+++ /dev/null
-//========================================================================
-//
-// JArithmeticDecoder.h
-//
-// Arithmetic decoder used by the JBIG2 and JPEG2000 decoders.
-//
-// Copyright 2002-2004 Glyph & Cog, LLC
-//
-//========================================================================
-
-#ifndef JARITHMETICDECODER_H
-#define JARITHMETICDECODER_H
-
-#include <aconf.h>
-
-#ifdef USE_GCC_PRAGMAS
-#pragma interface
-#endif
-
-#include "gtypes.h"
-
-class Stream;
-
-//------------------------------------------------------------------------
-// JArithmeticDecoderStats
-//------------------------------------------------------------------------
-
-class JArithmeticDecoderStats {
-public:
-
- JArithmeticDecoderStats(int contextSizeA);
- ~JArithmeticDecoderStats();
- JArithmeticDecoderStats *copy();
- void reset();
- int getContextSize() { return contextSize; }
- void copyFrom(JArithmeticDecoderStats *stats);
- void setEntry(Guint cx, int i, int mps);
-
-private:
-
- Guchar *cxTab; // cxTab[cx] = (i[cx] << 1) + mps[cx]
- int contextSize;
-
- friend class JArithmeticDecoder;
-};
-
-//------------------------------------------------------------------------
-// JArithmeticDecoder
-//------------------------------------------------------------------------
-
-class JArithmeticDecoder {
-public:
-
- JArithmeticDecoder();
- ~JArithmeticDecoder();
-
- void setStream(Stream *strA)
- { str = strA; dataLen = 0; limitStream = gFalse; }
- void setStream(Stream *strA, int dataLenA)
- { str = strA; dataLen = dataLenA; limitStream = gTrue; }
-
- // Start decoding on a new stream. This fills the byte buffers and
- // runs INITDEC.
- void start();
-
- // Restart decoding on an interrupted stream. This refills the
- // buffers if needed, but does not run INITDEC. (This is used in
- // JPEG 2000 streams when codeblock data is split across multiple
- // packets/layers.)
- void restart(int dataLenA);
-
- // Read any leftover data in the stream.
- void cleanup();
-
- // Decode one bit.
- int decodeBit(Guint context, JArithmeticDecoderStats *stats);
-
- // Decode eight bits.
- int decodeByte(Guint context, JArithmeticDecoderStats *stats);
-
- // Returns false for OOB, otherwise sets *<x> and returns true.
- GBool decodeInt(int *x, JArithmeticDecoderStats *stats);
-
- Guint decodeIAID(Guint codeLen,
- JArithmeticDecoderStats *stats);
-
-private:
-
- Guint readByte();
- int decodeIntBit(JArithmeticDecoderStats *stats);
- void byteIn();
-
- static Guint qeTab[47];
- static int nmpsTab[47];
- static int nlpsTab[47];
- static int switchTab[47];
-
- Guint buf0, buf1;
- Guint c, a;
- int ct;
-
- Guint prev; // for the integer decoder
-
- Stream *str;
- int dataLen;
- GBool limitStream;
-};
-
-#endif