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/**
47Write a bit
48@param bio BIO handle
49@param b Bit to write (0 or 1)
50*/
51static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b);
52/**
53Read a bit
54@param bio BIO handle
55@return Returns the read bit
56*/
57static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio);
58/**
59Write a byte
60@param bio BIO handle
61@return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise
62*/
63static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio);
64/**
65Read a byte
66@param bio BIO handle
67@return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise
68*/
69static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio);
70
71/*@}*/
72
73/*@}*/
74
75/*
76==========================================================
77 local functions
78==========================================================
79*/
80
81static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio)
82{
83 bio->buf = (bio->buf << 8) & 0xffff;
84 bio->ct = bio->buf == 0xff00 ? 7 : 8;
85 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) {
86 return OPJ_FALSE;
87 }
88 *bio->bp++ = (OPJ_BYTE)(bio->buf >> 8);
89 return OPJ_TRUE;
90}
91
92static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio)
93{
94 bio->buf = (bio->buf << 8) & 0xffff;
95 bio->ct = bio->buf == 0xff00 ? 7 : 8;
96 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) {
97 return OPJ_FALSE;
98 }
99 bio->buf |= *bio->bp++;
100 return OPJ_TRUE;
101}
102
103static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b)
104{
105 if (bio->ct == 0) {
106 opj_bio_byteout(
107 bio); /* MSD: why not check the return value of this function ? */
108 }
109 bio->ct--;
110 bio->buf |= b << bio->ct;
111}
112
113static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio)
114{
115 if (bio->ct == 0) {
116 opj_bio_bytein(
117 bio); /* MSD: why not check the return value of this function ? */
118 }
119 bio->ct--;
120 return (bio->buf >> bio->ct) & 1;
121}
122
123/*
124==========================================================
125 Bit Input/Output interface
126==========================================================
127*/
128
129opj_bio_t* opj_bio_create(void)
130{
131 opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t));
132 return bio;
133}
134
135void opj_bio_destroy(opj_bio_t *bio)
136{
137 if (bio) {
138 opj_free(bio);
139 }
140}
141
142ptrdiff_t opj_bio_numbytes(opj_bio_t *bio)
143{
144 return (bio->bp - bio->start);
145}
146
147void opj_bio_init_enc(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len)
148{
149 bio->start = bp;
150 bio->end = bp + len;
151 bio->bp = bp;
152 bio->buf = 0;
153 bio->ct = 8;
154}
155
156void opj_bio_init_dec(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len)
157{
158 bio->start = bp;
159 bio->end = bp + len;
160 bio->bp = bp;
161 bio->buf = 0;
162 bio->ct = 0;
163}
164
165void opj_bio_write(opj_bio_t *bio, OPJ_UINT32 v, OPJ_UINT32 n)
166{
167 OPJ_INT32 i;
168
169 assert((n > 0U) && (n <= 32U));
170 for (i = (OPJ_INT32)n - 1; i >= 0; i--) {
171 opj_bio_putbit(bio, (v >> i) & 1);
172 }
173}
174
175OPJ_UINT32 opj_bio_read(opj_bio_t *bio, OPJ_UINT32 n)
176{
177 OPJ_INT32 i;
178 OPJ_UINT32 v;
179
180 assert((n > 0U) /* && (n <= 32U)*/);
181#ifdef OPJ_UBSAN_BUILD
182 /* This assert fails for some corrupted images which are gracefully rejected */
183 /* Add this assert only for ubsan build. */
184 /* This is the condition for overflow not to occur below which is needed because of OPJ_NOSANITIZE */
185 assert(n <= 32U);
186#endif
187 v = 0U;
188 for (i = (OPJ_INT32)n - 1; i >= 0; i--) {
189 v |= opj_bio_getbit(bio) <<
190 i; /* can't overflow, opj_bio_getbit returns 0 or 1 */
191 }
192 return v;
193}
194
195OPJ_BOOL opj_bio_flush(opj_bio_t *bio)
196{
197 if (! opj_bio_byteout(bio)) {
198 return OPJ_FALSE;
199 }
200 if (bio->ct == 7) {
201 if (! opj_bio_byteout(bio)) {
202 return OPJ_FALSE;
203 }
204 }
205 return OPJ_TRUE;
206}
207
208OPJ_BOOL opj_bio_inalign(opj_bio_t *bio)
209{
210 if ((bio->buf & 0xff) == 0xff) {
211 if (! opj_bio_bytein(bio)) {
212 return OPJ_FALSE;
213 }
214 }
215 bio->ct = 0;
216 return OPJ_TRUE;
217}
218