/*
 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
 *   British Columbia.
 * Copyright (c) 2001-2003 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
 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * 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
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  NO ASSURANCES ARE
 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
 * PROPERTY RIGHTS OR OTHERWISE.  AS A CONDITION TO EXERCISING THE RIGHTS
 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
 * 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
 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
 * 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
 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
 * 
 * __END_OF_JASPER_LICENSE__
 */

/*
 * MQ Arithmetic Encoder
 *
 * $Id: jpc_mqenc.c,v 1.1 2005/05/22 18:33:05 malaterre Exp $
 */

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

#include <assert.h>
#include <stdlib.h>

#include "jasper/jas_stream.h"
#include "jasper/jas_malloc.h"
#include "jasper/jas_math.h"
#include "jasper/jas_debug.h"

#include "jpc_mqenc.h"

/******************************************************************************\
* Macros
\******************************************************************************/

#if defined(DEBUG)
#define  JPC_MQENC_CALL(n, x) \
  ((jas_getdbglevel() >= (n)) ? ((void)(x)) : ((void)0))
#else
#define  JPC_MQENC_CALL(n, x)
#endif

#define  jpc_mqenc_codemps9(areg, creg, ctreg, curctx, enc) \
{ \
  jpc_mqstate_t *state = *(curctx); \
  (areg) -= state->qeval; \
  if (!((areg) & 0x8000)) { \
    if ((areg) < state->qeval) { \
      (areg) = state->qeval; \
    } else { \
      (creg) += state->qeval; \
    } \
    *(curctx) = state->nmps; \
    jpc_mqenc_renorme((areg), (creg), (ctreg), (enc)); \
  } else { \
    (creg) += state->qeval; \
  } \
}

#define  jpc_mqenc_codelps2(areg, creg, ctreg, curctx, enc) \
{ \
  jpc_mqstate_t *state = *(curctx); \
  (areg) -= state->qeval; \
  if ((areg) < state->qeval) { \
    (creg) += state->qeval; \
  } else { \
    (areg) = state->qeval; \
  } \
  *(curctx) = state->nlps; \
  jpc_mqenc_renorme((areg), (creg), (ctreg), (enc)); \
}

#define  jpc_mqenc_renorme(areg, creg, ctreg, enc) \
{ \
  do { \
    (areg) <<= 1; \
    (creg) <<= 1; \
    if (!--(ctreg)) { \
      jpc_mqenc_byteout((areg), (creg), (ctreg), (enc)); \
    } \
  } while (!((areg) & 0x8000)); \
}

#define  jpc_mqenc_byteout(areg, creg, ctreg, enc) \
{ \
  if ((enc)->outbuf != 0xff) { \
    if ((creg) & 0x8000000) { \
      if (++((enc)->outbuf) == 0xff) { \
        (creg) &= 0x7ffffff; \
        jpc_mqenc_byteout2(enc); \
        enc->outbuf = ((creg) >> 20) & 0xff; \
        (creg) &= 0xfffff; \
        (ctreg) = 7; \
      } else { \
        jpc_mqenc_byteout2(enc); \
        enc->outbuf = ((creg) >> 19) & 0xff; \
        (creg) &= 0x7ffff; \
        (ctreg) = 8; \
      } \
    } else { \
      jpc_mqenc_byteout2(enc); \
      (enc)->outbuf = ((creg) >> 19) & 0xff; \
      (creg) &= 0x7ffff; \
      (ctreg) = 8; \
    } \
  } else { \
    jpc_mqenc_byteout2(enc); \
    (enc)->outbuf = ((creg) >> 20) & 0xff; \
    (creg) &= 0xfffff; \
    (ctreg) = 7; \
  } \
}

#define  jpc_mqenc_byteout2(enc) \
{ \
  if (enc->outbuf >= 0) { \
    if (jas_stream_putc(enc->out, (unsigned char)enc->outbuf) == EOF) { \
      enc->err |= 1; \
    } \
  } \
  enc->lastbyte = enc->outbuf; \
}

/******************************************************************************\
* Local function protoypes.
\******************************************************************************/

static void jpc_mqenc_setbits(jpc_mqenc_t *mqenc);

/******************************************************************************\
* Code for creation and destruction of encoder.
\******************************************************************************/

/* Create a MQ encoder. */

jpc_mqenc_t *jpc_mqenc_create(int maxctxs, jas_stream_t *out)
{
  jpc_mqenc_t *mqenc;

  /* Allocate memory for the MQ encoder. */
  if (!(mqenc = jas_malloc(sizeof(jpc_mqenc_t)))) {
    goto error;
  }
  mqenc->out = out;
  mqenc->maxctxs = maxctxs;

  /* Allocate memory for the per-context state information. */
  if (!(mqenc->ctxs = jas_malloc(mqenc->maxctxs * sizeof(jpc_mqstate_t *)))) {
    goto error;
  }

  /* Set the current context to the first one. */
  mqenc->curctx = mqenc->ctxs;

  jpc_mqenc_init(mqenc);

  /* Initialize the per-context state information to something sane. */
  jpc_mqenc_setctxs(mqenc, 0, 0);

  return mqenc;

error:
  if (mqenc) {
    jpc_mqenc_destroy(mqenc);
  }
  return 0;
}

/* Destroy a MQ encoder. */

void jpc_mqenc_destroy(jpc_mqenc_t *mqenc)
{
  if (mqenc->ctxs) {
    jas_free(mqenc->ctxs);
  }
  jas_free(mqenc);
}

/******************************************************************************\
* State initialization code.
\******************************************************************************/

/* Initialize the coding state of a MQ encoder. */

void jpc_mqenc_init(jpc_mqenc_t *mqenc)
{
  mqenc->areg = 0x8000;
  mqenc->outbuf = -1;
  mqenc->creg = 0;
  mqenc->ctreg = 12;
  mqenc->lastbyte = -1;
  mqenc->err = 0;
}

/* Initialize one or more contexts. */

void jpc_mqenc_setctxs(jpc_mqenc_t *mqenc, int numctxs, jpc_mqctx_t *ctxs)
{
  jpc_mqstate_t **ctx;
  int n;

  ctx = mqenc->ctxs;
  n = JAS_MIN(mqenc->maxctxs, numctxs);
  while (--n >= 0) {
    *ctx = &jpc_mqstates[2 * ctxs->ind + ctxs->mps];
    ++ctx;
    ++ctxs;
  }
  n = mqenc->maxctxs - numctxs;
  while (--n >= 0) {
    *ctx = &jpc_mqstates[0];
    ++ctx;
  }

}

/* Get the coding state for a MQ encoder. */

void jpc_mqenc_getstate(jpc_mqenc_t *mqenc, jpc_mqencstate_t *state)
{
  state->areg = mqenc->areg;
  state->creg = mqenc->creg;
  state->ctreg = mqenc->ctreg;
  state->lastbyte = mqenc->lastbyte;
}

/******************************************************************************\
* Code for coding symbols.
\******************************************************************************/

/* Encode a bit. */

int jpc_mqenc_putbit_func(jpc_mqenc_t *mqenc, int bit)
{
  const jpc_mqstate_t *state;
  JAS_DBGLOG(100, ("jpc_mqenc_putbit(%p, %d)\n", mqenc, bit));
  JPC_MQENC_CALL(100, jpc_mqenc_dump(mqenc, stderr));

  state = *(mqenc->curctx);

  if (state->mps == bit) {
    /* Apply the CODEMPS algorithm as defined in the standard. */
    mqenc->areg -= state->qeval;
    if (!(mqenc->areg & 0x8000)) {
      jpc_mqenc_codemps2(mqenc);
    } else {
      mqenc->creg += state->qeval;
    }
  } else {
    /* Apply the CODELPS algorithm as defined in the standard. */
    jpc_mqenc_codelps2(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc->curctx, mqenc);
  }

  return jpc_mqenc_error(mqenc) ? (-1) : 0;
}

int jpc_mqenc_codemps2(jpc_mqenc_t *mqenc)
{
  /* Note: This function only performs part of the work associated with
  the CODEMPS algorithm from the standard.  Some of the work is also
  performed by the caller. */

  jpc_mqstate_t *state = *(mqenc->curctx);
  if (mqenc->areg < state->qeval) {
    mqenc->areg = state->qeval;
  } else {
    mqenc->creg += state->qeval;
  }
  *mqenc->curctx = state->nmps;
  jpc_mqenc_renorme(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc);
  return jpc_mqenc_error(mqenc) ? (-1) : 0;
}

int jpc_mqenc_codelps(jpc_mqenc_t *mqenc)
{
  jpc_mqenc_codelps2(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc->curctx, mqenc);
  return jpc_mqenc_error(mqenc) ? (-1) : 0;
}

/******************************************************************************\
* Miscellaneous code.
\******************************************************************************/

/* Terminate the code word. */

int jpc_mqenc_flush(jpc_mqenc_t *mqenc, int termmode)
{
  int_fast16_t k;

  switch (termmode) {
  case JPC_MQENC_PTERM:
    k = 11 - mqenc->ctreg + 1;
    while (k > 0) {
      mqenc->creg <<= mqenc->ctreg;
      mqenc->ctreg = 0;
      jpc_mqenc_byteout(mqenc->areg, mqenc->creg, mqenc->ctreg,
        mqenc);
      k -= mqenc->ctreg;
    }
    if (mqenc->outbuf != 0xff) {
      jpc_mqenc_byteout(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc);
    }
    break;
  case JPC_MQENC_DEFTERM:
    jpc_mqenc_setbits(mqenc);
    mqenc->creg <<= mqenc->ctreg;
    jpc_mqenc_byteout(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc);
    mqenc->creg <<= mqenc->ctreg;
    jpc_mqenc_byteout(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc);
    if (mqenc->outbuf != 0xff) {
      jpc_mqenc_byteout(mqenc->areg, mqenc->creg, mqenc->ctreg, mqenc);
    }
    break;
  default:
    abort();
    break;
  }
  return 0;
}

static void jpc_mqenc_setbits(jpc_mqenc_t *mqenc)
{
  uint_fast32_t tmp = mqenc->creg + mqenc->areg;
  mqenc->creg |= 0xffff;
  if (mqenc->creg >= tmp) {
    mqenc->creg -= 0x8000;
  }
}

/* Dump a MQ encoder to a stream for debugging. */

int jpc_mqenc_dump(jpc_mqenc_t *mqenc, FILE *out)
{
  fprintf(out, "AREG = %08x, CREG = %08x, CTREG = %d\n",
    mqenc->areg, mqenc->creg, mqenc->ctreg);
  fprintf(out, "IND = %02d, MPS = %d, QEVAL = %04x\n",
    *mqenc->curctx - jpc_mqstates, (*mqenc->curctx)->mps,
    (*mqenc->curctx)->qeval);
  return 0;
}