1 files changed, 113 insertions, 0 deletions

diff --git a/noncore/apps/opie-reader/Coder.h b/noncore/apps/opie-reader/Coder.h
new file mode 100644
index 0000000..64587cf
--- a/dev/null
+++ b/noncore/apps/opie-reader/Coder.h
@@ -0,0 +1,113 @@
+#include "CSource.h"
+/****************************************************************************
+ *  This file is part of PPMd project                                       *
+ *  Contents: 'Carryless rangecoder' by Dmitry Subbotin                     *
+ *  Comments: this implementation is claimed to be a public domain          *
+ ****************************************************************************/
+/**********************  Original text  *************************************
+////////   Carryless rangecoder (c) 1999 by Dmitry Subbotin   ////////
+
+typedef unsigned int  uint;
+typedef unsigned char uc;
+
+#define  DO(n)     for (int _=0; _<n; _++)
+#define  TOP       (1<<24)
+#define  BOT       (1<<16)
+
+
+class RangeCoder
+{
+ uint  low, code, range, passed;
+ FILE  *f;
+
+ void OutByte (uc c)           { passed++; fputc(c,f); }
+ uc   InByte ()                { passed++; return fgetc(f); }
+
+public:
+
+ uint GetPassed ()             { return passed; }
+ void StartEncode (FILE *F)    { f=F; passed=low=0;  range= (uint) -1; }
+ void FinishEncode ()          { DO(4)  OutByte(low>>24), low<<=8; }
+ void StartDecode (FILE *F)    { passed=low=code=0;  range= (uint) -1;
+                                 f=F; DO(4) code= code<<8 | InByte();
+                               }
+
+ void Encode (uint cumFreq, uint freq, uint totFreq) {
+    assert(cumFreq+freq<totFreq && freq && totFreq<=BOT);
+    low  += cumFreq * (range/= totFreq);
+    range*= freq;
+    while ((low ^ low+range)<TOP || range<BOT && ((range= -low & BOT-1),1))
+       OutByte(low>>24), range<<=8, low<<=8;
+ }
+
+ uint GetFreq (uint totFreq) {
+   uint tmp= (code-low) / (range/= totFreq);
+   if (tmp >= totFreq)  throw ("Input data corrupt"); // or force it to return
+   return tmp;                                         // a valid value :)
+ }
+
+ void Decode (uint cumFreq, uint freq, uint totFreq) {
+    assert(cumFreq+freq<totFreq && freq && totFreq<=BOT);
+    low  += cumFreq*range;
+    range*= freq;
+    while ((low ^ low+range)<TOP || range<BOT && ((range= -low & BOT-1),1))
+       code= code<<8 | InByte(), range<<=8, low<<=8;
+ }
+};
+*****************************************************************************/
+
+static struct SUBRANGE {
+    DWORD LowCount, HighCount, scale;
+} SubRange;
+enum { TOP=1 << 24, BOT=1 << 15 };
+static DWORD low, code, range;
+
+inline void ariInitEncoder()
+{
+    low=0;                                  range=DWORD(-1);
+}
+#define ARI_ENC_NORMALIZE(stream) {                                         \
+    while ((low ^ (low+range)) < TOP || range < BOT &&                      \
+            ((range= -low & (BOT-1)),1)) {                                  \
+        _PPMD_E_PUTC(low >> 24,stream);                                     \
+        range <<= 8;                        low <<= 8;                      \
+    }                                                                       \
+}
+inline void ariEncodeSymbol()
+{
+    low += SubRange.LowCount*(range /= SubRange.scale);
+    range *= SubRange.HighCount-SubRange.LowCount;
+}
+inline void ariShiftEncodeSymbol(UINT SHIFT)
+{
+    low += SubRange.LowCount*(range >>= SHIFT);
+    range *= SubRange.HighCount-SubRange.LowCount;
+}
+#define ARI_FLUSH_ENCODER(stream) {                                         \
+    for (UINT i=0;i < 4;i++) {                                              \
+        _PPMD_E_PUTC(low >> 24,stream);                 low <<= 8;          \
+    }                                                                       \
+}
+#define ARI_INIT_DECODER(stream) {                                          \
+    low=code=0;                             range=DWORD(-1);                \
+    for (UINT i=0;i < 4;i++)                                                \
+            code=(code << 8) | _PPMD_D_GETC(stream);                        \
+}
+#define ARI_DEC_NORMALIZE(stream) {                                         \
+    while ((low ^ (low+range)) < TOP || range < BOT &&                      \
+            ((range= -low & (BOT-1)),1)) {                                  \
+        code=(code << 8) | _PPMD_D_GETC(stream);                            \
+        range <<= 8;                        low <<= 8;                      \
+    }                                                                       \
+}
+inline UINT ariGetCurrentCount() {
+    return (code-low)/(range /= SubRange.scale);
+}
+inline UINT ariGetCurrentShiftCount(UINT SHIFT) {
+    return (code-low)/(range >>= SHIFT);
+}
+inline void ariRemoveSubrange()
+{
+    low += range*SubRange.LowCount;
+    range *= SubRange.HighCount-SubRange.LowCount;
+}