Fix PascalCase

Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs

@@ -4,6 +4,7 @@ using Jellyfin.Api.Auth.FirstTimeSetupOrElevatedPolicy;
 using Jellyfin.Api.Auth.RequiresElevationPolicy;
 using Jellyfin.Api.Constants;
 using Jellyfin.Api.Controllers;
+using Jellyfin.Server.Formatters;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.Extensions.DependencyInjection;
@@ -66,6 +67,8 @@ namespace Jellyfin.Server.Extensions
             return serviceCollection.AddMvc(opts =>
                 {
                     opts.UseGeneralRoutePrefix(baseUrl);
+                    opts.OutputFormatters.Insert(0, new CamelCaseJsonProfileFormatter());
+                    opts.OutputFormatters.Insert(0, new PascalCaseJsonProfileFormatter());
                 })
 
                 // Clear app parts to avoid other assemblies being picked up

Jellyfin.Server/Formatters/PascalCaseJsonProfileFormatter.cs

@@ -0,0 +1,23 @@
+using System.Text.Json;
+using Microsoft.AspNetCore.Mvc.Formatters;
+using Microsoft.Net.Http.Headers;
+
+namespace Jellyfin.Server.Formatters
+{
+    /// <summary>
+    /// Pascal Case Json Profile Formatter.
+    /// </summary>
+    public class PascalCaseJsonProfileFormatter : SystemTextJsonOutputFormatter
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PascalCaseJsonProfileFormatter"/> class.
+        /// </summary>
+        public PascalCaseJsonProfileFormatter() : base(new JsonSerializerOptions { PropertyNamingPolicy = null })
+        {
+            SupportedMediaTypes.Clear();
+            // Add application/json for default formatter
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/json"));
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/json;profile=\"PascalCase\""));
+        }
+    }
+}