126 lines
3.2 KiB
C
126 lines
3.2 KiB
C
/*
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* Copyright (c) 2001-2002, David Janssens
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* Copyright (c) 2003, Yannick Verschueren
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* Copyright (c) 2003, Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "bio.h"
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#include <setjmp.h>
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static unsigned char *bio_start, *bio_end, *bio_bp;
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static unsigned int bio_buf;
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static int bio_ct;
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extern jmp_buf j2k_error;
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/// <summary>
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/// Number of bytes written.
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/// </summary>
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int bio_numbytes() {
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return bio_bp-bio_start;
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}
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/// <summary>
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/// Init decoder.
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/// </summary>
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/// <param name="bp">Input buffer</param>
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/// <param name="len">Input buffer length</param>
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void bio_init_dec(unsigned char *bp, int len) {
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bio_start=bp;
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bio_end=bp+len;
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bio_bp=bp;
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bio_buf=0;
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bio_ct=0;
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}
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int bio_byteout()
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{
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bio_buf = (bio_buf << 8) & 0xffff;
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bio_ct = bio_buf == 0xff00 ? 7 : 8;
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if (bio_bp >= bio_end)
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return 1;
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*bio_bp++ = bio_buf >> 8;
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return 0;
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}
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/// <summary>
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/// Read byte.
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/// </summary>
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int bio_bytein() {
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bio_buf=(bio_buf<<8)&0xffff;
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bio_ct=bio_buf==0xff00?7:8;
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if (bio_bp>=bio_end) return 1; //longjmp(j2k_error, 1);
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bio_buf|=*bio_bp++;
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return 0;
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}
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/// <summary>
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/// Read bit.
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/// </summary>
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int bio_getbit() {
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if (bio_ct==0) {
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bio_bytein();
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}
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bio_ct--;
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return (bio_buf>>bio_ct)&1;
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}
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/// <summary>
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/// Read bits.
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/// </summary>
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/// <param name="n">Number of bits to read</param>
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int bio_read(int n) {
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int i, v;
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v=0;
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for (i=n-1; i>=0; i--) {
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v+=bio_getbit()<<i;
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}
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return v;
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}
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/// <summary>
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/// Flush bits.
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/// </summary>
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int bio_flush() {
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bio_ct=0;
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bio_byteout();
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if (bio_ct==7) {
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bio_ct=0;
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if ( bio_byteout()) return 1;;
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}
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return 0;
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}
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/// <summary>
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/// </summary>
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int bio_inalign() {
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bio_ct=0;
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if ((bio_buf&0xff)==0xff) {
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if( bio_bytein()) return 1;
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bio_ct=0;
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}
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return 0;
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}
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