diff --git a/MediaBrowser.Controller/MediaBrowser.Controller.csproj b/MediaBrowser.Controller/MediaBrowser.Controller.csproj
index 1c03e11ddd..8c2895701e 100644
--- a/MediaBrowser.Controller/MediaBrowser.Controller.csproj
+++ b/MediaBrowser.Controller/MediaBrowser.Controller.csproj
@@ -146,7 +146,6 @@
     <Compile Include="Providers\FanartBaseProvider.cs" />
     <Compile Include="Providers\IImageEnhancer.cs" />
     <Compile Include="Providers\ImagesByNameProvider.cs" />
-    <Compile Include="Providers\MediaInfo\BaseFFMpegImageProvider.cs" />
     <Compile Include="Providers\MediaInfo\BaseFFMpegProvider.cs" />
     <Compile Include="Providers\MediaInfo\FFMpegAudioImageProvider.cs" />
     <Compile Include="Providers\MediaInfo\BaseFFProbeProvider.cs" />
diff --git a/MediaBrowser.Controller/MediaInfo/FFMpegManager.cs b/MediaBrowser.Controller/MediaInfo/FFMpegManager.cs
index 3a4f3cae7e..f0a960ce1b 100644
--- a/MediaBrowser.Controller/MediaInfo/FFMpegManager.cs
+++ b/MediaBrowser.Controller/MediaInfo/FFMpegManager.cs
@@ -735,16 +735,16 @@ namespace MediaBrowser.Controller.MediaInfo
         /// <summary>
         /// Extracts an image from an Audio file and returns a Task whose result indicates whether it was successful or not
         /// </summary>
-        /// <param name="input">The input.</param>
+        /// <param name="inputPath">The input path.</param>
         /// <param name="outputPath">The output path.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task{System.Boolean}.</returns>
         /// <exception cref="System.ArgumentNullException">input</exception>
-        public async Task<bool> ExtractImage(Audio input, string outputPath, CancellationToken cancellationToken)
+        public async Task<bool> ExtractAudioImage(string inputPath, string outputPath, CancellationToken cancellationToken)
         {
-            if (input == null)
+            if (string.IsNullOrEmpty(inputPath))
             {
-                throw new ArgumentNullException("input");
+                throw new ArgumentNullException("inputPath");
             }
 
             if (string.IsNullOrEmpty(outputPath))
@@ -759,7 +759,7 @@ namespace MediaBrowser.Controller.MediaInfo
                     CreateNoWindow = true,
                     UseShellExecute = false,
                     FileName = FFMpegPath,
-                    Arguments = string.Format("-i {0} -threads 0 -v quiet -f image2 \"{1}\"", GetInputArgument(input), outputPath),
+                    Arguments = string.Format("-i {0} -threads 0 -v quiet -f image2 \"{1}\"", GetFileInputArgument(inputPath), outputPath),
                     WindowStyle = ProcessWindowStyle.Hidden,
                     ErrorDialog = false
                 }
@@ -780,7 +780,7 @@ namespace MediaBrowser.Controller.MediaInfo
                 return true;
             }
 
-            _logger.Error("ffmpeg audio image extraction failed for {0}", input.Path);
+            _logger.Error("ffmpeg audio image extraction failed for {0}", inputPath);
             return false;
         }
 
@@ -1039,6 +1039,16 @@ namespace MediaBrowser.Controller.MediaInfo
             return string.Format("file:\"{0}\"", item.Path);
         }
 
+        /// <summary>
+        /// Gets the file input argument.
+        /// </summary>
+        /// <param name="path">The path.</param>
+        /// <returns>System.String.</returns>
+        private string GetFileInputArgument(string path)
+        {
+            return string.Format("file:\"{0}\"", path);
+        }
+
         /// <summary>
         /// Gets the input argument.
         /// </summary>
diff --git a/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegImageProvider.cs b/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegImageProvider.cs
deleted file mode 100644
index 902fdca27b..0000000000
--- a/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegImageProvider.cs
+++ /dev/null
@@ -1,23 +0,0 @@
-using MediaBrowser.Controller.Configuration;
-using MediaBrowser.Controller.Entities;
-using MediaBrowser.Model.Logging;
-
-namespace MediaBrowser.Controller.Providers.MediaInfo
-{
-    public abstract class BaseFFMpegImageProvider<T> : BaseFFMpegProvider<T>
-        where T : BaseItem
-    {
-        protected BaseFFMpegImageProvider(ILogManager logManager, IServerConfigurationManager configurationManager) : base(logManager, configurationManager)
-        {
-        }
-
-        /// <summary>
-        /// Gets the priority.
-        /// </summary>
-        /// <value>The priority.</value>
-        public override MetadataProviderPriority Priority
-        {
-            get { return MetadataProviderPriority.Last; }
-        }
-    }
-}
diff --git a/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegProvider.cs b/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegProvider.cs
index 20f59b22de..6edd28b245 100644
--- a/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegProvider.cs
+++ b/MediaBrowser.Controller/Providers/MediaInfo/BaseFFMpegProvider.cs
@@ -2,9 +2,9 @@
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Model.Entities;
+using MediaBrowser.Model.Logging;
 using System;
 using System.Threading.Tasks;
-using MediaBrowser.Model.Logging;
 
 namespace MediaBrowser.Controller.Providers.MediaInfo
 {
diff --git a/MediaBrowser.Controller/Providers/MediaInfo/FFMpegAudioImageProvider.cs b/MediaBrowser.Controller/Providers/MediaInfo/FFMpegAudioImageProvider.cs
index e752a863d4..68e552d3c4 100644
--- a/MediaBrowser.Controller/Providers/MediaInfo/FFMpegAudioImageProvider.cs
+++ b/MediaBrowser.Controller/Providers/MediaInfo/FFMpegAudioImageProvider.cs
@@ -1,21 +1,23 @@
-using MediaBrowser.Controller.Configuration;
+using System.Collections.Concurrent;
+using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Audio;
 using MediaBrowser.Model.Entities;
+using MediaBrowser.Model.Logging;
 using System;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using MediaBrowser.Model.Logging;
 
 namespace MediaBrowser.Controller.Providers.MediaInfo
 {
     /// <summary>
     /// Uses ffmpeg to create video images
     /// </summary>
-    public class FFMpegAudioImageProvider : BaseFFMpegImageProvider<Audio>
+    public class FFMpegAudioImageProvider : BaseFFMpegProvider<Audio>
     {
-        public FFMpegAudioImageProvider(ILogManager logManager, IServerConfigurationManager configurationManager) : base(logManager, configurationManager)
+        public FFMpegAudioImageProvider(ILogManager logManager, IServerConfigurationManager configurationManager)
+            : base(logManager, configurationManager)
         {
         }
 
@@ -24,6 +26,30 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
         /// </summary>
         protected static readonly Task<bool> TrueTaskResult = Task.FromResult(true);
 
+        /// <summary>
+        /// Gets the priority.
+        /// </summary>
+        /// <value>The priority.</value>
+        public override MetadataProviderPriority Priority
+        {
+            get { return MetadataProviderPriority.Last; }
+        }
+
+        /// <summary>
+        /// The _locks
+        /// </summary>
+        private readonly ConcurrentDictionary<string, SemaphoreSlim> _locks = new ConcurrentDictionary<string, SemaphoreSlim>();
+
+        /// <summary>
+        /// Gets the lock.
+        /// </summary>
+        /// <param name="filename">The filename.</param>
+        /// <returns>System.Object.</returns>
+        private SemaphoreSlim GetLock(string filename)
+        {
+            return _locks.GetOrAdd(filename, key => new SemaphoreSlim(1, 1));
+        }
+
         /// <summary>
         /// Fetches metadata and returns true or false indicating if any work that requires persistence was done
         /// </summary>
@@ -31,61 +57,71 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
         /// <param name="force">if set to <c>true</c> [force].</param>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task{System.Boolean}.</returns>
-        public override Task<bool> FetchAsync(BaseItem item, bool force, CancellationToken cancellationToken)
+        public override async Task<bool> FetchAsync(BaseItem item, bool force, CancellationToken cancellationToken)
         {
-            var audio = (Audio)item;
+            var success = ProviderRefreshStatus.Success;
 
-            if (string.IsNullOrEmpty(audio.PrimaryImagePath))
+            if (force || string.IsNullOrEmpty(item.PrimaryImagePath))
             {
-                // First try to use the parent's image
-                audio.PrimaryImagePath = audio.ResolveArgs.Parent.PrimaryImagePath;
+                var album = item.ResolveArgs.Parent as MusicAlbum;
+
+                if (album != null)
+                {
+                    // First try to use the parent's image
+                    item.PrimaryImagePath = item.ResolveArgs.Parent.PrimaryImagePath;
+                }
 
                 // If it's still empty see if there's an embedded image
-                if (string.IsNullOrEmpty(audio.PrimaryImagePath))
+                if (force || string.IsNullOrEmpty(item.PrimaryImagePath))
                 {
+                    var audio = (Audio)item;
+
                     if (audio.MediaStreams != null && audio.MediaStreams.Any(s => s.Type == MediaStreamType.Video))
                     {
-                        var filename = item.Id + "_" + item.DateModified.Ticks + "_primary";
+                        var filename = album != null && string.IsNullOrEmpty(audio.Album + album.DateModified.Ticks) ? (audio.Id.ToString() + audio.DateModified.Ticks) : audio.Album;
 
-                        var path = Kernel.Instance.FFMpegManager.AudioImageCache.GetResourcePath(filename, ".jpg");
+                        var path = Kernel.Instance.FFMpegManager.AudioImageCache.GetResourcePath(filename + "_primary", ".jpg");
 
                         if (!Kernel.Instance.FFMpegManager.AudioImageCache.ContainsFilePath(path))
                         {
-                            return ExtractImage(audio, path, cancellationToken);
-                        }
-
-                        // Image is already in the cache
-                        audio.PrimaryImagePath = path;
-                    }
+                            var semaphore = GetLock(path);
 
-                }
-            }
+                            // Acquire a lock
+                            await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
 
-            SetLastRefreshed(item, DateTime.UtcNow);
-            return TrueTaskResult;
-        }
+                            // Check again
+                            if (!Kernel.Instance.FFMpegManager.AudioImageCache.ContainsFilePath(path))
+                            {
+                                try
+                                {
+                                    var imageSucceeded = await Kernel.Instance.FFMpegManager.ExtractAudioImage(audio.Path, path, cancellationToken).ConfigureAwait(false);
 
-        /// <summary>
-        /// Extracts the image.
-        /// </summary>
-        /// <param name="audio">The audio.</param>
-        /// <param name="path">The path.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task{System.Boolean}.</returns>
-        private async Task<bool> ExtractImage(Audio audio, string path, CancellationToken cancellationToken)
-        {
-            var success = await Kernel.Instance.FFMpegManager.ExtractImage(audio, path, cancellationToken).ConfigureAwait(false);
+                                    if (!imageSucceeded)
+                                    {
+                                        success = ProviderRefreshStatus.Failure;
+                                    }
+                                }
+                                finally
+                                {
+                                    semaphore.Release();
+                                }
+                            }
+                            else
+                            {
+                                semaphore.Release();
+                            }
+                        }
 
-            if (success)
-            {
-                audio.PrimaryImagePath = path;
-                SetLastRefreshed(audio, DateTime.UtcNow);
-            }
-            else
-            {
-                SetLastRefreshed(audio, DateTime.UtcNow, ProviderRefreshStatus.Failure);
+                        if (success == ProviderRefreshStatus.Success)
+                        {
+                            // Image is already in the cache
+                            audio.PrimaryImagePath = path;
+                        }
+                    }
+                }
             }
 
+            SetLastRefreshed(item, DateTime.UtcNow, success);
             return true;
         }
     }
diff --git a/MediaBrowser.Controller/Providers/MediaInfo/FFMpegVideoImageProvider.cs b/MediaBrowser.Controller/Providers/MediaInfo/FFMpegVideoImageProvider.cs
index 3d258fe66b..9dec93a8c8 100644
--- a/MediaBrowser.Controller/Providers/MediaInfo/FFMpegVideoImageProvider.cs
+++ b/MediaBrowser.Controller/Providers/MediaInfo/FFMpegVideoImageProvider.cs
@@ -13,7 +13,7 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
     /// <summary>
     /// Uses ffmpeg to create video images
     /// </summary>
-    public class FfMpegVideoImageProvider : BaseFFMpegImageProvider<Video>
+    public class FfMpegVideoImageProvider : BaseFFMpegProvider<Video>
     {
         /// <summary>
         /// The _iso manager
@@ -30,6 +30,15 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
             : base(logManager, configurationManager)
         {
             _isoManager = isoManager;
+        }        
+        
+        /// <summary>
+        /// Gets the priority.
+        /// </summary>
+        /// <value>The priority.</value>
+        public override MetadataProviderPriority Priority
+        {
+            get { return MetadataProviderPriority.Last; }
         }
 
         /// <summary>
@@ -80,7 +89,7 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
         /// <returns>Task{System.Boolean}.</returns>
         public override Task<bool> FetchAsync(BaseItem item, bool force, CancellationToken cancellationToken)
         {
-            if (string.IsNullOrEmpty(item.PrimaryImagePath))
+            if (force || string.IsNullOrEmpty(item.PrimaryImagePath))
             {
                 var video = (Video)item;
 
diff --git a/MediaBrowser.Controller/Providers/MediaInfo/FFProbeAudioInfoProvider.cs b/MediaBrowser.Controller/Providers/MediaInfo/FFProbeAudioInfoProvider.cs
index a7cc4985b0..e5f57d704c 100644
--- a/MediaBrowser.Controller/Providers/MediaInfo/FFProbeAudioInfoProvider.cs
+++ b/MediaBrowser.Controller/Providers/MediaInfo/FFProbeAudioInfoProvider.cs
@@ -149,7 +149,7 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
             // There's several values in tags may or may not be present
             FetchStudios(audio, tags, "organization");
             FetchStudios(audio, tags, "ensemble");
-            FetchStudios(audio, tags, "publisher");
+            FetchPublishers(audio, tags, "publisher");
         }
 
         /// <summary>
@@ -168,6 +168,22 @@ namespace MediaBrowser.Controller.Providers.MediaInfo
             }
         }
 
+        /// <summary>
+        /// Fetches the publishers.
+        /// </summary>
+        /// <param name="audio">The audio.</param>
+        /// <param name="tags">The tags.</param>
+        /// <param name="tagName">Name of the tag.</param>
+        private void FetchPublishers(Audio audio, Dictionary<string, string> tags, string tagName)
+        {
+            var val = GetDictionaryValue(tags, tagName);
+
+            if (!string.IsNullOrEmpty(val))
+            {
+                audio.AddPublishers(val.Split(new[] { '/', '|' }, StringSplitOptions.RemoveEmptyEntries));
+            }
+        }
+
         /// <summary>
         /// Gets the genres from the tags collection
         /// </summary>
diff --git a/MediaBrowser.Server.Implementations/Library/LibraryManager.cs b/MediaBrowser.Server.Implementations/Library/LibraryManager.cs
index a57eb8eaa3..9bc47a0254 100644
--- a/MediaBrowser.Server.Implementations/Library/LibraryManager.cs
+++ b/MediaBrowser.Server.Implementations/Library/LibraryManager.cs
@@ -126,6 +126,9 @@ namespace MediaBrowser.Server.Implementations.Library
             }
         }
 
+        private ConcurrentDictionary<string, UserRootFolder> _userRootFolders =
+            new ConcurrentDictionary<string, UserRootFolder>();
+        
         /// <summary>
         /// Initializes a new instance of the <see cref="LibraryManager" /> class.
         /// </summary>
@@ -484,6 +487,16 @@ namespace MediaBrowser.Server.Implementations.Library
             return rootFolder;
         }
 
+        /// <summary>
+        /// Gets the user root folder.
+        /// </summary>
+        /// <param name="userRootPath">The user root path.</param>
+        /// <returns>UserRootFolder.</returns>
+        public UserRootFolder GetUserRootFolder(string userRootPath)
+        {
+            return _userRootFolders.GetOrAdd(userRootPath, key => Kernel.ItemRepository.RetrieveItem(userRootPath.GetMBId(typeof(UserRootFolder))) as UserRootFolder ?? (UserRootFolder)ResolvePath(userRootPath));
+        }
+        
         /// <summary>
         /// Gets a Person
         /// </summary>
@@ -739,14 +752,31 @@ namespace MediaBrowser.Server.Implementations.Library
             // Start by just validating the children of the root, but go no further
             await RootFolder.ValidateChildren(new Progress<double> { }, cancellationToken, recursive: false);
 
-            // Validate only the collection folders for each user, just to make them available as quickly as possible
-            var userCollectionFolderTasks = _userManager.Users.AsParallel().Select(user => user.ValidateCollectionFolders(new Progress<double> { }, cancellationToken));
-            await Task.WhenAll(userCollectionFolderTasks).ConfigureAwait(false);
+            foreach (var folder in _userManager.Users.Select(u => u.RootFolder).Distinct())
+            {
+                await ValidateCollectionFolders(folder, cancellationToken).ConfigureAwait(false);
+            }
 
             // Now validate the entire media library
             await RootFolder.ValidateChildren(progress, cancellationToken, recursive: true).ConfigureAwait(false);
         }
 
+        /// <summary>
+        /// Validates only the collection folders for a User and goes no further
+        /// </summary>
+        /// <param name="userRootFolder">The user root folder.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        private async Task ValidateCollectionFolders(UserRootFolder userRootFolder, CancellationToken cancellationToken)
+        {
+            _logger.Info("Validating collection folders within {0}", userRootFolder.Path);
+            await userRootFolder.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+
+            cancellationToken.ThrowIfCancellationRequested();
+
+            await userRootFolder.ValidateChildren(new Progress<double> { }, cancellationToken, recursive: false).ConfigureAwait(false);
+        }
+
         /// <summary>
         /// Gets the default view.
         /// </summary>
diff --git a/MediaBrowser.Server.Implementations/Providers/ProviderManager.cs b/MediaBrowser.Server.Implementations/Providers/ProviderManager.cs
index df6e061742..dced1ce28d 100644
--- a/MediaBrowser.Server.Implementations/Providers/ProviderManager.cs
+++ b/MediaBrowser.Server.Implementations/Providers/ProviderManager.cs
@@ -136,26 +136,24 @@ namespace MediaBrowser.Server.Implementations.Providers
             }
 
             var supportedProvidersHash = string.Join("+", supportedProviders.Select(i => i.GetType().Name)).GetMD5();
-            bool providersChanged;
+            bool providersChanged = false;
 
             item.ProviderData.TryGetValue(SupportedProvidersKey, out supportedProvidersInfo);
-            if (supportedProvidersInfo == null)
-            {
-                // First time
-                supportedProvidersInfo = new BaseProviderInfo { ProviderId = SupportedProvidersKey, FileSystemStamp = supportedProvidersHash };
-                providersChanged = force = true;
-            }
-            else
+            if (supportedProvidersInfo != null)
             {
                 // Force refresh if the supported providers have changed
                 providersChanged = force = force || supportedProvidersInfo.FileSystemStamp != supportedProvidersHash;
+
+                // If providers have changed, clear provider info and update the supported providers hash
+                if (providersChanged)
+                {
+                    _logger.Debug("Providers changed for {0}. Clearing and forcing refresh.", item.Name);
+                    item.ProviderData.Clear();
+                }
             }
 
-            // If providers have changed, clear provider info and update the supported providers hash
             if (providersChanged)
             {
-                _logger.Debug("Providers changed for {0}. Clearing and forcing refresh.", item.Name);
-                item.ProviderData.Clear();
                 supportedProvidersInfo.FileSystemStamp = supportedProvidersHash;
             }