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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_least32_t creg;
94
95 /* The A register. */
96 uint_least32_t areg;
97
98 /* The CT register. */
99 uint_least32_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 unsigned 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 bool eof;
118
119} jpc_mqdec_t;
120
121/******************************************************************************\
122* Functions/macros for construction and destruction.
123\******************************************************************************/
124
125/* Create a MQ decoder. */
126jpc_mqdec_t *jpc_mqdec_create(unsigned 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 static inline void jpc_mqdec_setcurctx(jpc_mqdec_t *dec, unsigned ctxno)
147{
148 dec->curctx = &dec->ctxs[ctxno];
149}
150
151/* Set the state information for all contexts of a MQ decoder. */
152 void jpc_mqdec_setctxs(const jpc_mqdec_t *dec, unsigned numctxs, const jpc_mqctx_t *ctxs);
153
154/******************************************************************************\
155* Functions/macros for decoding bits.
156\******************************************************************************/
157
158/* Decode a symbol. */
159#ifdef NDEBUG
160#define jpc_mqdec_getbit(dec) \
161 jpc_mqdec_getbit_macro(dec)
162#else
163#define jpc_mqdec_getbit(dec) \
164 jpc_mqdec_getbit_func(dec)
165#endif
166
167/* Decode a symbol (assuming an unskewed probability distribution). */
168#ifdef NDEBUG
169#define jpc_mqdec_getbitnoskew(dec) \
170 jpc_mqdec_getbit_macro(dec)
171#else
172#define jpc_mqdec_getbitnoskew(dec) \
173 jpc_mqdec_getbit_func(dec)
174#endif
175
176/******************************************************************************\
177* Functions/macros for debugging.
178\******************************************************************************/
179
180/* Dump the MQ decoder state for debugging. */
181 void jpc_mqdec_dump(const jpc_mqdec_t *dec);
182
183/******************************************************************************\
184* EVERYTHING BELOW THIS POINT IS IMPLEMENTATION SPECIFIC AND NOT PART OF THE
185* APPLICATION INTERFACE. DO NOT RELY ON ANY OF THE INTERNAL FUNCTIONS/MACROS
186* GIVEN BELOW.
187\******************************************************************************/
188
189 bool jpc_mqdec_mpsexchrenormd(jpc_mqdec_t *dec);
190 bool jpc_mqdec_lpsexchrenormd(jpc_mqdec_t *dec);
191
192JAS_FORCE_INLINE
193 static bool jpc_mqdec_getbit_macro(jpc_mqdec_t *dec)
194{
195 const jpc_mqstate_t *const state = *dec->curctx;
196
197 dec->areg -= state->qeval;
198
199 if (dec->creg >= (uint_least32_t)state->qeval << 16) {
200 dec->creg -= (uint_least32_t)state->qeval << 16;
201 return dec->areg & 0x8000
202 ? state->mps
203 : jpc_mqdec_mpsexchrenormd(dec);
204 } else {
205 return jpc_mqdec_lpsexchrenormd(dec);
206 }
207}
208
209JAS_FORCE_INLINE
210 static bool jpc_mqdec_mpsexchange(uint_least32_t areg, uint_least32_t delta, const jpc_mqstate_t **curctx)
211{
212 if (areg < delta) {
213 const jpc_mqstate_t *state = *curctx;
214 /* LPS decoded. */
215 *curctx = state->nlps;
216 return !state->mps;
217 } else {
218 const jpc_mqstate_t *state = *curctx;
219 /* MPS decoded. */
220 *curctx = state->nmps;
221 return state->mps;
222 }
223}
224
225JAS_FORCE_INLINE
226 static bool jpc_mqdec_lpsexchange(uint_least32_t *areg_p, uint_least32_t delta, const jpc_mqstate_t **curctx)
227{
228 if (*areg_p >= delta) {
229 const jpc_mqstate_t *state = *curctx;
230 *areg_p = delta;
231 *curctx = state->nlps;
232 return !state->mps;
233 } else {
234 const jpc_mqstate_t *state = *curctx;
235 *areg_p = delta;
236 *curctx = state->nmps;
237 return state->mps;
238 }
239}
240
241 bool jpc_mqdec_getbit_func(jpc_mqdec_t *dec);
242
243#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