ebcot_constants.h

JPEG2000 EBCOT算法源码

/*****************************************************************************/
/* File name: "ebcot_constants.h"                                            */
/* Author: David Taubman                                                     */
/* Copyright 1998, Hewlett-Packard Company                                   */
/* All rights reserved                                                       */
/*****************************************************************************/
#ifndef EBCOT_CONSTANTS_H
#define EBCOT_CONSTANTS_H
#include <line_block_ifc.h>

/* ========================================================================= */
/* ---------------------------- Context Assignment ------------------------- */
/* ========================================================================= */

#define TL_POS      0 /* Bit-pos for significance of top-left neighbour      */
#define TC_POS      1 /* Bit-pos for significance of top-centre neighbour    */
#define TR_POS      2 /* Bit-pos for significance of top-right neighbour     */
#define CL_POS      3 /* Bit-pos for significance of centre-left neighbour   */
#define CR_POS      4 /* Bit-pos for significance of centre-right neighbour  */
#define BL_POS      5 /* Bit-pos for significance of bottom-left neighbour   */
#define BC_POS      6 /* Bit-pos for significance of bottom-centre neighbour */
#define BR_POS      7 /* Bit-pos for significance of bottom-right neighbour  */
#define FAR_POS     8 /* Bit-pos for significance of far-left neighbour      */

#define SELF_POS    9  /* Bit-pos for significance of the current sample. */
#define REFINED_POS 10 /* Bit-pos indicating whether or not the sample has
                          been refined to the next bit-plane yet. */

#define V_PVE_POS 11 /* Bit-pos indicating >=1 +ve vertical neighbour   */
#define V_NVE_POS 12 /* Bit-pos indicating >=1 -ve vertical neighbour   */
#define H_PVE_POS 13 /* Bit-pos indicating >=1 +ve horizontal neighbour */
#define H_NVE_POS 14 /* Bit-pos indicating >=1 -ve horizontal neighbour */

#define OUT_OF_BOUNDS_POS 15 /* May be used to identify context words which
                                lie beyond the boundaries of the code block */

#define TL_SIG        ((std_short)(1<<TL_POS))
#define TC_SIG        ((std_short)(1<<TC_POS))
#define TR_SIG        ((std_short)(1<<TR_POS))
#define CL_SIG        ((std_short)(1<<CL_POS))
#define CR_SIG        ((std_short)(1<<CR_POS))
#define BL_SIG        ((std_short)(1<<BL_POS))
#define BC_SIG        ((std_short)(1<<BC_POS))
#define BR_SIG        ((std_short)(1<<BR_POS))
#define FAR_SIG       ((std_short)(1<<FAR_POS))
#define SELF_SIG      ((std_short)(1<<SELF_POS))
#define IS_REFINED    ((std_short)(1<<REFINED_POS))
#define V_PVE_SIG     ((std_short)(1<<V_PVE_POS))
#define V_NVE_SIG     ((std_short)(1<<V_NVE_POS))
#define H_PVE_SIG     ((std_short)(1<<H_PVE_POS))
#define H_NVE_SIG     ((std_short)(1<<H_NVE_POS))
#define OUT_OF_BOUNDS ((std_short)(1<<OUT_OF_BOUNDS_POS))

#define SIGN_POS V_PVE_POS /* Initial bit-pos for 4-bit sign context word. */
#define ZC_MASK ((std_short)(~((-1) << 9))) /* Zero-coding LUT index mask. */

#define AGG_CONTEXTS  1 /* Num context states devoted to aggregated zeros. */
#define ZC_CONTEXTS  10 /* Num context states devoted to zero coding. */
#define MAG_CONTEXTS  3 /* Num context states devoted to mag refinement. */
#define SC_CONTEXTS   5 /* Num context states devoted to sign coding. */

#define AGG_OFFSET 0
#define ZC_OFFSET (AGG_OFFSET+AGG_CONTEXTS)
#define MAG_OFFSET (ZC_OFFSET + ZC_CONTEXTS)
#define SC_OFFSET (MAG_OFFSET + MAG_CONTEXTS)

#define TOTAL_CONTEXTS (AGG_CONTEXTS+ZC_CONTEXTS+SC_CONTEXTS+MAG_CONTEXTS)

/* ========================================================================= */
/* ----------------------------- Arithmetic Coder -------------------------- */
/* ========================================================================= */

/* #define LOG_SYMBOLS */

#define W_BITS 16 /* Number of bits used to represent A register */
#define P_BITS 15 /* Number of bits used to represent probabilities
                     NB: Must have P_bits+W_bits=31 and P_bits<=15 */
#define S_BITS 9  /* Number of context state bits used for counting symbols. */
#define N_BITS 4  /* Number of context state bits used for counting 1's. */
#define S_MASK ((std_short)(~((-1)<<S_BITS)))
#define S_MSB  ((std_short)(1<<(S_BITS-1)))
#define CONTEXT_STATE_BITS (S_BITS+N_BITS)
#define N_OVFL ((std_short)(1<<CONTEXT_STATE_BITS))

/* ========================================================================= */
/* --------------------------- Quad-Tree Structure ------------------------- */
/* ========================================================================= */

#define QUAD_LEAVES             ((std_short) 1)
#define QUAD_PARENT_SIGNIFICANT ((std_short) 2)
#define QUAD_NODE_SIGNIFICANT   ((std_short) 4)

/* ========================================================================= */
/* -------------------------- Block Coding Structure ----------------------- */
/* ========================================================================= */

#define PASSES_PER_BITPLANE 4
#define MAX_PASSES ((IMPLEMENTATION_PRECISION-2)*PASSES_PER_BITPLANE+1)

/* ========================================================================= */
/* ----------------------------- MSE Computations -------------------------- */
/* ========================================================================= */

#define MSE_LUT_BITS 7
#define MSE_LUT_MASK ((std_short)(~((-1)<<MSE_LUT_BITS)))

/* ========================================================================= */
/* ----------------------------- Handy Constants --------------------------- */
/* ========================================================================= */

#define MIN_IFC_INT ((ifc_int)(((ifc_int) 1) << (IMPLEMENTATION_PRECISION-1)))
#define MAX_IFC_INT (~MIN_IFC_INT)

#endif /* EBCOT_CONSTANTS_H */