add source code

2025-06-05 21:59:32 +02:00 · 2020-01-02 02:05:09 +01:00
parent 30f3efc66e
commit 2e1a6c97b3
47 changed files with 9322 additions and 0 deletions
--- a/src/lib/entropyCoding.h
+++ b/src/lib/entropyCoding.h
@ -0,0 +1,79 @@
+/* entropyCoding.h - header file for class with lossless entropy coding capability
+ * written by C. R. Helmrich, last modified in 2019 - see License.htm for legal notices
+ *
+ * The copyright in this software is being made available under a Modified BSD-Style License
+ * and comes with ABSOLUTELY NO WARRANTY. This software may be subject to other third-
+ * party rights, including patent rights. No such rights are granted under this License.
+ *
+ * Copyright (c) 2018-2020 Christian R. Helmrich, project ecodis. All rights reserved.
+ */
+
+#ifndef _ENTROPY_CODING_H_
+#define _ENTROPY_CODING_H_
+
+#include "exhaleLibPch.h"
+
+// constants, experimental macro
+#define ARITH_ESCAPE          16
+#define ARITH_SIZE           742
+#define INDEX_OFFSET          60
+#define INDEX_SIZE           121
+#define EC_TRELLIS_OPT_CODING  1
+
+// lossless entropy coding class
+class EntropyCoder
+{
+private:
+
+  // member variables
+  uint8_t* m_qcCurr;         // curr. window's quantized context q[1]
+  uint8_t* m_qcPrev;         // prev. window's quantized context q[0]
+
+  uint16_t m_acBits;         // bits_to_follow in arith_encode, 0..31
+  uint16_t m_acHigh;         // high in arith_encode as in Annex B.25
+  uint16_t m_acLow;          // low in arith_encode, as in Annex B.25
+  uint16_t m_acSize;         // context window size (N/4 in Scl. 7.4)
+  uint32_t m_csCurr;         // context state, see initWindowCoding()
+  unsigned m_maxTupleLength; // maximum half-transform length (<4096)
+  bool     m_shortTrafoCurr; // used to derive N in Scl. 7.4 and B.25
+  bool     m_shortTrafoPrev; // used to derive previous_N in Scl. 7.4
+
+  // helper functions
+  unsigned arithCodeSymbol (const uint16_t symbol, const uint16_t* table, OutputStream* const stream = nullptr);
+  unsigned arithGetContext (const unsigned ctx, const unsigned idx);
+  unsigned arithMapContext (const bool arithResetFlag);
+#if EC_TRELLIS_OPT_CODING
+  void     arithSetContext (const unsigned newCtxState, const uint16_t sigEnd);
+#endif
+
+public:
+
+  // constructor
+  EntropyCoder ();
+  // destructor
+  ~EntropyCoder ();
+  // public functions
+  unsigned arithCodeSigMagn (const uint8_t* const magn, const uint16_t sigOffset, const uint16_t sigLength,
+                             const bool arithFinish = false, OutputStream* const stream = nullptr);
+  unsigned arithGetCodState () const                     { return ((unsigned) m_acHigh << 16) | (unsigned) m_acLow; }
+  unsigned arithGetCtxState () const                     { return m_csCurr; }
+  unsigned arithGetResetBit (const uint8_t* const magn, const uint16_t sigOffset, const uint16_t sigLength);
+  char*    arithGetTuplePtr () const                     { return (char*) m_qcCurr; }
+  void     arithResetMemory () { memset (m_qcPrev, 0, (m_maxTupleLength + 1) * sizeof (uint8_t)); m_acBits = 0; }
+  void     arithSetCodState (const unsigned newCodState) { m_acHigh = newCodState >> 16; m_acLow = newCodState & USHRT_MAX; }
+#if EC_TRELLIS_OPT_CODING
+  void     arithSetCtxState (const unsigned newCtxState, const uint16_t sigOffset = 0) { arithSetContext (newCtxState, sigOffset >> 1); }
+#else
+  void     arithSetCtxState (const unsigned newCtxState) { m_csCurr = newCtxState; }
+#endif
+  unsigned indexGetBitCount (const int scaleFactorDelta) const;
+  unsigned indexGetHuffCode (const int scaleFactorDelta) const;
+
+  unsigned initCodingMemory (const unsigned maxTransfLength);
+  unsigned initWindowCoding (const bool     forceArithReset, const bool shortWin = false);
+
+  bool     getIsShortWindow () const                     { return m_shortTrafoCurr; }
+  void     setIsShortWindow (const bool shortWin)        { m_shortTrafoCurr = shortWin; }
+}; // EntropyCoder
+
+#endif // _ENTROPY_CODING_H_