Backport pull request #18059 from jellyfin/release-12.z

Fix transcoding settings migration failure caused by null EncoderPreset

Original-merge: 3e27c7ef7f7ec20199bd0493cd8eba42390b22a7

Merged-by: crobibero <cody@robibe.ro>

Backported-by: Cody Robibero <cody@robibe.ro>

4 files changed, 199 insertions, 2 deletions

diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index f5f844bcbc..63ba6bf52d 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -242,6 +242,8 @@
  - [m0g3r](https://github.com/m0g3r)
  - [martin-77](https://github.com/martin-77)
  - [Oggeb1](https://github.com/Oggeb1)
+ - [scr4bble](https://github.com/scr4bble)
+ - [Mateus Bandeira](https://github.com/mateusbandeiraa)
 
 # Emby Contributors
 
diff --git a/Jellyfin.Server/Migrations/PreStartupRoutines/MigrateEncodingOptions.cs b/Jellyfin.Server/Migrations/PreStartupRoutines/MigrateEncodingOptions.cs
index 0141b43c96..a5006c9bfa 100644
--- a/Jellyfin.Server/Migrations/PreStartupRoutines/MigrateEncodingOptions.cs
+++ b/Jellyfin.Server/Migrations/PreStartupRoutines/MigrateEncodingOptions.cs
@@ -79,8 +79,8 @@ public class MigrateEncodingOptions : IMigrationRoutine
             tonemappingRange = parsedTonemappingRange;
         }
 
-        var encoderPreset = EncoderPreset.superfast;
-        if (Enum.TryParse<EncoderPreset>(oldConfig.TonemappingRange, true, out var parsedEncoderPreset))
+        var encoderPreset = EncoderPreset.auto;
+        if (Enum.TryParse<EncoderPreset>(oldConfig.EncoderPreset, true, out var parsedEncoderPreset))
         {
             encoderPreset = parsedEncoderPreset;
         }
diff --git a/Jellyfin.Server/Migrations/Routines/20260915104305_FixNullEncoderPreset.cs b/Jellyfin.Server/Migrations/Routines/20260915104305_FixNullEncoderPreset.cs
new file mode 100644
index 0000000000..f8e63f1920
--- /dev/null
+++ b/Jellyfin.Server/Migrations/Routines/20260915104305_FixNullEncoderPreset.cs
@@ -0,0 +1,77 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Xml;
+using System.Xml.Linq;
+using Jellyfin.Server.Migrations.Stages;
+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Entities;
+using Microsoft.Extensions.Logging;
+
+namespace Jellyfin.Server.Migrations.Routines;
+
+/// <summary>
+/// Replaces the nullable encoder preset written by older versions with the default preset.
+/// </summary>
+[JellyfinMigration("2026-09-15T10:43:05", nameof(FixNullEncoderPreset), Stage = JellyfinMigrationStageTypes.PreInitialisation)]
+internal class FixNullEncoderPreset : IAsyncMigrationRoutine
+{
+    private static readonly XNamespace _xsiNamespace = "http://www.w3.org/2001/XMLSchema-instance";
+
+    private readonly IApplicationPaths _applicationPaths;
+    private readonly ILogger<FixNullEncoderPreset> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="FixNullEncoderPreset"/> class.
+    /// </summary>
+    /// <param name="applicationPaths">The application paths.</param>
+    /// <param name="logger">The logger.</param>
+    public FixNullEncoderPreset(IApplicationPaths applicationPaths, ILogger<FixNullEncoderPreset> logger)
+    {
+        _applicationPaths = applicationPaths;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public Task PerformAsync(CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+
+        var path = Path.Combine(_applicationPaths.ConfigurationDirectoryPath, "encoding.xml");
+        if (!File.Exists(path))
+        {
+            return Task.CompletedTask;
+        }
+
+        XDocument document;
+        try
+        {
+            document = XDocument.Load(path, LoadOptions.PreserveWhitespace);
+        }
+        catch (XmlException ex)
+        {
+            _logger.LogWarning(ex, "Could not parse encoding configuration; skipping null encoder preset migration");
+            return Task.CompletedTask;
+        }
+
+        var encoderPreset = document.Root?.Element(nameof(EncodingOptions.EncoderPreset));
+        if (encoderPreset is null)
+        {
+            return Task.CompletedTask;
+        }
+
+        var nilAttribute = encoderPreset.Attribute(_xsiNamespace + "nil");
+        if (!string.Equals(nilAttribute?.Value, "true", StringComparison.OrdinalIgnoreCase) && !string.IsNullOrEmpty(encoderPreset.Value))
+        {
+            return Task.CompletedTask;
+        }
+
+        nilAttribute?.Remove();
+        encoderPreset.Value = nameof(EncoderPreset.auto);
+        document.Save(path, SaveOptions.DisableFormatting);
+        _logger.LogInformation("Replaced null encoder preset with auto in encoding configuration");
+        return Task.CompletedTask;
+    }
+}
diff --git a/tests/Jellyfin.Server.Tests/Migrations/FixNullEncoderPresetTests.cs b/tests/Jellyfin.Server.Tests/Migrations/FixNullEncoderPresetTests.cs
new file mode 100644
index 0000000000..a6ebc82425
--- /dev/null
+++ b/tests/Jellyfin.Server.Tests/Migrations/FixNullEncoderPresetTests.cs
@@ -0,0 +1,118 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using System.Xml.Serialization;
+using Emby.Server.Implementations;
+using Jellyfin.Server.Migrations.PreStartupRoutines;
+using Jellyfin.Server.Migrations.Routines;
+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Entities;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace Jellyfin.Server.Tests.Migrations;
+
+public sealed class FixNullEncoderPresetTests : IDisposable
+{
+    private readonly string _configurationDirectory;
+    private readonly string _encodingConfigurationPath;
+    private readonly FixNullEncoderPreset _migration;
+
+    public FixNullEncoderPresetTests()
+    {
+        _configurationDirectory = Directory.CreateTempSubdirectory("jellyfin-migration-test-").FullName;
+        _encodingConfigurationPath = Path.Combine(_configurationDirectory, "encoding.xml");
+
+        var applicationPaths = new Mock<IApplicationPaths>();
+        applicationPaths.SetupGet(paths => paths.ConfigurationDirectoryPath).Returns(_configurationDirectory);
+        _migration = new FixNullEncoderPreset(applicationPaths.Object, NullLogger<FixNullEncoderPreset>.Instance);
+    }
+
+    [Fact]
+    public async Task PerformAsync_ReplacesNullEncoderPresetWithAuto()
+    {
+        const string Configuration = """
+            <?xml version="1.0" encoding="utf-8"?>
+            <EncodingOptions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+              <HardwareAccelerationType>qsv</HardwareAccelerationType>
+              <EncoderPreset xsi:nil="true" />
+              <EnableHardwareEncoding>true</EnableHardwareEncoding>
+            </EncodingOptions>
+            """;
+        await File.WriteAllTextAsync(_encodingConfigurationPath, Configuration, TestContext.Current.CancellationToken);
+
+        await _migration.PerformAsync(TestContext.Current.CancellationToken);
+
+        var serializer = new XmlSerializer(typeof(EncodingOptions));
+        using var reader = File.OpenRead(_encodingConfigurationPath);
+        var encodingOptions = Assert.IsType<EncodingOptions>(serializer.Deserialize(reader));
+        Assert.Equal(EncoderPreset.auto, encodingOptions.EncoderPreset);
+        Assert.Equal(HardwareAccelerationType.qsv, encodingOptions.HardwareAccelerationType);
+        Assert.True(encodingOptions.EnableHardwareEncoding);
+    }
+
+    [Fact]
+    public async Task PerformAsync_LeavesValidEncoderPresetUnchanged()
+    {
+        const string Configuration = """
+            <?xml version="1.0" encoding="utf-8"?>
+            <EncodingOptions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+              <EncoderPreset>fast</EncoderPreset>
+            </EncodingOptions>
+            """;
+        await File.WriteAllTextAsync(_encodingConfigurationPath, Configuration, TestContext.Current.CancellationToken);
+
+        await _migration.PerformAsync(TestContext.Current.CancellationToken);
+
+        Assert.Equal(Configuration, await File.ReadAllTextAsync(_encodingConfigurationPath, TestContext.Current.CancellationToken));
+    }
+
+    [Fact]
+    public async Task PerformAsync_LeavesMalformedConfigurationUnchanged()
+    {
+        const string Configuration = "<EncodingOptions><EncoderPreset xsi:nil=\"true\" />";
+        await File.WriteAllTextAsync(_encodingConfigurationPath, Configuration, TestContext.Current.CancellationToken);
+
+        await _migration.PerformAsync(TestContext.Current.CancellationToken);
+
+        Assert.Equal(Configuration, await File.ReadAllTextAsync(_encodingConfigurationPath, TestContext.Current.CancellationToken));
+    }
+
+    [Fact]
+    public async Task MigrateEncodingOptions_UsesAutoForNullEncoderPreset()
+    {
+        const string Configuration = """
+            <?xml version="1.0" encoding="utf-8"?>
+            <EncodingOptions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+              <HardwareAccelerationType>qsv</HardwareAccelerationType>
+              <TonemappingRange>tv</TonemappingRange>
+              <EncoderPreset xsi:nil="true" />
+              <EnableHardwareEncoding>true</EnableHardwareEncoding>
+            </EncodingOptions>
+            """;
+        await File.WriteAllTextAsync(_encodingConfigurationPath, Configuration, TestContext.Current.CancellationToken);
+        var applicationPaths = new ServerApplicationPaths(
+            _configurationDirectory,
+            _configurationDirectory,
+            _configurationDirectory,
+            _configurationDirectory,
+            _configurationDirectory);
+
+        var migration = new MigrateEncodingOptions(applicationPaths, NullLoggerFactory.Instance);
+        migration.Perform();
+
+        var serializer = new XmlSerializer(typeof(EncodingOptions));
+        using var reader = File.OpenRead(_encodingConfigurationPath);
+        var encodingOptions = Assert.IsType<EncodingOptions>(serializer.Deserialize(reader));
+        Assert.Equal(EncoderPreset.auto, encodingOptions.EncoderPreset);
+        Assert.Equal(HardwareAccelerationType.qsv, encodingOptions.HardwareAccelerationType);
+        Assert.True(encodingOptions.EnableHardwareEncoding);
+    }
+
+    public void Dispose()
+    {
+        Directory.Delete(_configurationDirectory, true);
+    }
+}