1 /* 2 * The copyright in this software is being made available under the 2-clauses 3 * BSD License, included below. This software may be subject to other third 4 * party and contributor rights, including patent rights, and no such rights 5 * are granted under this license. 6 * 7 * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium 8 * Copyright (c) 2002-2014, Professor Benoit Macq 9 * Copyright (c) 2001-2003, David Janssens 10 * Copyright (c) 2002-2003, Yannick Verschueren 11 * Copyright (c) 2003-2007, Francois-Olivier Devaux 12 * Copyright (c) 2003-2014, Antonin Descampe 13 * Copyright (c) 2005, Herve Drolon, FreeImage Team 14 * All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS' 26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include "opj_includes.h" 39 40 /** @defgroup BIO BIO - Individual bit input-output stream */ 41 /*@{*/ 42 43 /** @name Local static functions */ 44 /*@{*/ 45 46 /** 47 Write a bit 48 @param bio BIO handle 49 @param b Bit to write (0 or 1) 50 */ 51 static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b); 52 /** 53 Read a bit 54 @param bio BIO handle 55 @return Returns the read bit 56 */ 57 static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio); 58 /** 59 Write a byte 60 @param bio BIO handle 61 @return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise 62 */ 63 static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio); 64 /** 65 Read a byte 66 @param bio BIO handle 67 @return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise 68 */ 69 static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio); 70 71 /*@}*/ 72 73 /*@}*/ 74 75 /* 76 ========================================================== 77 local functions 78 ========================================================== 79 */ 80 81 static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio) { 82 bio->buf = (bio->buf << 8) & 0xffff; 83 bio->ct = bio->buf == 0xff00 ? 7 : 8; 84 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) { 85 return OPJ_FALSE; 86 } 87 *bio->bp++ = (OPJ_BYTE)(bio->buf >> 8); 88 return OPJ_TRUE; 89 } 90 91 static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio) { 92 bio->buf = (bio->buf << 8) & 0xffff; 93 bio->ct = bio->buf == 0xff00 ? 7 : 8; 94 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) { 95 return OPJ_FALSE; 96 } 97 bio->buf |= *bio->bp++; 98 return OPJ_TRUE; 99 } 100 101 static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b) { 102 if (bio->ct == 0) { 103 opj_bio_byteout(bio); /* MSD: why not check the return value of this function ? */ 104 } 105 bio->ct--; 106 bio->buf |= b << bio->ct; 107 } 108 109 static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio) { 110 if (bio->ct == 0) { 111 opj_bio_bytein(bio); /* MSD: why not check the return value of this function ? */ 112 } 113 bio->ct--; 114 return (bio->buf >> bio->ct) & 1; 115 } 116 117 /* 118 ========================================================== 119 Bit Input/Output interface 120 ========================================================== 121 */ 122 123 opj_bio_t* opj_bio_create(void) { 124 opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t)); 125 return bio; 126 } 127 128 void opj_bio_destroy(opj_bio_t *bio) { 129 if(bio) { 130 opj_free(bio); 131 } 132 } 133 134 ptrdiff_t opj_bio_numbytes(opj_bio_t *bio) { 135 return (bio->bp - bio->start); 136 } 137 138 void opj_bio_init_enc(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) { 139 bio->start = bp; 140 bio->end = bp + len; 141 bio->bp = bp; 142 bio->buf = 0; 143 bio->ct = 8; 144 } 145 146 void opj_bio_init_dec(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) { 147 bio->start = bp; 148 bio->end = bp + len; 149 bio->bp = bp; 150 bio->buf = 0; 151 bio->ct = 0; 152 } 153 154 void opj_bio_write(opj_bio_t *bio, OPJ_UINT32 v, OPJ_UINT32 n) { 155 OPJ_UINT32 i; 156 for (i = n - 1; i < n; i--) { 157 opj_bio_putbit(bio, (v >> i) & 1); 158 } 159 } 160 161 OPJ_UINT32 opj_bio_read(opj_bio_t *bio, OPJ_UINT32 n) { 162 OPJ_UINT32 i; 163 OPJ_UINT32 v; 164 v = 0; 165 for (i = n - 1; i < n; i--) { 166 v += opj_bio_getbit(bio) << i; 167 } 168 return v; 169 } 170 171 OPJ_BOOL opj_bio_flush(opj_bio_t *bio) { 172 if (! opj_bio_byteout(bio)) { 173 return OPJ_FALSE; 174 } 175 if (bio->ct == 7) { 176 if (! opj_bio_byteout(bio)) { 177 return OPJ_FALSE; 178 } 179 } 180 return OPJ_TRUE; 181 } 182 183 OPJ_BOOL opj_bio_inalign(opj_bio_t *bio) { 184 if ((bio->buf & 0xff) == 0xff) { 185 if (! opj_bio_bytein(bio)) { 186 return OPJ_FALSE; 187 } 188 } 189 bio->ct = 0; 190 return OPJ_TRUE; 191 } 192
