Add SRT Detector

Author: Jin Jae-yeon

Daramee.FileTypeDetector/AbstractRegexSignatureDetector.cs

@@ -17,15 +17,32 @@ public abstract class AbstractRegexSignatureDetector : IDetector
 
 		public virtual bool Detect ( Stream stream )
 		{
-			int readBufferSize = Signature.ToString ().Length * 4;
+			int readBufferSize = Signature.ToString ().Length * 64;
+			char [] buffer = new char [ readBufferSize ];
 
-			var encodings = new [] { Encoding.UTF8, Encoding.Unicode, Encoding.BigEndianUnicode };
+			var encodings = new []
+			{
+				Encoding.GetEncoding ( "ascii" ),
+				Encoding.GetEncoding ( "ks_c_5601-1987" ),
+				Encoding.GetEncoding ( "iso-2022-kr" ),
+				Encoding.GetEncoding ( "shift_jis" ),
+				Encoding.GetEncoding ( "csISO2022JP" ),
+				Encoding.GetEncoding ( "windows-1250" ),
+				Encoding.GetEncoding ( "windows-1251" ),
+				Encoding.GetEncoding ( "windows-1252" ),
+				Encoding.GetEncoding ( "windows-1253" ),
+				Encoding.GetEncoding ( "windows-1254" ),
+				Encoding.UTF8,
+				Encoding.GetEncoding ( "utf-7" ),
+				Encoding.GetEncoding ( "utf-32" ),
+				Encoding.Unicode,
+				Encoding.BigEndianUnicode
+			};
 			foreach ( var encoding in encodings )
 			{
 				stream.Position = 0;
 				using ( StreamReader reader = new StreamReader ( stream, encoding, true, readBufferSize, true ) )
 				{
-					char [] buffer = new char [ readBufferSize ];
 					reader.ReadBlock ( buffer, 0, readBufferSize );
 					if ( Signature.IsMatch ( new string ( buffer ) ) )
 						return true;

Daramee.FileTypeDetector/Daramee.FileTypeDetector.csproj

@@ -99,6 +99,7 @@
     <Compile Include="Detectors\RichTextFormatDetector.cs" />
     <Compile Include="Detectors\ShockwaveFlashDetector.cs" />
     <Compile Include="Detectors\SQLiteDetector.cs" />
+    <Compile Include="Detectors\SRTDetector.cs" />
     <Compile Include="Detectors\UStarFormatTarDetector.cs" />
     <Compile Include="Detectors\TextDetector.cs" />
     <Compile Include="Detectors\ThumbsDBDetector.cs" />

Daramee.FileTypeDetector/Detectors/SRTDetector.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+
+namespace Daramee.FileTypeDetector.Detectors
+{
+	class SRTDetector : AbstractRegexSignatureDetector
+	{
+		public override string Precondition => "txt";
+		public override string Extension => "srt";
+
+		protected override Regex Signature => new Regex ( "\\d+\r?\n(\\d\\d:\\d\\d:\\d\\d,\\d\\d\\d) --> (\\d\\d:\\d\\d:\\d\\d,\\d\\d\\d)\r?\n(.*)\r?\n\r?\n" );
+
+		public override string ToString () => "SubRip Subtitle Detector";
+	}
+}

Daramee.FileTypeDetector/Detectors/TextDetector.cs

@@ -82,7 +82,7 @@ public bool Detect ( Stream stream )
 
 			foreach ( var encoding in encodings )
 			{
-				for ( int count = readed; count >= ( readed - 4 ); --count )
+				for ( int count = readed; count >= ( readed - 16 ); --count )
 				{
 					bool succeed = true;
 
@@ -100,9 +100,9 @@ public bool Detect ( Stream stream )
 
 					int byted = encoding.GetBytes ( TextBuffer, 0, texted, EncodingBuffer, 0 );
 
-					if ( succeed && readed == byted )
+					if ( succeed/* && readed == byted*/ )
 					{
-						for ( int i = 0; i < readed; ++i )
+						for ( int i = 0; i < count; ++i )
 						{
 							if ( ReadBuffer [ i ] != EncodingBuffer [ i ] )
 							{