1 files changed, 120 insertions, 0 deletions
diff --git a/mpeglib/lib/splay/huffmanlookup.cpp b/mpeglib/lib/splay/huffmanlookup.cpp
new file mode 100644
index 00000000..e4b37453
--- /dev/null
+++ b/mpeglib/lib/splay/huffmanlookup.cpp
@@ -0,0 +1,120 @@
+    /*
+
+    Copyright (C) 2000 Stefan Westerfeld
+                       stefan@space.twc.de
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+  
+    This library 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
+    Library General Public License for more details.
+   
+    You should have received a copy of the GNU Library General Public License
+    along with this library; see the file COPYING.LIB.  If not, write to
+    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+    Boston, MA 02111-1307, USA.
+
+    */
+
+#include "huffmanlookup.h"
+#include <assert.h>
+
+
+
+
+struct HuffmanLookup::decodeData HuffmanLookup::qdecode[32][256];
+/* for initialization */
+static HuffmanLookup l;
+
+HuffmanLookup::HuffmanLookup()
+{
+	int table,p,x,y;
+
+	for(table = 0; table < 32; table++)
+	{
+		// 8 bits pattern
+		for(p = 0; p < 256; p++)
+		{
+			bits = 24;
+			pattern = (p << 16);
+
+			huffmandecoder_1(&Mpegtoraw::ht[table], &x,&y);
+
+			int used = 24 - bits;
+			qdecode[table][p].skip = (used <= 8)?used:0;
+			qdecode[table][p].x = x;
+			qdecode[table][p].y = y;
+		}
+	}
+}
+
+int HuffmanLookup::wgetbit()   
+{
+	return (pattern >> --bits) & 1;
+}
+
+int HuffmanLookup::wgetbits (int b)
+{
+   	bits -= b;
+	return (pattern >> bits) & ((1 << b) - 1);
+}
+
+void HuffmanLookup::huffmandecoder_1(const HUFFMANCODETABLE *h, int *x, int *y)
+{  
+  typedef unsigned int HUFFBITS;
+
+  HUFFBITS level=(1<<(sizeof(HUFFBITS)*8-1));
+  int point=0;
+  /* Lookup in Huffman table. */
+  for(;;)
+  {
+    if(h->val[point][0]==0)
+    {   /*end of tree*/
+      int xx,yy;
+
+      xx=h->val[point][1]>>4;
+      yy=h->val[point][1]&0xf;
+
+      if(h->linbits)
+      {
+	if((h->xlen)==(unsigned)xx)xx+=wgetbits(h->linbits);
+	if(xx)if(wgetbit())xx=-xx;
+	if((h->ylen)==(unsigned)yy)yy+=wgetbits(h->linbits);
+	if(yy)if(wgetbit())yy=-yy;
+      }
+      else
+      {
+	if(xx)if(wgetbit())xx=-xx;
+	if(yy)if(wgetbit())yy=-yy;
+      }
+      *x=xx;*y=yy;
+      break;
+    } 
+
+    point+=h->val[point][wgetbit()];
+    
+    level>>=1;
+    if(!(level || ((unsigned)point<Mpegtoraw::ht->treelen)))
+    {
+      register int xx,yy;
+
+      xx=(h->xlen<<1);// set x and y to a medium value as a simple concealment
+      yy=(h->ylen<<1);
+
+      // h->xlen and h->ylen can't be 1 under tablename 32
+      //      if(xx)
+	if(wgetbit())xx=-xx;
+      //      if(yy)
+	if(wgetbit())yy=-yy;
+
+      *x=xx;*y=yy;
+      break;
+    }
+  }
+}
+
+