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 /******************************************************************************\
71 * Includes.
72 \******************************************************************************/
73
74 #include "jpc_mqdec.h"
75
76 #include "jasper/jas_types.h"
77 #include "jasper/jas_malloc.h"
78 #include "jasper/jas_math.h"
79 #include "jasper/jas_debug.h"
80
81 #include <assert.h>
82
83 /******************************************************************************\
84 * Local macros.
85 \******************************************************************************/
86
87 #ifndef NDEBUG
88 #define MQDEC_CALL(n, x) \
89 ((jas_getdbglevel() >= (n)) ? ((void)(x)) : ((void)0))
90 #else
91 #define MQDEC_CALL(n, x)
92 #endif
93
94 /******************************************************************************\
95 * Local function prototypes.
96 \******************************************************************************/
97
98 static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec);
99
100 /******************************************************************************\
101 * Code for creation and destruction of a MQ decoder.
102 \******************************************************************************/
103
104 /* Create a MQ decoder. */
jpc_mqdec_create(unsigned maxctxs,jas_stream_t * in)105 jpc_mqdec_t *jpc_mqdec_create(unsigned maxctxs, jas_stream_t *in)
106 {
107 jpc_mqdec_t *mqdec;
108
109 /* There must be at least one context. */
110 assert(maxctxs > 0);
111
112 /* Allocate memory for the MQ decoder. */
113 if (!(mqdec = jas_malloc(sizeof(jpc_mqdec_t)))) {
114 goto error;
115 }
116 mqdec->in = in;
117 mqdec->maxctxs = maxctxs;
118 /* Allocate memory for the per-context state information. */
119 if (!(mqdec->ctxs = jas_alloc2(mqdec->maxctxs, sizeof(jpc_mqstate_t *)))) {
120 goto error;
121 }
122 /* Set the current context to the first context. */
123 mqdec->curctx = mqdec->ctxs;
124
125 /* If an input stream has been associated with the MQ decoder,
126 initialize the decoder state from the stream. */
127 if (mqdec->in) {
128 jpc_mqdec_init(mqdec);
129 }
130 /* Initialize the per-context state information. */
131 jpc_mqdec_setctxs(mqdec, 0, 0);
132
133 return mqdec;
134
135 error:
136 /* Oops... Something has gone wrong. */
137 if (mqdec) {
138 jpc_mqdec_destroy(mqdec);
139 }
140 return 0;
141 }
142
143 /* Destroy a MQ decoder. */
jpc_mqdec_destroy(jpc_mqdec_t * mqdec)144 void jpc_mqdec_destroy(jpc_mqdec_t *mqdec)
145 {
146 jas_free(mqdec->ctxs);
147 jas_free(mqdec);
148 }
149
150 /******************************************************************************\
151 * Code for initialization of a MQ decoder.
152 \******************************************************************************/
153
154 /* Initialize the state of a MQ decoder. */
155
jpc_mqdec_init(jpc_mqdec_t * mqdec)156 void jpc_mqdec_init(jpc_mqdec_t *mqdec)
157 {
158 int c;
159
160 mqdec->eof = false;
161 mqdec->creg = 0;
162 /* Get the next byte from the input stream. */
163 if ((c = jas_stream_getc(mqdec->in)) == EOF) {
164 /* We have encountered an I/O error or EOF. */
165 c = 0xff;
166 mqdec->eof = true;
167 }
168 mqdec->inbuffer = c;
169 mqdec->creg += mqdec->inbuffer << 16;
170 jpc_mqdec_bytein(mqdec);
171 mqdec->creg <<= 7;
172 mqdec->ctreg -= 7;
173 mqdec->areg = 0x8000;
174 }
175
176 /* Set the input stream for a MQ decoder. */
177
jpc_mqdec_setinput(jpc_mqdec_t * mqdec,jas_stream_t * in)178 void jpc_mqdec_setinput(jpc_mqdec_t *mqdec, jas_stream_t *in)
179 {
180 mqdec->in = in;
181 }
182
183 /* Initialize one or more contexts. */
184
jpc_mqdec_setctxs(const jpc_mqdec_t * mqdec,unsigned numctxs,const jpc_mqctx_t * ctxs)185 void jpc_mqdec_setctxs(const jpc_mqdec_t *mqdec, unsigned numctxs, const jpc_mqctx_t *ctxs)
186 {
187 const jpc_mqstate_t **ctx;
188
189 ctx = mqdec->ctxs;
190 unsigned n = JAS_MIN(mqdec->maxctxs, numctxs);
191 while (n-- > 0) {
192 *ctx = &jpc_mqstates[2 * ctxs->ind + ctxs->mps];
193 ++ctx;
194 ++ctxs;
195 }
196 n = mqdec->maxctxs - numctxs;
197 while (n-- > 0) {
198 *ctx = &jpc_mqstates[0];
199 ++ctx;
200 }
201 }
202
203 /******************************************************************************\
204 * Code for decoding a bit.
205 \******************************************************************************/
206
207 /* Decode a bit. */
208
jpc_mqdec_getbit_func(register jpc_mqdec_t * mqdec)209 bool jpc_mqdec_getbit_func(register jpc_mqdec_t *mqdec)
210 {
211 bool bit;
212 JAS_DBGLOG(100, ("jpc_mqdec_getbit_func(%p)\n", mqdec));
213 MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr));
214 bit = jpc_mqdec_getbit_macro(mqdec);
215 MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr));
216 JAS_DBGLOG(100, ("ctx = %d, decoded %d\n", mqdec->curctx -
217 mqdec->ctxs, bit));
218 return bit;
219 }
220
jpc_mqdec_renormd(jpc_mqdec_t * mqdec)221 static void jpc_mqdec_renormd(jpc_mqdec_t *mqdec)
222 {
223 do {
224 if (!mqdec->ctreg)
225 jpc_mqdec_bytein(mqdec);
226
227 mqdec->areg <<= 1;
228 mqdec->creg <<= 1;
229 --mqdec->ctreg;
230 } while (!(mqdec->areg & 0x8000));
231 }
232
233 /* Apply MPS_EXCHANGE algorithm (with RENORMD). */
jpc_mqdec_mpsexchrenormd(register jpc_mqdec_t * mqdec)234 bool jpc_mqdec_mpsexchrenormd(register jpc_mqdec_t *mqdec)
235 {
236 register const jpc_mqstate_t *state = *mqdec->curctx;
237 bool ret = jpc_mqdec_mpsexchange(mqdec->areg, state->qeval, mqdec->curctx);
238 jpc_mqdec_renormd(mqdec);
239 return ret;
240 }
241
242 /* Apply LPS_EXCHANGE algorithm (with RENORMD). */
jpc_mqdec_lpsexchrenormd(register jpc_mqdec_t * mqdec)243 bool jpc_mqdec_lpsexchrenormd(register jpc_mqdec_t *mqdec)
244 {
245 register const jpc_mqstate_t *state = *mqdec->curctx;
246 bool ret = jpc_mqdec_lpsexchange(&mqdec->areg, state->qeval, mqdec->curctx);
247 jpc_mqdec_renormd(mqdec);
248 return ret;
249 }
250
251 /******************************************************************************\
252 * Support code.
253 \******************************************************************************/
254
255 /* Apply the BYTEIN algorithm. */
jpc_mqdec_bytein(jpc_mqdec_t * mqdec)256 static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec)
257 {
258 int c;
259 unsigned char prevbuf;
260
261 if (!mqdec->eof) {
262 if ((c = jas_stream_getc(mqdec->in)) == EOF) {
263 mqdec->eof = true;
264 c = 0xff;
265 }
266 prevbuf = mqdec->inbuffer;
267 mqdec->inbuffer = c;
268 if (prevbuf == 0xff) {
269 if (c > 0x8f) {
270 mqdec->creg += 0xff00;
271 mqdec->ctreg = 8;
272 } else {
273 mqdec->creg += c << 9;
274 mqdec->ctreg = 7;
275 }
276 } else {
277 mqdec->creg += c << 8;
278 mqdec->ctreg = 8;
279 }
280 } else {
281 mqdec->creg += 0xff00;
282 mqdec->ctreg = 8;
283 }
284 }
285
286 /******************************************************************************\
287 * Code for debugging.
288 \******************************************************************************/
289
290 /* Dump a MQ decoder to a stream for debugging. */
291
jpc_mqdec_dump(const jpc_mqdec_t * mqdec,FILE * out)292 void jpc_mqdec_dump(const jpc_mqdec_t *mqdec, FILE *out)
293 {
294 fprintf(out, "MQDEC A = %08lx, C = %08lx, CT=%08lx, ",
295 (unsigned long) mqdec->areg, (unsigned long) mqdec->creg,
296 (unsigned long) mqdec->ctreg);
297 fprintf(out, "CTX = %" PRIdPTR ", ", mqdec->curctx - mqdec->ctxs);
298 fprintf(out, "IND %" PRIdPTR ", MPS %d, QEVAL %"PRIxLEAST16"\n", *mqdec->curctx -
299 jpc_mqstates, (*mqdec->curctx)->mps, (*mqdec->curctx)->qeval);
300 }
301