Add validation for level input

Jellyfin.Api/Controllers/AudioController.cs

@@ -114,7 +114,7 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -281,7 +281,7 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,

Jellyfin.Api/Controllers/DynamicHlsController.cs

@@ -188,7 +188,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -431,7 +431,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -608,7 +608,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -777,7 +777,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -950,7 +950,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -1130,7 +1130,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -1316,7 +1316,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,

Jellyfin.Api/Controllers/VideosController.cs

@@ -337,7 +337,7 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -578,7 +578,7 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,

MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs

@@ -37,6 +37,12 @@ namespace MediaBrowser.Controller.MediaEncoding
         /// </summary>
         public const string ContainerValidationRegex = @"^[a-zA-Z0-9\-\._,|]{0,40}$";
 
+        /// <summary>
+        /// The level validation regex.
+        /// This regular expression matches strings representing a double.
+        /// </summary>
+        public const string LevelValidationRegex = @"-?\d+(?:\.\d+)?";
+
         private const string _defaultMjpegEncoder = "mjpeg";
 
         private const string QsvAlias = "qs";