183 lines
4.1 KiB
C
183 lines
4.1 KiB
C
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/*
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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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*
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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 <stdio.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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{
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return bio_bp - bio_start;
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}
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/* <summary> */
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/* Init encoder. */
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/* </summary> */
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/* <param name="bp">Output buffer</param> */
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/* <param name="len">Output buffer length</param> */
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void bio_init_enc(unsigned char *bp, int len)
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{
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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 = 8;
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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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{
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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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/* <summary> */
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/* Write byte. --> function modified to eliminate longjmp !!! */
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/* </summary> */
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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. --> function modified to eliminate longjmp !! */
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/* </summary> */
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int bio_bytein()
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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_buf |= *bio_bp++;
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return 0;
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}
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/* <summary> */
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/* Write bit. */
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/* </summary> */
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/* <param name="b">Bit to write (0 or 1)</param> */
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void bio_putbit(int b)
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{
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if (bio_ct == 0) {
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bio_byteout();
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}
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bio_ct--;
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bio_buf |= b << bio_ct;
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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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{
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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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/* Write bits. */
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/* </summary> */
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/* <param name="v">Value of bits</param> */
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/* <param name="n">Number of bits to write</param> */
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void bio_write(int v, int n)
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{
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int i;
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for (i = n - 1; i >= 0; i--) {
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bio_putbit((v >> i) & 1);
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}
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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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{
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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. MOdified to eliminate longjmp !! */
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/* </summary> */
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int bio_flush()
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{
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bio_ct = 0;
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if (bio_byteout())
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return 1;
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if (bio_ct == 7) {
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bio_ct = 0;
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if (bio_byteout())
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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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{
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bio_ct = 0;
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if ((bio_buf & 0xff) == 0xff) {
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if (bio_bytein())
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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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