New: Don't try to analyze disk image files (iso, img, etc)

(cherry picked from commit 764c08498783865834e607bd41feaaedf69a254a)

src/NzbDrone.Core/MediaFiles/MediaFileExtensions.cs

@@ -72,6 +72,7 @@ namespace NzbDrone.Core.MediaFiles
         }
 
         public static HashSet<string> Extensions => new HashSet<string>(_fileExtensions.Keys, StringComparer.OrdinalIgnoreCase);
+        public static HashSet<string> DiskExtensions => new HashSet<string>(new[] { ".img", ".iso", ".vob" }, StringComparer.OrdinalIgnoreCase);
 
         public static Quality GetQualityForExtension(string extension)
         {

src/NzbDrone.Core/MediaFiles/MediaInfo/VideoFileInfoReader.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using FFMpegCore;
+using FFMpegCore.Enums;
 using NLog;
 using NzbDrone.Common.Disk;
 using NzbDrone.Common.Extensions;
@@ -55,6 +56,11 @@ namespace NzbDrone.Core.MediaFiles.MediaInfo
                 throw new FileNotFoundException("Media file does not exist: " + filename);
             }
 
+            if (MediaFileExtensions.DiskExtensions.Contains(Path.GetExtension(filename)))
+            {
+                return null;
+            }
+
             // TODO: Cache media info by path, mtime and length so we don't need to read files multiple times
             try
             {