Home | History | Annotate | Download | only in jbig2
      1 // Copyright 2015 PDFium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
      6 
      7 #include "core/fxcodec/jbig2/JBig2_SddProc.h"
      8 
      9 #include <algorithm>
     10 #include <memory>
     11 #include <utility>
     12 #include <vector>
     13 
     14 #include "core/fxcodec/jbig2/JBig2_ArithIntDecoder.h"
     15 #include "core/fxcodec/jbig2/JBig2_GrdProc.h"
     16 #include "core/fxcodec/jbig2/JBig2_GrrdProc.h"
     17 #include "core/fxcodec/jbig2/JBig2_HuffmanDecoder.h"
     18 #include "core/fxcodec/jbig2/JBig2_HuffmanTable.h"
     19 #include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
     20 #include "core/fxcodec/jbig2/JBig2_SymbolDict.h"
     21 #include "core/fxcodec/jbig2/JBig2_TrdProc.h"
     22 #include "third_party/base/ptr_util.h"
     23 
     24 std::unique_ptr<CJBig2_SymbolDict> CJBig2_SDDProc::decode_Arith(
     25     CJBig2_ArithDecoder* pArithDecoder,
     26     std::vector<JBig2ArithCtx>* gbContext,
     27     std::vector<JBig2ArithCtx>* grContext) {
     28   std::vector<std::unique_ptr<CJBig2_Image>> SDNEWSYMS;
     29   uint32_t HCHEIGHT, NSYMSDECODED;
     30   int32_t HCDH;
     31   uint32_t SYMWIDTH, TOTWIDTH;
     32   int32_t DW;
     33   uint32_t I, J, REFAGGNINST;
     34   std::vector<bool> EXFLAGS;
     35   uint32_t EXINDEX;
     36   bool CUREXFLAG;
     37   uint32_t EXRUNLENGTH;
     38   uint32_t nTmp;
     39   uint32_t SBNUMSYMS;
     40   uint8_t SBSYMCODELEN;
     41   int32_t RDXI, RDYI;
     42   uint32_t num_ex_syms;
     43   // Pointers are not owned
     44   std::vector<CJBig2_Image*> SBSYMS;
     45   std::unique_ptr<CJBig2_ArithIaidDecoder> IAID;
     46   std::unique_ptr<CJBig2_SymbolDict> pDict;
     47   auto IADH = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     48   auto IADW = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     49   auto IAAI = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     50   auto IARDX = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     51   auto IARDY = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     52   auto IAEX = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     53   auto IADT = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     54   auto IAFS = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     55   auto IADS = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     56   auto IAIT = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     57   auto IARI = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     58   auto IARDW = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     59   auto IARDH = pdfium::MakeUnique<CJBig2_ArithIntDecoder>();
     60   nTmp = 0;
     61   while ((uint32_t)(1 << nTmp) < (SDNUMINSYMS + SDNUMNEWSYMS)) {
     62     nTmp++;
     63   }
     64   IAID = pdfium::MakeUnique<CJBig2_ArithIaidDecoder>((uint8_t)nTmp);
     65   SDNEWSYMS.resize(SDNUMNEWSYMS);
     66 
     67   HCHEIGHT = 0;
     68   NSYMSDECODED = 0;
     69   while (NSYMSDECODED < SDNUMNEWSYMS) {
     70     std::unique_ptr<CJBig2_Image> BS;
     71     IADH->decode(pArithDecoder, &HCDH);
     72     HCHEIGHT = HCHEIGHT + HCDH;
     73     if ((int)HCHEIGHT < 0 || (int)HCHEIGHT > JBIG2_MAX_IMAGE_SIZE)
     74       return nullptr;
     75 
     76     SYMWIDTH = 0;
     77     TOTWIDTH = 0;
     78     for (;;) {
     79       if (!IADW->decode(pArithDecoder, &DW))
     80         break;
     81 
     82       if (NSYMSDECODED >= SDNUMNEWSYMS)
     83         return nullptr;
     84 
     85       SYMWIDTH = SYMWIDTH + DW;
     86       if ((int)SYMWIDTH < 0 || (int)SYMWIDTH > JBIG2_MAX_IMAGE_SIZE)
     87         return nullptr;
     88 
     89       if (HCHEIGHT == 0 || SYMWIDTH == 0) {
     90         TOTWIDTH = TOTWIDTH + SYMWIDTH;
     91         SDNEWSYMS[NSYMSDECODED] = nullptr;
     92         NSYMSDECODED = NSYMSDECODED + 1;
     93         continue;
     94       }
     95       TOTWIDTH = TOTWIDTH + SYMWIDTH;
     96       if (SDREFAGG == 0) {
     97         auto pGRD = pdfium::MakeUnique<CJBig2_GRDProc>();
     98         pGRD->MMR = 0;
     99         pGRD->GBW = SYMWIDTH;
    100         pGRD->GBH = HCHEIGHT;
    101         pGRD->GBTEMPLATE = SDTEMPLATE;
    102         pGRD->TPGDON = 0;
    103         pGRD->USESKIP = 0;
    104         pGRD->GBAT[0] = SDAT[0];
    105         pGRD->GBAT[1] = SDAT[1];
    106         pGRD->GBAT[2] = SDAT[2];
    107         pGRD->GBAT[3] = SDAT[3];
    108         pGRD->GBAT[4] = SDAT[4];
    109         pGRD->GBAT[5] = SDAT[5];
    110         pGRD->GBAT[6] = SDAT[6];
    111         pGRD->GBAT[7] = SDAT[7];
    112         BS = pGRD->decode_Arith(pArithDecoder, gbContext->data());
    113         if (!BS)
    114           return nullptr;
    115       } else {
    116         IAAI->decode(pArithDecoder, (int*)&REFAGGNINST);
    117         if (REFAGGNINST > 1) {
    118           auto pDecoder = pdfium::MakeUnique<CJBig2_TRDProc>();
    119           pDecoder->SBHUFF = SDHUFF;
    120           pDecoder->SBREFINE = 1;
    121           pDecoder->SBW = SYMWIDTH;
    122           pDecoder->SBH = HCHEIGHT;
    123           pDecoder->SBNUMINSTANCES = REFAGGNINST;
    124           pDecoder->SBSTRIPS = 1;
    125           pDecoder->SBNUMSYMS = SDNUMINSYMS + NSYMSDECODED;
    126           SBNUMSYMS = pDecoder->SBNUMSYMS;
    127           nTmp = 0;
    128           while ((uint32_t)(1 << nTmp) < SBNUMSYMS) {
    129             nTmp++;
    130           }
    131           SBSYMCODELEN = (uint8_t)nTmp;
    132           pDecoder->SBSYMCODELEN = SBSYMCODELEN;
    133           SBSYMS.resize(SBNUMSYMS);
    134           std::copy(SDINSYMS, SDINSYMS + SDNUMINSYMS, SBSYMS.begin());
    135           for (size_t i = 0; i < NSYMSDECODED; ++i)
    136             SBSYMS[i + SDNUMINSYMS] = SDNEWSYMS[i].get();
    137           pDecoder->SBSYMS = SBSYMS.data();
    138           pDecoder->SBDEFPIXEL = 0;
    139           pDecoder->SBCOMBOP = JBIG2_COMPOSE_OR;
    140           pDecoder->TRANSPOSED = 0;
    141           pDecoder->REFCORNER = JBIG2_CORNER_TOPLEFT;
    142           pDecoder->SBDSOFFSET = 0;
    143           auto SBHUFFFS = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    144               HuffmanTable_B6, HuffmanTable_B6_Size, HuffmanTable_HTOOB_B6);
    145           auto SBHUFFDS = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    146               HuffmanTable_B8, HuffmanTable_B8_Size, HuffmanTable_HTOOB_B8);
    147           auto SBHUFFDT = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    148               HuffmanTable_B11, HuffmanTable_B11_Size, HuffmanTable_HTOOB_B11);
    149           auto SBHUFFRDW = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    150               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    151           auto SBHUFFRDH = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    152               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    153           auto SBHUFFRDX = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    154               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    155           auto SBHUFFRDY = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    156               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    157           auto SBHUFFRSIZE = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    158               HuffmanTable_B1, HuffmanTable_B1_Size, HuffmanTable_HTOOB_B1);
    159           pDecoder->SBHUFFFS = SBHUFFFS.get();
    160           pDecoder->SBHUFFDS = SBHUFFDS.get();
    161           pDecoder->SBHUFFDT = SBHUFFDT.get();
    162           pDecoder->SBHUFFRDW = SBHUFFRDW.get();
    163           pDecoder->SBHUFFRDH = SBHUFFRDH.get();
    164           pDecoder->SBHUFFRDX = SBHUFFRDX.get();
    165           pDecoder->SBHUFFRDY = SBHUFFRDY.get();
    166           pDecoder->SBHUFFRSIZE = SBHUFFRSIZE.get();
    167           pDecoder->SBRTEMPLATE = SDRTEMPLATE;
    168           pDecoder->SBRAT[0] = SDRAT[0];
    169           pDecoder->SBRAT[1] = SDRAT[1];
    170           pDecoder->SBRAT[2] = SDRAT[2];
    171           pDecoder->SBRAT[3] = SDRAT[3];
    172           JBig2IntDecoderState ids;
    173           ids.IADT = IADT.get();
    174           ids.IAFS = IAFS.get();
    175           ids.IADS = IADS.get();
    176           ids.IAIT = IAIT.get();
    177           ids.IARI = IARI.get();
    178           ids.IARDW = IARDW.get();
    179           ids.IARDH = IARDH.get();
    180           ids.IARDX = IARDX.get();
    181           ids.IARDY = IARDY.get();
    182           ids.IAID = IAID.get();
    183           BS = pDecoder->decode_Arith(pArithDecoder, grContext->data(), &ids);
    184           if (!BS)
    185             return nullptr;
    186         } else if (REFAGGNINST == 1) {
    187           SBNUMSYMS = SDNUMINSYMS + NSYMSDECODED;
    188           uint32_t IDI;
    189           IAID->decode(pArithDecoder, &IDI);
    190           IARDX->decode(pArithDecoder, &RDXI);
    191           IARDY->decode(pArithDecoder, &RDYI);
    192           if (IDI >= SBNUMSYMS)
    193             return nullptr;
    194 
    195           SBSYMS.resize(SBNUMSYMS);
    196           std::copy(SDINSYMS, SDINSYMS + SDNUMINSYMS, SBSYMS.begin());
    197           for (size_t i = 0; i < NSYMSDECODED; ++i)
    198             SBSYMS[i + SDNUMINSYMS] = SDNEWSYMS[i].get();
    199           if (!SBSYMS[IDI])
    200             return nullptr;
    201 
    202           auto pGRRD = pdfium::MakeUnique<CJBig2_GRRDProc>();
    203           pGRRD->GRW = SYMWIDTH;
    204           pGRRD->GRH = HCHEIGHT;
    205           pGRRD->GRTEMPLATE = SDRTEMPLATE;
    206           pGRRD->GRREFERENCE = SBSYMS[IDI];
    207           pGRRD->GRREFERENCEDX = RDXI;
    208           pGRRD->GRREFERENCEDY = RDYI;
    209           pGRRD->TPGRON = 0;
    210           pGRRD->GRAT[0] = SDRAT[0];
    211           pGRRD->GRAT[1] = SDRAT[1];
    212           pGRRD->GRAT[2] = SDRAT[2];
    213           pGRRD->GRAT[3] = SDRAT[3];
    214           BS = pGRRD->decode(pArithDecoder, grContext->data());
    215           if (!BS)
    216             return nullptr;
    217         }
    218       }
    219       SDNEWSYMS[NSYMSDECODED] = std::move(BS);
    220       NSYMSDECODED = NSYMSDECODED + 1;
    221     }
    222   }
    223   EXINDEX = 0;
    224   CUREXFLAG = 0;
    225   EXFLAGS.resize(SDNUMINSYMS + SDNUMNEWSYMS);
    226   num_ex_syms = 0;
    227   while (EXINDEX < SDNUMINSYMS + SDNUMNEWSYMS) {
    228     IAEX->decode(pArithDecoder, (int*)&EXRUNLENGTH);
    229     if (EXINDEX + EXRUNLENGTH > SDNUMINSYMS + SDNUMNEWSYMS)
    230       return nullptr;
    231 
    232     if (EXRUNLENGTH != 0) {
    233       for (I = EXINDEX; I < EXINDEX + EXRUNLENGTH; I++) {
    234         if (CUREXFLAG)
    235           num_ex_syms++;
    236         EXFLAGS[I] = CUREXFLAG;
    237       }
    238     }
    239     EXINDEX = EXINDEX + EXRUNLENGTH;
    240     CUREXFLAG = !CUREXFLAG;
    241   }
    242   if (num_ex_syms > SDNUMEXSYMS)
    243     return nullptr;
    244 
    245   pDict = pdfium::MakeUnique<CJBig2_SymbolDict>();
    246   I = J = 0;
    247   for (I = 0; I < SDNUMINSYMS + SDNUMNEWSYMS; I++) {
    248     if (!EXFLAGS[I] || J >= SDNUMEXSYMS)
    249       continue;
    250     if (I < SDNUMINSYMS) {
    251       pDict->AddImage(SDINSYMS[I]
    252                           ? pdfium::MakeUnique<CJBig2_Image>(*SDINSYMS[I])
    253                           : nullptr);
    254     } else {
    255       pDict->AddImage(std::move(SDNEWSYMS[I - SDNUMINSYMS]));
    256     }
    257     ++J;
    258   }
    259   return pDict;
    260 }
    261 
    262 std::unique_ptr<CJBig2_SymbolDict> CJBig2_SDDProc::decode_Huffman(
    263     CJBig2_BitStream* pStream,
    264     std::vector<JBig2ArithCtx>* gbContext,
    265     std::vector<JBig2ArithCtx>* grContext) {
    266   std::vector<std::unique_ptr<CJBig2_Image>> SDNEWSYMS;
    267   std::vector<uint32_t> SDNEWSYMWIDTHS;
    268   uint32_t HCHEIGHT, NSYMSDECODED;
    269   int32_t HCDH;
    270   uint32_t SYMWIDTH, TOTWIDTH, HCFIRSTSYM;
    271   int32_t DW;
    272   uint32_t I, J, REFAGGNINST;
    273   std::vector<bool> EXFLAGS;
    274   uint32_t EXINDEX;
    275   bool CUREXFLAG;
    276   uint32_t EXRUNLENGTH;
    277   int32_t nVal;
    278   uint32_t nTmp;
    279   uint32_t SBNUMSYMS;
    280   uint8_t SBSYMCODELEN;
    281   uint32_t IDI;
    282   int32_t RDXI, RDYI;
    283   uint32_t BMSIZE;
    284   uint32_t stride;
    285   uint32_t num_ex_syms;
    286   // Pointers are not owned
    287   std::vector<CJBig2_Image*> SBSYMS;
    288   auto pHuffmanDecoder = pdfium::MakeUnique<CJBig2_HuffmanDecoder>(pStream);
    289   SDNEWSYMS.resize(SDNUMNEWSYMS);
    290   if (SDREFAGG == 0)
    291     SDNEWSYMWIDTHS.resize(SDNUMNEWSYMS);
    292   auto pDict = pdfium::MakeUnique<CJBig2_SymbolDict>();
    293   std::unique_ptr<CJBig2_HuffmanTable> pTable;
    294 
    295   HCHEIGHT = 0;
    296   NSYMSDECODED = 0;
    297   std::unique_ptr<CJBig2_Image> BS;
    298   while (NSYMSDECODED < SDNUMNEWSYMS) {
    299     if (pHuffmanDecoder->decodeAValue(SDHUFFDH, &HCDH) != 0)
    300       return nullptr;
    301 
    302     HCHEIGHT = HCHEIGHT + HCDH;
    303     if ((int)HCHEIGHT < 0 || (int)HCHEIGHT > JBIG2_MAX_IMAGE_SIZE)
    304       return nullptr;
    305 
    306     SYMWIDTH = 0;
    307     TOTWIDTH = 0;
    308     HCFIRSTSYM = NSYMSDECODED;
    309     for (;;) {
    310       nVal = pHuffmanDecoder->decodeAValue(SDHUFFDW, &DW);
    311       if (nVal == JBIG2_OOB)
    312         break;
    313       if (nVal != 0)
    314         return nullptr;
    315       if (NSYMSDECODED >= SDNUMNEWSYMS)
    316         return nullptr;
    317 
    318       SYMWIDTH = SYMWIDTH + DW;
    319       if ((int)SYMWIDTH < 0 || (int)SYMWIDTH > JBIG2_MAX_IMAGE_SIZE)
    320         return nullptr;
    321       if (HCHEIGHT == 0 || SYMWIDTH == 0) {
    322         TOTWIDTH = TOTWIDTH + SYMWIDTH;
    323         SDNEWSYMS[NSYMSDECODED] = nullptr;
    324         NSYMSDECODED = NSYMSDECODED + 1;
    325         continue;
    326       }
    327       TOTWIDTH = TOTWIDTH + SYMWIDTH;
    328       if (SDREFAGG == 1) {
    329         if (pHuffmanDecoder->decodeAValue(SDHUFFAGGINST, (int*)&REFAGGNINST) !=
    330             0) {
    331           return nullptr;
    332         }
    333         BS = nullptr;
    334         if (REFAGGNINST > 1) {
    335           auto pDecoder = pdfium::MakeUnique<CJBig2_TRDProc>();
    336           pDecoder->SBHUFF = SDHUFF;
    337           pDecoder->SBREFINE = 1;
    338           pDecoder->SBW = SYMWIDTH;
    339           pDecoder->SBH = HCHEIGHT;
    340           pDecoder->SBNUMINSTANCES = REFAGGNINST;
    341           pDecoder->SBSTRIPS = 1;
    342           pDecoder->SBNUMSYMS = SDNUMINSYMS + NSYMSDECODED;
    343           SBNUMSYMS = pDecoder->SBNUMSYMS;
    344           std::vector<JBig2HuffmanCode> SBSYMCODES(SBNUMSYMS);
    345           nTmp = 1;
    346           while (static_cast<uint32_t>(1 << nTmp) < SBNUMSYMS)
    347             ++nTmp;
    348           for (I = 0; I < SBNUMSYMS; ++I) {
    349             SBSYMCODES[I].codelen = nTmp;
    350             SBSYMCODES[I].code = I;
    351           }
    352           pDecoder->SBSYMCODES = std::move(SBSYMCODES);
    353           SBSYMS.resize(SBNUMSYMS);
    354           std::copy(SDINSYMS, SDINSYMS + SDNUMINSYMS, SBSYMS.begin());
    355           for (size_t i = 0; i < NSYMSDECODED; ++i)
    356             SBSYMS[i + SDNUMINSYMS] = SDNEWSYMS[i].get();
    357           pDecoder->SBSYMS = SBSYMS.data();
    358           pDecoder->SBDEFPIXEL = 0;
    359           pDecoder->SBCOMBOP = JBIG2_COMPOSE_OR;
    360           pDecoder->TRANSPOSED = 0;
    361           pDecoder->REFCORNER = JBIG2_CORNER_TOPLEFT;
    362           pDecoder->SBDSOFFSET = 0;
    363           auto SBHUFFFS = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    364               HuffmanTable_B6, HuffmanTable_B6_Size, HuffmanTable_HTOOB_B6);
    365           auto SBHUFFDS = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    366               HuffmanTable_B8, HuffmanTable_B8_Size, HuffmanTable_HTOOB_B8);
    367           auto SBHUFFDT = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    368               HuffmanTable_B11, HuffmanTable_B11_Size, HuffmanTable_HTOOB_B11);
    369           auto SBHUFFRDW = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    370               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    371           auto SBHUFFRDH = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    372               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    373           auto SBHUFFRDX = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    374               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    375           auto SBHUFFRDY = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    376               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    377           auto SBHUFFRSIZE = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    378               HuffmanTable_B1, HuffmanTable_B1_Size, HuffmanTable_HTOOB_B1);
    379           pDecoder->SBHUFFFS = SBHUFFFS.get();
    380           pDecoder->SBHUFFDS = SBHUFFDS.get();
    381           pDecoder->SBHUFFDT = SBHUFFDT.get();
    382           pDecoder->SBHUFFRDW = SBHUFFRDW.get();
    383           pDecoder->SBHUFFRDH = SBHUFFRDH.get();
    384           pDecoder->SBHUFFRDX = SBHUFFRDX.get();
    385           pDecoder->SBHUFFRDY = SBHUFFRDY.get();
    386           pDecoder->SBHUFFRSIZE = SBHUFFRSIZE.get();
    387           pDecoder->SBRTEMPLATE = SDRTEMPLATE;
    388           pDecoder->SBRAT[0] = SDRAT[0];
    389           pDecoder->SBRAT[1] = SDRAT[1];
    390           pDecoder->SBRAT[2] = SDRAT[2];
    391           pDecoder->SBRAT[3] = SDRAT[3];
    392           BS = pDecoder->decode_Huffman(pStream, grContext->data());
    393           if (!BS)
    394             return nullptr;
    395 
    396         } else if (REFAGGNINST == 1) {
    397           SBNUMSYMS = SDNUMINSYMS + SDNUMNEWSYMS;
    398           nTmp = 1;
    399           while ((uint32_t)(1 << nTmp) < SBNUMSYMS) {
    400             nTmp++;
    401           }
    402           SBSYMCODELEN = (uint8_t)nTmp;
    403           uint32_t uVal = 0;
    404           for (;;) {
    405             if (pStream->read1Bit(&nTmp) != 0)
    406               return nullptr;
    407 
    408             uVal = (uVal << 1) | nTmp;
    409             if (uVal >= SBNUMSYMS)
    410               return nullptr;
    411 
    412             IDI = SBSYMCODELEN == 0 ? uVal : SBNUMSYMS;
    413             if (IDI < SBNUMSYMS)
    414               break;
    415           }
    416           auto SBHUFFRDX = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    417               HuffmanTable_B15, HuffmanTable_B15_Size, HuffmanTable_HTOOB_B15);
    418           auto SBHUFFRSIZE = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    419               HuffmanTable_B1, HuffmanTable_B1_Size, HuffmanTable_HTOOB_B1);
    420           if ((pHuffmanDecoder->decodeAValue(SBHUFFRDX.get(), &RDXI) != 0) ||
    421               (pHuffmanDecoder->decodeAValue(SBHUFFRDX.get(), &RDYI) != 0) ||
    422               (pHuffmanDecoder->decodeAValue(SBHUFFRSIZE.get(), &nVal) != 0)) {
    423             return nullptr;
    424           }
    425           pStream->alignByte();
    426           nTmp = pStream->getOffset();
    427           SBSYMS.resize(SBNUMSYMS);
    428           std::copy(SDINSYMS, SDINSYMS + SDNUMINSYMS, SBSYMS.begin());
    429           for (size_t i = 0; i < NSYMSDECODED; ++i)
    430             SBSYMS[i + SDNUMINSYMS] = SDNEWSYMS[i].get();
    431           auto pGRRD = pdfium::MakeUnique<CJBig2_GRRDProc>();
    432           pGRRD->GRW = SYMWIDTH;
    433           pGRRD->GRH = HCHEIGHT;
    434           pGRRD->GRTEMPLATE = SDRTEMPLATE;
    435           pGRRD->GRREFERENCE = SBSYMS[IDI];
    436           pGRRD->GRREFERENCEDX = RDXI;
    437           pGRRD->GRREFERENCEDY = RDYI;
    438           pGRRD->TPGRON = 0;
    439           pGRRD->GRAT[0] = SDRAT[0];
    440           pGRRD->GRAT[1] = SDRAT[1];
    441           pGRRD->GRAT[2] = SDRAT[2];
    442           pGRRD->GRAT[3] = SDRAT[3];
    443           auto pArithDecoder = pdfium::MakeUnique<CJBig2_ArithDecoder>(pStream);
    444           BS = pGRRD->decode(pArithDecoder.get(), grContext->data());
    445           if (!BS)
    446             return nullptr;
    447 
    448           pStream->alignByte();
    449           pStream->offset(2);
    450           if ((uint32_t)nVal != (pStream->getOffset() - nTmp))
    451             return nullptr;
    452         }
    453         SDNEWSYMS[NSYMSDECODED] = std::move(BS);
    454       }
    455       if (SDREFAGG == 0)
    456         SDNEWSYMWIDTHS[NSYMSDECODED] = SYMWIDTH;
    457       NSYMSDECODED = NSYMSDECODED + 1;
    458     }
    459     if (SDREFAGG == 0) {
    460       if (pHuffmanDecoder->decodeAValue(SDHUFFBMSIZE, (int32_t*)&BMSIZE) != 0)
    461         return nullptr;
    462 
    463       pStream->alignByte();
    464       std::unique_ptr<CJBig2_Image> BHC;
    465       if (BMSIZE == 0) {
    466         stride = (TOTWIDTH + 7) >> 3;
    467         if (pStream->getByteLeft() >= stride * HCHEIGHT) {
    468           BHC = pdfium::MakeUnique<CJBig2_Image>(TOTWIDTH, HCHEIGHT);
    469           for (I = 0; I < HCHEIGHT; I++) {
    470             JBIG2_memcpy(BHC->data() + I * BHC->stride(), pStream->getPointer(),
    471                          stride);
    472             pStream->offset(stride);
    473           }
    474         } else {
    475           return nullptr;
    476         }
    477       } else {
    478         auto pGRD = pdfium::MakeUnique<CJBig2_GRDProc>();
    479         pGRD->MMR = 1;
    480         pGRD->GBW = TOTWIDTH;
    481         pGRD->GBH = HCHEIGHT;
    482         pGRD->Start_decode_MMR(&BHC, pStream);
    483         pStream->alignByte();
    484       }
    485       nTmp = 0;
    486       if (!BHC)
    487         continue;
    488 
    489       for (I = HCFIRSTSYM; I < NSYMSDECODED; ++I) {
    490         SDNEWSYMS[I] = BHC->subImage(nTmp, 0, SDNEWSYMWIDTHS[I], HCHEIGHT);
    491         nTmp += SDNEWSYMWIDTHS[I];
    492       }
    493     }
    494   }
    495   EXINDEX = 0;
    496   CUREXFLAG = 0;
    497   pTable = pdfium::MakeUnique<CJBig2_HuffmanTable>(
    498       HuffmanTable_B1, HuffmanTable_B1_Size, HuffmanTable_HTOOB_B1);
    499   EXFLAGS.resize(SDNUMINSYMS + SDNUMNEWSYMS);
    500   num_ex_syms = 0;
    501   while (EXINDEX < SDNUMINSYMS + SDNUMNEWSYMS) {
    502     if (pHuffmanDecoder->decodeAValue(pTable.get(), (int*)&EXRUNLENGTH) != 0)
    503       return nullptr;
    504 
    505     if (EXINDEX + EXRUNLENGTH > SDNUMINSYMS + SDNUMNEWSYMS)
    506       return nullptr;
    507 
    508     if (EXRUNLENGTH != 0) {
    509       for (I = EXINDEX; I < EXINDEX + EXRUNLENGTH; ++I) {
    510         if (CUREXFLAG)
    511           num_ex_syms++;
    512 
    513         EXFLAGS[I] = CUREXFLAG;
    514       }
    515     }
    516     EXINDEX = EXINDEX + EXRUNLENGTH;
    517     CUREXFLAG = !CUREXFLAG;
    518   }
    519   if (num_ex_syms > SDNUMEXSYMS)
    520     return nullptr;
    521 
    522   I = J = 0;
    523   for (I = 0; I < SDNUMINSYMS + SDNUMNEWSYMS; ++I) {
    524     if (!EXFLAGS[I] || J >= SDNUMEXSYMS)
    525       continue;
    526     if (I < SDNUMINSYMS) {
    527       pDict->AddImage(SDINSYMS[I]
    528                           ? pdfium::MakeUnique<CJBig2_Image>(*SDINSYMS[I])
    529                           : nullptr);
    530     } else {
    531       pDict->AddImage(std::move(SDNEWSYMS[I - SDNUMINSYMS]));
    532     }
    533     ++J;
    534   }
    535   return pDict;
    536 }
    537