Address comments

Emby.Server.Implementations/Dto/DtoService.cs

@@ -900,6 +900,7 @@ namespace Emby.Server.Implementations.Dto
 
             if (item.LUFS.HasValue)
             {
+                // -18 LUFS reference, same as ReplayGain 2.0, compatible with ReplayGain 1.0
                 dto.NormalizationGain = -18f - item.LUFS;
             }
             else if (item.NormalizationGain.HasValue)

MediaBrowser.Controller/Entities/BaseItem.cs

@@ -140,7 +140,7 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Gets or sets the gain required for audio normalization.
         /// </summary>
-        /// <value>The gain required for audio normalization..</value>
+        /// <value>The gain required for audio normalization.</value>
         [JsonIgnore]
         public float? NormalizationGain { get; set; }
 

MediaBrowser.Model/Dto/BaseItemDto.cs

@@ -784,7 +784,7 @@ namespace MediaBrowser.Model.Dto
         /// <summary>
         /// Gets or sets the gain required for audio normalization.
         /// </summary>
-        /// <value>The gain required for audio normalization..</value>
+        /// <value>The gain required for audio normalization.</value>
         public float? NormalizationGain { get; set; }
 
         /// <summary>