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      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 (at) 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