Add manual MIME type resolution for TagLib file creation

osu.Game/Rulesets/Edit/Checks/CheckAudioInVideo.cs

@@ -9,6 +9,7 @@ using osu.Game.Beatmaps;
 using osu.Game.IO.FileAbstraction;
 using osu.Game.Rulesets.Edit.Checks.Components;
 using osu.Game.Storyboards;
+using osu.Game.Utils;
 using TagLib;
 using File = TagLib.File;
 
@@ -61,7 +62,7 @@ namespace osu.Game.Rulesets.Edit.Checks
                 {
                     // We use TagLib here for platform invariance; BASS cannot detect audio presence on Linux.
                     using (Stream data = context.WorkingBeatmap.GetStream(storagePath))
-                    using (File tagFile = File.Create(new StreamFileAbstraction(filename, data)))
+                    using (File tagFile = TagLibUtils.CreateFile(new StreamFileAbstraction(filename, data)))
                     {
                         if (tagFile.Properties.AudioChannels == 0)
                             continue;

osu.Game/Rulesets/Edit/Checks/CheckVideoResolution.cs

@@ -9,6 +9,7 @@ using osu.Game.Beatmaps;
 using osu.Game.IO.FileAbstraction;
 using osu.Game.Rulesets.Edit.Checks.Components;
 using osu.Game.Storyboards;
+using osu.Game.Utils;
 using TagLib;
 using File = TagLib.File;
 
@@ -45,7 +46,7 @@ namespace osu.Game.Rulesets.Edit.Checks
                 try
                 {
                     using (Stream data = context.WorkingBeatmap.GetStream(storagePath))
-                    using (File tagFile = File.Create(new StreamFileAbstraction(filename, data)))
+                    using (File tagFile = TagLibUtils.CreateFile(new StreamFileAbstraction(filename, data)))
                     {
                         int height = tagFile.Properties.VideoHeight;
                         int width = tagFile.Properties.VideoWidth;

osu.Game/Screens/Edit/Setup/ResourcesSection.cs

@@ -102,7 +102,7 @@ namespace osu.Game.Screens.Edit.Setup
 
             try
             {
-                tagSource = TagLib.File.Create(source.FullName);
+                tagSource = TagLibUtils.CreateFile(source.FullName);
             }
             catch (Exception e)
             {

osu.Game/Utils/TagLibUtils.cs

@@ -0,0 +1,32 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.IO;
+using osu.Game.IO.FileAbstraction;
+using TagLib;
+
+namespace osu.Game.Utils
+{
+    public class TagLibUtils
+    {
+        /// <summary>
+        /// Creates a <see cref="TagLib.File"/> with culture-invariant MIME type detection.
+        /// </summary>
+        /// <param name="fileAbstraction">The file abstraction of the file to be created.</param>
+        /// <returns>The <see cref="TagLib.File"/> created.</returns>
+        public static TagLib.File CreateFile(StreamFileAbstraction fileAbstraction) =>
+            TagLib.File.Create(fileAbstraction, getMimeType(fileAbstraction.Name), ReadStyle.Average);
+
+        /// <summary>
+        /// Creates a <see cref="TagLib.File"/> with culture-invariant MIME type detection.
+        /// </summary>
+        /// <param name="filePath">The full path of the file to be created.</param>
+        /// <returns>The <see cref="TagLib.File"/> created.</returns>
+        public static TagLib.File CreateFile(string filePath) =>
+            TagLib.File.Create(filePath, getMimeType(filePath), ReadStyle.Average);
+
+        // Manual MIME type resolution to avoid culture variance (ie. https://github.com/ppy/osu/issues/32962)
+        private static string getMimeType(string fileName) =>
+            @"taglib/" + Path.GetExtension(fileName).TrimStart('.');
+    }
+}