update encoding detection

1 files changed, 175 insertions, 0 deletions

diff --git a/Emby.Common.Implementations/TextEncoding/UniversalDetector/Core/MBCSGroupProber.cs b/Emby.Common.Implementations/TextEncoding/UniversalDetector/Core/MBCSGroupProber.cs
new file mode 100644
index 000000000..abf49aacd
--- /dev/null
+++ b/Emby.Common.Implementations/TextEncoding/UniversalDetector/Core/MBCSGroupProber.cs
@@ -0,0 +1,175 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Universal charset detector code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2001
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *          Shy Shalom <shooshX@gmail.com>
+ *          Rudi Pettazzi <rudi.pettazzi@gmail.com> (C# port)
+ * 
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+using System;
+
+namespace UniversalDetector.Core
+{
+    /// <summary>
+    /// Multi-byte charsets probers
+    /// </summary>
+    public class MBCSGroupProber : CharsetProber
+    {
+        private const int PROBERS_NUM = 7;
+        private readonly static string[] ProberName = 
+            { "UTF8", "SJIS", "EUCJP", "GB18030", "EUCKR", "Big5", "EUCTW" };
+        private CharsetProber[] probers = new CharsetProber[PROBERS_NUM];
+        private bool[] isActive = new bool[PROBERS_NUM];
+        private int bestGuess;
+        private int activeNum;
+            
+        public MBCSGroupProber()
+        {
+            probers[0] = new UTF8Prober();
+            probers[1] = new SJISProber();
+            probers[2] = new EUCJPProber();
+            probers[3] = new GB18030Prober();
+            probers[4] = new EUCKRProber();
+            probers[5] = new Big5Prober();
+            probers[6] = new EUCTWProber();
+            Reset();        
+        }
+
+        public override string GetCharsetName()
+        {
+            if (bestGuess == -1) {
+                GetConfidence();
+                if (bestGuess == -1)
+                    bestGuess = 0;
+            }
+            return probers[bestGuess].GetCharsetName();
+        }
+
+        public override void Reset()
+        {
+            activeNum = 0;
+            for (int i = 0; i < probers.Length; i++) {
+                if (probers[i] != null) {
+                   probers[i].Reset();
+                   isActive[i] = true;
+                   ++activeNum;
+                } else {
+                   isActive[i] = false;
+                }
+            }
+            bestGuess = -1;
+            state = ProbingState.Detecting;
+        }
+
+        public override ProbingState HandleData(byte[] buf, int offset, int len)
+        {
+            // do filtering to reduce load to probers
+            byte[] highbyteBuf = new byte[len];
+            int hptr = 0;
+            //assume previous is not ascii, it will do no harm except add some noise
+            bool keepNext = true;
+            int max = offset + len;
+            
+            for (int i = offset; i < max; i++) {
+                if ((buf[i] & 0x80) != 0) {
+                    highbyteBuf[hptr++] = buf[i];
+                    keepNext = true;
+                } else {
+                    //if previous is highbyte, keep this even it is a ASCII
+                    if (keepNext) {
+                        highbyteBuf[hptr++] = buf[i];
+                        keepNext = false;
+                    }
+                }
+            }
+            
+            ProbingState st = ProbingState.NotMe;
+            
+            for (int i = 0; i < probers.Length; i++) {
+                if (!isActive[i])
+                    continue;
+                st = probers[i].HandleData(highbyteBuf, 0, hptr);
+                if (st == ProbingState.FoundIt) {
+                    bestGuess = i;
+                    state = ProbingState.FoundIt;
+                    break;
+                } else if (st == ProbingState.NotMe) {
+                    isActive[i] = false;
+                    activeNum--;
+                    if (activeNum <= 0) {
+                        state = ProbingState.NotMe;
+                        break;
+                    }
+                }
+            }
+            return state;
+        }
+
+        public override float GetConfidence()
+        {
+            float bestConf = 0.0f;
+            float cf = 0.0f;
+            
+            if (state == ProbingState.FoundIt) {
+                return 0.99f;
+            } else if (state == ProbingState.NotMe) {
+                return 0.01f;
+            } else {
+                for (int i = 0; i < PROBERS_NUM; i++) {
+                    if (!isActive[i])
+                        continue;
+                    cf = probers[i].GetConfidence();
+                    if (bestConf < cf) {
+                        bestConf = cf;
+                        bestGuess = i;
+                    }
+                }
+            }
+            return bestConf;
+        }
+
+        public override void DumpStatus()
+        {
+            float cf;
+            GetConfidence();
+            for (int i = 0; i < PROBERS_NUM; i++) {
+                if (!isActive[i]) {
+                    //Console.WriteLine("  MBCS inactive: {0} (confidence is too low).", ProberName[i]);
+                } else {
+                    cf = probers[i].GetConfidence();
+                    //Console.WriteLine("  MBCS {0}: [{1}]", cf, ProberName[i]);
+                }
+            }
+        }
+    }
+}