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/*
* The copyright in this software is being made available under the 2-clauses
* BSD License, included below. This software may be subject to other third
* party and contributor rights, including patent rights, and no such rights
* are granted under this license.
*
* Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
* Copyright (c) 2002-2014, Professor Benoit Macq
* Copyright (c) 2001-2003, David Janssens
* Copyright (c) 2002-2003, Yannick Verschueren
* Copyright (c) 2003-2007, Francois-Olivier Devaux
* Copyright (c) 2003-2014, 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 */
/*@{*/
/**
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
==========================================================
*/
static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio)
{
bio->buf = (bio->buf << 8) & 0xffff;
bio->ct = bio->buf == 0xff00 ? 7 : 8;
if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) {
return OPJ_FALSE;
}
*bio->bp++ = (OPJ_BYTE)(bio->buf >> 8);
return OPJ_TRUE;
}
static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio)
{
bio->buf = (bio->buf << 8) & 0xffff;
bio->ct = bio->buf == 0xff00 ? 7 : 8;
if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) {
return OPJ_FALSE;
}
bio->buf |= *bio->bp++;
return OPJ_TRUE;
}
static 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_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;
}
void opj_bio_write(opj_bio_t *bio, OPJ_UINT32 v, OPJ_UINT32 n)
{
OPJ_INT32 i;
assert((n > 0U) && (n <= 32U));
for (i = (OPJ_INT32)n - 1; i >= 0; i--) {
opj_bio_putbit(bio, (v >> i) & 1);
}
}
OPJ_UINT32 opj_bio_read(opj_bio_t *bio, OPJ_UINT32 n)
{
OPJ_INT32 i;
OPJ_UINT32 v;
assert((n > 0U) /* && (n <= 32U)*/);
#ifdef OPJ_UBSAN_BUILD
/* This assert fails for some corrupted images which are gracefully rejected */
/* Add this assert only for ubsan build. */
/* This is the condition for overflow not to occur below which is needed because of OPJ_NOSANITIZE */
assert(n <= 32U);
#endif
v = 0U;
for (i = (OPJ_INT32)n - 1; i >= 0; i--) {
v |= opj_bio_getbit(bio) <<
i; /* can't overflow, opj_bio_getbit returns 0 or 1 */
}
return v;
}
OPJ_BOOL opj_bio_flush(opj_bio_t *bio)
{
if (! opj_bio_byteout(bio)) {
return OPJ_FALSE;
}
if (bio->ct == 7) {
if (! opj_bio_byteout(bio)) {
return OPJ_FALSE;
}
}
return OPJ_TRUE;
}
OPJ_BOOL opj_bio_inalign(opj_bio_t *bio)
{
if ((bio->buf & 0xff) == 0xff) {
if (! opj_bio_bytein(bio)) {
return OPJ_FALSE;
}
}
bio->ct = 0;
return OPJ_TRUE;
}