/*

 * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium

 * Copyright (c) 2002-2007, Professor Benoit Macq

 * Copyright (c) 2001-2003, David Janssens

 * Copyright (c) 2002-2003, Yannick Verschueren

 * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe

 * Copyright (c) 2005, Herve Drolon, FreeImage Team

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#include "opj_includes.h"

/** @defgroup BIO BIO - Individual bit input-output stream */

/*@{*/

/** @name Local static functions */

/*@{*/

/**

Write a bit

@param bio BIO handle

@param b Bit to write (0 or 1)

*/

static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b);

/**

Read a bit

@param bio BIO handle

@return Returns the read bit

*/

static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio);

/**

Write a byte

@param bio BIO handle

@return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise

*/

static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio);

/**

Read a byte

@param bio BIO handle

@return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise

*/

static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio);

/*@}*/

/*@}*/

/* 

==========================================================

   local functions

==========================================================

*/

OPJ_BOOL opj_bio_byteout(opj_bio_t *bio) {

  bio->buf = (bio->buf << 8) & 0xffff;

  bio->ct = bio->buf == 0xff00 ? 7 : 8;

  if (bio->bp >= bio->end) {

    return OPJ_FALSE;

  }

  *bio->bp++ = (OPJ_BYTE)(bio->buf >> 8);

  return OPJ_TRUE;

}

OPJ_BOOL opj_bio_bytein(opj_bio_t *bio) {

  bio->buf = (bio->buf << 8) & 0xffff;

  bio->ct = bio->buf == 0xff00 ? 7 : 8;

  if (bio->bp >= bio->end) {

    return OPJ_FALSE;

  }

  bio->buf |= *bio->bp++;

  return OPJ_TRUE;

}

void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b) {

  if (bio->ct == 0) {

    opj_bio_byteout(bio); /* MSD: why not check the return value of this function ? */

  }

  bio->ct--;

  bio->buf |= b << bio->ct;

}

OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio) {

  if (bio->ct == 0) {

    opj_bio_bytein(bio); /* MSD: why not check the return value of this function ? */

  }

  bio->ct--;

  return (bio->buf >> bio->ct) & 1;

}

/* 

==========================================================

   Bit Input/Output interface

==========================================================

*/

opj_bio_t* opj_bio_create(void) {

  opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t));

  return bio;

}

void opj_bio_destroy(opj_bio_t *bio) {

  if(bio) {

    opj_free(bio);

  }

}

ptrdiff_t opj_bio_numbytes(opj_bio_t *bio) {

  return (bio->bp - bio->start);

}

void opj_bio_init_enc(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) {

  bio->start = bp;

  bio->end = bp + len;

  bio->bp = bp;

  bio->buf = 0;

  bio->ct = 8;

}

void opj_bio_init_dec(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) {

  bio->start = bp;

  bio->end = bp + len;

  bio->bp = bp;

  bio->buf = 0;

  bio->ct = 0;

}

void opj_bio_write(opj_bio_t *bio, OPJ_UINT32 v, OPJ_UINT32 n) {

  OPJ_UINT32 i;

  for (i = n - 1; i < n; i--) {

    opj_bio_putbit(bio, (v >> i) & 1);

  }

}

OPJ_UINT32 opj_bio_read(opj_bio_t *bio, OPJ_UINT32 n) {

  OPJ_UINT32 i;

    OPJ_UINT32 v;

  v = 0;

  for (i = n - 1; i < n; i--) {

    v += opj_bio_getbit(bio) << i;

  }

  return v;

}

OPJ_BOOL opj_bio_flush(opj_bio_t *bio) {

  bio->ct = 0;

  if (! opj_bio_byteout(bio)) {

    return OPJ_FALSE;

  }

  if (bio->ct == 7) {

    bio->ct = 0;

    if (! opj_bio_byteout(bio)) {

      return OPJ_FALSE;

    }

  }

  return OPJ_TRUE;

}

OPJ_BOOL opj_bio_inalign(opj_bio_t *bio) {

  bio->ct = 0;

  if ((bio->buf & 0xff) == 0xff) {

    if (! opj_bio_bytein(bio)) {

      return OPJ_FALSE;

    }

    bio->ct = 0;

  }

  return OPJ_TRUE;

}