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
opj_bio_byteout(opj_bio_t * bio)81 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 (bio->bp >= bio->end) {
85 return OPJ_FALSE;
86 }
87 *bio->bp++ = (OPJ_BYTE)(bio->buf >> 8);
88 return OPJ_TRUE;
89 }
90
opj_bio_bytein(opj_bio_t * bio)91 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 (bio->bp >= bio->end) {
95 return OPJ_FALSE;
96 }
97 bio->buf |= *bio->bp++;
98 return OPJ_TRUE;
99 }
100
opj_bio_putbit(opj_bio_t * bio,OPJ_UINT32 b)101 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
opj_bio_getbit(opj_bio_t * bio)109 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
opj_bio_create(void)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
opj_bio_destroy(opj_bio_t * bio)128 void opj_bio_destroy(opj_bio_t *bio) {
129 if(bio) {
130 opj_free(bio);
131 }
132 }
133
opj_bio_numbytes(opj_bio_t * bio)134 ptrdiff_t opj_bio_numbytes(opj_bio_t *bio) {
135 return (bio->bp - bio->start);
136 }
137
opj_bio_init_enc(opj_bio_t * bio,OPJ_BYTE * bp,OPJ_UINT32 len)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
opj_bio_init_dec(opj_bio_t * bio,OPJ_BYTE * bp,OPJ_UINT32 len)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
opj_bio_write(opj_bio_t * bio,OPJ_UINT32 v,OPJ_UINT32 n)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
opj_bio_read(opj_bio_t * bio,OPJ_UINT32 n)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
opj_bio_flush(opj_bio_t * bio)171 OPJ_BOOL opj_bio_flush(opj_bio_t *bio) {
172 bio->ct = 0;
173 if (! opj_bio_byteout(bio)) {
174 return OPJ_FALSE;
175 }
176 if (bio->ct == 7) {
177 bio->ct = 0;
178 if (! opj_bio_byteout(bio)) {
179 return OPJ_FALSE;
180 }
181 }
182 return OPJ_TRUE;
183 }
184
opj_bio_inalign(opj_bio_t * bio)185 OPJ_BOOL opj_bio_inalign(opj_bio_t *bio) {
186 bio->ct = 0;
187 if ((bio->buf & 0xff) == 0xff) {
188 if (! opj_bio_bytein(bio)) {
189 return OPJ_FALSE;
190 }
191 bio->ct = 0;
192 }
193 return OPJ_TRUE;
194 }
195