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/*
* Copyright (c) 2001-2003, David Janssens
* Copyright (c) 2002-2003, Yannick Verschueren
* Copyright (c) 2003-2005, Francois Devaux and Antonin Descampe
* Copyright (c) 2005, Herv Drolon, FreeImage Team
* Copyright (c) 2002-2005, Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
* 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 bio_putbit(opj_bio_t *bio, int b);
/**
Read a bit
@param bio BIO handle
@return Returns the read bit
*/
static int bio_getbit(opj_bio_t *bio);
/**
Write a byte
@param bio BIO handle
@return Returns 0 if successful, returns 1 otherwise
*/
static int bio_byteout(opj_bio_t *bio);
/**
Read a byte
@param bio BIO handle
@return Returns 0 if successful, returns 1 otherwise
*/
static int bio_bytein(opj_bio_t *bio);
/*@}*/
/*@}*/
/*
==========================================================
local functions
==========================================================
*/
static int 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 1;
}
*bio->bp++ = bio->buf >> 8;
return 0;
}
static int 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 1;
}
bio->buf |= *bio->bp++;
return 0;
}
static void bio_putbit(opj_bio_t *bio, int b) {
if (bio->ct == 0) {
bio_byteout(bio);
}
bio->ct--;
bio->buf |= b << bio->ct;
}
static int bio_getbit(opj_bio_t *bio) {
if (bio->ct == 0) {
bio_bytein(bio);
}
bio->ct--;
return (bio->buf >> bio->ct) & 1;
}
/*
==========================================================
Bit Input/Output interface
==========================================================
*/
opj_bio_t* bio_create() {
opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t));
return bio;
}
void bio_destroy(opj_bio_t *bio) {
if(bio) {
opj_free(bio);
}
}
int bio_numbytes(opj_bio_t *bio) {
return (int)(bio->bp - bio->start);
}
void bio_init_enc(opj_bio_t *bio, unsigned char *bp, int len) {
bio->start = bp;
bio->end = bp + len;
bio->bp = bp;
bio->buf = 0;
bio->ct = 8;
}
void bio_init_dec(opj_bio_t *bio, unsigned char *bp, int len) {
bio->start = bp;
bio->end = bp + len;
bio->bp = bp;
bio->buf = 0;
bio->ct = 0;
}
void bio_write(opj_bio_t *bio, int v, int n) {
int i;
for (i = n - 1; i >= 0; i--) {
bio_putbit(bio, (v >> i) & 1);
}
}
int bio_read(opj_bio_t *bio, int n) {
int i, v;
v = 0;
for (i = n - 1; i >= 0; i--) {
v += bio_getbit(bio) << i;
}
return v;
}
int bio_flush(opj_bio_t *bio) {
bio->ct = 0;
if (bio_byteout(bio)) {
return 1;
}
if (bio->ct == 7) {
bio->ct = 0;
if (bio_byteout(bio)) {
return 1;
}
}
return 0;
}
int bio_inalign(opj_bio_t *bio) {
bio->ct = 0;
if ((bio->buf & 0xff) == 0xff) {
if (bio_bytein(bio)) {
return 1;
}
bio->ct = 0;
}
return 0;
}
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