Fixed error when burning subtitle with some special charaters in path

FFMpegCore.Test/ArgumentBuilderTest.cs

@@ -341,7 +341,22 @@ public void Builder_BuildString_SubtitleHardBurnFilter()
                                 .WithParameter("PrimaryColour", "&HAA00FF00")))))
                 .Arguments;
 
-            Assert.AreEqual("-i \"input.mp4\" -vf \"subtitles=sample.srt:charenc=UTF-8:original_size=1366x768:stream_index=0:force_style='FontName=DejaVu Serif\\,PrimaryColour=&HAA00FF00'\" \"output.mp4\"",
+            Assert.AreEqual("-i \"input.mp4\" -vf \"subtitles='sample.srt':charenc=UTF-8:original_size=1366x768:stream_index=0:force_style='FontName=DejaVu Serif\\,PrimaryColour=&HAA00FF00'\" \"output.mp4\"",
+                str);
+        }
+
+        [TestMethod]
+        public void Builder_BuildString_SubtitleHardBurnFilterFixedPaths()
+        {
+            var str = FFMpegArguments
+                .FromFileInput("input.mp4")
+                .OutputToFile("output.mp4", false, opt => opt
+                    .WithVideoFilters(filterOptions => filterOptions
+                        .HardBurnSubtitle(SubtitleHardBurnOptions
+                            .Create(subtitlePath: @"sample( \ : [ ] , ).srt"))))
+                .Arguments;
+
+            Assert.AreEqual(@"-i ""input.mp4"" -vf ""subtitles='sample( \\ \: \[ \] \, ).srt'"" ""output.mp4""",
                 str);
         }
 

FFMpegCore/Extend/StringExtensions.cs

@@ -1,7 +1,19 @@
-namespace FFMpegCore.Extend
+using System.Collections.Generic;
+using System.Text;
+
+namespace FFMpegCore.Extend
 {
     internal static class StringExtensions
     {
+        private static Dictionary<char, string> CharactersSubstitution { get; } = new Dictionary<char, string>
+        {
+            {'\\', @"\\"},
+            {':', @"\:"},
+            {'[', @"\["},
+            {']', @"\]"},
+            // {'\'', @"\'"} TODO: Quotes need to be escaped but i failed miserably
+        };
+
         /// <summary>
         ///     Enclose string between quotes if contains an space character
         /// </summary>
@@ -11,5 +23,48 @@ public static string EncloseIfContainsSpace(this string input)
         {
             return input.Contains(" ") ? $"'{input}'" : input;
         }
+
+        /// <summary>
+        /// Enclose an string in quotes
+        /// </summary>
+        /// <param name="input"></param>
+        /// <returns></returns>
+        public static string EncloseInQuotes(this string input)
+        {
+            return $"'{input}'";
+        }
+
+        /// <summary>
+        ///     Scape several characters in subtitle path used by FFmpeg
+        /// </summary>
+        /// <remarks>
+        ///     This is needed because internally FFmpeg use Libav Filters
+        ///     and the info send to it must be in an specific format
+        /// </remarks>
+        /// <param name="source"></param>
+        /// <returns>Scaped path</returns>
+        public static string ToFFmpegLibavfilterPath(this string source)
+        {
+            return source.Replace(CharactersSubstitution);
+        }
+
+        public static string Replace(this string str, Dictionary<char, string> replaceList)
+        {
+            var parsedString = new StringBuilder();
+
+            foreach (var l in str)
+            {
+                if (replaceList.ContainsKey(l))
+                {
+                    parsedString.Append(replaceList[l]);
+                }
+                else
+                {
+                    parsedString.Append(l);
+                }
+            }
+
+            return parsedString.ToString();
+        }
     }
 }

FFMpegCore/FFMpeg/Arguments/SubtitleHardBurnArgument.cs

@@ -103,7 +103,7 @@ public SubtitleHardBurnOptions WithParameter(string key, string value)
             return this;
         }
 
-        internal string TextInternal => string.Join(":", new[] { _subtitle.EncloseIfContainsSpace() }.Concat(Parameters.Select(parameter => parameter.FormatArgumentPair(enclose: true))));
+        internal string TextInternal => string.Join(":", new[] { _subtitle.ToFFmpegLibavfilterPath().EncloseInQuotes() }.Concat(Parameters.Select(parameter => parameter.FormatArgumentPair(enclose: true))));
     }
 
     public class StyleOptions