diff --git a/Jellyfin.Api/Controllers/AudioController.cs b/Jellyfin.Api/Controllers/AudioController.cs
index 33f21db714..9e3065824f 100644
--- a/Jellyfin.Api/Controllers/AudioController.cs
+++ b/Jellyfin.Api/Controllers/AudioController.cs
@@ -92,18 +92,18 @@ public class AudioController : BaseJellyfinApiController
     [ProducesAudioFile]
     public async Task<ActionResult> GetAudioStream(
         [FromRoute, Required] Guid itemId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? container,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? container,
         [FromQuery] bool? @static,
         [FromQuery] string? @params,
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -133,8 +133,8 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -259,18 +259,18 @@ public class AudioController : BaseJellyfinApiController
     [ProducesAudioFile]
     public async Task<ActionResult> GetAudioStreamByContainer(
         [FromRoute, Required] Guid itemId,
-        [FromRoute, Required] [RegularExpression(EncodingHelper.ValidationRegex)] string container,
+        [FromRoute, Required] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string container,
         [FromQuery] bool? @static,
         [FromQuery] string? @params,
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -300,8 +300,8 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
diff --git a/Jellyfin.Api/Controllers/DynamicHlsController.cs b/Jellyfin.Api/Controllers/DynamicHlsController.cs
index 90dcbd59e2..f59ce3834b 100644
--- a/Jellyfin.Api/Controllers/DynamicHlsController.cs
+++ b/Jellyfin.Api/Controllers/DynamicHlsController.cs
@@ -166,18 +166,18 @@ public class DynamicHlsController : BaseJellyfinApiController
     [ProducesPlaylistFile]
     public async Task<ActionResult> GetLiveHlsStream(
         [FromRoute, Required] Guid itemId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? container,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? container,
         [FromQuery] bool? @static,
         [FromQuery] string? @params,
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -207,8 +207,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -415,12 +415,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery, Required] string mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -452,8 +452,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -591,12 +591,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery, Required] string mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -627,8 +627,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -761,12 +761,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -798,8 +798,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -933,12 +933,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -969,8 +969,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -1106,7 +1106,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromRoute, Required] Guid itemId,
         [FromRoute, Required] string playlistId,
         [FromRoute, Required] int segmentId,
-        [FromRoute, Required] [RegularExpression(EncodingHelper.ValidationRegex)] string container,
+        [FromRoute, Required] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string container,
         [FromQuery, Required] long runtimeTicks,
         [FromQuery, Required] long actualSegmentLengthTicks,
         [FromQuery] bool? @static,
@@ -1114,12 +1114,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -1151,8 +1151,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -1291,7 +1291,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromRoute, Required] Guid itemId,
         [FromRoute, Required] string playlistId,
         [FromRoute, Required] int segmentId,
-        [FromRoute, Required] [RegularExpression(EncodingHelper.ValidationRegex)] string container,
+        [FromRoute, Required] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string container,
         [FromQuery, Required] long runtimeTicks,
         [FromQuery, Required] long actualSegmentLengthTicks,
         [FromQuery] bool? @static,
@@ -1299,12 +1299,12 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -1335,8 +1335,8 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
diff --git a/Jellyfin.Api/Controllers/LiveTvController.cs b/Jellyfin.Api/Controllers/LiveTvController.cs
index 172686cadb..10f1789ad8 100644
--- a/Jellyfin.Api/Controllers/LiveTvController.cs
+++ b/Jellyfin.Api/Controllers/LiveTvController.cs
@@ -1192,7 +1192,7 @@ public class LiveTvController : BaseJellyfinApiController
     [ProducesVideoFile]
     public ActionResult GetLiveStreamFile(
         [FromRoute, Required] string streamId,
-        [FromRoute, Required] [RegularExpression(EncodingHelper.ValidationRegex)] string container)
+        [FromRoute, Required] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string container)
     {
         var liveStreamInfo = _mediaSourceManager.GetLiveStreamInfoByUniqueId(streamId);
         if (liveStreamInfo is null)
diff --git a/Jellyfin.Api/Controllers/UniversalAudioController.cs b/Jellyfin.Api/Controllers/UniversalAudioController.cs
index a5b5fde626..fd63347030 100644
--- a/Jellyfin.Api/Controllers/UniversalAudioController.cs
+++ b/Jellyfin.Api/Controllers/UniversalAudioController.cs
@@ -102,13 +102,13 @@ public class UniversalAudioController : BaseJellyfinApiController
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
         [FromQuery] Guid? userId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] int? transcodingAudioChannels,
         [FromQuery] int? maxStreamingBitrate,
         [FromQuery] int? audioBitRate,
         [FromQuery] long? startTimeTicks,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? transcodingContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? transcodingContainer,
         [FromQuery] MediaStreamProtocol? transcodingProtocol,
         [FromQuery] int? maxAudioSampleRate,
         [FromQuery] int? maxAudioBitDepth,
diff --git a/Jellyfin.Api/Controllers/VideosController.cs b/Jellyfin.Api/Controllers/VideosController.cs
index 685d502e42..714d4ba72a 100644
--- a/Jellyfin.Api/Controllers/VideosController.cs
+++ b/Jellyfin.Api/Controllers/VideosController.cs
@@ -315,18 +315,18 @@ public class VideosController : BaseJellyfinApiController
     [ProducesVideoFile]
     public async Task<ActionResult> GetVideoStream(
         [FromRoute, Required] Guid itemId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? container,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? container,
         [FromQuery] bool? @static,
         [FromQuery] string? @params,
         [FromQuery] string? tag,
         [FromQuery, ParameterObsolete] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -358,8 +358,8 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
@@ -556,18 +556,18 @@ public class VideosController : BaseJellyfinApiController
     [ProducesVideoFile]
     public Task<ActionResult> GetVideoStreamByContainer(
         [FromRoute, Required] Guid itemId,
-        [FromRoute, Required] [RegularExpression(EncodingHelper.ValidationRegex)] string container,
+        [FromRoute, Required] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string container,
         [FromQuery] bool? @static,
         [FromQuery] string? @params,
         [FromQuery] string? tag,
         [FromQuery] string? deviceProfileId,
         [FromQuery] string? playSessionId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? segmentContainer,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? segmentContainer,
         [FromQuery] int? segmentLength,
         [FromQuery] int? minSegments,
         [FromQuery] string? mediaSourceId,
         [FromQuery] string? deviceId,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? audioCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? audioCodec,
         [FromQuery] bool? enableAutoStreamCopy,
         [FromQuery] bool? allowVideoStreamCopy,
         [FromQuery] bool? allowAudioStreamCopy,
@@ -599,8 +599,8 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? cpuCoreLimit,
         [FromQuery] string? liveStreamId,
         [FromQuery] bool? enableMpegtsM2TsMode,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? videoCodec,
-        [FromQuery] [RegularExpression(EncodingHelper.ValidationRegex)] string? subtitleCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? videoCodec,
+        [FromQuery] [RegularExpression(EncodingHelper.ContainerValidationRegex)] string? subtitleCodec,
         [FromQuery] string? transcodeReasons,
         [FromQuery] int? audioStreamIndex,
         [FromQuery] int? videoStreamIndex,
diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index cf76f336c8..ed80de6355 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -37,7 +37,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         /// periods, underscores, commas, and vertical bars, with a length between 0 and 40 characters.
         /// This should matches all common valid codecs.
         /// </summary>
-        public const string ValidationRegex = @"^[a-zA-Z0-9\-\._,|]{0,40}$";
+        public const string ContainerValidationRegex = @"^[a-zA-Z0-9\-\._,|]{0,40}$";
 
         private const string _defaultMjpegEncoder = "mjpeg";
 
@@ -77,7 +77,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         private readonly Version _minFFmpegVaapiDeviceVendorId = new Version(7, 0, 1);
         private readonly Version _minFFmpegQsvVppScaleModeOption = new Version(6, 0);
 
-        private static readonly Regex _validationRegex = new(ValidationRegex, RegexOptions.Compiled);
+        private static readonly Regex _containerValidationRegex = new(ContainerValidationRegex, RegexOptions.Compiled);
 
         private static readonly string[] _videoProfilesH264 =
         [
@@ -452,7 +452,7 @@ namespace MediaBrowser.Controller.MediaEncoding
                     return GetMjpegEncoder(state, encodingOptions);
                 }
 
-                if (_validationRegex.IsMatch(codec))
+                if (_containerValidationRegex.IsMatch(codec))
                 {
                     return codec.ToLowerInvariant();
                 }
@@ -493,7 +493,7 @@ namespace MediaBrowser.Controller.MediaEncoding
 
         public static string GetInputFormat(string container)
         {
-            if (string.IsNullOrEmpty(container) || !_validationRegex.IsMatch(container))
+            if (string.IsNullOrEmpty(container) || !_containerValidationRegex.IsMatch(container))
             {
                 return null;
             }
@@ -711,7 +711,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         {
             var codec = state.OutputAudioCodec;
 
-            if (!_validationRegex.IsMatch(codec))
+            if (!_containerValidationRegex.IsMatch(codec))
             {
                 codec = "aac";
             }