/*
 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
 *   British Columbia.
 * Copyright (c) 2001-2002 Michael David Adams.
 * All rights reserved.
 */

/* __START_OF_JASPER_LICENSE__
 * 
 * JasPer License Version 2.0
 * 
 * Copyright (c) 1999-2000 Image Power, Inc.
 * Copyright (c) 1999-2000 The University of British Columbia
 * Copyright (c) 2001-2003 Michael David Adams
 * 
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person (the
 * "User") obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, and/or sell copies of the Software, and to permit
 * persons to whom the Software is furnished to do so, subject to the
 * following conditions:
 * 
 * 1.  The above copyright notices and this permission notice (which
 * includes the disclaimer below) shall be included in all copies or
 * substantial portions of the Software.
 * 
 * 2.  The name of a copyright holder shall not be used to endorse or
 * promote products derived from the Software without specific prior
 * written permission.
 * 
 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
 * LICENSE.  NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
 * THIS DISCLAIMER.  THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
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 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.  IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
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 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY.  THE SOFTWARE
 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
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 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
 * RISK ACTIVITIES").  THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
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 * __END_OF_JASPER_LICENSE__
 */

/*
 * MQ Arithmetic Encoder
 *
 * $Id: jpc_mqenc.h,v 1.2 2005/06/08 17:12:49 malaterre Exp $
 */

#ifndef JPC_MQENC_H
#define JPC_MQENC_H

/******************************************************************************\
* Includes.
\******************************************************************************/

#include "jasper/jas_types.h"
#include "jasper/jas_stream.h"

#include "jpc_mqcod.h"

/******************************************************************************\
* Constants.
\******************************************************************************/

/*
 * Termination modes.
 */

#define  JPC_MQENC_DEFTERM  0  /* default termination */
#define  JPC_MQENC_PTERM    1  /* predictable termination */

/******************************************************************************\
* Types.
\******************************************************************************/

/* MQ arithmetic encoder class. */

typedef struct {

  /* The C register. */
  uint_fast32_t creg;

  /* The A register. */
  uint_fast32_t areg;

  /* The CT register. */
  uint_fast32_t ctreg;

  /* The maximum number of contexts. */
  int maxctxs;

  /* The per-context information. */
  jpc_mqstate_t **ctxs;

  /* The current context. */
  jpc_mqstate_t **curctx;

  /* The stream for encoder output. */
  jas_stream_t *out;

  /* The byte buffer (i.e., the B variable in the standard). */
  int_fast16_t outbuf;

  /* The last byte output. */
  int_fast16_t lastbyte;

  /* The error indicator. */
  int err;
  
} jpc_mqenc_t;

/* MQ arithmetic encoder state information. */

typedef struct {

  /* The A register. */
  unsigned areg;

  /* The C register. */
  unsigned creg;

  /* The CT register. */
  unsigned ctreg;

  /* The last byte output by the encoder. */
  int lastbyte;

} jpc_mqencstate_t;

/******************************************************************************\
* Functions/macros for construction and destruction.
\******************************************************************************/

/* Create a MQ encoder. */
jpc_mqenc_t *jpc_mqenc_create(int maxctxs, jas_stream_t *out);

/* Destroy a MQ encoder. */
void jpc_mqenc_destroy(jpc_mqenc_t *enc);

/******************************************************************************\
* Functions/macros for initialization.
\******************************************************************************/

/* Initialize a MQ encoder. */
void jpc_mqenc_init(jpc_mqenc_t *enc);

/******************************************************************************\
* Functions/macros for context manipulation.
\******************************************************************************/

/* Set the current context. */
#define  jpc_mqenc_setcurctx(enc, ctxno) \
        ((enc)->curctx = &(enc)->ctxs[ctxno]);

/* Set the state information for a particular context. */
void jpc_mqenc_setctx(jpc_mqenc_t *enc, int ctxno, jpc_mqctx_t *ctx);

/* Set the state information for multiple contexts. */
void jpc_mqenc_setctxs(jpc_mqenc_t *enc, int numctxs, jpc_mqctx_t *ctxs);

/******************************************************************************\
* Miscellaneous functions/macros.
\******************************************************************************/

/* Get the error state of a MQ encoder. */
#define  jpc_mqenc_error(enc) \
  ((enc)->err)

/* Get the current encoder state. */
void jpc_mqenc_getstate(jpc_mqenc_t *enc, jpc_mqencstate_t *state);

/* Terminate the code. */
int jpc_mqenc_flush(jpc_mqenc_t *enc, int termmode);

/******************************************************************************\
* Functions/macros for encoding bits.
\******************************************************************************/

/* Encode a bit. */
#if !defined(DEBUG)
#define  jpc_mqenc_putbit(enc, bit)  jpc_mqenc_putbit_macro(enc, bit)
#else
#define  jpc_mqenc_putbit(enc, bit)  jpc_mqenc_putbit_func(enc, bit)
#endif

/******************************************************************************\
* Functions/macros for debugging.
\******************************************************************************/

int jpc_mqenc_dump(jpc_mqenc_t *mqenc, FILE *out);

/******************************************************************************\
* Implementation-specific details.
\******************************************************************************/

/* Note: This macro is included only to satisfy the needs of
  the mqenc_putbit macro. */
/* The cast to 'unsigned' allow us to get rid of multiple annoying warnings
 * on gcc: 
 * jpc_t1enc.c:958: warning: signed and unsigned type in conditional expression
 * I am not sure this is the best patch ever since jpc_mqenc_codemps2 is
 * only returning 0 or -1 ... */
#define  jpc_mqenc_putbit_macro(enc, bit) \
  (((*((enc)->curctx))->mps == (bit)) ? \
    (((enc)->areg -= (*(enc)->curctx)->qeval), \
    ((!((enc)->areg & 0x8000)) ? ((unsigned)jpc_mqenc_codemps2(enc)) : \
    ((enc)->creg += (*(enc)->curctx)->qeval))) : \
    (unsigned)jpc_mqenc_codelps(enc))

/* Note: These function prototypes are included only to satisfy the
  needs of the mqenc_putbit_macro macro.  Do not call any of these
  functions directly. */
int jpc_mqenc_codemps2(jpc_mqenc_t *enc);
int jpc_mqenc_codelps(jpc_mqenc_t *enc);

/* Note: This function prototype is included only to satisfy the needs of
  the mqenc_putbit macro. */
int jpc_mqenc_putbit_func(jpc_mqenc_t *enc, int bit);

#endif