1 files changed, 105 insertions, 0 deletions
diff --git a/core/src/fxcodec/jbig2/JBig2_ArithIntDecoder.cpp b/core/src/fxcodec/jbig2/JBig2_ArithIntDecoder.cpp
new file mode 100644
index 0000000000..bb4e0bba9f
--- /dev/null
+++ b/core/src/fxcodec/jbig2/JBig2_ArithIntDecoder.cpp
@@ -0,0 +1,105 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+ 
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "JBig2_ArithIntDecoder.h"
+CJBig2_ArithIntDecoder::CJBig2_ArithIntDecoder()
+{
+    IAx = (JBig2ArithCtx*)m_pModule->JBig2_Malloc2(sizeof(JBig2ArithCtx), 512);
+    JBIG2_memset(IAx, 0, sizeof(JBig2ArithCtx) * 512);
+}
+CJBig2_ArithIntDecoder::~CJBig2_ArithIntDecoder()
+{
+    m_pModule->JBig2_Free(IAx);
+}
+int CJBig2_ArithIntDecoder::decode(CJBig2_ArithDecoder *pArithDecoder, int *nResult)
+{
+    int PREV, V;
+    int S, D;
+    int nNeedBits, nTemp, i;
+    PREV = 1;
+    S = pArithDecoder->DECODE(IAx + PREV);
+    PREV = (PREV << 1) | S;
+    D = pArithDecoder->DECODE(IAx + PREV);
+    PREV = (PREV << 1) | D;
+    if(D) {
+        D = pArithDecoder->DECODE(IAx + PREV);
+        PREV = (PREV << 1) | D;
+        if(D) {
+            D = pArithDecoder->DECODE(IAx + PREV);
+            PREV = (PREV << 1) | D;
+            if(D) {
+                D = pArithDecoder->DECODE(IAx + PREV);
+                PREV = (PREV << 1) | D;
+                if(D) {
+                    D = pArithDecoder->DECODE(IAx + PREV);
+                    PREV = (PREV << 1) | D;
+                    if(D) {
+                        nNeedBits = 32;
+                        V = 4436;
+                    } else {
+                        nNeedBits = 12;
+                        V = 340;
+                    }
+                } else {
+                    nNeedBits = 8;
+                    V = 84;
+                }
+            } else {
+                nNeedBits = 6;
+                V = 20;
+            }
+        } else {
+            nNeedBits = 4;
+            V = 4;
+        }
+    } else {
+        nNeedBits = 2;
+        V = 0;
+    }
+    nTemp = 0;
+    for(i = 0; i < nNeedBits; i++) {
+        D = pArithDecoder->DECODE(IAx + PREV);
+        if(PREV < 256) {
+            PREV = (PREV << 1) | D;
+        } else {
+            PREV = (((PREV << 1) | D) & 511) | 256;
+        }
+        nTemp = (nTemp << 1) | D;
+    }
+    V += nTemp;
+    if(S == 1 && V > 0) {
+        V = -V;
+    }
+    *nResult = V;
+    if(S == 1 && V == 0) {
+        return JBIG2_OOB;
+    }
+    return 0;
+}
+CJBig2_ArithIaidDecoder::CJBig2_ArithIaidDecoder(unsigned char SBSYMCODELENA)
+{
+    SBSYMCODELEN = SBSYMCODELENA;
+    IAID = (JBig2ArithCtx*)m_pModule->JBig2_Malloc2(sizeof(JBig2ArithCtx), (1 << SBSYMCODELEN));
+    JBIG2_memset(IAID, 0, sizeof(JBig2ArithCtx) * (int)(1 << SBSYMCODELEN));
+}
+CJBig2_ArithIaidDecoder::~CJBig2_ArithIaidDecoder()
+{
+    m_pModule->JBig2_Free(IAID);
+}
+int CJBig2_ArithIaidDecoder::decode(CJBig2_ArithDecoder *pArithDecoder, int *nResult)
+{
+    int PREV;
+    int D;
+    int i;
+    PREV = 1;
+    for(i = 0; i < SBSYMCODELEN; i++) {
+        D = pArithDecoder->DECODE(IAID + PREV);
+        PREV = (PREV << 1) | D;
+    }
+    PREV = PREV - (1 << SBSYMCODELEN);
+    *nResult = PREV;
+    return 0;
+}