jpc_bs.h (8679B)
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) 1999-2000 Image Power, Inc. 13 * Copyright (c) 1999-2000 The University of British Columbia 14 * Copyright (c) 2001-2003 Michael David Adams 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: jpc_bs.h 1918 2005-07-24 14:12:08Z baford $ 68 */ 69 70 #ifndef JPC_BS_H 71 #define JPC_BS_H 72 73 /******************************************************************************\ 74 * Includes. 75 \******************************************************************************/ 76 77 #include <stdio.h> 78 79 #include "jasper/jas_types.h" 80 #include "jasper/jas_stream.h" 81 82 /******************************************************************************\ 83 * Constants. 84 \******************************************************************************/ 85 86 /* 87 * Bit stream open mode flags. 88 */ 89 90 /* Bit stream open for reading. */ 91 #define JPC_BITSTREAM_READ 0x01 92 /* Bit stream open for writing. */ 93 #define JPC_BITSTREAM_WRITE 0x02 94 95 /* 96 * Bit stream flags. 97 */ 98 99 /* Do not close underlying character stream. */ 100 #define JPC_BITSTREAM_NOCLOSE 0x01 101 /* End of file has been reached while reading. */ 102 #define JPC_BITSTREAM_EOF 0x02 103 /* An I/O error has occured. */ 104 #define JPC_BITSTREAM_ERR 0x04 105 106 /******************************************************************************\ 107 * Types. 108 \******************************************************************************/ 109 110 /* Bit stream class. */ 111 112 typedef struct { 113 114 /* Some miscellaneous flags. */ 115 int flags_; 116 117 /* The input/output buffer. */ 118 uint_fast16_t buf_; 119 120 /* The number of bits remaining in the byte being read/written. */ 121 int cnt_; 122 123 /* The underlying stream associated with this bit stream. */ 124 jas_stream_t *stream_; 125 126 /* The mode in which this bit stream was opened. */ 127 int openmode_; 128 129 } jpc_bitstream_t; 130 131 /******************************************************************************\ 132 * Functions/macros for opening and closing bit streams.. 133 \******************************************************************************/ 134 135 /* Open a stream as a bit stream. */ 136 jpc_bitstream_t *jpc_bitstream_sopen(jas_stream_t *stream, char *mode); 137 138 /* Close a bit stream. */ 139 int jpc_bitstream_close(jpc_bitstream_t *bitstream); 140 141 /******************************************************************************\ 142 * Functions/macros for reading from and writing to bit streams.. 143 \******************************************************************************/ 144 145 /* Read a bit from a bit stream. */ 146 #if defined(DEBUG) 147 #define jpc_bitstream_getbit(bitstream) \ 148 jpc_bitstream_getbit_func(bitstream) 149 #else 150 #define jpc_bitstream_getbit(bitstream) \ 151 jpc_bitstream_getbit_macro(bitstream) 152 #endif 153 154 /* Write a bit to a bit stream. */ 155 #if defined(DEBUG) 156 #define jpc_bitstream_putbit(bitstream, v) \ 157 jpc_bitstream_putbit_func(bitstream, v) 158 #else 159 #define jpc_bitstream_putbit(bitstream, v) \ 160 jpc_bitstream_putbit_macro(bitstream, v) 161 #endif 162 163 /* Read one or more bits from a bit stream. */ 164 long jpc_bitstream_getbits(jpc_bitstream_t *bitstream, int n); 165 166 /* Write one or more bits to a bit stream. */ 167 int jpc_bitstream_putbits(jpc_bitstream_t *bitstream, int n, long v); 168 169 /******************************************************************************\ 170 * Functions/macros for flushing and aligning bit streams. 171 \******************************************************************************/ 172 173 /* Align the current position within the bit stream to the next byte 174 boundary. */ 175 int jpc_bitstream_align(jpc_bitstream_t *bitstream); 176 177 /* Align the current position in the bit stream with the next byte boundary, 178 ensuring that certain bits consumed in the process match a particular 179 pattern. */ 180 int jpc_bitstream_inalign(jpc_bitstream_t *bitstream, int fillmask, 181 int filldata); 182 183 /* Align the current position in the bit stream with the next byte boundary, 184 writing bits from the specified pattern (if necessary) in the process. */ 185 int jpc_bitstream_outalign(jpc_bitstream_t *bitstream, int filldata); 186 187 /* Check if a bit stream needs alignment. */ 188 int jpc_bitstream_needalign(jpc_bitstream_t *bitstream); 189 190 /* How many additional bytes would be output if the bit stream was aligned? */ 191 int jpc_bitstream_pending(jpc_bitstream_t *bitstream); 192 193 /******************************************************************************\ 194 * Functions/macros for querying state information for bit streams. 195 \******************************************************************************/ 196 197 /* Has EOF been encountered on a bit stream? */ 198 #define jpc_bitstream_eof(bitstream) \ 199 ((bitstream)->flags_ & JPC_BITSTREAM_EOF) 200 201 /******************************************************************************\ 202 * Internals. 203 \******************************************************************************/ 204 205 /* DO NOT DIRECTLY INVOKE ANY OF THE MACROS OR FUNCTIONS BELOW. THEY ARE 206 FOR INTERNAL USE ONLY. */ 207 208 int jpc_bitstream_getbit_func(jpc_bitstream_t *bitstream); 209 210 int jpc_bitstream_putbit_func(jpc_bitstream_t *bitstream, int v); 211 212 int jpc_bitstream_fillbuf(jpc_bitstream_t *bitstream); 213 214 #define jpc_bitstream_getbit_macro(bitstream) \ 215 (assert((bitstream)->openmode_ & JPC_BITSTREAM_READ), \ 216 (--(bitstream)->cnt_ >= 0) ? \ 217 ((int)(((bitstream)->buf_ >> (bitstream)->cnt_) & 1)) : \ 218 jpc_bitstream_fillbuf(bitstream)) 219 220 #define jpc_bitstream_putbit_macro(bitstream, bit) \ 221 (assert((bitstream)->openmode_ & JPC_BITSTREAM_WRITE), \ 222 (--(bitstream)->cnt_ < 0) ? \ 223 ((bitstream)->buf_ = ((bitstream)->buf_ << 8) & 0xffff, \ 224 (bitstream)->cnt_ = ((bitstream)->buf_ == 0xff00) ? 6 : 7, \ 225 (bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \ 226 (jas_stream_putc((bitstream)->stream_, (bitstream)->buf_ >> 8) == EOF) \ 227 ? (EOF) : ((bit) & 1)) : \ 228 ((bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \ 229 (bit) & 1)) 230 231 #endif