1 /*
2  * The copyright in this software is being made available under the 2-clauses
3  * BSD License, included below. This software may be subject to other third
4  * party and contributor rights, including patent rights, and no such rights
5  * are granted under this license.
6  *
7  * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
8  * Copyright (c) 2002-2014, Professor Benoit Macq
9  * Copyright (c) 2001-2003, David Janssens
10  * Copyright (c) 2002-2003, Yannick Verschueren
11  * Copyright (c) 2003-2007, Francois-Olivier Devaux
12  * Copyright (c) 2003-2014, Antonin Descampe
13  * Copyright (c) 2005, Herve Drolon, FreeImage Team
14  * Copyright (c) 2008, Jerome Fimes, Communications & Systemes <jerome.fimes@c-s.fr>
15  * All rights reserved.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
27  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #ifndef OPJ_MQC_INL_H
40 #define OPJ_MQC_INL_H
41 
42 /* For internal use of opj_mqc_decode_macro() */
43 #define opj_mqc_mpsexchange_macro(d, curctx, a) \
44 { \
45     if (a < (*curctx)->qeval) { \
46         d = !((*curctx)->mps); \
47         *curctx = (*curctx)->nlps; \
48     } else { \
49         d = (*curctx)->mps; \
50         *curctx = (*curctx)->nmps; \
51     } \
52 }
53 
54 /* For internal use of opj_mqc_decode_macro() */
55 #define opj_mqc_lpsexchange_macro(d, curctx, a) \
56 { \
57     if (a < (*curctx)->qeval) { \
58         a = (*curctx)->qeval; \
59         d = (*curctx)->mps; \
60         *curctx = (*curctx)->nmps; \
61     } else { \
62         a = (*curctx)->qeval; \
63         d = !((*curctx)->mps); \
64         *curctx = (*curctx)->nlps; \
65     } \
66 }
67 
68 
69 /**
70 Decode a symbol using raw-decoder. Cfr p.506 TAUBMAN
71 @param mqc MQC handle
72 @return Returns the decoded symbol (0 or 1)
73 */
74 static INLINE OPJ_UINT32 opj_mqc_raw_decode(opj_mqc_t *mqc)
75 {
76     OPJ_UINT32 d;
77     if (mqc->ct == 0) {
78         /* Given opj_mqc_raw_init_dec() we know that at some point we will */
79         /* have a 0xFF 0xFF artificial marker */
80         if (mqc->c == 0xff) {
81             if (*mqc->bp  > 0x8f) {
82                 mqc->c = 0xff;
83                 mqc->ct = 8;
84             } else {
85                 mqc->c = *mqc->bp;
86                 mqc->bp ++;
87                 mqc->ct = 7;
88             }
89         } else {
90             mqc->c = *mqc->bp;
91             mqc->bp ++;
92             mqc->ct = 8;
93         }
94     }
95     mqc->ct--;
96     d = ((OPJ_UINT32)mqc->c >> mqc->ct) & 0x01U;
97 
98     return d;
99 }
100 
101 
102 #define opj_mqc_bytein_macro(mqc, c, ct) \
103 { \
104         OPJ_UINT32 l_c;  \
105         /* Given opj_mqc_init_dec() we know that at some point we will */ \
106         /* have a 0xFF 0xFF artificial marker */ \
107         l_c = *(mqc->bp + 1); \
108         if (*mqc->bp == 0xff) { \
109             if (l_c > 0x8f) { \
110                 c += 0xff00; \
111                 ct = 8; \
112                 mqc->end_of_byte_stream_counter ++; \
113             } else { \
114                 mqc->bp++; \
115                 c += l_c << 9; \
116                 ct = 7; \
117             } \
118         } else { \
119             mqc->bp++; \
120             c += l_c << 8; \
121             ct = 8; \
122         } \
123 }
124 
125 /* For internal use of opj_mqc_decode_macro() */
126 #define opj_mqc_renormd_macro(mqc, a, c, ct) \
127 { \
128     do { \
129         if (ct == 0) { \
130             opj_mqc_bytein_macro(mqc, c, ct); \
131         } \
132         a <<= 1; \
133         c <<= 1; \
134         ct--; \
135     } while (a < 0x8000); \
136 }
137 
138 #define opj_mqc_decode_macro(d, mqc, curctx, a, c, ct) \
139 { \
140     /* Implements ISO 15444-1 C.3.2 Decoding a decision (DECODE) */ \
141     /* Note: alternate "J.2 - Decoding an MPS or an LPS in the */ \
142     /* software-conventions decoder" has been tried, but does not bring any */ \
143     /* improvement. See https://github.com/uclouvain/openjpeg/issues/921 */ \
144     a -= (*curctx)->qeval;  \
145     if ((c >> 16) < (*curctx)->qeval) {  \
146         opj_mqc_lpsexchange_macro(d, curctx, a);  \
147         opj_mqc_renormd_macro(mqc, a, c, ct);  \
148     } else {  \
149         c -= (*curctx)->qeval << 16;  \
150         if ((a & 0x8000) == 0) { \
151             opj_mqc_mpsexchange_macro(d, curctx, a); \
152             opj_mqc_renormd_macro(mqc, a, c, ct); \
153         } else { \
154             d = (*curctx)->mps; \
155         } \
156     } \
157 }
158 
159 #define DOWNLOAD_MQC_VARIABLES(mqc, curctx, c, a, ct) \
160         register const opj_mqc_state_t **curctx = mqc->curctx; \
161         register OPJ_UINT32 c = mqc->c; \
162         register OPJ_UINT32 a = mqc->a; \
163         register OPJ_UINT32 ct = mqc->ct
164 
165 #define UPLOAD_MQC_VARIABLES(mqc, curctx, c, a, ct) \
166         mqc->curctx = curctx; \
167         mqc->c = c; \
168         mqc->a = a; \
169         mqc->ct = ct;
170 
171 /**
172 Input a byte
173 @param mqc MQC handle
174 */
175 static INLINE void opj_mqc_bytein(opj_mqc_t *const mqc)
176 {
177     opj_mqc_bytein_macro(mqc, mqc->c, mqc->ct);
178 }
179 
180 /**
181 Renormalize mqc->a and mqc->c while decoding
182 @param mqc MQC handle
183 */
184 #define opj_mqc_renormd(mqc) \
185     opj_mqc_renormd_macro(mqc, mqc->a, mqc->c, mqc->ct)
186 
187 /**
188 Decode a symbol
189 @param d OPJ_UINT32 value where to store the decoded symbol
190 @param mqc MQC handle
191 @return Returns the decoded symbol (0 or 1) in d
192 */
193 #define opj_mqc_decode(d, mqc) \
194     opj_mqc_decode_macro(d, mqc, mqc->curctx, mqc->a, mqc->c, mqc->ct)
195 
196 #endif /* OPJ_MQC_INL_H */
197