increase unification of param building

MediaBrowser.Controller/MediaEncoding/EncodingJobOptions.cs

@@ -198,6 +198,8 @@ namespace MediaBrowser.Controller.MediaEncoding
         [ApiMember(Name = "VideoCodec", Description = "Optional. Specify a video codec to encode to, e.g. h264. If omitted the server will auto-select using the url's extension. Options: h264, mpeg4, theora, vpx, wmv.", IsRequired = false, DataType = "string", ParameterType = "query", Verb = "GET")]
         public string VideoCodec { get; set; }
 
+        public string SubtitleCodec { get; set; }
+
         /// <summary>
         /// Gets or sets the index of the audio stream.
         /// </summary>