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jpc_bs.h
1/*
2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
3 * British Columbia.
4 * Copyright (c) 2001-2002 Michael David Adams.
5 * All rights reserved.
6 */
7
8/* __START_OF_JASPER_LICENSE__
9 *
10 * JasPer License Version 2.0
11 *
12 * Copyright (c) 2001-2006 Michael David Adams
13 * Copyright (c) 1999-2000 Image Power, Inc.
14 * Copyright (c) 1999-2000 The University of British Columbia
15 *
16 * All rights reserved.
17 *
18 * Permission is hereby granted, free of charge, to any person (the
19 * "User") obtaining a copy of this software and associated documentation
20 * files (the "Software"), to deal in the Software without restriction,
21 * including without limitation the rights to use, copy, modify, merge,
22 * publish, distribute, and/or sell copies of the Software, and to permit
23 * persons to whom the Software is furnished to do so, subject to the
24 * following conditions:
25 *
26 * 1. The above copyright notices and this permission notice (which
27 * includes the disclaimer below) shall be included in all copies or
28 * substantial portions of the Software.
29 *
30 * 2. The name of a copyright holder shall not be used to endorse or
31 * promote products derived from the Software without specific prior
32 * written permission.
33 *
34 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
35 * LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
36 * THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
37 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
38 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
39 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
40 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
41 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
42 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
43 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
44 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
45 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
46 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
47 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
48 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
49 * PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
50 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
51 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
52 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
53 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
54 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
55 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
56 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
57 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
58 * RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
59 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
60 *
61 * __END_OF_JASPER_LICENSE__
62 */
63
64/*
65 * Bit Stream Class
66 *
67 * $Id$
68 */
69
70#ifndef JPC_BS_H
71#define JPC_BS_H
72
73/******************************************************************************\
74* Includes.
75\******************************************************************************/
76
77#include "jasper/jas_types.h"
78#include "jasper/jas_stream.h"
79
80#include <assert.h>
81#include <stdio.h>
82
83/******************************************************************************\
84* Constants.
85\******************************************************************************/
86
87/*
88 * Bit stream open mode flags.
89 */
90
91/* Bit stream open for reading. */
92#define JPC_BITSTREAM_READ 0x01
93/* Bit stream open for writing. */
94#define JPC_BITSTREAM_WRITE 0x02
95
96/*
97 * Bit stream flags.
98 */
99
100/* Do not close underlying character stream. */
101#define JPC_BITSTREAM_NOCLOSE 0x01
102/* End of file has been reached while reading. */
103#define JPC_BITSTREAM_EOF 0x02
104/* An I/O error has occured. */
105#define JPC_BITSTREAM_ERR 0x04
106
107/******************************************************************************\
108* Types.
109\******************************************************************************/
110
111/* Bit stream class. */
112
113 typedef struct {
114
115 /* Some miscellaneous flags. */
116 int flags_;
117
118 /* The input/output buffer. */
119 uint_fast16_t buf_;
120
121 /* The number of bits remaining in the byte being read/written. */
122 int cnt_;
123
124 /* The underlying stream associated with this bit stream. */
125 jas_stream_t *stream_;
126
127 /* The mode in which this bit stream was opened. */
128 int openmode_;
129
130} jpc_bitstream_t;
131
132/******************************************************************************\
133* Functions/macros for opening and closing bit streams..
134\******************************************************************************/
135
136/* Open a stream as a bit stream. */
137jpc_bitstream_t *jpc_bitstream_sopen(jas_stream_t *stream, const char *mode);
138
139/* Close a bit stream. */
140 int jpc_bitstream_close(jpc_bitstream_t *bitstream);
141
142/******************************************************************************\
143* Functions/macros for reading from and writing to bit streams..
144\******************************************************************************/
145
146/* Read a bit from a bit stream. */
147#ifndef NDEBUG
148#define jpc_bitstream_getbit(bitstream) \
149 jpc_bitstream_getbit_func(bitstream)
150#else
151#define jpc_bitstream_getbit(bitstream) \
152 jpc_bitstream_getbit_macro(bitstream)
153#endif
154
155/* Write a bit to a bit stream. */
156#ifndef NDEBUG
157#define jpc_bitstream_putbit(bitstream, v) \
158 jpc_bitstream_putbit_func(bitstream, v)
159#else
160#define jpc_bitstream_putbit(bitstream, v) \
161 jpc_bitstream_putbit_macro(bitstream, v)
162#endif
163
164/* Read one or more bits from a bit stream. */
165 long jpc_bitstream_getbits(jpc_bitstream_t *bitstream, int n);
166
167/* Write one or more bits to a bit stream. */
168 int jpc_bitstream_putbits(jpc_bitstream_t *bitstream, int n, long v);
169
170/******************************************************************************\
171* Functions/macros for flushing and aligning bit streams.
172\******************************************************************************/
173
174/* Align the current position within the bit stream to the next byte
175 boundary. */
176 int jpc_bitstream_align(jpc_bitstream_t *bitstream);
177
178/* Align the current position in the bit stream with the next byte boundary,
179 ensuring that certain bits consumed in the process match a particular
180 pattern. */
181 int jpc_bitstream_inalign(jpc_bitstream_t *bitstream, int fillmask,
182 int filldata);
183
184/* Align the current position in the bit stream with the next byte boundary,
185 writing bits from the specified pattern (if necessary) in the process. */
186 int jpc_bitstream_outalign(jpc_bitstream_t *bitstream, int filldata);
187
188/* Check if a bit stream needs alignment. */
189JAS_ATTRIBUTE_PURE
190 int jpc_bitstream_needalign(const jpc_bitstream_t *bitstream);
191
192/* How many additional bytes would be output if the bit stream was aligned? */
193JAS_ATTRIBUTE_PURE
194 int jpc_bitstream_pending(const jpc_bitstream_t *bitstream);
195
196/******************************************************************************\
197* Functions/macros for querying state information for bit streams.
198\******************************************************************************/
199
200/* Has EOF been encountered on a bit stream? */
201#define jpc_bitstream_eof(bitstream) \
202 ((bitstream)->flags_ & JPC_BITSTREAM_EOF)
203
204/******************************************************************************\
205* Internals.
206\******************************************************************************/
207
208/* DO NOT DIRECTLY INVOKE ANY OF THE MACROS OR FUNCTIONS BELOW. THEY ARE
209 FOR INTERNAL USE ONLY. */
210
211 int jpc_bitstream_getbit_func(jpc_bitstream_t *bitstream);
212
213 int jpc_bitstream_putbit_func(jpc_bitstream_t *bitstream, int v);
214
215 int jpc_bitstream_fillbuf(jpc_bitstream_t *bitstream);
216
217#define jpc_bitstream_getbit_macro(bitstream) \
218 (assert((bitstream)->openmode_ & JPC_BITSTREAM_READ), \
219 (--(bitstream)->cnt_ >= 0) ? \
220 ((int)(((bitstream)->buf_ >> (bitstream)->cnt_) & 1)) : \
221 jpc_bitstream_fillbuf(bitstream))
222
223#define jpc_bitstream_putbit_macro(bitstream, bit) \
224 (assert((bitstream)->openmode_ & JPC_BITSTREAM_WRITE), \
225 (--(bitstream)->cnt_ < 0) ? \
226 ((bitstream)->buf_ = ((bitstream)->buf_ << 8) & 0xffff, \
227 (bitstream)->cnt_ = ((bitstream)->buf_ == 0xff00) ? 6 : 7, \
228 (bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \
229 (jas_stream_putc((bitstream)->stream_, (bitstream)->buf_ >> 8) == EOF) \
230 ? (EOF) : ((bit) & 1)) : \
231 ((bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \
232 (bit) & 1))
233
234#endif
jas_stream.h
I/O Stream Class.
jas_types.h
Primitive Types.
jas_stream_t
I/O stream object.
Definition: jas_stream.h:213