diff --git a/common/rfb/Decoder.cxx b/common/rfb/Decoder.cxx
new file mode 100644
index 0000000..b6e4fd5
--- /dev/null
+++ b/common/rfb/Decoder.cxx
@@ -0,0 +1,70 @@
+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+#include <stdio.h>
+#include <rfb/Exception.h>
+#include <rfb/Decoder.h>
+#include <rfb/RawDecoder.h>
+#include <rfb/RREDecoder.h>
+#include <rfb/HextileDecoder.h>
+#include <rfb/ZRLEDecoder.h>
+#include <rfb/TightDecoder.h>
+
+using namespace rfb;
+
+Decoder::~Decoder()
+{
+}
+
+DecoderCreateFnType Decoder::createFns[encodingMax+1] = { 0 };
+
+bool Decoder::supported(unsigned int encoding)
+{
+  return encoding <= encodingMax && createFns[encoding];
+}
+
+Decoder* Decoder::createDecoder(unsigned int encoding, CMsgReader* reader)
+{
+  if (encoding <= encodingMax && createFns[encoding])
+    return (*createFns[encoding])(reader);
+  return 0;
+}
+
+void Decoder::registerDecoder(unsigned int encoding,
+                              DecoderCreateFnType createFn)
+{
+  if (encoding > encodingMax)
+    throw Exception("Decoder::registerDecoder: encoding out of range");
+
+  if (createFns[encoding])
+    fprintf(stderr,"Replacing existing decoder for encoding %s (%d)\n",
+            encodingName(encoding), encoding);
+  createFns[encoding] = createFn;
+}
+
+int DecoderInit::count = 0;
+
+DecoderInit::DecoderInit()
+{
+  if (count++ != 0) return;
+
+  Decoder::registerDecoder(encodingRaw, RawDecoder::create);
+  Decoder::registerDecoder(encodingRRE, RREDecoder::create);
+  Decoder::registerDecoder(encodingHextile, HextileDecoder::create);
+  Decoder::registerDecoder(encodingZRLE, ZRLEDecoder::create);
+  Decoder::registerDecoder(encodingTight, TightDecoder::create);
+}