Improve audio normalization

* Move calculation of LUFS to a scheduled task as it's pretty slow
* Correctly calculate album LUFS
* Don't try to convert replaygain tags to LUFS values

2 files changed, 11 insertions, 5 deletions

diff --git a/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs b/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
index 237345206..5b3349108 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
@@ -183,14 +183,13 @@ namespace MediaBrowser.Controller.Entities.Audio
                 progress.Report(percent * 95);
             }
 
-            // get album LUFS
-            LUFS = items.OfType<Audio>().Max(item => item.LUFS);
-
             var parentRefreshOptions = refreshOptions;
             if (childUpdateType > ItemUpdateType.None)
             {
-                parentRefreshOptions = new MetadataRefreshOptions(refreshOptions);
-                parentRefreshOptions.MetadataRefreshMode = MetadataRefreshMode.FullRefresh;
+                parentRefreshOptions = new MetadataRefreshOptions(refreshOptions)
+                {
+                    MetadataRefreshMode = MetadataRefreshMode.FullRefresh
+                };
             }
 
             // Refresh current item
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index 474b093d5..3dd4d1e39 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -138,6 +138,13 @@ namespace MediaBrowser.Controller.Entities
         public float? LUFS { get; set; }
 
         /// <summary>
+        /// Gets or sets the gain required for audio normalization.
+        /// </summary>
+        /// <value>The gain required for audio normalization..</value>
+        [JsonIgnore]
+        public float? NormalizationGain { get; set; }
+
+        /// <summary>
         /// Gets or sets the channel identifier.
         /// </summary>
         /// <value>The channel identifier.</value>