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_GrrdProc.h"
8 
9 #include <memory>
10 
11 #include "core/fxcodec/jbig2/JBig2_ArithDecoder.h"
12 #include "core/fxcodec/jbig2/JBig2_BitStream.h"
13 #include "core/fxcodec/jbig2/JBig2_Image.h"
14 
decode(CJBig2_ArithDecoder * pArithDecoder,JBig2ArithCtx * grContext)15 CJBig2_Image* CJBig2_GRRDProc::decode(CJBig2_ArithDecoder* pArithDecoder,
16                                       JBig2ArithCtx* grContext) {
17   if (GRW == 0 || GRH == 0)
18     return new CJBig2_Image(GRW, GRH);
19 
20   if (!GRTEMPLATE) {
21     if ((GRAT[0] == -1) && (GRAT[1] == -1) && (GRAT[2] == -1) &&
22         (GRAT[3] == -1) && (GRREFERENCEDX == 0) &&
23         (GRW == (uint32_t)GRREFERENCE->width())) {
24       return decode_Template0_opt(pArithDecoder, grContext);
25     }
26     return decode_Template0_unopt(pArithDecoder, grContext);
27   }
28 
29   if ((GRREFERENCEDX == 0) && (GRW == (uint32_t)GRREFERENCE->width()))
30     return decode_Template1_opt(pArithDecoder, grContext);
31   return decode_Template1_unopt(pArithDecoder, grContext);
32 }
33 
decode_Template0_unopt(CJBig2_ArithDecoder * pArithDecoder,JBig2ArithCtx * grContext)34 CJBig2_Image* CJBig2_GRRDProc::decode_Template0_unopt(
35     CJBig2_ArithDecoder* pArithDecoder,
36     JBig2ArithCtx* grContext) {
37   int LTP = 0;
38   std::unique_ptr<CJBig2_Image> GRREG(new CJBig2_Image(GRW, GRH));
39   GRREG->fill(0);
40   for (uint32_t h = 0; h < GRH; h++) {
41     if (TPGRON)
42       LTP = LTP ^ pArithDecoder->DECODE(&grContext[0x0010]);
43     if (!LTP) {
44       uint32_t line1 = GRREG->getPixel(1, h - 1);
45       line1 |= GRREG->getPixel(0, h - 1) << 1;
46       uint32_t line2 = 0;
47       uint32_t line3 =
48           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY - 1);
49       line3 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY - 1)
50                << 1;
51       uint32_t line4 =
52           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY);
53       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY) << 1;
54       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY)
55                << 2;
56       uint32_t line5 =
57           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY + 1);
58       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY + 1)
59                << 1;
60       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY + 1)
61                << 2;
62       for (uint32_t w = 0; w < GRW; w++) {
63         uint32_t CONTEXT = line5;
64         CONTEXT |= line4 << 3;
65         CONTEXT |= line3 << 6;
66         CONTEXT |= GRREFERENCE->getPixel(w - GRREFERENCEDX + GRAT[2],
67                                          h - GRREFERENCEDY + GRAT[3])
68                    << 8;
69         CONTEXT |= line2 << 9;
70         CONTEXT |= line1 << 10;
71         CONTEXT |= GRREG->getPixel(w + GRAT[0], h + GRAT[1]) << 12;
72         int bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
73         GRREG->setPixel(w, h, bVal);
74         line1 = ((line1 << 1) | GRREG->getPixel(w + 2, h - 1)) & 0x03;
75         line2 = ((line2 << 1) | bVal) & 0x01;
76         line3 = ((line3 << 1) |
77                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
78                                        h - GRREFERENCEDY - 1)) &
79                 0x03;
80         line4 =
81             ((line4 << 1) |
82              GRREFERENCE->getPixel(w - GRREFERENCEDX + 2, h - GRREFERENCEDY)) &
83             0x07;
84         line5 = ((line5 << 1) |
85                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
86                                        h - GRREFERENCEDY + 1)) &
87                 0x07;
88       }
89     } else {
90       uint32_t line1 = GRREG->getPixel(1, h - 1);
91       line1 |= GRREG->getPixel(0, h - 1) << 1;
92       uint32_t line2 = 0;
93       uint32_t line3 =
94           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY - 1);
95       line3 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY - 1)
96                << 1;
97       uint32_t line4 =
98           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY);
99       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY) << 1;
100       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY)
101                << 2;
102       uint32_t line5 =
103           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY + 1);
104       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY + 1)
105                << 1;
106       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY + 1)
107                << 2;
108       for (uint32_t w = 0; w < GRW; w++) {
109         int bVal = GRREFERENCE->getPixel(w, h);
110         if (!(TPGRON && (bVal == GRREFERENCE->getPixel(w - 1, h - 1)) &&
111               (bVal == GRREFERENCE->getPixel(w, h - 1)) &&
112               (bVal == GRREFERENCE->getPixel(w + 1, h - 1)) &&
113               (bVal == GRREFERENCE->getPixel(w - 1, h)) &&
114               (bVal == GRREFERENCE->getPixel(w + 1, h)) &&
115               (bVal == GRREFERENCE->getPixel(w - 1, h + 1)) &&
116               (bVal == GRREFERENCE->getPixel(w, h + 1)) &&
117               (bVal == GRREFERENCE->getPixel(w + 1, h + 1)))) {
118           uint32_t CONTEXT = line5;
119           CONTEXT |= line4 << 3;
120           CONTEXT |= line3 << 6;
121           CONTEXT |= GRREFERENCE->getPixel(w - GRREFERENCEDX + GRAT[2],
122                                            h - GRREFERENCEDY + GRAT[3])
123                      << 8;
124           CONTEXT |= line2 << 9;
125           CONTEXT |= line1 << 10;
126           CONTEXT |= GRREG->getPixel(w + GRAT[0], h + GRAT[1]) << 12;
127           bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
128         }
129         GRREG->setPixel(w, h, bVal);
130         line1 = ((line1 << 1) | GRREG->getPixel(w + 2, h - 1)) & 0x03;
131         line2 = ((line2 << 1) | bVal) & 0x01;
132         line3 = ((line3 << 1) |
133                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
134                                        h - GRREFERENCEDY - 1)) &
135                 0x03;
136         line4 =
137             ((line4 << 1) |
138              GRREFERENCE->getPixel(w - GRREFERENCEDX + 2, h - GRREFERENCEDY)) &
139             0x07;
140         line5 = ((line5 << 1) |
141                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
142                                        h - GRREFERENCEDY + 1)) &
143                 0x07;
144       }
145     }
146   }
147   return GRREG.release();
148 }
149 
decode_Template0_opt(CJBig2_ArithDecoder * pArithDecoder,JBig2ArithCtx * grContext)150 CJBig2_Image* CJBig2_GRRDProc::decode_Template0_opt(
151     CJBig2_ArithDecoder* pArithDecoder,
152     JBig2ArithCtx* grContext) {
153   if (!GRREFERENCE->m_pData)
154     return nullptr;
155 
156   int32_t iGRW = static_cast<int32_t>(GRW);
157   int32_t iGRH = static_cast<int32_t>(GRH);
158   std::unique_ptr<CJBig2_Image> GRREG(new CJBig2_Image(iGRW, iGRH));
159   if (!GRREG->m_pData)
160     return nullptr;
161 
162   int LTP = 0;
163   uint8_t* pLine = GRREG->m_pData;
164   uint8_t* pLineR = GRREFERENCE->m_pData;
165   intptr_t nStride = GRREG->stride();
166   intptr_t nStrideR = GRREFERENCE->stride();
167   int32_t GRWR = GRREFERENCE->width();
168   int32_t GRHR = GRREFERENCE->height();
169   if (GRREFERENCEDY < -GRHR + 1 || GRREFERENCEDY > GRHR - 1)
170     GRREFERENCEDY = 0;
171   intptr_t nOffset = -GRREFERENCEDY * nStrideR;
172   for (int32_t h = 0; h < iGRH; h++) {
173     if (TPGRON)
174       LTP = LTP ^ pArithDecoder->DECODE(&grContext[0x0010]);
175     uint32_t line1 = (h > 0) ? pLine[-nStride] << 4 : 0;
176     int32_t reference_h = h - GRREFERENCEDY;
177     bool line1_r_ok = (reference_h > 0 && reference_h < GRHR + 1);
178     bool line2_r_ok = (reference_h > -1 && reference_h < GRHR);
179     bool line3_r_ok = (reference_h > -2 && reference_h < GRHR - 1);
180     uint32_t line1_r = line1_r_ok ? pLineR[nOffset - nStrideR] : 0;
181     uint32_t line2_r = line2_r_ok ? pLineR[nOffset] : 0;
182     uint32_t line3_r = line3_r_ok ? pLineR[nOffset + nStrideR] : 0;
183     if (!LTP) {
184       uint32_t CONTEXT = (line1 & 0x1c00) | (line1_r & 0x01c0) |
185                          ((line2_r >> 3) & 0x0038) | ((line3_r >> 6) & 0x0007);
186       for (int32_t w = 0; w < iGRW; w += 8) {
187         int32_t nBits = iGRW - w > 8 ? 8 : iGRW - w;
188         if (h > 0) {
189           line1 = (line1 << 8) |
190                   (w + 8 < iGRW ? pLine[-nStride + (w >> 3) + 1] << 4 : 0);
191         }
192         if (h > GRHR + GRREFERENCEDY + 1) {
193           line1_r = 0;
194           line2_r = 0;
195           line3_r = 0;
196         } else {
197           if (line1_r_ok) {
198             line1_r =
199                 (line1_r << 8) |
200                 (w + 8 < GRWR ? pLineR[nOffset - nStrideR + (w >> 3) + 1] : 0);
201           }
202           if (line2_r_ok) {
203             line2_r = (line2_r << 8) |
204                       (w + 8 < GRWR ? pLineR[nOffset + (w >> 3) + 1] : 0);
205           }
206           if (line3_r_ok) {
207             line3_r =
208                 (line3_r << 8) |
209                 (w + 8 < GRWR ? pLineR[nOffset + nStrideR + (w >> 3) + 1] : 0);
210           } else {
211             line3_r = 0;
212           }
213         }
214         uint8_t cVal = 0;
215         for (int32_t k = 0; k < nBits; k++) {
216           int bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
217           cVal |= bVal << (7 - k);
218           CONTEXT = ((CONTEXT & 0x0cdb) << 1) | (bVal << 9) |
219                     ((line1 >> (7 - k)) & 0x0400) |
220                     ((line1_r >> (7 - k)) & 0x0040) |
221                     ((line2_r >> (10 - k)) & 0x0008) |
222                     ((line3_r >> (13 - k)) & 0x0001);
223         }
224         pLine[w >> 3] = cVal;
225       }
226     } else {
227       uint32_t CONTEXT = (line1 & 0x1c00) | (line1_r & 0x01c0) |
228                          ((line2_r >> 3) & 0x0038) | ((line3_r >> 6) & 0x0007);
229       for (int32_t w = 0; w < iGRW; w += 8) {
230         int32_t nBits = iGRW - w > 8 ? 8 : iGRW - w;
231         if (h > 0) {
232           line1 = (line1 << 8) |
233                   (w + 8 < iGRW ? pLine[-nStride + (w >> 3) + 1] << 4 : 0);
234         }
235         if (line1_r_ok) {
236           line1_r =
237               (line1_r << 8) |
238               (w + 8 < GRWR ? pLineR[nOffset - nStrideR + (w >> 3) + 1] : 0);
239         }
240         if (line2_r_ok) {
241           line2_r = (line2_r << 8) |
242                     (w + 8 < GRWR ? pLineR[nOffset + (w >> 3) + 1] : 0);
243         }
244         if (line3_r_ok) {
245           line3_r =
246               (line3_r << 8) |
247               (w + 8 < GRWR ? pLineR[nOffset + nStrideR + (w >> 3) + 1] : 0);
248         } else {
249           line3_r = 0;
250         }
251         uint8_t cVal = 0;
252         for (int32_t k = 0; k < nBits; k++) {
253           int bVal = GRREFERENCE->getPixel(w + k, h);
254           if (!(TPGRON && (bVal == GRREFERENCE->getPixel(w + k - 1, h - 1)) &&
255                 (bVal == GRREFERENCE->getPixel(w + k, h - 1)) &&
256                 (bVal == GRREFERENCE->getPixel(w + k + 1, h - 1)) &&
257                 (bVal == GRREFERENCE->getPixel(w + k - 1, h)) &&
258                 (bVal == GRREFERENCE->getPixel(w + k + 1, h)) &&
259                 (bVal == GRREFERENCE->getPixel(w + k - 1, h + 1)) &&
260                 (bVal == GRREFERENCE->getPixel(w + k, h + 1)) &&
261                 (bVal == GRREFERENCE->getPixel(w + k + 1, h + 1)))) {
262             bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
263           }
264           cVal |= bVal << (7 - k);
265           CONTEXT = ((CONTEXT & 0x0cdb) << 1) | (bVal << 9) |
266                     ((line1 >> (7 - k)) & 0x0400) |
267                     ((line1_r >> (7 - k)) & 0x0040) |
268                     ((line2_r >> (10 - k)) & 0x0008) |
269                     ((line3_r >> (13 - k)) & 0x0001);
270         }
271         pLine[w >> 3] = cVal;
272       }
273     }
274     pLine += nStride;
275     if (h < GRHR + GRREFERENCEDY) {
276       pLineR += nStrideR;
277     }
278   }
279   return GRREG.release();
280 }
281 
decode_Template1_unopt(CJBig2_ArithDecoder * pArithDecoder,JBig2ArithCtx * grContext)282 CJBig2_Image* CJBig2_GRRDProc::decode_Template1_unopt(
283     CJBig2_ArithDecoder* pArithDecoder,
284     JBig2ArithCtx* grContext) {
285   int LTP = 0;
286   std::unique_ptr<CJBig2_Image> GRREG(new CJBig2_Image(GRW, GRH));
287   GRREG->fill(0);
288   for (uint32_t h = 0; h < GRH; h++) {
289     if (TPGRON)
290       LTP = LTP ^ pArithDecoder->DECODE(&grContext[0x0008]);
291     if (!LTP) {
292       uint32_t line1 = GRREG->getPixel(1, h - 1);
293       line1 |= GRREG->getPixel(0, h - 1) << 1;
294       line1 |= GRREG->getPixel(-1, h - 1) << 2;
295       uint32_t line2 = 0;
296       uint32_t line3 =
297           GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY - 1);
298       uint32_t line4 =
299           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY);
300       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY) << 1;
301       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY)
302                << 2;
303       uint32_t line5 =
304           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY + 1);
305       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY + 1)
306                << 1;
307       for (uint32_t w = 0; w < GRW; w++) {
308         uint32_t CONTEXT = line5;
309         CONTEXT |= line4 << 2;
310         CONTEXT |= line3 << 5;
311         CONTEXT |= line2 << 6;
312         CONTEXT |= line1 << 7;
313         int bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
314         GRREG->setPixel(w, h, bVal);
315         line1 = ((line1 << 1) | GRREG->getPixel(w + 2, h - 1)) & 0x07;
316         line2 = ((line2 << 1) | bVal) & 0x01;
317         line3 = ((line3 << 1) |
318                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 1,
319                                        h - GRREFERENCEDY - 1)) &
320                 0x01;
321         line4 =
322             ((line4 << 1) |
323              GRREFERENCE->getPixel(w - GRREFERENCEDX + 2, h - GRREFERENCEDY)) &
324             0x07;
325         line5 = ((line5 << 1) |
326                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
327                                        h - GRREFERENCEDY + 1)) &
328                 0x03;
329       }
330     } else {
331       uint32_t line1 = GRREG->getPixel(1, h - 1);
332       line1 |= GRREG->getPixel(0, h - 1) << 1;
333       line1 |= GRREG->getPixel(-1, h - 1) << 2;
334       uint32_t line2 = 0;
335       uint32_t line3 =
336           GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY - 1);
337       uint32_t line4 =
338           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY);
339       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY) << 1;
340       line4 |= GRREFERENCE->getPixel(-GRREFERENCEDX - 1, h - GRREFERENCEDY)
341                << 2;
342       uint32_t line5 =
343           GRREFERENCE->getPixel(-GRREFERENCEDX + 1, h - GRREFERENCEDY + 1);
344       line5 |= GRREFERENCE->getPixel(-GRREFERENCEDX, h - GRREFERENCEDY + 1)
345                << 1;
346       for (uint32_t w = 0; w < GRW; w++) {
347         int bVal = GRREFERENCE->getPixel(w, h);
348         if (!(TPGRON && (bVal == GRREFERENCE->getPixel(w - 1, h - 1)) &&
349               (bVal == GRREFERENCE->getPixel(w, h - 1)) &&
350               (bVal == GRREFERENCE->getPixel(w + 1, h - 1)) &&
351               (bVal == GRREFERENCE->getPixel(w - 1, h)) &&
352               (bVal == GRREFERENCE->getPixel(w + 1, h)) &&
353               (bVal == GRREFERENCE->getPixel(w - 1, h + 1)) &&
354               (bVal == GRREFERENCE->getPixel(w, h + 1)) &&
355               (bVal == GRREFERENCE->getPixel(w + 1, h + 1)))) {
356           uint32_t CONTEXT = line5;
357           CONTEXT |= line4 << 2;
358           CONTEXT |= line3 << 5;
359           CONTEXT |= line2 << 6;
360           CONTEXT |= line1 << 7;
361           bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
362         }
363         GRREG->setPixel(w, h, bVal);
364         line1 = ((line1 << 1) | GRREG->getPixel(w + 2, h - 1)) & 0x07;
365         line2 = ((line2 << 1) | bVal) & 0x01;
366         line3 = ((line3 << 1) |
367                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 1,
368                                        h - GRREFERENCEDY - 1)) &
369                 0x01;
370         line4 =
371             ((line4 << 1) |
372              GRREFERENCE->getPixel(w - GRREFERENCEDX + 2, h - GRREFERENCEDY)) &
373             0x07;
374         line5 = ((line5 << 1) |
375                  GRREFERENCE->getPixel(w - GRREFERENCEDX + 2,
376                                        h - GRREFERENCEDY + 1)) &
377                 0x03;
378       }
379     }
380   }
381   return GRREG.release();
382 }
383 
decode_Template1_opt(CJBig2_ArithDecoder * pArithDecoder,JBig2ArithCtx * grContext)384 CJBig2_Image* CJBig2_GRRDProc::decode_Template1_opt(
385     CJBig2_ArithDecoder* pArithDecoder,
386     JBig2ArithCtx* grContext) {
387   if (!GRREFERENCE->m_pData)
388     return nullptr;
389 
390   int32_t iGRW = static_cast<int32_t>(GRW);
391   int32_t iGRH = static_cast<int32_t>(GRH);
392   std::unique_ptr<CJBig2_Image> GRREG(new CJBig2_Image(iGRW, iGRH));
393   if (!GRREG->m_pData)
394     return nullptr;
395 
396   int LTP = 0;
397   uint8_t* pLine = GRREG->m_pData;
398   uint8_t* pLineR = GRREFERENCE->m_pData;
399   intptr_t nStride = GRREG->stride();
400   intptr_t nStrideR = GRREFERENCE->stride();
401   int32_t GRWR = GRREFERENCE->width();
402   int32_t GRHR = GRREFERENCE->height();
403   if (GRREFERENCEDY < -GRHR + 1 || GRREFERENCEDY > GRHR - 1) {
404     GRREFERENCEDY = 0;
405   }
406   intptr_t nOffset = -GRREFERENCEDY * nStrideR;
407   for (int32_t h = 0; h < iGRH; h++) {
408     if (TPGRON)
409       LTP = LTP ^ pArithDecoder->DECODE(&grContext[0x0008]);
410     uint32_t line1 = (h > 0) ? pLine[-nStride] << 1 : 0;
411     int32_t reference_h = h - GRREFERENCEDY;
412     bool line1_r_ok = (reference_h > 0 && reference_h < GRHR + 1);
413     bool line2_r_ok = (reference_h > -1 && reference_h < GRHR);
414     bool line3_r_ok = (reference_h > -2 && reference_h < GRHR - 1);
415     uint32_t line1_r = line1_r_ok ? pLineR[nOffset - nStrideR] : 0;
416     uint32_t line2_r = line2_r_ok ? pLineR[nOffset] : 0;
417     uint32_t line3_r = line3_r_ok ? pLineR[nOffset + nStrideR] : 0;
418     if (!LTP) {
419       uint32_t CONTEXT = (line1 & 0x0380) | ((line1_r >> 2) & 0x0020) |
420                          ((line2_r >> 4) & 0x001c) | ((line3_r >> 6) & 0x0003);
421       for (int32_t w = 0; w < iGRW; w += 8) {
422         int32_t nBits = iGRW - w > 8 ? 8 : iGRW - w;
423         if (h > 0)
424           line1 = (line1 << 8) |
425                   (w + 8 < iGRW ? pLine[-nStride + (w >> 3) + 1] << 1 : 0);
426         if (line1_r_ok)
427           line1_r =
428               (line1_r << 8) |
429               (w + 8 < GRWR ? pLineR[nOffset - nStrideR + (w >> 3) + 1] : 0);
430         if (line2_r_ok)
431           line2_r = (line2_r << 8) |
432                     (w + 8 < GRWR ? pLineR[nOffset + (w >> 3) + 1] : 0);
433         if (line3_r_ok) {
434           line3_r =
435               (line3_r << 8) |
436               (w + 8 < GRWR ? pLineR[nOffset + nStrideR + (w >> 3) + 1] : 0);
437         } else {
438           line3_r = 0;
439         }
440         uint8_t cVal = 0;
441         for (int32_t k = 0; k < nBits; k++) {
442           int bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
443           cVal |= bVal << (7 - k);
444           CONTEXT = ((CONTEXT & 0x018d) << 1) | (bVal << 6) |
445                     ((line1 >> (7 - k)) & 0x0080) |
446                     ((line1_r >> (9 - k)) & 0x0020) |
447                     ((line2_r >> (11 - k)) & 0x0004) |
448                     ((line3_r >> (13 - k)) & 0x0001);
449         }
450         pLine[w >> 3] = cVal;
451       }
452     } else {
453       uint32_t CONTEXT = (line1 & 0x0380) | ((line1_r >> 2) & 0x0020) |
454                          ((line2_r >> 4) & 0x001c) | ((line3_r >> 6) & 0x0003);
455       for (int32_t w = 0; w < iGRW; w += 8) {
456         int32_t nBits = iGRW - w > 8 ? 8 : iGRW - w;
457         if (h > 0)
458           line1 = (line1 << 8) |
459                   (w + 8 < iGRW ? pLine[-nStride + (w >> 3) + 1] << 1 : 0);
460         if (line1_r_ok)
461           line1_r =
462               (line1_r << 8) |
463               (w + 8 < GRWR ? pLineR[nOffset - nStrideR + (w >> 3) + 1] : 0);
464         if (line2_r_ok)
465           line2_r = (line2_r << 8) |
466                     (w + 8 < GRWR ? pLineR[nOffset + (w >> 3) + 1] : 0);
467         if (line3_r_ok) {
468           line3_r =
469               (line3_r << 8) |
470               (w + 8 < GRWR ? pLineR[nOffset + nStrideR + (w >> 3) + 1] : 0);
471         } else {
472           line3_r = 0;
473         }
474         uint8_t cVal = 0;
475         for (int32_t k = 0; k < nBits; k++) {
476           int bVal = GRREFERENCE->getPixel(w + k, h);
477           if (!(TPGRON && (bVal == GRREFERENCE->getPixel(w + k - 1, h - 1)) &&
478                 (bVal == GRREFERENCE->getPixel(w + k, h - 1)) &&
479                 (bVal == GRREFERENCE->getPixel(w + k + 1, h - 1)) &&
480                 (bVal == GRREFERENCE->getPixel(w + k - 1, h)) &&
481                 (bVal == GRREFERENCE->getPixel(w + k + 1, h)) &&
482                 (bVal == GRREFERENCE->getPixel(w + k - 1, h + 1)) &&
483                 (bVal == GRREFERENCE->getPixel(w + k, h + 1)) &&
484                 (bVal == GRREFERENCE->getPixel(w + k + 1, h + 1)))) {
485             bVal = pArithDecoder->DECODE(&grContext[CONTEXT]);
486           }
487           cVal |= bVal << (7 - k);
488           CONTEXT = ((CONTEXT & 0x018d) << 1) | (bVal << 6) |
489                     ((line1 >> (7 - k)) & 0x0080) |
490                     ((line1_r >> (9 - k)) & 0x0020) |
491                     ((line2_r >> (11 - k)) & 0x0004) |
492                     ((line3_r >> (13 - k)) & 0x0001);
493         }
494         pLine[w >> 3] = cVal;
495       }
496     }
497     pLine += nStride;
498     if (h < GRHR + GRREFERENCEDY) {
499       pLineR += nStrideR;
500     }
501   }
502   return GRREG.release();
503 }
504