Better detection of the ISO DVD/BD types

The ISO image will be opened and checked for disc-type specific
folders.
Can be overridden using NAME.dvd.iso / NAME.bluray.iso

Emby.Server.Implementations/Emby.Server.Implementations.csproj

@@ -23,6 +23,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="DiscUtils.Udf" Version="0.16.4" />
     <PackageReference Include="Jellyfin.XmlTv" Version="10.6.2" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="5.0.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="5.0.0" />

Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs

@@ -5,6 +5,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using DiscUtils.Udf;
 using Emby.Naming.Video;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
@@ -201,6 +202,22 @@ namespace Emby.Server.Implementations.Library.Resolvers
                 {
                     video.IsoType = IsoType.BluRay;
                 }
+                else
+                {
+                    // use disc-utils, both DVDs and BDs use UDF filesystem
+                    using (var videoFileStream = File.Open(video.Path, FileMode.Open, FileAccess.Read))
+                    {
+                        UdfReader udfReader = new UdfReader(videoFileStream);
+                        if (udfReader.DirectoryExists("VIDEO_TS"))
+                        {
+                            video.IsoType = IsoType.Dvd;
+                        }
+                        else if (udfReader.DirectoryExists("BDMV"))
+                        {
+                            video.IsoType = IsoType.BluRay;
+                        }
+                    }
+                }
             }
         }