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/*
* Copyright (c) 2001-2002, David Janssens
* Copyright (c) 2003, Yannick Verschueren
* Copyright (c) 2003, 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 "bio.h"
#include <setjmp.h>
static unsigned char *bio_start, *bio_end, *bio_bp;
static unsigned int bio_buf;
static int bio_ct;
extern jmp_buf j2k_error;
/// <summary>
/// Number of bytes written.
/// </summary>
int bio_numbytes() {
return bio_bp-bio_start;
}
/// <summary>
/// Init decoder.
/// </summary>
/// <param name="bp">Input buffer</param>
/// <param name="len">Input buffer length</param>
void bio_init_dec(unsigned char *bp, int len) {
bio_start=bp;
bio_end=bp+len;
bio_bp=bp;
bio_buf=0;
bio_ct=0;
}
int bio_byteout()
{
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;
}
/// <summary>
/// Read byte.
/// </summary>
int bio_bytein() {
bio_buf=(bio_buf<<8)&0xffff;
bio_ct=bio_buf==0xff00?7:8;
if (bio_bp>=bio_end) return 1; //longjmp(j2k_error, 1);
bio_buf|=*bio_bp++;
return 0;
}
/// <summary>
/// Read bit.
/// </summary>
int bio_getbit() {
if (bio_ct==0) {
bio_bytein();
}
bio_ct--;
return (bio_buf>>bio_ct)&1;
}
/// <summary>
/// Read bits.
/// </summary>
/// <param name="n">Number of bits to read</param>
int bio_read(int n) {
int i, v;
v=0;
for (i=n-1; i>=0; i--) {
v+=bio_getbit()<<i;
}
return v;
}
/// <summary>
/// Flush bits.
/// </summary>
int bio_flush() {
bio_ct=0;
bio_byteout();
if (bio_ct==7) {
bio_ct=0;
if ( bio_byteout()) return 1;;
}
return 0;
}
/// <summary>
/// </summary>
int bio_inalign() {
bio_ct=0;
if ((bio_buf&0xff)==0xff) {
if( bio_bytein()) return 1;
bio_ct=0;
}
return 0;
}
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