My Project: jpc_mqdec.h Source File

My Project 2.0.19 |

jpc_mqdec.h
1 /*
2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
3 * British Columbia.
4 * Copyright (c) 2001-2003 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 * MQ Arithmetic Decoder
66 *
67 * $Id$
68 */
69
70 #ifndef JPC_MQDEC_H
71 #define JPC_MQDEC_H
72
73 /******************************************************************************\
74 * Includes.
75 \******************************************************************************/
76
77 #include "jasper/jas_types.h"
78 #include "jasper/jas_stream.h"
79
80 #include "jpc_mqcod.h"
81
82 #include <stdio.h>
83
84 /******************************************************************************\
85 * Types.
86 \******************************************************************************/
87
88 /* MQ arithmetic decoder. */
89
90 typedef struct {
91
92 /* The C register. */
93 uint_fast32_t creg;
94
95 /* The A register. */
96 uint_fast32_t areg;
97
98 /* The CT register. */
99 uint_fast32_t ctreg;
100
101 /* The current context. */
102 const jpc_mqstate_t **curctx;
103
104 /* The per-context information. */
105 const jpc_mqstate_t **ctxs;
106
107 /* The maximum number of contexts. */
108 int maxctxs;
109
110 /* The stream from which to read data. */
111 jas_stream_t *in;
112
113 /* The last character read. */
114 jas_uchar inbuffer;
115
116 /* The EOF indicator. */
117 int eof;
118
119 } jpc_mqdec_t;
120
121 /******************************************************************************\
122 * Functions/macros for construction and destruction.
123 \******************************************************************************/
124
125 /* Create a MQ decoder. */
126 jpc_mqdec_t *jpc_mqdec_create(int maxctxs, jas_stream_t *in);
127
128 /* Destroy a MQ decoder. */
129 void jpc_mqdec_destroy(jpc_mqdec_t *dec);
130
131 /******************************************************************************\
132 * Functions/macros for initialization.
133 \******************************************************************************/
134
135 /* Set the input stream associated with a MQ decoder. */
136 void jpc_mqdec_setinput(jpc_mqdec_t *dec, jas_stream_t *in);
137
138 /* Initialize a MQ decoder. */
139 void jpc_mqdec_init(jpc_mqdec_t *dec);
140
141 /******************************************************************************\
142 * Functions/macros for manipulating contexts.
143 \******************************************************************************/
144
145 /* Set the current context for a MQ decoder. */
146 #define jpc_mqdec_setcurctx(dec, ctxno) \
147 ((mqdec)->curctx = &(mqdec)->ctxs[ctxno]);
148
149 /* Set the state information for a particular context of a MQ decoder. */
150 void jpc_mqdec_setctx(jpc_mqdec_t *dec, int ctxno, const jpc_mqctx_t *ctx);
151
152 /* Set the state information for all contexts of a MQ decoder. */
153 void jpc_mqdec_setctxs(const jpc_mqdec_t *dec, int numctxs, const jpc_mqctx_t *ctxs);
154
155 /******************************************************************************\
156 * Functions/macros for decoding bits.
157 \******************************************************************************/
158
159 /* Decode a symbol. */
160 #if !defined(DEBUG)
161 #define jpc_mqdec_getbit(dec) \
162 jpc_mqdec_getbit_macro(dec)
163 #else
164 #define jpc_mqdec_getbit(dec) \
165 jpc_mqdec_getbit_func(dec)
166 #endif
167
168 /* Decode a symbol (assuming an unskewed probability distribution). */
169 #if !defined(DEBUG)
170 #define jpc_mqdec_getbitnoskew(dec) \
171 jpc_mqdec_getbit_macro(dec)
172 #else
173 #define jpc_mqdec_getbitnoskew(dec) \
174 jpc_mqdec_getbit_func(dec)
175 #endif
176
177 /******************************************************************************\
178 * Functions/macros for debugging.
179 \******************************************************************************/
180
181 /* Dump the MQ decoder state for debugging. */
182 void jpc_mqdec_dump(const jpc_mqdec_t *dec, FILE *out);
183
184 /******************************************************************************\
185 * EVERYTHING BELOW THIS POINT IS IMPLEMENTATION SPECIFIC AND NOT PART OF THE
186 * APPLICATION INTERFACE. DO NOT RELY ON ANY OF THE INTERNAL FUNCTIONS/MACROS
187 * GIVEN BELOW.
188 \******************************************************************************/
189
190 #define jpc_mqdec_getbit_macro(dec) \
191 ((((dec)->areg -= (*(dec)->curctx)->qeval), \
192 (dec)->creg >> 16 >= (*(dec)->curctx)->qeval) ? \
193 ((((dec)->creg -= (*(dec)->curctx)->qeval << 16), \
194 (dec)->areg & 0x8000) ? (*(dec)->curctx)->mps : \
195 jpc_mqdec_mpsexchrenormd(dec)) : \
196 jpc_mqdec_lpsexchrenormd(dec))
197
198 #define jpc_mqdec_mpsexchange(areg, delta, curctx, bit) \
199 { \
200 if ((areg) < (delta)) { \
201 register const jpc_mqstate_t *state = *(curctx); \
202 /* LPS decoded. */ \
203 (bit) = state->mps ^ 1; \
204 *(curctx) = state->nlps; \
205 } else { \
206 register const jpc_mqstate_t *state = *(curctx); \
207 /* MPS decoded. */ \
208 (bit) = state->mps; \
209 *(curctx) = state->nmps; \
210 } \
211 }
212
213 #define jpc_mqdec_lpsexchange(areg, delta, curctx, bit) \
214 { \
215 if ((areg) >= (delta)) { \
216 register const jpc_mqstate_t *state = *(curctx); \
217 (areg) = (delta); \
218 (bit) = state->mps ^ 1; \
219 *(curctx) = state->nlps; \
220 } else { \
221 register const jpc_mqstate_t *state = *(curctx); \
222 (areg) = (delta); \
223 (bit) = state->mps; \
224 *(curctx) = state->nmps; \
225 } \
226 }
227
228 #define jpc_mqdec_renormd(areg, creg, ctreg, in, eof, inbuf) \
229 { \
230 do { \
231 if (!(ctreg)) { \
232 jpc_mqdec_bytein2(creg, ctreg, in, eof, inbuf); \
233 } \
234 (areg) <<= 1; \
235 (creg) <<= 1; \
236 --(ctreg); \
237 } while (!((areg) & 0x8000)); \
238 }
239
240 #define jpc_mqdec_bytein2(creg, ctreg, in, eof, inbuf) \
241 { \
242 int c; \
243 unsigned char prevbuf; \
244 if (!(eof)) { \
245 if ((c = jas_stream_getc(in)) == EOF) { \
246 (eof) = 1; \
247 c = 0xff; \
248 } \
249 prevbuf = (inbuf); \
250 (inbuf) = c; \
251 if (prevbuf == 0xff) { \
252 if (c > 0x8f) { \
253 (creg) += 0xff00; \
254 (ctreg) = 8; \
255 } else { \
256 (creg) += c << 9; \
257 (ctreg) = 7; \
258 } \
259 } else { \
260 (creg) += c << 8; \
261 (ctreg) = 8; \
262 } \
263 } else { \
264 (creg) += 0xff00; \
265 (ctreg) = 8; \
266 } \
267 }
268
269 int jpc_mqdec_getbit_func(jpc_mqdec_t *dec);
270 int jpc_mqdec_mpsexchrenormd(jpc_mqdec_t *dec);
271 int jpc_mqdec_lpsexchrenormd(jpc_mqdec_t *dec);
272
273 #endif