases unmanaged and - optionally - managed resources.
-        /// </summary>
-        /// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
-        protected virtual void Dispose(bool dispose)
-        {
-            if (dispose)
-            {
-                _stopwatch.Stop();
-                string message;
-                if (_stopwatch.ElapsedMilliseconds > 300000)
-                {
-                    message = string.Format(
-                        CultureInfo.InvariantCulture,
-                        "{0} took {1} minutes.",
-                        _name,
-                        ((float)_stopwatch.ElapsedMilliseconds / 60000).ToString("F", CultureInfo.InvariantCulture));
-                }
-                else
-                {
-                    message = string.Format(
-                        CultureInfo.InvariantCulture,
-                        "{0} took {1} seconds.",
-                        _name,
-                        ((float)_stopwatch.ElapsedMilliseconds / 1000).ToString("#0.000", CultureInfo.InvariantCulture));
-                }
-
-                _logger.LogInformation(message);
-            }
-        }
-    }
-}
diff --git a/MediaBrowser.Controller/LiveTv/ActiveRecordingInfo.cs b/MediaBrowser.Controller/LiveTv/ActiveRecordingInfo.cs
new file mode 100644
index 000000000..463061e68
--- /dev/null
+++ b/MediaBrowser.Controller/LiveTv/ActiveRecordingInfo.cs
@@ -0,0 +1,19 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System.Threading;
+
+namespace MediaBrowser.Controller.LiveTv
+{
+    public class ActiveRecordingInfo
+    {
+        public string Id { get; set; }
+
+        public string Path { get; set; }
+
+        public TimerInfo Timer { get; set; }
+
+        public CancellationTokenSource CancellationTokenSource { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/LiveTv/ChannelInfo.cs b/MediaBrowser.Controller/LiveTv/ChannelInfo.cs
index a55fd670d..699c15f93 100644
--- a/MediaBrowser.Controller/LiveTv/ChannelInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/ChannelInfo.cs
@@ -24,7 +24,7 @@ namespace MediaBrowser.Controller.LiveTv
         public string Number { get; set; }
 
         /// <summary>
-        /// Get or sets the Id.
+        /// Gets or sets the Id.
         /// </summary>
         /// <value>The id of the channel.</value>
         public string Id { get; set; }
@@ -54,13 +54,13 @@ namespace MediaBrowser.Controller.LiveTv
         public string ChannelGroup { get; set; }
 
         /// <summary>
-        /// Supply the image path if it can be accessed directly from the file system.
+        /// Gets or sets the the image path if it can be accessed directly from the file system.
         /// </summary>
         /// <value>The image path.</value>
         public string ImagePath { get; set; }
 
         /// <summary>
-        /// Supply the image url if it can be downloaded.
+        /// Gets or sets the image url if it can be downloaded.
         /// </summary>
         /// <value>The image URL.</value>
         public string ImageUrl { get; set; }
diff --git a/MediaBrowser.Controller/LiveTv/ILiveTvManager.cs b/MediaBrowser.Controller/LiveTv/ILiveTvManager.cs
index c28e0426b..f4dc18e11 100644
--- a/MediaBrowser.Controller/LiveTv/ILiveTvManager.cs
+++ b/MediaBrowser.Controller/LiveTv/ILiveTvManager.cs
@@ -268,16 +268,21 @@ namespace MediaBrowser.Controller.LiveTv
         void AddChannelInfo(IReadOnlyCollection<(BaseItemDto, LiveTvChannel)> items, DtoOptions options, User user);
 
         Task<List<ChannelInfo>> GetChannelsForListingsProvider(string id, CancellationToken cancellationToken);
+
         Task<List<ChannelInfo>> GetChannelsFromListingsProviderData(string id, CancellationToken cancellationToken);
 
         IListingsProvider[] ListingProviders { get; }
 
         List<NameIdPair> GetTunerHostTypes();
+
         Task<List<TunerHostInfo>> DiscoverTuners(bool newDevicesOnly, CancellationToken cancellationToken);
 
         event EventHandler<GenericEventArgs<TimerEventInfo>> SeriesTimerCancelled;
+
         event EventHandler<GenericEventArgs<TimerEventInfo>> TimerCancelled;
+
         event EventHandler<GenericEventArgs<TimerEventInfo>> TimerCreated;
+
         event EventHandler<GenericEventArgs<TimerEventInfo>> SeriesTimerCreated;
 
         string GetEmbyTvActiveRecordingPath(string id);
@@ -288,15 +293,4 @@ namespace MediaBrowser.Controller.LiveTv
 
         List<BaseItem> GetRecordingFolders(User user);
     }
-
-    public class ActiveRecordingInfo
-    {
-        public string Id { get; set; }
-
-        public string Path { get; set; }
-
-        public TimerInfo Timer { get; set; }
-
-        public CancellationTokenSource CancellationTokenSource { get; set; }
-    }
 }
diff --git a/MediaBrowser.Controller/LiveTv/LiveTvChannel.cs b/MediaBrowser.Controller/LiveTv/LiveTvChannel.cs
index 02678cfb6..bf759bc54 100644
--- a/MediaBrowser.Controller/LiveTv/LiveTvChannel.cs
+++ b/MediaBrowser.Controller/LiveTv/LiveTvChannel.cs
@@ -146,7 +146,7 @@ namespace MediaBrowser.Controller.LiveTv
         public bool IsNews { get; set; }
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is kids.
+        /// Gets a value indicating whether this instance is kids.
         /// </summary>
         /// <value><c>true</c> if this instance is kids; otherwise, <c>false</c>.</value>
         [JsonIgnore]
diff --git a/MediaBrowser.Controller/LiveTv/LiveTvProgram.cs b/MediaBrowser.Controller/LiveTv/LiveTvProgram.cs
index d9634a731..9d638a0bf 100644
--- a/MediaBrowser.Controller/LiveTv/LiveTvProgram.cs
+++ b/MediaBrowser.Controller/LiveTv/LiveTvProgram.cs
@@ -53,6 +53,7 @@ namespace MediaBrowser.Controller.LiveTv
         }
 
         private static string EmbyServiceName = "Emby";
+
         public override double GetDefaultPrimaryImageAspectRatio()
         {
             var serviceName = ServiceName;
@@ -71,7 +72,7 @@ namespace MediaBrowser.Controller.LiveTv
         public override SourceType SourceType => SourceType.LiveTV;
 
         /// <summary>
-        /// The start date of the program, in UTC.
+        /// Gets or sets start date of the program, in UTC.
         /// </summary>
         [JsonIgnore]
         public DateTime StartDate { get; set; }
@@ -101,7 +102,7 @@ namespace MediaBrowser.Controller.LiveTv
         public bool IsMovie { get; set; }
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is sports.
+        /// Gets a value indicating whether this instance is sports.
         /// </summary>
         /// <value><c>true</c> if this instance is sports; otherwise, <c>false</c>.</value>
         [JsonIgnore]
@@ -115,49 +116,49 @@ namespace MediaBrowser.Controller.LiveTv
         public bool IsSeries { get; set; }
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is live.
+        /// Gets a value indicating whether this instance is live.
         /// </summary>
         /// <value><c>true</c> if this instance is live; otherwise, <c>false</c>.</value>
         [JsonIgnore]
         public bool IsLive => Tags.Contains("Live", StringComparer.OrdinalIgnoreCase);
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is news.
+        /// Gets a value indicating whether this instance is news.
         /// </summary>
         /// <value><c>true</c> if this instance is news; otherwise, <c>false</c>.</value>
         [JsonIgnore]
         public bool IsNews => Tags.Contains("News", StringComparer.OrdinalIgnoreCase);
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is kids.
+        /// Gets a value indicating whether this instance is kids.
         /// </summary>
         /// <value><c>true</c> if this instance is kids; otherwise, <c>false</c>.</value>
         [JsonIgnore]
         public bool IsKids => Tags.Contains("Kids", StringComparer.OrdinalIgnoreCase);
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is premiere.
+        /// Gets a value indicating whether this instance is premiere.
         /// </summary>
         /// <value><c>true</c> if this instance is premiere; otherwise, <c>false</c>.</value>
         [JsonIgnore]
         public bool IsPremiere => Tags.Contains("Premiere", StringComparer.OrdinalIgnoreCase);
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
         [JsonIgnore]
         public override string ContainingFolderPath => Path;
 
-        //[JsonIgnore]
+        // [JsonIgnore]
         // public override string MediaType
-        //{
+        // {
         //    get
         //    {
         //        return ChannelType == ChannelType.TV ? Model.Entities.MediaType.Video : Model.Entities.MediaType.Audio;
         //    }
-        //}
+        // }
 
         [JsonIgnore]
         public bool IsAiring
diff --git a/MediaBrowser.Controller/LiveTv/ProgramInfo.cs b/MediaBrowser.Controller/LiveTv/ProgramInfo.cs
index 4a977c5cc..3c3ac2471 100644
--- a/MediaBrowser.Controller/LiveTv/ProgramInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/ProgramInfo.cs
@@ -10,8 +10,16 @@ namespace MediaBrowser.Controller.LiveTv
 {
     public class ProgramInfo
     {
+        public ProgramInfo()
+        {
+            Genres = new List<string>();
+
+            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            SeriesProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        }
+
         /// <summary>
-        /// Id of the program.
+        /// Gets or sets the id of the program.
         /// </summary>
         public string Id { get; set; }
 
@@ -22,7 +30,7 @@ namespace MediaBrowser.Controller.LiveTv
         public string ChannelId { get; set; }
 
         /// <summary>
-        /// Name of the program.
+        /// Gets or sets the name of the program.
         /// </summary>
         public string Name { get; set; }
 
@@ -45,17 +53,17 @@ namespace MediaBrowser.Controller.LiveTv
         public string ShortOverview { get; set; }
 
         /// <summary>
-        /// The start date of the program, in UTC.
+        /// Gets or sets the start date of the program, in UTC.
         /// </summary>
         public DateTime StartDate { get; set; }
 
         /// <summary>
-        /// The end date of the program, in UTC.
+        /// Gets or sets the end date of the program, in UTC.
         /// </summary>
         public DateTime EndDate { get; set; }
 
         /// <summary>
-        /// Genre of the program.
+        /// Gets or sets the genre of the program.
         /// </summary>
         public List<string> Genres { get; set; }
 
@@ -71,6 +79,9 @@ namespace MediaBrowser.Controller.LiveTv
         /// <value><c>true</c> if this instance is hd; otherwise, <c>false</c>.</value>
         public bool? IsHD { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether this instance is 3d.
+        /// </summary>
         public bool? Is3D { get; set; }
 
         /// <summary>
@@ -100,13 +111,13 @@ namespace MediaBrowser.Controller.LiveTv
         public string EpisodeTitle { get; set; }
 
         /// <summary>
-        /// Supply the image path if it can be accessed directly from the file system.
+        /// Gets or sets the image path if it can be accessed directly from the file system.
         /// </summary>
         /// <value>The image path.</value>
         public string ImagePath { get; set; }
 
         /// <summary>
-        /// Supply the image url if it can be downloaded.
+        /// Gets or sets the image url if it can be downloaded.
         /// </summary>
         /// <value>The image URL.</value>
         public string ImageUrl { get; set; }
@@ -212,13 +223,5 @@ namespace MediaBrowser.Controller.LiveTv
         public Dictionary<string, string> ProviderIds { get; set; }
 
         public Dictionary<string, string> SeriesProviderIds { get; set; }
-
-        public ProgramInfo()
-        {
-            Genres = new List<string>();
-
-            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-            SeriesProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        }
     }
 }
diff --git a/MediaBrowser.Controller/LiveTv/RecordingInfo.cs b/MediaBrowser.Controller/LiveTv/RecordingInfo.cs
index 00135afa8..1dcf7a58f 100644
--- a/MediaBrowser.Controller/LiveTv/RecordingInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/RecordingInfo.cs
@@ -10,8 +10,13 @@ namespace MediaBrowser.Controller.LiveTv
 {
     public class RecordingInfo
     {
+        public RecordingInfo()
+        {
+            Genres = new List<string>();
+        }
+
         /// <summary>
-        /// Id of the recording.
+        /// Gets or sets the id of the recording.
         /// </summary>
         public string Id { get; set; }
 
@@ -28,7 +33,7 @@ namespace MediaBrowser.Controller.LiveTv
         public string TimerId { get; set; }
 
         /// <summary>
-        /// ChannelId of the recording.
+        /// Gets or sets the channelId of the recording.
         /// </summary>
         public string ChannelId { get; set; }
 
@@ -39,7 +44,7 @@ namespace MediaBrowser.Controller.LiveTv
         public ChannelType ChannelType { get; set; }
 
         /// <summary>
-        /// Name of the recording.
+        /// Gets or sets the name of the recording.
         /// </summary>
         public string Name { get; set; }
 
@@ -62,12 +67,12 @@ namespace MediaBrowser.Controller.LiveTv
         public string Overview { get; set; }
 
         /// <summary>
-        /// The start date of the recording, in UTC.
+        /// Gets or sets the start date of the recording, in UTC.
         /// </summary>
         public DateTime StartDate { get; set; }
 
         /// <summary>
-        /// The end date of the recording, in UTC.
+        /// Gets or sets the end date of the recording, in UTC.
         /// </summary>
         public DateTime EndDate { get; set; }
 
@@ -84,7 +89,7 @@ namespace MediaBrowser.Controller.LiveTv
         public RecordingStatus Status { get; set; }
 
         /// <summary>
-        /// Genre of the program.
+        /// Gets or sets the genre of the program.
         /// </summary>
         public List<string> Genres { get; set; }
 
@@ -173,13 +178,13 @@ namespace MediaBrowser.Controller.LiveTv
         public float? CommunityRating { get; set; }
 
         /// <summary>
-        /// Supply the image path if it can be accessed directly from the file system.
+        /// Gets or sets the image path if it can be accessed directly from the file system.
         /// </summary>
         /// <value>The image path.</value>
         public string ImagePath { get; set; }
 
         /// <summary>
-        /// Supply the image url if it can be downloaded.
+        /// Gets or sets the image url if it can be downloaded.
         /// </summary>
         /// <value>The image URL.</value>
         public string ImageUrl { get; set; }
@@ -201,10 +206,5 @@ namespace MediaBrowser.Controller.LiveTv
         /// </summary>
         /// <value>The date last updated.</value>
         public DateTime DateLastUpdated { get; set; }
-
-        public RecordingInfo()
-        {
-            Genres = new List<string>();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/LiveTv/SeriesTimerInfo.cs b/MediaBrowser.Controller/LiveTv/SeriesTimerInfo.cs
index 1bb649a99..d6811fe14 100644
--- a/MediaBrowser.Controller/LiveTv/SeriesTimerInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/SeriesTimerInfo.cs
@@ -10,13 +10,20 @@ namespace MediaBrowser.Controller.LiveTv
 {
     public class SeriesTimerInfo
     {
+        public SeriesTimerInfo()
+        {
+            Days = new List<DayOfWeek>();
+            SkipEpisodesInLibrary = true;
+            KeepUntil = KeepUntil.UntilDeleted;
+        }
+
         /// <summary>
-        /// Id of the recording.
+        /// Gets or sets the id of the recording.
         /// </summary>
         public string Id { get; set; }
 
         /// <summary>
-        /// ChannelId of the recording.
+        /// Gets or sets the channelId of the recording.
         /// </summary>
         public string ChannelId { get; set; }
 
@@ -27,24 +34,27 @@ namespace MediaBrowser.Controller.LiveTv
         public string ProgramId { get; set; }
 
         /// <summary>
-        /// Name of the recording.
+        /// Gets or sets the name of the recording.
         /// </summary>
         public string Name { get; set; }
 
+        /// <summary>
+        /// Gets or sets the service name.
+        /// </summary>
         public string ServiceName { get; set; }
 
         /// <summary>
-        /// Description of the recording.
+        /// Gets or sets the description of the recording.
         /// </summary>
         public string Overview { get; set; }
 
         /// <summary>
-        /// The start date of the recording, in UTC.
+        /// Gets or sets the start date of the recording, in UTC.
         /// </summary>
         public DateTime StartDate { get; set; }
 
         /// <summary>
-        /// The end date of the recording, in UTC.
+        /// Gets or sets the end date of the recording, in UTC.
         /// </summary>
         public DateTime EndDate { get; set; }
 
@@ -113,12 +123,5 @@ namespace MediaBrowser.Controller.LiveTv
         /// </summary>
         /// <value>The series identifier.</value>
         public string SeriesId { get; set; }
-
-        public SeriesTimerInfo()
-        {
-            Days = new List<DayOfWeek>();
-            SkipEpisodesInLibrary = true;
-            KeepUntil = KeepUntil.UntilDeleted;
-        }
     }
 }
diff --git a/MediaBrowser.Controller/LiveTv/TimerEventInfo.cs b/MediaBrowser.Controller/LiveTv/TimerEventInfo.cs
index 728387c56..92eb0be9c 100644
--- a/MediaBrowser.Controller/LiveTv/TimerEventInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/TimerEventInfo.cs
@@ -1,6 +1,3 @@
-#nullable disable
-
-#nullable enable
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/LiveTv/TimerInfo.cs b/MediaBrowser.Controller/LiveTv/TimerInfo.cs
index e54dc967c..1a2e8acb3 100644
--- a/MediaBrowser.Controller/LiveTv/TimerInfo.cs
+++ b/MediaBrowser.Controller/LiveTv/TimerInfo.cs
@@ -28,18 +28,17 @@ namespace MediaBrowser.Controller.LiveTv
         public string[] Tags { get; set; }
 
         /// <summary>
-        /// Id of the recording.
+        /// Gets or sets the id of the recording.
         /// </summary>
         public string Id { get; set; }
 
         /// <summary>
         /// Gets or sets the series timer identifier.
         /// </summary>
-        /// <value>The series timer identifier.</value>
         public string SeriesTimerId { get; set; }
 
         /// <summary>
-        /// ChannelId of the recording.
+        /// Gets or sets the channelId of the recording.
         /// </summary>
         public string ChannelId { get; set; }
 
@@ -52,24 +51,24 @@ namespace MediaBrowser.Controller.LiveTv
         public string ShowId { get; set; }
 
         /// <summary>
-        /// Name of the recording.
+        /// Gets or sets the name of the recording.
         /// </summary>
         public string Name { get; set; }
 
         /// <summary>
-        /// Description of the recording.
+        /// Gets or sets the description of the recording.
         /// </summary>
         public string Overview { get; set; }
 
         public string SeriesId { get; set; }
 
         /// <summary>
-        /// The start date of the recording, in UTC.
+        /// Gets or sets the start date of the recording, in UTC.
         /// </summary>
         public DateTime StartDate { get; set; }
 
         /// <summary>
-        /// The end date of the recording, in UTC.
+        /// Gets or sets the end date of the recording, in UTC.
         /// </summary>
         public DateTime EndDate { get; set; }
 
@@ -133,7 +132,7 @@ namespace MediaBrowser.Controller.LiveTv
         public bool IsSeries { get; set; }
 
         /// <summary>
-        /// Gets or sets a value indicating whether this instance is live.
+        /// Gets a value indicating whether this instance is live.
         /// </summary>
         /// <value><c>true</c> if this instance is live; otherwise, <c>false</c>.</value>
         [JsonIgnore]
diff --git a/MediaBrowser.Controller/MediaBrowser.Controller.csproj b/MediaBrowser.Controller/MediaBrowser.Controller.csproj
index 37ce35fc2..ee76ff080 100644
--- a/MediaBrowser.Controller/MediaBrowser.Controller.csproj
+++ b/MediaBrowser.Controller/MediaBrowser.Controller.csproj
@@ -16,13 +16,14 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="5.0.0" />
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
     <PackageReference Include="System.Threading.Tasks.Dataflow" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\MediaBrowser.Model\MediaBrowser.Model.csproj" />
-    <ProjectReference Include="..\MediaBrowser.Common\MediaBrowser.Common.csproj" />
+    <ProjectReference Include="../Emby.Naming/Emby.Naming.csproj" />
+    <ProjectReference Include="../MediaBrowser.Model/MediaBrowser.Model.csproj" />
+    <ProjectReference Include="../MediaBrowser.Common/MediaBrowser.Common.csproj" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingJobOptions.cs b/MediaBrowser.Controller/MediaEncoding/BaseEncodingJobOptions.cs
index 88de5b292..745ee6bdb 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingJobOptions.cs
+++ b/MediaBrowser.Controller/MediaEncoding/BaseEncodingJobOptions.cs
@@ -1,63 +1,13 @@
-#nullable disable
+#nullable disable
 
 #pragma warning disable CS1591
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using MediaBrowser.Model.Dlna;
 
 namespace MediaBrowser.Controller.MediaEncoding
 {
-    public class EncodingJobOptions : BaseEncodingJobOptions
-    {
-        public string OutputDirectory { get; set; }
-
-        public string ItemId { get; set; }
-
-        public string TempDirectory { get; set; }
-
-        public bool ReadInputAtNativeFramerate { get; set; }
-
-        /// <summary>
-        /// Gets a value indicating whether this instance has fixed resolution.
-        /// </summary>
-        /// <value><c>true</c> if this instance has fixed resolution; otherwise, <c>false</c>.</value>
-        public bool HasFixedResolution => Width.HasValue || Height.HasValue;
-
-        public DeviceProfile DeviceProfile { get; set; }
-
-        public EncodingJobOptions(StreamInfo info, DeviceProfile deviceProfile)
-        {
-            Container = info.Container;
-            StartTimeTicks = info.StartPositionTicks;
-            MaxWidth = info.MaxWidth;
-            MaxHeight = info.MaxHeight;
-            MaxFramerate = info.MaxFramerate;
-            Id = info.ItemId;
-            MediaSourceId = info.MediaSourceId;
-            AudioCodec = info.TargetAudioCodec.FirstOrDefault();
-            MaxAudioChannels = info.GlobalMaxAudioChannels;
-            AudioBitRate = info.AudioBitrate;
-            AudioSampleRate = info.TargetAudioSampleRate;
-            DeviceProfile = deviceProfile;
-            VideoCodec = info.TargetVideoCodec.FirstOrDefault();
-            VideoBitRate = info.VideoBitrate;
-            AudioStreamIndex = info.AudioStreamIndex;
-            SubtitleMethod = info.SubtitleDeliveryMethod;
-            Context = info.Context;
-            TranscodingMaxAudioChannels = info.TranscodingMaxAudioChannels;
-
-            if (info.SubtitleDeliveryMethod != SubtitleDeliveryMethod.External)
-            {
-                SubtitleStreamIndex = info.SubtitleStreamIndex;
-            }
-
-            StreamOptions = info.StreamOptions;
-        }
-    }
-
-    // For now until api and media encoding layers are unified
     public class BaseEncodingJobOptions
     {
         /// <summary>
@@ -251,4 +201,4 @@ namespace MediaBrowser.Controller.MediaEncoding
             StreamOptions = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         }
     }
-}
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index 97cb8d63b..26b0bc3de 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -596,7 +596,8 @@ namespace MediaBrowser.Controller.MediaEncoding
                     && string.Equals(encodingOptions.HardwareAccelerationType, "nvenc", StringComparison.OrdinalIgnoreCase)
                     && isNvdecDecoder)
                 {
-                    arg.Append("-hwaccel_output_format cuda -autorotate 0 ");
+                    // Fix for 'No decoder surfaces left' error. https://trac.ffmpeg.org/ticket/7562
+                    arg.Append("-hwaccel_output_format cuda -extra_hw_frames 3 -autorotate 0 ");
                 }
 
                 if (state.IsVideoRequest
@@ -1070,7 +1071,6 @@ namespace MediaBrowser.Controller.MediaEncoding
             else if (string.Equals(videoEncoder, "h264_nvenc", StringComparison.OrdinalIgnoreCase) // h264 (h264_nvenc)
                      || string.Equals(videoEncoder, "hevc_nvenc", StringComparison.OrdinalIgnoreCase)) // hevc (hevc_nvenc)
             {
-                // following preset will be deprecated in ffmpeg 4.4, use p1~p7 instead.
                 switch (encodingOptions.EncoderPreset)
                 {
                     case "veryslow":
@@ -1166,7 +1166,9 @@ namespace MediaBrowser.Controller.MediaEncoding
                 profileScore = Math.Min(profileScore, 2);
 
                 // http://www.webmproject.org/docs/encoder-parameters/
-                param += string.Format(CultureInfo.InvariantCulture, " -speed 16 -quality good -profile:v {0} -slices 8 -crf {1} -qmin {2} -qmax {3}",
+                param += string.Format(
+                    CultureInfo.InvariantCulture,
+                    " -speed 16 -quality good -profile:v {0} -slices 8 -crf {1} -qmin {2} -qmax {3}",
                     profileScore.ToString(_usCulture),
                     crf,
                     qmin,
@@ -1251,7 +1253,7 @@ namespace MediaBrowser.Controller.MediaEncoding
             }
 
             if (string.Equals(videoEncoder, "h264_amf", StringComparison.OrdinalIgnoreCase)
-                && profile.Contains("constrainedbaseline", StringComparison.OrdinalIgnoreCase))
+                && profile.Contains("baseline", StringComparison.OrdinalIgnoreCase))
             {
                 profile = "constrained_baseline";
             }
@@ -1296,7 +1298,7 @@ namespace MediaBrowser.Controller.MediaEncoding
                     // hevc_qsv use -level 51 instead of -level 153.
                     if (double.TryParse(level, NumberStyles.Any, _usCulture, out double hevcLevel))
                     {
-                        param += " -level " + hevcLevel / 3;
+                        param += " -level " + (hevcLevel / 3);
                     }
                 }
                 else if (string.Equals(videoEncoder, "h264_amf", StringComparison.OrdinalIgnoreCase)
@@ -1392,7 +1394,7 @@ namespace MediaBrowser.Controller.MediaEncoding
                 var requestedProfile = requestedProfiles[0];
                 // strip spaces because they may be stripped out on the query string as well
                 if (!string.IsNullOrEmpty(videoStream.Profile)
-                    && !requestedProfiles.Contains(videoStream.Profile.Replace(" ", "", StringComparison.Ordinal), StringComparer.OrdinalIgnoreCase))
+                    && !requestedProfiles.Contains(videoStream.Profile.Replace(" ", string.Empty, StringComparison.Ordinal), StringComparer.OrdinalIgnoreCase))
                 {
                     var currentScore = GetVideoProfileScore(videoStream.Profile);
                     var requestedScore = GetVideoProfileScore(requestedProfile);
@@ -1801,7 +1803,7 @@ namespace MediaBrowser.Controller.MediaEncoding
             if (isTranscodingAudio
                 && state.TranscodingType != TranscodingJobType.Progressive
                 && resultChannels.HasValue
-                && (resultChannels.Value > 2 && resultChannels.Value < 6 || resultChannels.Value == 7))
+                && ((resultChannels.Value > 2 && resultChannels.Value < 6) || resultChannels.Value == 7))
             {
                 resultChannels = 2;
             }
@@ -2129,8 +2131,8 @@ namespace MediaBrowser.Controller.MediaEncoding
                 return (null, null);
             }
 
-            decimal inputWidth = Convert.ToDecimal(videoWidth ?? requestedWidth);
-            decimal inputHeight = Convert.ToDecimal(videoHeight ?? requestedHeight);
+            decimal inputWidth = Convert.ToDecimal(videoWidth ?? requestedWidth, CultureInfo.InvariantCulture);
+            decimal inputHeight = Convert.ToDecimal(videoHeight ?? requestedHeight, CultureInfo.InvariantCulture);
             decimal outputWidth = requestedWidth.HasValue ? Convert.ToDecimal(requestedWidth.Value) : inputWidth;
             decimal outputHeight = requestedHeight.HasValue ? Convert.ToDecimal(requestedHeight.Value) : inputHeight;
             decimal maximumWidth = requestedMaxWidth.HasValue ? Convert.ToDecimal(requestedMaxWidth.Value) : outputWidth;
@@ -2197,12 +2199,11 @@ namespace MediaBrowser.Controller.MediaEncoding
                 var isQsvHevcEncoder = videoEncoder.Contains("hevc_qsv", StringComparison.OrdinalIgnoreCase);
                 var isTonemappingSupported = IsTonemappingSupported(state, options);
                 var isVppTonemappingSupported = IsVppTonemappingSupported(state, options);
-                var isTonemappingSupportedOnVaapi = string.Equals(options.HardwareAccelerationType, "vaapi", StringComparison.OrdinalIgnoreCase)&& isVaapiDecoder && (isVaapiH264Encoder || isVaapiHevcEncoder);
+                var isTonemappingSupportedOnVaapi = string.Equals(options.HardwareAccelerationType, "vaapi", StringComparison.OrdinalIgnoreCase) && isVaapiDecoder && (isVaapiH264Encoder || isVaapiHevcEncoder);
                 var isTonemappingSupportedOnQsv = string.Equals(options.HardwareAccelerationType, "qsv", StringComparison.OrdinalIgnoreCase) && isVaapiDecoder && (isQsvH264Encoder || isQsvHevcEncoder);
                 var isP010PixFmtRequired = (isTonemappingSupportedOnVaapi && (isTonemappingSupported || isVppTonemappingSupported))
                     || (isTonemappingSupportedOnQsv && isVppTonemappingSupported);
 
-
                 var outputPixFmt = "format=nv12";
                 if (isP010PixFmtRequired)
                 {
@@ -2933,6 +2934,7 @@ namespace MediaBrowser.Controller.MediaEncoding
 
             return threads;
         }
+
 #nullable disable
         public void TryStreamCopy(EncodingJobInfo state)
         {
@@ -3174,8 +3176,8 @@ namespace MediaBrowser.Controller.MediaEncoding
             state.ReadInputAtNativeFramerate = mediaSource.ReadAtNativeFramerate;
 
             if (state.ReadInputAtNativeFramerate
-                || mediaSource.Protocol == MediaProtocol.File
-                && string.Equals(mediaSource.Container, "wtv", StringComparison.OrdinalIgnoreCase))
+                || (mediaSource.Protocol == MediaProtocol.File
+                && string.Equals(mediaSource.Container, "wtv", StringComparison.OrdinalIgnoreCase)))
             {
                 state.InputVideoSync = "-1";
                 state.InputAudioSync = "1";
@@ -3548,7 +3550,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Gets a hw decoder name
+        /// Gets a hw decoder name.
         /// </summary>
         public string GetHwDecoderName(EncodingOptions options, string decoder, string videoCodec, bool isColorDepth10)
         {
@@ -3566,7 +3568,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Gets a hwaccel type to use as a hardware decoder(dxva/vaapi) depending on the system
+        /// Gets a hwaccel type to use as a hardware decoder(dxva/vaapi) depending on the system.
         /// </summary>
         public string GetHwaccelType(EncodingJobInfo state, EncodingOptions options, string videoCodec, bool isColorDepth10)
         {
@@ -3692,7 +3694,7 @@ namespace MediaBrowser.Controller.MediaEncoding
 
             if (flags.Count > 0)
             {
-                return " -fflags " + string.Join("", flags);
+                return " -fflags " + string.Join(string.Empty, flags);
             }
 
             return string.Empty;
diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingJobInfo.cs b/MediaBrowser.Controller/MediaEncoding/EncodingJobInfo.cs
index 1e13382b7..bc0318ad7 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingJobInfo.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingJobInfo.cs
@@ -69,6 +69,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         private TranscodeReason[] _transcodeReasons = null;
+
         public TranscodeReason[] TranscodeReasons
         {
             get
@@ -274,6 +275,16 @@ namespace MediaBrowser.Controller.MediaEncoding
 
         public int? GetRequestedAudioChannels(string codec)
         {
+            if (!string.IsNullOrEmpty(codec))
+            {
+                var value = BaseRequest.GetOption(codec, "audiochannels");
+                if (!string.IsNullOrEmpty(value)
+                    && int.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out var result))
+                {
+                    return result;
+                }
+            }
+
             if (BaseRequest.MaxAudioChannels.HasValue)
             {
                 return BaseRequest.MaxAudioChannels;
@@ -289,16 +300,6 @@ namespace MediaBrowser.Controller.MediaEncoding
                 return BaseRequest.TranscodingMaxAudioChannels;
             }
 
-            if (!string.IsNullOrEmpty(codec))
-            {
-                var value = BaseRequest.GetOption(codec, "audiochannels");
-                if (!string.IsNullOrEmpty(value)
-                    && int.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out var result))
-                {
-                    return result;
-                }
-            }
-
             return null;
         }
 
@@ -430,7 +431,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Predicts the audio sample rate that will be in the output stream.
+        /// Gets the target video level.
         /// </summary>
         public double? TargetVideoLevel
         {
@@ -453,7 +454,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Predicts the audio sample rate that will be in the output stream.
+        /// Gets the target video bit depth.
         /// </summary>
         public int? TargetVideoBitDepth
         {
@@ -488,7 +489,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Predicts the audio sample rate that will be in the output stream.
+        /// Gets the target framerate.
         /// </summary>
         public float? TargetFramerate
         {
@@ -520,7 +521,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Predicts the audio sample rate that will be in the output stream.
+        /// Gets the target packet length.
         /// </summary>
         public int? TargetPacketLength
         {
@@ -536,7 +537,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         }
 
         /// <summary>
-        /// Predicts the audio sample rate that will be in the output stream.
+        /// Gets the target video profile.
         /// </summary>
         public string TargetVideoProfile
         {
@@ -700,25 +701,4 @@ namespace MediaBrowser.Controller.MediaEncoding
             Progress.Report(percentComplete.Value);
         }
     }
-
-    /// <summary>
-    /// Enum TranscodingJobType.
-    /// </summary>
-    public enum TranscodingJobType
-    {
-        /// <summary>
-        /// The progressive.
-        /// </summary>
-        Progressive,
-
-        /// <summary>
-        /// The HLS.
-        /// </summary>
-        Hls,
-
-        /// <summary>
-        /// The dash.
-        /// </summary>
-        Dash
-    }
 }
diff --git a/MediaBrowser.Controller/MediaEncoding/IMediaEncoder.cs b/MediaBrowser.Controller/MediaEncoding/IMediaEncoder.cs
index d3260280a..76a9fd7c7 100644
--- a/MediaBrowser.Controller/MediaEncoding/IMediaEncoder.cs
+++ b/MediaBrowser.Controller/MediaEncoding/IMediaEncoder.cs
@@ -20,7 +20,7 @@ namespace MediaBrowser.Controller.MediaEncoding
     public interface IMediaEncoder : ITranscoderSupport
     {
         /// <summary>
-        /// The location of the discovered FFmpeg tool.
+        /// Gets location of the discovered FFmpeg tool.
         /// </summary>
         FFmpegLocation EncoderLocation { get; }
 
diff --git a/MediaBrowser.Controller/MediaEncoding/JobLogger.cs b/MediaBrowser.Controller/MediaEncoding/JobLogger.cs
index aa5e2c403..b23c95112 100644
--- a/MediaBrowser.Controller/MediaEncoding/JobLogger.cs
+++ b/MediaBrowser.Controller/MediaEncoding/JobLogger.cs
@@ -6,6 +6,7 @@ using System;
 using System.Globalization;
 using System.IO;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 
diff --git a/MediaBrowser.Controller/MediaEncoding/TranscodingJobType.cs b/MediaBrowser.Controller/MediaEncoding/TranscodingJobType.cs
new file mode 100644
index 000000000..66b628371
--- /dev/null
+++ b/MediaBrowser.Controller/MediaEncoding/TranscodingJobType.cs
@@ -0,0 +1,23 @@
+namespace MediaBrowser.Controller.MediaEncoding
+{
+    /// <summary>
+    /// Enum TranscodingJobType.
+    /// </summary>
+    public enum TranscodingJobType
+    {
+        /// <summary>
+        /// The progressive.
+        /// </summary>
+        Progressive,
+
+        /// <summary>
+        /// The HLS.
+        /// </summary>
+        Hls,
+
+        /// <summary>
+        /// The dash.
+        /// </summary>
+        Dash
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Net/BasePeriodicWebSocketListener.cs b/MediaBrowser.Controller/Net/BasePeriodicWebSocketListener.cs
index 855467e8e..d8995ce74 100644
--- a/MediaBrowser.Controller/Net/BasePeriodicWebSocketListener.cs
+++ b/MediaBrowser.Controller/Net/BasePeriodicWebSocketListener.cs
@@ -270,13 +270,4 @@ namespace MediaBrowser.Controller.Net
             GC.SuppressFinalize(this);
         }
     }
-
-    public class WebSocketListenerState
-    {
-        public DateTime DateLastSendUtc { get; set; }
-
-        public long InitialDelayMs { get; set; }
-
-        public long IntervalMs { get; set; }
-    }
 }
diff --git a/MediaBrowser.Controller/Net/ISessionContext.cs b/MediaBrowser.Controller/Net/ISessionContext.cs
index a60dc2ea1..6b896b41f 100644
--- a/MediaBrowser.Controller/Net/ISessionContext.cs
+++ b/MediaBrowser.Controller/Net/ISessionContext.cs
@@ -10,10 +10,10 @@ namespace MediaBrowser.Controller.Net
     {
         SessionInfo GetSession(object requestContext);
 
-        User GetUser(object requestContext);
+        User? GetUser(object requestContext);
 
         SessionInfo GetSession(HttpContext requestContext);
 
-        User GetUser(HttpContext requestContext);
+        User? GetUser(HttpContext requestContext);
     }
 }
diff --git a/MediaBrowser.Controller/Net/IWebSocketConnection.cs b/MediaBrowser.Controller/Net/IWebSocketConnection.cs
index 5e9fce550..c8c5caf80 100644
--- a/MediaBrowser.Controller/Net/IWebSocketConnection.cs
+++ b/MediaBrowser.Controller/Net/IWebSocketConnection.cs
@@ -1,9 +1,5 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
-#nullable enable
-
 using System;
 using System.Net;
 using System.Net.WebSockets;
@@ -34,7 +30,7 @@ namespace MediaBrowser.Controller.Net
         DateTime LastKeepAliveDate { get; set; }
 
         /// <summary>
-        /// Gets or sets the query string.
+        /// Gets the query string.
         /// </summary>
         /// <value>The query string.</value>
         IQueryCollection QueryString { get; }
@@ -60,11 +56,11 @@ namespace MediaBrowser.Controller.Net
         /// <summary>
         /// Sends a message asynchronously.
         /// </summary>
-        /// <typeparam name="T"></typeparam>
+        /// <typeparam name="T">The type of websocket message data.</typeparam>
         /// <param name="message">The message.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        /// <exception cref="ArgumentNullException">message</exception>
+        /// <exception cref="ArgumentNullException">The message is null.</exception>
         Task SendAsync<T>(WebSocketMessage<T> message, CancellationToken cancellationToken);
 
         Task ProcessAsync(CancellationToken cancellationToken = default);
diff --git a/MediaBrowser.Controller/Net/WebSocketListenerState.cs b/MediaBrowser.Controller/Net/WebSocketListenerState.cs
new file mode 100644
index 000000000..70604d60a
--- /dev/null
+++ b/MediaBrowser.Controller/Net/WebSocketListenerState.cs
@@ -0,0 +1,17 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System;
+
+namespace MediaBrowser.Controller.Net
+{
+    public class WebSocketListenerState
+    {
+        public DateTime DateLastSendUtc { get; set; }
+
+        public long InitialDelayMs { get; set; }
+
+        public long IntervalMs { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Persistence/IItemRepository.cs b/MediaBrowser.Controller/Persistence/IItemRepository.cs
index 56fb36af2..0a9073e7f 100644
--- a/MediaBrowser.Controller/Persistence/IItemRepository.cs
+++ b/MediaBrowser.Controller/Persistence/IItemRepository.cs
@@ -49,21 +49,23 @@ namespace MediaBrowser.Controller.Persistence
         /// <summary>
         /// Gets chapters for an item.
         /// </summary>
-        /// <param name="id"></param>
-        /// <returns></returns>
+        /// <param name="id">The item.</param>
+        /// <returns>The list of chapter info.</returns>
         List<ChapterInfo> GetChapters(BaseItem id);
 
         /// <summary>
         /// Gets a single chapter for an item.
         /// </summary>
-        /// <param name="id"></param>
-        /// <param name="index"></param>
-        /// <returns></returns>
+        /// <param name="id">The item.</param>
+        /// <param name="index">The chapter index.</param>
+        /// <returns>The chapter info at the specified index.</returns>
         ChapterInfo GetChapter(BaseItem id, int index);
 
         /// <summary>
         /// Saves the chapters.
         /// </summary>
+        /// <param name="id">The item id.</param>
+        /// <param name="chapters">The list of chapters to save.</param>
         void SaveChapters(Guid id, IReadOnlyList<ChapterInfo> chapters);
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Persistence/IUserDataRepository.cs b/MediaBrowser.Controller/Persistence/IUserDataRepository.cs
index 6f5f02123..5fa5834c8 100644
--- a/MediaBrowser.Controller/Persistence/IUserDataRepository.cs
+++ b/MediaBrowser.Controller/Persistence/IUserDataRepository.cs
@@ -40,17 +40,16 @@ namespace MediaBrowser.Controller.Persistence
         /// <summary>
         /// Return all user data associated with the given user.
         /// </summary>
-        /// <param name="userId"></param>
-        /// <returns></returns>
+        /// <param name="userId">The user id.</param>
+        /// <returns>The list of user item data.</returns>
         List<UserItemData> GetAllUserData(long userId);
 
         /// <summary>
         /// Save all user data associated with the given user.
         /// </summary>
-        /// <param name="userId"></param>
-        /// <param name="userData"></param>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
+        /// <param name="userId">The user id.</param>
+        /// <param name="userData">The user item data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         void SaveAllUserData(long userId, UserItemData[] userData, CancellationToken cancellationToken);
     }
 }
diff --git a/MediaBrowser.Controller/Playlists/Playlist.cs b/MediaBrowser.Controller/Playlists/Playlist.cs
index a80c11643..3eaf23515 100644
--- a/MediaBrowser.Controller/Playlists/Playlist.cs
+++ b/MediaBrowser.Controller/Playlists/Playlist.cs
@@ -22,14 +22,14 @@ namespace MediaBrowser.Controller.Playlists
 {
     public class Playlist : Folder, IHasShares
     {
-        public static string[] SupportedExtensions =
-            {
-                ".m3u",
-                ".m3u8",
-                ".pls",
-                ".wpl",
-                ".zpl"
-            };
+        public static readonly IReadOnlyList<string> SupportedExtensions = new[]
+        {
+            ".m3u",
+            ".m3u8",
+            ".pls",
+            ".wpl",
+            ".zpl"
+        };
 
         public Guid OwnerUserId { get; set; }
 
@@ -101,7 +101,7 @@ namespace MediaBrowser.Controller.Playlists
             return new List<BaseItem>();
         }
 
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             return Task.CompletedTask;
         }
diff --git a/MediaBrowser.Controller/Plugins/IRunBeforeStartup.cs b/MediaBrowser.Controller/Plugins/IRunBeforeStartup.cs
new file mode 100644
index 000000000..2b831103a
--- /dev/null
+++ b/MediaBrowser.Controller/Plugins/IRunBeforeStartup.cs
@@ -0,0 +1,9 @@
+namespace MediaBrowser.Controller.Plugins
+{
+    /// <summary>
+    /// Indicates that a <see cref="IServerEntryPoint"/> should be invoked as a pre-startup task.
+    /// </summary>
+    public interface IRunBeforeStartup
+    {
+    }
+}
diff --git a/MediaBrowser.Controller/Plugins/IServerEntryPoint.cs b/MediaBrowser.Controller/Plugins/IServerEntryPoint.cs
index b44e2531e..6024661e1 100644
--- a/MediaBrowser.Controller/Plugins/IServerEntryPoint.cs
+++ b/MediaBrowser.Controller/Plugins/IServerEntryPoint.cs
@@ -14,13 +14,7 @@ namespace MediaBrowser.Controller.Plugins
         /// <summary>
         /// Run the initialization for this module. This method is invoked at application start.
         /// </summary>
+        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
         Task RunAsync();
     }
-
-    /// <summary>
-    /// Indicates that a <see cref="IServerEntryPoint"/> should be invoked as a pre-startup task.
-    /// </summary>
-    public interface IRunBeforeStartup
-    {
-    }
 }
diff --git a/MediaBrowser.Controller/Providers/AlbumInfo.cs b/MediaBrowser.Controller/Providers/AlbumInfo.cs
index 276bcf125..c7fad5974 100644
--- a/MediaBrowser.Controller/Providers/AlbumInfo.cs
+++ b/MediaBrowser.Controller/Providers/AlbumInfo.cs
@@ -7,6 +7,13 @@ namespace MediaBrowser.Controller.Providers
 {
     public class AlbumInfo : ItemLookupInfo
     {
+        public AlbumInfo()
+        {
+            ArtistProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            SongInfos = new List<SongInfo>();
+            AlbumArtists = Array.Empty<string>();
+        }
+
         /// <summary>
         /// Gets or sets the album artist.
         /// </summary>
@@ -20,12 +27,5 @@ namespace MediaBrowser.Controller.Providers
         public Dictionary<string, string> ArtistProviderIds { get; set; }
 
         public List<SongInfo> SongInfos { get; set; }
-
-        public AlbumInfo()
-        {
-            ArtistProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-            SongInfos = new List<SongInfo>();
-            AlbumArtists = Array.Empty<string>();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/ArtistInfo.cs b/MediaBrowser.Controller/Providers/ArtistInfo.cs
index adf885baa..e9181f476 100644
--- a/MediaBrowser.Controller/Providers/ArtistInfo.cs
+++ b/MediaBrowser.Controller/Providers/ArtistInfo.cs
@@ -6,11 +6,11 @@ namespace MediaBrowser.Controller.Providers
 {
     public class ArtistInfo : ItemLookupInfo
     {
-        public List<SongInfo> SongInfos { get; set; }
-
         public ArtistInfo()
         {
             SongInfos = new List<SongInfo>();
         }
+
+        public List<SongInfo> SongInfos { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/DirectoryService.cs b/MediaBrowser.Controller/Providers/DirectoryService.cs
index 291a26883..b31270270 100644
--- a/MediaBrowser.Controller/Providers/DirectoryService.cs
+++ b/MediaBrowser.Controller/Providers/DirectoryService.cs
@@ -25,15 +25,16 @@ namespace MediaBrowser.Controller.Providers
 
         public FileSystemMetadata[] GetFileSystemEntries(string path)
         {
-            return _cache.GetOrAdd(path, p => _fileSystem.GetFileSystemEntries(p).ToArray());
+            return _cache.GetOrAdd(path, (p, fileSystem) => fileSystem.GetFileSystemEntries(p).ToArray(), _fileSystem);
         }
 
         public List<FileSystemMetadata> GetFiles(string path)
         {
             var list = new List<FileSystemMetadata>();
             var items = GetFileSystemEntries(path);
-            foreach (var item in items)
+            for (var i = 0; i < items.Length; i++)
             {
+                var item = items[i];
                 if (!item.IsDirectory)
                 {
                     list.Add(item);
@@ -48,10 +49,9 @@ namespace MediaBrowser.Controller.Providers
             if (!_fileCache.TryGetValue(path, out var result))
             {
                 var file = _fileSystem.GetFileInfo(path);
-                var res = file != null && file.Exists ? file : null;
-                if (res != null)
+                if (file.Exists)
                 {
-                    result = res;
+                    result = file;
                     _fileCache.TryAdd(path, result);
                 }
             }
@@ -62,14 +62,21 @@ namespace MediaBrowser.Controller.Providers
         public IReadOnlyList<string> GetFilePaths(string path)
             => GetFilePaths(path, false);
 
-        public IReadOnlyList<string> GetFilePaths(string path, bool clearCache)
+        public IReadOnlyList<string> GetFilePaths(string path, bool clearCache, bool sort = false)
         {
             if (clearCache)
             {
                 _filePathCache.TryRemove(path, out _);
             }
 
-            return _filePathCache.GetOrAdd(path, p => _fileSystem.GetFilePaths(p).ToList());
+            var filePaths = _filePathCache.GetOrAdd(path, (p, fileSystem) => fileSystem.GetFilePaths(p).ToList(), _fileSystem);
+
+            if (sort)
+            {
+                filePaths.Sort();
+            }
+
+            return filePaths;
         }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/EpisodeInfo.cs b/MediaBrowser.Controller/Providers/EpisodeInfo.cs
index 341bf6936..0c932fa87 100644
--- a/MediaBrowser.Controller/Providers/EpisodeInfo.cs
+++ b/MediaBrowser.Controller/Providers/EpisodeInfo.cs
@@ -9,6 +9,11 @@ namespace MediaBrowser.Controller.Providers
 {
     public class EpisodeInfo : ItemLookupInfo
     {
+        public EpisodeInfo()
+        {
+            SeriesProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        }
+
         public Dictionary<string, string> SeriesProviderIds { get; set; }
 
         public int? IndexNumberEnd { get; set; }
@@ -16,10 +21,5 @@ namespace MediaBrowser.Controller.Providers
         public bool IsMissingEpisode { get; set; }
 
         public string SeriesDisplayOrder { get; set; }
-
-        public EpisodeInfo()
-        {
-            SeriesProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/IDirectoryService.cs b/MediaBrowser.Controller/Providers/IDirectoryService.cs
index 9cee06a4c..b1a36e102 100644
--- a/MediaBrowser.Controller/Providers/IDirectoryService.cs
+++ b/MediaBrowser.Controller/Providers/IDirectoryService.cs
@@ -15,6 +15,6 @@ namespace MediaBrowser.Controller.Providers
 
         IReadOnlyList<string> GetFilePaths(string path);
 
-        IReadOnlyList<string> GetFilePaths(string path, bool clearCache);
+        IReadOnlyList<string> GetFilePaths(string path, bool clearCache, bool sort = false);
     }
 }
diff --git a/MediaBrowser.Controller/Providers/IMetadataService.cs b/MediaBrowser.Controller/Providers/IMetadataService.cs
index 5f3d4274e..05fbb18ee 100644
--- a/MediaBrowser.Controller/Providers/IMetadataService.cs
+++ b/MediaBrowser.Controller/Providers/IMetadataService.cs
@@ -11,6 +11,12 @@ namespace MediaBrowser.Controller.Providers
     public interface IMetadataService
     {
         /// <summary>
+        /// Gets the order.
+        /// </summary>
+        /// <value>The order.</value>
+        int Order { get; }
+
+        /// <summary>
         /// Determines whether this instance can refresh the specified item.
         /// </summary>
         /// <param name="item">The item.</param>
@@ -27,11 +33,5 @@ namespace MediaBrowser.Controller.Providers
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
         Task<ItemUpdateType> RefreshMetadata(BaseItem item, MetadataRefreshOptions refreshOptions, CancellationToken cancellationToken);
-
-        /// <summary>
-        /// Gets the order.
-        /// </summary>
-        /// <value>The order.</value>
-        int Order { get; }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/IProviderManager.cs b/MediaBrowser.Controller/Providers/IProviderManager.cs
index b4d91f396..684bd9e68 100644
--- a/MediaBrowser.Controller/Providers/IProviderManager.cs
+++ b/MediaBrowser.Controller/Providers/IProviderManager.cs
@@ -191,11 +191,4 @@ namespace MediaBrowser.Controller.Providers
 
         double? GetRefreshProgress(Guid id);
     }
-
-    public enum RefreshPriority
-    {
-        High = 0,
-        Normal = 1,
-        Low = 2
-    }
 }
diff --git a/MediaBrowser.Controller/Providers/ItemLookupInfo.cs b/MediaBrowser.Controller/Providers/ItemLookupInfo.cs
index f16669a78..2fd89e3bb 100644
--- a/MediaBrowser.Controller/Providers/ItemLookupInfo.cs
+++ b/MediaBrowser.Controller/Providers/ItemLookupInfo.cs
@@ -10,6 +10,12 @@ namespace MediaBrowser.Controller.Providers
 {
     public class ItemLookupInfo : IHasProviderIds
     {
+        public ItemLookupInfo()
+        {
+            IsAutomated = true;
+            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        }
+
         /// <summary>
         /// Gets or sets the name.
         /// </summary>
@@ -17,6 +23,12 @@ namespace MediaBrowser.Controller.Providers
         public string Name { get; set; }
 
         /// <summary>
+        /// Gets or sets the original title
+        /// </summary>
+        /// <value>The original title of the item.</value>
+        public string OriginalTitle { get; set; }
+
+        /// <summary>
         /// Gets or sets the path.
         /// </summary>
         /// <value>The path.</value>
@@ -53,11 +65,5 @@ namespace MediaBrowser.Controller.Providers
         public DateTime? PremiereDate { get; set; }
 
         public bool IsAutomated { get; set; }
-
-        public ItemLookupInfo()
-        {
-            IsAutomated = true;
-            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Providers/MetadataRefreshOptions.cs b/MediaBrowser.Controller/Providers/MetadataRefreshOptions.cs
index 5afc358ba..2cf536779 100644
--- a/MediaBrowser.Controller/Providers/MetadataRefreshOptions.cs
+++ b/MediaBrowser.Controller/Providers/MetadataRefreshOptions.cs
@@ -11,21 +11,6 @@ namespace MediaBrowser.Controller.Providers
 {
     public class MetadataRefreshOptions : ImageRefreshOptions
     {
-        /// <summary>
-        /// When paired with MetadataRefreshMode=FullRefresh, all existing data will be overwritten with new data from the providers.
-        /// </summary>
-        public bool ReplaceAllMetadata { get; set; }
-
-        public MetadataRefreshMode MetadataRefreshMode { get; set; }
-
-        public RemoteSearchResult SearchResult { get; set; }
-
-        public string[] RefreshPaths { get; set; }
-
-        public bool ForceSave { get; set; }
-
-        public bool EnableRemoteContentProbe { get; set; }
-
         public MetadataRefreshOptions(IDirectoryService directoryService)
             : base(directoryService)
         {
@@ -53,6 +38,22 @@ namespace MediaBrowser.Controller.Providers
             }
         }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether all existing data should be overwritten with new data from providers
+        /// when paired with MetadataRefreshMode=FullRefresh.
+        /// </summary>
+        public bool ReplaceAllMetadata { get; set; }
+
+        public MetadataRefreshMode MetadataRefreshMode { get; set; }
+
+        public RemoteSearchResult SearchResult { get; set; }
+
+        public string[] RefreshPaths { get; set; }
+
+        public bool ForceSave { get; set; }
+
+        public bool EnableRemoteContentProbe { get; set; }
+
         public bool RefreshItem(BaseItem item)
         {
             if (RefreshPaths != null && RefreshPaths.Length > 0)
diff --git a/MediaBrowser.Controller/Providers/MetadataResult.cs b/MediaBrowser.Controller/Providers/MetadataResult.cs
index 8b0967a6e..7ec1eefcd 100644
--- a/MediaBrowser.Controller/Providers/MetadataResult.cs
+++ b/MediaBrowser.Controller/Providers/MetadataResult.cs
@@ -12,16 +12,26 @@ namespace MediaBrowser.Controller.Providers
 {
     public class MetadataResult<T>
     {
+        // Images aren't always used so the allocation is a waste a lot of the time
+        private List<LocalImageInfo> _images;
+        private List<(string url, ImageType type)> _remoteImages;
+
         public MetadataResult()
         {
-            Images = new List<LocalImageInfo>();
-            RemoteImages = new List<(string url, ImageType type)>();
             ResultLanguage = "en";
         }
 
-        public List<LocalImageInfo> Images { get; set; }
+        public List<LocalImageInfo> Images
+        {
+            get => _images ??= new List<LocalImageInfo>();
+            set => _images = value;
+        }
 
-        public List<(string url, ImageType type)> RemoteImages { get; set; }
+        public List<(string url, ImageType type)> RemoteImages
+        {
+            get => _remoteImages ??= new List<(string url, ImageType type)>();
+            set => _remoteImages = value;
+        }
 
         public List<UserItemData> UserDataList { get; set; }
 
diff --git a/MediaBrowser.Controller/Providers/RefreshPriority.cs b/MediaBrowser.Controller/Providers/RefreshPriority.cs
new file mode 100644
index 000000000..3619f679d
--- /dev/null
+++ b/MediaBrowser.Controller/Providers/RefreshPriority.cs
@@ -0,0 +1,23 @@
+namespace MediaBrowser.Controller.Providers
+{
+    /// <summary>
+    /// Provider refresh priority.
+    /// </summary>
+    public enum RefreshPriority
+    {
+        /// <summary>
+        /// High priority.
+        /// </summary>
+        High = 0,
+
+        /// <summary>
+        /// Normal priority.
+        /// </summary>
+        Normal = 1,
+
+        /// <summary>
+        /// Low priority.
+        /// </summary>
+        Low = 2
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Providers/RemoteSearchQuery.cs b/MediaBrowser.Controller/Providers/RemoteSearchQuery.cs
index d830231cf..d4df5fa0d 100644
--- a/MediaBrowser.Controller/Providers/RemoteSearchQuery.cs
+++ b/MediaBrowser.Controller/Providers/RemoteSearchQuery.cs
@@ -14,7 +14,7 @@ namespace MediaBrowser.Controller.Providers
         public Guid ItemId { get; set; }
 
         /// <summary>
-        /// Will only search within the given provider when set.
+        /// Gets or sets the provider name to search within if set.
         /// </summary>
         public string SearchProviderName { get; set; }
 
diff --git a/MediaBrowser.Controller/Providers/SeasonInfo.cs b/MediaBrowser.Controller/Providers/SeasonInfo.cs
index 2a4c1f03c..7e39bc37a 100644
--- a/MediaBrowser.Controller/Providers/SeasonInfo.cs
+++ b/MediaBrowser.Controller/Providers/SeasonInfo.cs
@@ -7,11 +7,11 @@ namespace MediaBrowser.Controller.Providers
 {
     public class SeasonInfo : ItemLookupInfo
     {
-        public Dictionary<string, string> SeriesProviderIds { get; set; }
-
         public SeasonInfo()
         {
             SeriesProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         }
+
+        public Dictionary<string, string> SeriesProviderIds { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Resolvers/IResolverIgnoreRule.cs b/MediaBrowser.Controller/Resolvers/IResolverIgnoreRule.cs
index bb80e6025..a07b3e898 100644
--- a/MediaBrowser.Controller/Resolvers/IResolverIgnoreRule.cs
+++ b/MediaBrowser.Controller/Resolvers/IResolverIgnoreRule.cs
@@ -4,7 +4,7 @@ using MediaBrowser.Model.IO;
 namespace MediaBrowser.Controller.Resolvers
 {
     /// <summary>
-    /// Provides a base "rule" that anyone can use to have paths ignored by the resolver
+    /// Provides a base "rule" that anyone can use to have paths ignored by the resolver.
     /// </summary>
     public interface IResolverIgnoreRule
     {
diff --git a/MediaBrowser.Controller/Resolvers/BaseItemResolver.cs b/MediaBrowser.Controller/Resolvers/ItemResolver.cs
index e77593a03..7fd54fcc6 100644
--- a/MediaBrowser.Controller/Resolvers/BaseItemResolver.cs
+++ b/MediaBrowser.Controller/Resolvers/ItemResolver.cs
@@ -8,7 +8,7 @@ namespace MediaBrowser.Controller.Resolvers
     /// <summary>
     /// Class ItemResolver.
     /// </summary>
-    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="T">The type of BaseItem.</typeparam>
     public abstract class ItemResolver<T> : IItemResolver
         where T : BaseItem, new()
     {
diff --git a/MediaBrowser.Controller/Session/ISessionManager.cs b/MediaBrowser.Controller/Session/ISessionManager.cs
index 7eda49c60..4c3cf5ffe 100644
--- a/MediaBrowser.Controller/Session/ISessionManager.cs
+++ b/MediaBrowser.Controller/Session/ISessionManager.cs
@@ -346,21 +346,19 @@ namespace MediaBrowser.Controller.Session
         /// Logouts the specified access token.
         /// </summary>
         /// <param name="accessToken">The access token.</param>
-        /// <returns>Task.</returns>
         void Logout(string accessToken);
+
         void Logout(AuthenticationInfo accessToken);
 
         /// <summary>
         /// Revokes the user tokens.
         /// </summary>
-        /// <returns>Task.</returns>
         void RevokeUserTokens(Guid userId, string currentAccessToken);
 
         /// <summary>
         /// Revokes the token.
         /// </summary>
         /// <param name="id">The identifier.</param>
-        /// <returns>Task.</returns>
         void RevokeToken(string id);
 
         void CloseIfNeeded(SessionInfo session);
diff --git a/MediaBrowser.Controller/Session/SessionInfo.cs b/MediaBrowser.Controller/Session/SessionInfo.cs
index 5da3783bf..6134c0cf3 100644
--- a/MediaBrowser.Controller/Session/SessionInfo.cs
+++ b/MediaBrowser.Controller/Session/SessionInfo.cs
@@ -54,7 +54,7 @@ namespace MediaBrowser.Controller.Session
         public string RemoteEndPoint { get; set; }
 
         /// <summary>
-        /// Gets or sets the playable media types.
+        /// Gets the playable media types.
         /// </summary>
         /// <value>The playable media types.</value>
         public IReadOnlyList<string> PlayableMediaTypes
@@ -230,7 +230,7 @@ namespace MediaBrowser.Controller.Session
         public string UserPrimaryImageTag { get; set; }
 
         /// <summary>
-        /// Gets or sets the supported commands.
+        /// Gets the supported commands.
         /// </summary>
         /// <value>The supported commands.</value>
         public IReadOnlyList<GeneralCommandType> SupportedCommands
diff --git a/MediaBrowser.Controller/Sorting/AlphanumComparator.cs b/MediaBrowser.Controller/Sorting/AlphanumComparator.cs
index 4d9b98889..e00cadca2 100644
--- a/MediaBrowser.Controller/Sorting/AlphanumComparator.cs
+++ b/MediaBrowser.Controller/Sorting/AlphanumComparator.cs
@@ -121,7 +121,9 @@ namespace MediaBrowser.Controller.Sorting
                         return result;
                     }
                 }
+#pragma warning disable SA1500 // TODO remove with StyleCop.Analyzers v1.2.0 https://github.com/DotNetAnalyzers/StyleCopAnalyzers/pull/3196
             } while (pos1 < len1 && pos2 < len2);
+#pragma warning restore SA1500
 
             return len1 - len2;
         }
diff --git a/MediaBrowser.Controller/Sorting/IBaseItemComparer.cs b/MediaBrowser.Controller/Sorting/IBaseItemComparer.cs
index 727cbe639..07fe1ea8a 100644
--- a/MediaBrowser.Controller/Sorting/IBaseItemComparer.cs
+++ b/MediaBrowser.Controller/Sorting/IBaseItemComparer.cs
@@ -6,7 +6,7 @@ namespace MediaBrowser.Controller.Sorting
     /// <summary>
     /// Interface IBaseItemComparer.
     /// </summary>
-    public interface IBaseItemComparer : IComparer<BaseItem>
+    public interface IBaseItemComparer : IComparer<BaseItem?>
     {
         /// <summary>
         /// Gets the name.
diff --git a/MediaBrowser.Controller/Sync/IHasDynamicAccess.cs b/MediaBrowser.Controller/Sync/IHasDynamicAccess.cs
deleted file mode 100644
index 3d3e44da0..000000000
--- a/MediaBrowser.Controller/Sync/IHasDynamicAccess.cs
+++ /dev/null
@@ -1,22 +0,0 @@
-#nullable disable
-
-#pragma warning disable CS1591
-
-using System.Threading;
-using System.Threading.Tasks;
-using MediaBrowser.Model.Sync;
-
-namespace MediaBrowser.Controller.Sync
-{
-    public interface IHasDynamicAccess
-    {
-        /// <summary>
-        /// Gets the synced file information.
-        /// </summary>
-        /// <param name="id">The identifier.</param>
-        /// <param name="target">The target.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task&lt;SyncedFileInfo&gt;.</returns>
-        Task<SyncedFileInfo> GetSyncedFileInfo(string id, SyncTarget target, CancellationToken cancellationToken);
-    }
-}
diff --git a/MediaBrowser.Controller/Sync/IRemoteSyncProvider.cs b/MediaBrowser.Controller/Sync/IRemoteSyncProvider.cs
deleted file mode 100644
index b2c53365c..000000000
--- a/MediaBrowser.Controller/Sync/IRemoteSyncProvider.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-namespace MediaBrowser.Controller.Sync
-{
-    /// <summary>
-    /// A marker interface.
-    /// </summary>
-    public interface IRemoteSyncProvider
-    {
-    }
-}
diff --git a/MediaBrowser.Controller/Sync/IServerSyncProvider.cs b/MediaBrowser.Controller/Sync/IServerSyncProvider.cs
deleted file mode 100644
index 3891ac0a6..000000000
--- a/MediaBrowser.Controller/Sync/IServerSyncProvider.cs
+++ /dev/null
@@ -1,32 +0,0 @@
-#nullable disable
-
-#pragma warning disable CS1591
-
-using System;
-using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
-using MediaBrowser.Model.IO;
-using MediaBrowser.Model.Querying;
-using MediaBrowser.Model.Sync;
-
-namespace MediaBrowser.Controller.Sync
-{
-    public interface IServerSyncProvider : ISyncProvider
-    {
-        /// <summary>
-        /// Transfers the file.
-        /// </summary>
-        Task<SyncedFileInfo> SendFile(SyncJob syncJob, string originalMediaPath, Stream inputStream, bool isMedia, string[] outputPathParts, SyncTarget target, IProgress<double> progress, CancellationToken cancellationToken);
-
-        Task<QueryResult<FileSystemMetadata>> GetFiles(string[] directoryPathParts, SyncTarget target, CancellationToken cancellationToken);
-    }
-
-    public interface ISupportsDirectCopy
-    {
-        /// <summary>
-        /// Sends the file.
-        /// </summary>
-        Task<SyncedFileInfo> SendFile(SyncJob syncJob, string originalMediaPath, string inputPath, bool isMedia, string[] outputPathParts, SyncTarget target, IProgress<double> progress, CancellationToken cancellationToken);
-    }
-}
diff --git a/MediaBrowser.Controller/Sync/ISyncProvider.cs b/MediaBrowser.Controller/Sync/ISyncProvider.cs
deleted file mode 100644
index ea20014c7..000000000
--- a/MediaBrowser.Controller/Sync/ISyncProvider.cs
+++ /dev/null
@@ -1,31 +0,0 @@
-#nullable disable
-
-#pragma warning disable CS1591
-
-using System.Collections.Generic;
-using MediaBrowser.Model.Sync;
-
-namespace MediaBrowser.Controller.Sync
-{
-    public interface ISyncProvider
-    {
-        /// <summary>
-        /// Gets the name.
-        /// </summary>
-        /// <value>The name.</value>
-        string Name { get; }
-
-        /// <summary>
-        /// Gets the synchronize targets.
-        /// </summary>
-        /// <param name="userId">The user identifier.</param>
-        /// <returns>IEnumerable&lt;SyncTarget&gt;.</returns>
-        List<SyncTarget> GetSyncTargets(string userId);
-
-        /// <summary>
-        /// Gets all synchronize targets.
-        /// </summary>
-        /// <returns>IEnumerable&lt;SyncTarget&gt;.</returns>
-        List<SyncTarget> GetAllSyncTargets();
-    }
-}
diff --git a/MediaBrowser.Controller/Sync/SyncedFileInfo.cs b/MediaBrowser.Controller/Sync/SyncedFileInfo.cs
deleted file mode 100644
index 7eac52299..000000000
--- a/MediaBrowser.Controller/Sync/SyncedFileInfo.cs
+++ /dev/null
@@ -1,43 +0,0 @@
-#nullable disable
-
-#pragma warning disable CS1591
-
-using System.Collections.Generic;
-using MediaBrowser.Model.MediaInfo;
-
-namespace MediaBrowser.Controller.Sync
-{
-    public class SyncedFileInfo
-    {
-        public SyncedFileInfo()
-        {
-            RequiredHttpHeaders = new Dictionary<string, string>();
-        }
-
-        /// <summary>
-        /// Gets or sets the path.
-        /// </summary>
-        /// <value>The path.</value>
-        public string Path { get; set; }
-
-        public string[] PathParts { get; set; }
-
-        /// <summary>
-        /// Gets or sets the protocol.
-        /// </summary>
-        /// <value>The protocol.</value>
-        public MediaProtocol Protocol { get; set; }
-
-        /// <summary>
-        /// Gets or sets the required HTTP headers.
-        /// </summary>
-        /// <value>The required HTTP headers.</value>
-        public Dictionary<string, string> RequiredHttpHeaders { get; set; }
-
-        /// <summary>
-        /// Gets or sets the identifier.
-        /// </summary>
-        /// <value>The identifier.</value>
-        public string Id { get; set; }
-    }
-}
diff --git a/MediaBrowser.Controller/TV/ITVSeriesManager.cs b/MediaBrowser.Controller/TV/ITVSeriesManager.cs
index 291dea04e..e066c03fd 100644
--- a/MediaBrowser.Controller/TV/ITVSeriesManager.cs
+++ b/MediaBrowser.Controller/TV/ITVSeriesManager.cs
@@ -6,16 +6,26 @@ using MediaBrowser.Model.Querying;
 
 namespace MediaBrowser.Controller.TV
 {
+    /// <summary>
+    /// The TV Series manager.
+    /// </summary>
     public interface ITVSeriesManager
     {
         /// <summary>
         /// Gets the next up.
         /// </summary>
+        /// <param name="query">The next up query.</param>
+        /// <param name="options">The dto options.</param>
+        /// <returns>The next up items.</returns>
         QueryResult<BaseItem> GetNextUp(NextUpQuery query, DtoOptions options);
 
         /// <summary>
         /// Gets the next up.
         /// </summary>
+        /// <param name="request">The next up request.</param>
+        /// <param name="parentsFolders">The list of parent folders.</param>
+        /// <param name="options">The dto options.</param>
+        /// <returns>The next up items.</returns>
         QueryResult<BaseItem> GetNextUp(NextUpQuery request, BaseItem[] parentsFolders, DtoOptions options);
     }
 }