2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
4 * Copyright (c) 2001-2003 Michael David Adams.
8 /* __START_OF_JASPER_LICENSE__
10 * JasPer License Version 2.0
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
16 * All rights reserved.
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:
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.
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
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.
61 * __END_OF_JASPER_LICENSE__
65 * MQ Arithmetic Decoder
67 * $Id: jpc_mqdec.h,v 1.1 2005/05/22 18:33:05 malaterre Exp $
73 /******************************************************************************\
75 \******************************************************************************/
77 #include "jasper/jas_types.h"
78 #include "jasper/jas_stream.h"
80 #include "jpc_mqcod.h"
82 /******************************************************************************\
84 \******************************************************************************/
86 /* MQ arithmetic decoder. */
96 /* The CT register. */
99 /* The current context. */
100 jpc_mqstate_t **curctx;
102 /* The per-context information. */
103 jpc_mqstate_t **ctxs;
105 /* The maximum number of contexts. */
108 /* The stream from which to read data. */
111 /* The last character read. */
114 /* The EOF indicator. */
119 /******************************************************************************\
120 * Functions/macros for construction and destruction.
121 \******************************************************************************/
123 /* Create a MQ decoder. */
124 jpc_mqdec_t *jpc_mqdec_create(int maxctxs, jas_stream_t *in);
126 /* Destroy a MQ decoder. */
127 void jpc_mqdec_destroy(jpc_mqdec_t *dec);
129 /******************************************************************************\
130 * Functions/macros for initialization.
131 \******************************************************************************/
133 /* Set the input stream associated with a MQ decoder. */
134 void jpc_mqdec_setinput(jpc_mqdec_t *dec, jas_stream_t *in);
136 /* Initialize a MQ decoder. */
137 void jpc_mqdec_init(jpc_mqdec_t *dec);
139 /******************************************************************************\
140 * Functions/macros for manipulating contexts.
141 \******************************************************************************/
143 /* Set the current context for a MQ decoder. */
144 #define jpc_mqdec_setcurctx(dec, ctxno) \
145 ((mqdec)->curctx = &(mqdec)->ctxs[ctxno]);
147 /* Set the state information for a particular context of a MQ decoder. */
148 void jpc_mqdec_setctx(jpc_mqdec_t *dec, int ctxno, jpc_mqctx_t *ctx);
150 /* Set the state information for all contexts of a MQ decoder. */
151 void jpc_mqdec_setctxs(jpc_mqdec_t *dec, int numctxs, jpc_mqctx_t *ctxs);
153 /******************************************************************************\
154 * Functions/macros for decoding bits.
155 \******************************************************************************/
157 /* Decode a symbol. */
159 #define jpc_mqdec_getbit(dec) \
160 jpc_mqdec_getbit_macro(dec)
162 #define jpc_mqdec_getbit(dec) \
163 jpc_mqdec_getbit_func(dec)
166 /* Decode a symbol (assuming an unskewed probability distribution). */
168 #define jpc_mqdec_getbitnoskew(dec) \
169 jpc_mqdec_getbit_macro(dec)
171 #define jpc_mqdec_getbitnoskew(dec) \
172 jpc_mqdec_getbit_func(dec)
175 /******************************************************************************\
176 * Functions/macros for debugging.
177 \******************************************************************************/
179 /* Dump the MQ decoder state for debugging. */
180 void jpc_mqdec_dump(jpc_mqdec_t *dec, FILE *out);
182 /******************************************************************************\
183 * EVERYTHING BELOW THIS POINT IS IMPLEMENTATION SPECIFIC AND NOT PART OF THE
184 * APPLICATION INTERFACE. DO NOT RELY ON ANY OF THE INTERNAL FUNCTIONS/MACROS
186 \******************************************************************************/
188 #define jpc_mqdec_getbit_macro(dec) \
189 ((((dec)->areg -= (*(dec)->curctx)->qeval), \
190 (dec)->creg >> 16 >= (*(dec)->curctx)->qeval) ? \
191 ((((dec)->creg -= (*(dec)->curctx)->qeval << 16), \
192 (dec)->areg & 0x8000) ? (*(dec)->curctx)->mps : \
193 jpc_mqdec_mpsexchrenormd(dec)) : \
194 jpc_mqdec_lpsexchrenormd(dec))
196 #define jpc_mqdec_mpsexchange(areg, delta, curctx, bit) \
198 if ((areg) < (delta)) { \
199 register jpc_mqstate_t *state = *(curctx); \
201 (bit) = state->mps ^ 1; \
202 *(curctx) = state->nlps; \
204 register jpc_mqstate_t *state = *(curctx); \
206 (bit) = state->mps; \
207 *(curctx) = state->nmps; \
211 #define jpc_mqdec_lpsexchange(areg, delta, curctx, bit) \
213 if ((areg) >= (delta)) { \
214 register jpc_mqstate_t *state = *(curctx); \
216 (bit) = state->mps ^ 1; \
217 *(curctx) = state->nlps; \
219 register jpc_mqstate_t *state = *(curctx); \
221 (bit) = state->mps; \
222 *(curctx) = state->nmps; \
226 #define jpc_mqdec_renormd(areg, creg, ctreg, in, eof, inbuf) \
230 jpc_mqdec_bytein2(creg, ctreg, in, eof, inbuf); \
235 } while (!((areg) & 0x8000)); \
238 #define jpc_mqdec_bytein2(creg, ctreg, in, eof, inbuf) \
241 unsigned char prevbuf; \
243 if ((c = jas_stream_getc(in)) == EOF) { \
249 if (prevbuf == 0xff) { \
267 int jpc_mqdec_getbit_func(jpc_mqdec_t *dec);
268 int jpc_mqdec_mpsexchrenormd(jpc_mqdec_t *dec);
269 int jpc_mqdec_lpsexchrenormd(jpc_mqdec_t *dec);