File: transupp.c

package info (click to toggle)
fbi 2.10-3
  • links: PTS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 1,780 kB
  • sloc: ansic: 22,994; sh: 120; perl: 12; makefile: 6
file content (1630 lines) | stat: -rw-r--r-- 58,205 bytes parent folder | download | duplicates (9)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
/*
 * transupp.c
 *
 * This file was part of the Independent JPEG Group's software:
 * Copyright (C) 1997-2011, Thomas G. Lane, Guido Vollbeding.
 * libjpeg-turbo Modifications:
 * Copyright (C) 2010, D. R. Commander.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains image transformation routines and other utility code
 * used by the jpegtran sample application.  These are NOT part of the core
 * JPEG library.  But we keep these routines separate from jpegtran.c to
 * ease the task of maintaining jpegtran-like programs that have other user
 * interfaces.
 */

/* Although this file really shouldn't have access to the library internals,
 * it's helpful to let it call jround_up() and jcopy_block_row().
 */
#define JPEG_INTERNALS

#include "jinclude.h"
#include "jpeglib.h"
#include "transupp.h"		/* My own external interface */
#include "jpegcomp.h"
#include <ctype.h>		/* to declare isdigit() */


#if JPEG_LIB_VERSION >= 70
#define dstinfo_min_DCT_h_scaled_size dstinfo->min_DCT_h_scaled_size
#define dstinfo_min_DCT_v_scaled_size dstinfo->min_DCT_v_scaled_size
#else
#define dstinfo_min_DCT_h_scaled_size DCTSIZE
#define dstinfo_min_DCT_v_scaled_size DCTSIZE
#endif


#if TRANSFORMS_SUPPORTED

/*
 * Lossless image transformation routines.  These routines work on DCT
 * coefficient arrays and thus do not require any lossy decompression
 * or recompression of the image.
 * Thanks to Guido Vollbeding for the initial design and code of this feature,
 * and to Ben Jackson for introducing the cropping feature.
 *
 * Horizontal flipping is done in-place, using a single top-to-bottom
 * pass through the virtual source array.  It will thus be much the
 * fastest option for images larger than main memory.
 *
 * The other routines require a set of destination virtual arrays, so they
 * need twice as much memory as jpegtran normally does.  The destination
 * arrays are always written in normal scan order (top to bottom) because
 * the virtual array manager expects this.  The source arrays will be scanned
 * in the corresponding order, which means multiple passes through the source
 * arrays for most of the transforms.  That could result in much thrashing
 * if the image is larger than main memory.
 *
 * If cropping or trimming is involved, the destination arrays may be smaller
 * than the source arrays.  Note it is not possible to do horizontal flip
 * in-place when a nonzero Y crop offset is specified, since we'd have to move
 * data from one block row to another but the virtual array manager doesn't
 * guarantee we can touch more than one row at a time.  So in that case,
 * we have to use a separate destination array.
 *
 * Some notes about the operating environment of the individual transform
 * routines:
 * 1. Both the source and destination virtual arrays are allocated from the
 *    source JPEG object, and therefore should be manipulated by calling the
 *    source's memory manager.
 * 2. The destination's component count should be used.  It may be smaller
 *    than the source's when forcing to grayscale.
 * 3. Likewise the destination's sampling factors should be used.  When
 *    forcing to grayscale the destination's sampling factors will be all 1,
 *    and we may as well take that as the effective iMCU size.
 * 4. When "trim" is in effect, the destination's dimensions will be the
 *    trimmed values but the source's will be untrimmed.
 * 5. When "crop" is in effect, the destination's dimensions will be the
 *    cropped values but the source's will be uncropped.  Each transform
 *    routine is responsible for picking up source data starting at the
 *    correct X and Y offset for the crop region.  (The X and Y offsets
 *    passed to the transform routines are measured in iMCU blocks of the
 *    destination.)
 * 6. All the routines assume that the source and destination buffers are
 *    padded out to a full iMCU boundary.  This is true, although for the
 *    source buffer it is an undocumented property of jdcoefct.c.
 */


LOCAL(void)
do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	 jvirt_barray_ptr *src_coef_arrays,
	 jvirt_barray_ptr *dst_coef_arrays)
/* Crop.  This is only used when no rotate/flip is requested with the crop. */
{
  JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
  int ci, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  jpeg_component_info *compptr;

  /* We simply have to copy the right amount of data (the destination's
   * image size) starting at the given X and Y offsets in the source.
   */
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      src_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, src_coef_arrays[ci],
	 dst_blk_y + y_crop_blocks,
	 (JDIMENSION) compptr->v_samp_factor, FALSE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
			dst_buffer[offset_y],
			compptr->width_in_blocks);
      }
    }
  }
}


LOCAL(void)
do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
		   JDIMENSION x_crop_offset,
		   jvirt_barray_ptr *src_coef_arrays)
/* Horizontal flip; done in-place, so no separate dest array is required.
 * NB: this only works when y_crop_offset is zero.
 */
{
  JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;
  int ci, k, offset_y;
  JBLOCKARRAY buffer;
  JCOEFPTR ptr1, ptr2;
  JCOEF temp1, temp2;
  jpeg_component_info *compptr;

  /* Horizontal mirroring of DCT blocks is accomplished by swapping
   * pairs of blocks in-place.  Within a DCT block, we perform horizontal
   * mirroring by changing the signs of odd-numbered columns.
   * Partial iMCUs at the right edge are left untouched.
   */
  MCU_cols = srcinfo->output_width /
    (dstinfo->max_h_samp_factor * dstinfo_min_DCT_h_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    for (blk_y = 0; blk_y < compptr->height_in_blocks;
	 blk_y += compptr->v_samp_factor) {
      buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	/* Do the mirroring */
	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
	  ptr1 = buffer[offset_y][blk_x];
	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];
	  /* this unrolled loop doesn't need to know which row it's on... */
	  for (k = 0; k < DCTSIZE2; k += 2) {
	    temp1 = *ptr1;	/* swap even column */
	    temp2 = *ptr2;
	    *ptr1++ = temp2;
	    *ptr2++ = temp1;
	    temp1 = *ptr1;	/* swap odd column with sign change */
	    temp2 = *ptr2;
	    *ptr1++ = -temp2;
	    *ptr2++ = -temp1;
	  }
	}
	if (x_crop_blocks > 0) {
	  /* Now left-justify the portion of the data to be kept.
	   * We can't use a single jcopy_block_row() call because that routine
	   * depends on memcpy(), whose behavior is unspecified for overlapping
	   * source and destination areas.  Sigh.
	   */
	  for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
	    jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,
			    buffer[offset_y] + blk_x,
			    (JDIMENSION) 1);
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	   jvirt_barray_ptr *src_coef_arrays,
	   jvirt_barray_ptr *dst_coef_arrays)
/* Horizontal flip in general cropping case */
{
  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, k, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JBLOCKROW src_row_ptr, dst_row_ptr;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Here we must output into a separate array because we can't touch
   * different rows of a single virtual array simultaneously.  Otherwise,
   * this is essentially the same as the routine above.
   */
  MCU_cols = srcinfo->output_width /
    (dstinfo->max_h_samp_factor * dstinfo_min_DCT_h_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      src_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, src_coef_arrays[ci],
	 dst_blk_y + y_crop_blocks,
	 (JDIMENSION) compptr->v_samp_factor, FALSE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	dst_row_ptr = dst_buffer[offset_y];
	src_row_ptr = src_buffer[offset_y];
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
	  if (x_crop_blocks + dst_blk_x < comp_width) {
	    /* Do the mirrorable blocks */
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
	    /* this unrolled loop doesn't need to know which row it's on... */
	    for (k = 0; k < DCTSIZE2; k += 2) {
	      *dst_ptr++ = *src_ptr++;	 /* copy even column */
	      *dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
	    }
	  } else {
	    /* Copy last partial block(s) verbatim */
	    jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
			    dst_row_ptr + dst_blk_x,
			    (JDIMENSION) 1);
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	   jvirt_barray_ptr *src_coef_arrays,
	   jvirt_barray_ptr *dst_coef_arrays)
/* Vertical flip */
{
  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JBLOCKROW src_row_ptr, dst_row_ptr;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* We output into a separate array because we can't touch different
   * rows of the source virtual array simultaneously.  Otherwise, this
   * is a pretty straightforward analog of horizontal flip.
   * Within a DCT block, vertical mirroring is done by changing the signs
   * of odd-numbered rows.
   * Partial iMCUs at the bottom edge are copied verbatim.
   */
  MCU_rows = srcinfo->output_height /
    (dstinfo->max_v_samp_factor * dstinfo_min_DCT_v_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_height = MCU_rows * compptr->v_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      if (y_crop_blocks + dst_blk_y < comp_height) {
	/* Row is within the mirrorable area. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   comp_height - y_crop_blocks - dst_blk_y -
	   (JDIMENSION) compptr->v_samp_factor,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      } else {
	/* Bottom-edge blocks will be copied verbatim. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   dst_blk_y + y_crop_blocks,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      }
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	if (y_crop_blocks + dst_blk_y < comp_height) {
	  /* Row is within the mirrorable area. */
	  dst_row_ptr = dst_buffer[offset_y];
	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
	  src_row_ptr += x_crop_blocks;
	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	       dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    src_ptr = src_row_ptr[dst_blk_x];
	    for (i = 0; i < DCTSIZE; i += 2) {
	      /* copy even row */
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = *src_ptr++;
	      /* copy odd row with sign change */
	      for (j = 0; j < DCTSIZE; j++)
		*dst_ptr++ = - *src_ptr++;
	    }
	  }
	} else {
	  /* Just copy row verbatim. */
	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
			  dst_buffer[offset_y],
			  compptr->width_in_blocks);
	}
      }
    }
  }
}


LOCAL(void)
do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	      JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	      jvirt_barray_ptr *src_coef_arrays,
	      jvirt_barray_ptr *dst_coef_arrays)
/* Transpose source into destination */
{
  JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Transposing pixels within a block just requires transposing the
   * DCT coefficients.
   * Partial iMCUs at the edges require no special treatment; we simply
   * process all the available DCT blocks for every component.
   */
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	     dst_blk_x + x_crop_blocks,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];
	    for (i = 0; i < DCTSIZE; i++)
	      for (j = 0; j < DCTSIZE; j++)
		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	   jvirt_barray_ptr *src_coef_arrays,
	   jvirt_barray_ptr *dst_coef_arrays)
/* 90 degree rotation is equivalent to
 *   1. Transposing the image;
 *   2. Horizontal mirroring.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs
   * at the (output) right edge properly.  They just get transposed and
   * not mirrored.
   */
  MCU_cols = srcinfo->output_height /
    (dstinfo->max_h_samp_factor * dstinfo_min_DCT_h_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  if (x_crop_blocks + dst_blk_x < comp_width) {
	    /* Block is within the mirrorable area. */
	    src_buffer = (*srcinfo->mem->access_virt_barray)
	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	       comp_width - x_crop_blocks - dst_blk_x -
	       (JDIMENSION) compptr->h_samp_factor,
	       (JDIMENSION) compptr->h_samp_factor, FALSE);
	  } else {
	    /* Edge blocks are transposed but not mirrored. */
	    src_buffer = (*srcinfo->mem->access_virt_barray)
	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	       dst_blk_x + x_crop_blocks,
	       (JDIMENSION) compptr->h_samp_factor, FALSE);
	  }
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    if (x_crop_blocks + dst_blk_x < comp_width) {
	      /* Block is within the mirrorable area. */
	      src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
		[dst_blk_y + offset_y + y_crop_blocks];
	      for (i = 0; i < DCTSIZE; i++) {
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		i++;
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
	      }
	    } else {
	      /* Edge blocks are transposed but not mirrored. */
	      src_ptr = src_buffer[offset_x]
		[dst_blk_y + offset_y + y_crop_blocks];
	      for (i = 0; i < DCTSIZE; i++)
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	    }
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	    jvirt_barray_ptr *src_coef_arrays,
	    jvirt_barray_ptr *dst_coef_arrays)
/* 270 degree rotation is equivalent to
 *   1. Horizontal mirroring;
 *   2. Transposing the image.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs
   * at the (output) bottom edge properly.  They just get transposed and
   * not mirrored.
   */
  MCU_rows = srcinfo->output_width /
    (dstinfo->max_v_samp_factor * dstinfo_min_DCT_v_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_height = MCU_rows * compptr->v_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  src_buffer = (*srcinfo->mem->access_virt_barray)
	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	     dst_blk_x + x_crop_blocks,
	     (JDIMENSION) compptr->h_samp_factor, FALSE);
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    if (y_crop_blocks + dst_blk_y < comp_height) {
	      /* Block is within the mirrorable area. */
	      src_ptr = src_buffer[offset_x]
		[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
	      for (i = 0; i < DCTSIZE; i++) {
		for (j = 0; j < DCTSIZE; j++) {
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  j++;
		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		}
	      }
	    } else {
	      /* Edge blocks are transposed but not mirrored. */
	      src_ptr = src_buffer[offset_x]
		[dst_blk_y + offset_y + y_crop_blocks];
	      for (i = 0; i < DCTSIZE; i++)
		for (j = 0; j < DCTSIZE; j++)
		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	    }
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	    jvirt_barray_ptr *src_coef_arrays,
	    jvirt_barray_ptr *dst_coef_arrays)
/* 180 degree rotation is equivalent to
 *   1. Vertical mirroring;
 *   2. Horizontal mirroring.
 * These two steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JBLOCKROW src_row_ptr, dst_row_ptr;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  MCU_cols = srcinfo->output_width /
    (dstinfo->max_h_samp_factor * dstinfo_min_DCT_h_scaled_size);
  MCU_rows = srcinfo->output_height /
    (dstinfo->max_v_samp_factor * dstinfo_min_DCT_v_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    comp_height = MCU_rows * compptr->v_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      if (y_crop_blocks + dst_blk_y < comp_height) {
	/* Row is within the vertically mirrorable area. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   comp_height - y_crop_blocks - dst_blk_y -
	   (JDIMENSION) compptr->v_samp_factor,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      } else {
	/* Bottom-edge rows are only mirrored horizontally. */
	src_buffer = (*srcinfo->mem->access_virt_barray)
	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	   dst_blk_y + y_crop_blocks,
	   (JDIMENSION) compptr->v_samp_factor, FALSE);
      }
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	dst_row_ptr = dst_buffer[offset_y];
	if (y_crop_blocks + dst_blk_y < comp_height) {
	  /* Row is within the mirrorable area. */
	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
	    dst_ptr = dst_row_ptr[dst_blk_x];
	    if (x_crop_blocks + dst_blk_x < comp_width) {
	      /* Process the blocks that can be mirrored both ways. */
	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
	      for (i = 0; i < DCTSIZE; i += 2) {
		/* For even row, negate every odd column. */
		for (j = 0; j < DCTSIZE; j += 2) {
		  *dst_ptr++ = *src_ptr++;
		  *dst_ptr++ = - *src_ptr++;
		}
		/* For odd row, negate every even column. */
		for (j = 0; j < DCTSIZE; j += 2) {
		  *dst_ptr++ = - *src_ptr++;
		  *dst_ptr++ = *src_ptr++;
		}
	      }
	    } else {
	      /* Any remaining right-edge blocks are only mirrored vertically. */
	      src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];
	      for (i = 0; i < DCTSIZE; i += 2) {
		for (j = 0; j < DCTSIZE; j++)
		  *dst_ptr++ = *src_ptr++;
		for (j = 0; j < DCTSIZE; j++)
		  *dst_ptr++ = - *src_ptr++;
	      }
	    }
	  }
	} else {
	  /* Remaining rows are just mirrored horizontally. */
	  src_row_ptr = src_buffer[offset_y];
	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
	    if (x_crop_blocks + dst_blk_x < comp_width) {
	      /* Process the blocks that can be mirrored. */
	      dst_ptr = dst_row_ptr[dst_blk_x];
	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
	      for (i = 0; i < DCTSIZE2; i += 2) {
		*dst_ptr++ = *src_ptr++;
		*dst_ptr++ = - *src_ptr++;
	      }
	    } else {
	      /* Any remaining right-edge blocks are only copied. */
	      jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
			      dst_row_ptr + dst_blk_x,
			      (JDIMENSION) 1);
	    }
	  }
	}
      }
    }
  }
}


LOCAL(void)
do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
	       JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
	       jvirt_barray_ptr *src_coef_arrays,
	       jvirt_barray_ptr *dst_coef_arrays)
/* Transverse transpose is equivalent to
 *   1. 180 degree rotation;
 *   2. Transposition;
 * or
 *   1. Horizontal mirroring;
 *   2. Transposition;
 *   3. Horizontal mirroring.
 * These steps are merged into a single processing routine.
 */
{
  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
  JDIMENSION x_crop_blocks, y_crop_blocks;
  int ci, i, j, offset_x, offset_y;
  JBLOCKARRAY src_buffer, dst_buffer;
  JCOEFPTR src_ptr, dst_ptr;
  jpeg_component_info *compptr;

  MCU_cols = srcinfo->output_height /
    (dstinfo->max_h_samp_factor * dstinfo_min_DCT_h_scaled_size);
  MCU_rows = srcinfo->output_width /
    (dstinfo->max_v_samp_factor * dstinfo_min_DCT_v_scaled_size);

  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    comp_width = MCU_cols * compptr->h_samp_factor;
    comp_height = MCU_rows * compptr->v_samp_factor;
    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
	 dst_blk_y += compptr->v_samp_factor) {
      dst_buffer = (*srcinfo->mem->access_virt_barray)
	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
	 (JDIMENSION) compptr->v_samp_factor, TRUE);
      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
	     dst_blk_x += compptr->h_samp_factor) {
	  if (x_crop_blocks + dst_blk_x < comp_width) {
	    /* Block is within the mirrorable area. */
	    src_buffer = (*srcinfo->mem->access_virt_barray)
	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	       comp_width - x_crop_blocks - dst_blk_x -
	       (JDIMENSION) compptr->h_samp_factor,
	       (JDIMENSION) compptr->h_samp_factor, FALSE);
	  } else {
	    src_buffer = (*srcinfo->mem->access_virt_barray)
	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
	       dst_blk_x + x_crop_blocks,
	       (JDIMENSION) compptr->h_samp_factor, FALSE);
	  }
	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
	    if (y_crop_blocks + dst_blk_y < comp_height) {
	      if (x_crop_blocks + dst_blk_x < comp_width) {
		/* Block is within the mirrorable area. */
		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		  }
		  i++;
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  }
		}
	      } else {
		/* Right-edge blocks are mirrored in y only */
		src_ptr = src_buffer[offset_x]
		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++) {
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		    j++;
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		  }
		}
	      }
	    } else {
	      if (x_crop_blocks + dst_blk_x < comp_width) {
		/* Bottom-edge blocks are mirrored in x only */
		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
		  [dst_blk_y + offset_y + y_crop_blocks];
		for (i = 0; i < DCTSIZE; i++) {
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
		  i++;
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
		}
	      } else {
		/* At lower right corner, just transpose, no mirroring */
		src_ptr = src_buffer[offset_x]
		  [dst_blk_y + offset_y + y_crop_blocks];
		for (i = 0; i < DCTSIZE; i++)
		  for (j = 0; j < DCTSIZE; j++)
		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
	      }
	    }
	  }
	}
      }
    }
  }
}


/* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.
 * Returns TRUE if valid integer found, FALSE if not.
 * *strptr is advanced over the digit string, and *result is set to its value.
 */

LOCAL(boolean)
jt_read_integer (const char ** strptr, JDIMENSION * result)
{
  const char * ptr = *strptr;
  JDIMENSION val = 0;

  for (; isdigit(*ptr); ptr++) {
    val = val * 10 + (JDIMENSION) (*ptr - '0');
  }
  *result = val;
  if (ptr == *strptr)
    return FALSE;		/* oops, no digits */
  *strptr = ptr;
  return TRUE;
}


/* Parse a crop specification (written in X11 geometry style).
 * The routine returns TRUE if the spec string is valid, FALSE if not.
 *
 * The crop spec string should have the format
 *	<width>[f]x<height>[f]{+-}<xoffset>{+-}<yoffset>
 * where width, height, xoffset, and yoffset are unsigned integers.
 * Each of the elements can be omitted to indicate a default value.
 * (A weakness of this style is that it is not possible to omit xoffset
 * while specifying yoffset, since they look alike.)
 *
 * This code is loosely based on XParseGeometry from the X11 distribution.
 */

GLOBAL(boolean)
jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
{
  info->crop = FALSE;
  info->crop_width_set = JCROP_UNSET;
  info->crop_height_set = JCROP_UNSET;
  info->crop_xoffset_set = JCROP_UNSET;
  info->crop_yoffset_set = JCROP_UNSET;

  if (isdigit(*spec)) {
    /* fetch width */
    if (! jt_read_integer(&spec, &info->crop_width))
      return FALSE;
    if (*spec == 'f' || *spec == 'F') {
      spec++;
      info->crop_width_set = JCROP_FORCE;
    } else
      info->crop_width_set = JCROP_POS;
  }
  if (*spec == 'x' || *spec == 'X') {
    /* fetch height */
    spec++;
    if (! jt_read_integer(&spec, &info->crop_height))
      return FALSE;
    if (*spec == 'f' || *spec == 'F') {
      spec++;
      info->crop_height_set = JCROP_FORCE;
    } else
      info->crop_height_set = JCROP_POS;
  }
  if (*spec == '+' || *spec == '-') {
    /* fetch xoffset */
    info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
    spec++;
    if (! jt_read_integer(&spec, &info->crop_xoffset))
      return FALSE;
  }
  if (*spec == '+' || *spec == '-') {
    /* fetch yoffset */
    info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
    spec++;
    if (! jt_read_integer(&spec, &info->crop_yoffset))
      return FALSE;
  }
  /* We had better have gotten to the end of the string. */
  if (*spec != '\0')
    return FALSE;
  info->crop = TRUE;
  return TRUE;
}


/* Trim off any partial iMCUs on the indicated destination edge */

LOCAL(void)
trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)
{
  JDIMENSION MCU_cols;

  MCU_cols = info->output_width / info->iMCU_sample_width;
  if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==
      full_width / info->iMCU_sample_width)
    info->output_width = MCU_cols * info->iMCU_sample_width;
}

LOCAL(void)
trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)
{
  JDIMENSION MCU_rows;

  MCU_rows = info->output_height / info->iMCU_sample_height;
  if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==
      full_height / info->iMCU_sample_height)
    info->output_height = MCU_rows * info->iMCU_sample_height;
}


/* Request any required workspace.
 *
 * This routine figures out the size that the output image will be
 * (which implies that all the transform parameters must be set before
 * it is called).
 *
 * We allocate the workspace virtual arrays from the source decompression
 * object, so that all the arrays (both the original data and the workspace)
 * will be taken into account while making memory management decisions.
 * Hence, this routine must be called after jpeg_read_header (which reads
 * the image dimensions) and before jpeg_read_coefficients (which realizes
 * the source's virtual arrays).
 *
 * This function returns FALSE right away if -perfect is given
 * and transformation is not perfect.  Otherwise returns TRUE.
 */

GLOBAL(boolean)
jtransform_request_workspace (j_decompress_ptr srcinfo,
			      jpeg_transform_info *info)
{
  jvirt_barray_ptr *coef_arrays;
  boolean need_workspace, transpose_it;
  jpeg_component_info *compptr;
  JDIMENSION xoffset, yoffset;
  JDIMENSION width_in_iMCUs, height_in_iMCUs;
  JDIMENSION width_in_blocks, height_in_blocks;
  int ci, h_samp_factor, v_samp_factor;

  /* Determine number of components in output image */
  if (info->force_grayscale &&
      srcinfo->jpeg_color_space == JCS_YCbCr &&
      srcinfo->num_components == 3)
    /* We'll only process the first component */
    info->num_components = 1;
  else
    /* Process all the components */
    info->num_components = srcinfo->num_components;

  /* Compute output image dimensions and related values. */
#if JPEG_LIB_VERSION >= 80
  jpeg_core_output_dimensions(srcinfo);
#else
  srcinfo->output_width = srcinfo->image_width;
  srcinfo->output_height = srcinfo->image_height;
#endif

  /* Return right away if -perfect is given and transformation is not perfect.
   */
  if (info->perfect) {
    if (info->num_components == 1) {
      if (!jtransform_perfect_transform(srcinfo->output_width,
	  srcinfo->output_height,
	  srcinfo->_min_DCT_h_scaled_size,
	  srcinfo->_min_DCT_v_scaled_size,
	  info->transform))
	return FALSE;
    } else {
      if (!jtransform_perfect_transform(srcinfo->output_width,
	  srcinfo->output_height,
	  srcinfo->max_h_samp_factor * srcinfo->_min_DCT_h_scaled_size,
	  srcinfo->max_v_samp_factor * srcinfo->_min_DCT_v_scaled_size,
	  info->transform))
	return FALSE;
    }
  }

  /* If there is only one output component, force the iMCU size to be 1;
   * else use the source iMCU size.  (This allows us to do the right thing
   * when reducing color to grayscale, and also provides a handy way of
   * cleaning up "funny" grayscale images whose sampling factors are not 1x1.)
   */
  switch (info->transform) {
  case JXFORM_TRANSPOSE:
  case JXFORM_TRANSVERSE:
  case JXFORM_ROT_90:
  case JXFORM_ROT_270:
    info->output_width = srcinfo->output_height;
    info->output_height = srcinfo->output_width;
    if (info->num_components == 1) {
      info->iMCU_sample_width = srcinfo->_min_DCT_v_scaled_size;
      info->iMCU_sample_height = srcinfo->_min_DCT_h_scaled_size;
    } else {
      info->iMCU_sample_width =
	srcinfo->max_v_samp_factor * srcinfo->_min_DCT_v_scaled_size;
      info->iMCU_sample_height =
	srcinfo->max_h_samp_factor * srcinfo->_min_DCT_h_scaled_size;
    }
    break;
  default:
    info->output_width = srcinfo->output_width;
    info->output_height = srcinfo->output_height;
    if (info->num_components == 1) {
      info->iMCU_sample_width = srcinfo->_min_DCT_h_scaled_size;
      info->iMCU_sample_height = srcinfo->_min_DCT_v_scaled_size;
    } else {
      info->iMCU_sample_width =
	srcinfo->max_h_samp_factor * srcinfo->_min_DCT_h_scaled_size;
      info->iMCU_sample_height =
	srcinfo->max_v_samp_factor * srcinfo->_min_DCT_v_scaled_size;
    }
    break;
  }

  /* If cropping has been requested, compute the crop area's position and
   * dimensions, ensuring that its upper left corner falls at an iMCU boundary.
   */
  if (info->crop) {
    /* Insert default values for unset crop parameters */
    if (info->crop_xoffset_set == JCROP_UNSET)
      info->crop_xoffset = 0;	/* default to +0 */
    if (info->crop_yoffset_set == JCROP_UNSET)
      info->crop_yoffset = 0;	/* default to +0 */
    if (info->crop_xoffset >= info->output_width ||
	info->crop_yoffset >= info->output_height)
      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
    if (info->crop_width_set == JCROP_UNSET)
      info->crop_width = info->output_width - info->crop_xoffset;
    if (info->crop_height_set == JCROP_UNSET)
      info->crop_height = info->output_height - info->crop_yoffset;
    /* Ensure parameters are valid */
    if (info->crop_width <= 0 || info->crop_width > info->output_width ||
	info->crop_height <= 0 || info->crop_height > info->output_height ||
	info->crop_xoffset > info->output_width - info->crop_width ||
	info->crop_yoffset > info->output_height - info->crop_height)
      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
    /* Convert negative crop offsets into regular offsets */
    if (info->crop_xoffset_set == JCROP_NEG)
      xoffset = info->output_width - info->crop_width - info->crop_xoffset;
    else
      xoffset = info->crop_xoffset;
    if (info->crop_yoffset_set == JCROP_NEG)
      yoffset = info->output_height - info->crop_height - info->crop_yoffset;
    else
      yoffset = info->crop_yoffset;
    /* Now adjust so that upper left corner falls at an iMCU boundary */
    if (info->crop_width_set == JCROP_FORCE)
      info->output_width = info->crop_width;
    else
      info->output_width =
        info->crop_width + (xoffset % info->iMCU_sample_width);
    if (info->crop_height_set == JCROP_FORCE)
      info->output_height = info->crop_height;
    else
      info->output_height =
        info->crop_height + (yoffset % info->iMCU_sample_height);
    /* Save x/y offsets measured in iMCUs */
    info->x_crop_offset = xoffset / info->iMCU_sample_width;
    info->y_crop_offset = yoffset / info->iMCU_sample_height;
  } else {
    info->x_crop_offset = 0;
    info->y_crop_offset = 0;
  }

  /* Figure out whether we need workspace arrays,
   * and if so whether they are transposed relative to the source.
   */
  need_workspace = FALSE;
  transpose_it = FALSE;
  switch (info->transform) {
  case JXFORM_NONE:
    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
      need_workspace = TRUE;
    /* No workspace needed if neither cropping nor transforming */
    break;
  case JXFORM_FLIP_H:
    if (info->trim)
      trim_right_edge(info, srcinfo->output_width);
    if (info->y_crop_offset != 0 || info->slow_hflip)
      need_workspace = TRUE;
    /* do_flip_h_no_crop doesn't need a workspace array */
    break;
  case JXFORM_FLIP_V:
    if (info->trim)
      trim_bottom_edge(info, srcinfo->output_height);
    /* Need workspace arrays having same dimensions as source image. */
    need_workspace = TRUE;
    break;
  case JXFORM_TRANSPOSE:
    /* transpose does NOT have to trim anything */
    /* Need workspace arrays having transposed dimensions. */
    need_workspace = TRUE;
    transpose_it = TRUE;
    break;
  case JXFORM_TRANSVERSE:
    if (info->trim) {
      trim_right_edge(info, srcinfo->output_height);
      trim_bottom_edge(info, srcinfo->output_width);
    }
    /* Need workspace arrays having transposed dimensions. */
    need_workspace = TRUE;
    transpose_it = TRUE;
    break;
  case JXFORM_ROT_90:
    if (info->trim)
      trim_right_edge(info, srcinfo->output_height);
    /* Need workspace arrays having transposed dimensions. */
    need_workspace = TRUE;
    transpose_it = TRUE;
    break;
  case JXFORM_ROT_180:
    if (info->trim) {
      trim_right_edge(info, srcinfo->output_width);
      trim_bottom_edge(info, srcinfo->output_height);
    }
    /* Need workspace arrays having same dimensions as source image. */
    need_workspace = TRUE;
    break;
  case JXFORM_ROT_270:
    if (info->trim)
      trim_bottom_edge(info, srcinfo->output_width);
    /* Need workspace arrays having transposed dimensions. */
    need_workspace = TRUE;
    transpose_it = TRUE;
    break;
  }

  /* Allocate workspace if needed.
   * Note that we allocate arrays padded out to the next iMCU boundary,
   * so that transform routines need not worry about missing edge blocks.
   */
  if (need_workspace) {
    coef_arrays = (jvirt_barray_ptr *)
      (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
		SIZEOF(jvirt_barray_ptr) * info->num_components);
    width_in_iMCUs = (JDIMENSION)
      jdiv_round_up((long) info->output_width,
		    (long) info->iMCU_sample_width);
    height_in_iMCUs = (JDIMENSION)
      jdiv_round_up((long) info->output_height,
		    (long) info->iMCU_sample_height);
    for (ci = 0; ci < info->num_components; ci++) {
      compptr = srcinfo->comp_info + ci;
      if (info->num_components == 1) {
	/* we're going to force samp factors to 1x1 in this case */
	h_samp_factor = v_samp_factor = 1;
      } else if (transpose_it) {
	h_samp_factor = compptr->v_samp_factor;
	v_samp_factor = compptr->h_samp_factor;
      } else {
	h_samp_factor = compptr->h_samp_factor;
	v_samp_factor = compptr->v_samp_factor;
      }
      width_in_blocks = width_in_iMCUs * h_samp_factor;
      height_in_blocks = height_in_iMCUs * v_samp_factor;
      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
	 width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
    }
    info->workspace_coef_arrays = coef_arrays;
  } else
    info->workspace_coef_arrays = NULL;

  return TRUE;
}


/* Transpose destination image parameters */

LOCAL(void)
transpose_critical_parameters (j_compress_ptr dstinfo)
{
  int tblno, i, j, ci, itemp;
  jpeg_component_info *compptr;
  JQUANT_TBL *qtblptr;
  JDIMENSION jtemp;
  UINT16 qtemp;

  /* Transpose image dimensions */
  jtemp = dstinfo->image_width;
  dstinfo->image_width = dstinfo->image_height;
  dstinfo->image_height = jtemp;
#if JPEG_LIB_VERSION >= 70
  itemp = dstinfo->min_DCT_h_scaled_size;
  dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
  dstinfo->min_DCT_v_scaled_size = itemp;
#endif

  /* Transpose sampling factors */
  for (ci = 0; ci < dstinfo->num_components; ci++) {
    compptr = dstinfo->comp_info + ci;
    itemp = compptr->h_samp_factor;
    compptr->h_samp_factor = compptr->v_samp_factor;
    compptr->v_samp_factor = itemp;
  }

  /* Transpose quantization tables */
  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
    qtblptr = dstinfo->quant_tbl_ptrs[tblno];
    if (qtblptr != NULL) {
      for (i = 0; i < DCTSIZE; i++) {
	for (j = 0; j < i; j++) {
	  qtemp = qtblptr->quantval[i*DCTSIZE+j];
	  qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
	  qtblptr->quantval[j*DCTSIZE+i] = qtemp;
	}
      }
    }
  }
}


/* Adjust Exif image parameters.
 *
 * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
 */

#if JPEG_LIB_VERSION >= 70
LOCAL(void)
adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
			JDIMENSION new_width, JDIMENSION new_height)
{
  boolean is_motorola; /* Flag for byte order */
  unsigned int number_of_tags, tagnum;
  unsigned int firstoffset, offset;
  JDIMENSION new_value;

  if (length < 12) return; /* Length of an IFD entry */

  /* Discover byte order */
  if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
    is_motorola = FALSE;
  else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
    is_motorola = TRUE;
  else
    return;

  /* Check Tag Mark */
  if (is_motorola) {
    if (GETJOCTET(data[2]) != 0) return;
    if (GETJOCTET(data[3]) != 0x2A) return;
  } else {
    if (GETJOCTET(data[3]) != 0) return;
    if (GETJOCTET(data[2]) != 0x2A) return;
  }

  /* Get first IFD offset (offset to IFD0) */
  if (is_motorola) {
    if (GETJOCTET(data[4]) != 0) return;
    if (GETJOCTET(data[5]) != 0) return;
    firstoffset = GETJOCTET(data[6]);
    firstoffset <<= 8;
    firstoffset += GETJOCTET(data[7]);
  } else {
    if (GETJOCTET(data[7]) != 0) return;
    if (GETJOCTET(data[6]) != 0) return;
    firstoffset = GETJOCTET(data[5]);
    firstoffset <<= 8;
    firstoffset += GETJOCTET(data[4]);
  }
  if (firstoffset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this IFD */
  if (is_motorola) {
    number_of_tags = GETJOCTET(data[firstoffset]);
    number_of_tags <<= 8;
    number_of_tags += GETJOCTET(data[firstoffset+1]);
  } else {
    number_of_tags = GETJOCTET(data[firstoffset+1]);
    number_of_tags <<= 8;
    number_of_tags += GETJOCTET(data[firstoffset]);
  }
  if (number_of_tags == 0) return;
  firstoffset += 2;

  /* Search for ExifSubIFD offset Tag in IFD0 */
  for (;;) {
    if (firstoffset > length - 12) return; /* check end of data segment */
    /* Get Tag number */
    if (is_motorola) {
      tagnum = GETJOCTET(data[firstoffset]);
      tagnum <<= 8;
      tagnum += GETJOCTET(data[firstoffset+1]);
    } else {
      tagnum = GETJOCTET(data[firstoffset+1]);
      tagnum <<= 8;
      tagnum += GETJOCTET(data[firstoffset]);
    }
    if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
    if (--number_of_tags == 0) return;
    firstoffset += 12;
  }

  /* Get the ExifSubIFD offset */
  if (is_motorola) {
    if (GETJOCTET(data[firstoffset+8]) != 0) return;
    if (GETJOCTET(data[firstoffset+9]) != 0) return;
    offset = GETJOCTET(data[firstoffset+10]);
    offset <<= 8;
    offset += GETJOCTET(data[firstoffset+11]);
  } else {
    if (GETJOCTET(data[firstoffset+11]) != 0) return;
    if (GETJOCTET(data[firstoffset+10]) != 0) return;
    offset = GETJOCTET(data[firstoffset+9]);
    offset <<= 8;
    offset += GETJOCTET(data[firstoffset+8]);
  }
  if (offset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this SubIFD */
  if (is_motorola) {
    number_of_tags = GETJOCTET(data[offset]);
    number_of_tags <<= 8;
    number_of_tags += GETJOCTET(data[offset+1]);
  } else {
    number_of_tags = GETJOCTET(data[offset+1]);
    number_of_tags <<= 8;
    number_of_tags += GETJOCTET(data[offset]);
  }
  if (number_of_tags < 2) return;
  offset += 2;

  /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
  do {
    if (offset > length - 12) return; /* check end of data segment */
    /* Get Tag number */
    if (is_motorola) {
      tagnum = GETJOCTET(data[offset]);
      tagnum <<= 8;
      tagnum += GETJOCTET(data[offset+1]);
    } else {
      tagnum = GETJOCTET(data[offset+1]);
      tagnum <<= 8;
      tagnum += GETJOCTET(data[offset]);
    }
    if (tagnum == 0xA002 || tagnum == 0xA003) {
      if (tagnum == 0xA002)
	new_value = new_width; /* ExifImageWidth Tag */
      else
	new_value = new_height; /* ExifImageHeight Tag */
      if (is_motorola) {
	data[offset+2] = 0; /* Format = unsigned long (4 octets) */
	data[offset+3] = 4;
	data[offset+4] = 0; /* Number Of Components = 1 */
	data[offset+5] = 0;
	data[offset+6] = 0;
	data[offset+7] = 1;
	data[offset+8] = 0;
	data[offset+9] = 0;
	data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
	data[offset+11] = (JOCTET)(new_value & 0xFF);
      } else {
	data[offset+2] = 4; /* Format = unsigned long (4 octets) */
	data[offset+3] = 0;
	data[offset+4] = 1; /* Number Of Components = 1 */
	data[offset+5] = 0;
	data[offset+6] = 0;
	data[offset+7] = 0;
	data[offset+8] = (JOCTET)(new_value & 0xFF);
	data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
	data[offset+10] = 0;
	data[offset+11] = 0;
      }
    }
    offset += 12;
  } while (--number_of_tags);
}
#endif


/* Adjust output image parameters as needed.
 *
 * This must be called after jpeg_copy_critical_parameters()
 * and before jpeg_write_coefficients().
 *
 * The return value is the set of virtual coefficient arrays to be written
 * (either the ones allocated by jtransform_request_workspace, or the
 * original source data arrays).  The caller will need to pass this value
 * to jpeg_write_coefficients().
 */

GLOBAL(jvirt_barray_ptr *)
jtransform_adjust_parameters (j_decompress_ptr srcinfo,
			      j_compress_ptr dstinfo,
			      jvirt_barray_ptr *src_coef_arrays,
			      jpeg_transform_info *info)
{
  /* If force-to-grayscale is requested, adjust destination parameters */
  if (info->force_grayscale) {
    /* First, ensure we have YCbCr or grayscale data, and that the source's
     * Y channel is full resolution.  (No reasonable person would make Y
     * be less than full resolution, so actually coping with that case
     * isn't worth extra code space.  But we check it to avoid crashing.)
     */
    if (((dstinfo->jpeg_color_space == JCS_YCbCr &&
	  dstinfo->num_components == 3) ||
	 (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
	  dstinfo->num_components == 1)) &&
	srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
	srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
      /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
       * properly.  Among other things, it sets the target h_samp_factor &
       * v_samp_factor to 1, which typically won't match the source.
       * We have to preserve the source's quantization table number, however.
       */
      int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
      jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
      dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
    } else {
      /* Sorry, can't do it */
      ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
    }
  } else if (info->num_components == 1) {
    /* For a single-component source, we force the destination sampling factors
     * to 1x1, with or without force_grayscale.  This is useful because some
     * decoders choke on grayscale images with other sampling factors.
     */
    dstinfo->comp_info[0].h_samp_factor = 1;
    dstinfo->comp_info[0].v_samp_factor = 1;
  }

  /* Correct the destination's image dimensions as necessary
   * for rotate/flip, resize, and crop operations.
   */
#if JPEG_LIB_VERSION >= 70
  dstinfo->jpeg_width = info->output_width;
  dstinfo->jpeg_height = info->output_height;
#endif

  /* Transpose destination image parameters */
  switch (info->transform) {
  case JXFORM_TRANSPOSE:
  case JXFORM_TRANSVERSE:
  case JXFORM_ROT_90:
  case JXFORM_ROT_270:
#if JPEG_LIB_VERSION < 70
    dstinfo->image_width = info->output_height;
    dstinfo->image_height = info->output_width;
#endif
    transpose_critical_parameters(dstinfo);
    break;
  default:
#if JPEG_LIB_VERSION < 70
    dstinfo->image_width = info->output_width;
    dstinfo->image_height = info->output_height;
#endif
    break;
  }

  /* Adjust Exif properties */
  if (srcinfo->marker_list != NULL &&
      srcinfo->marker_list->marker == JPEG_APP0+1 &&
      srcinfo->marker_list->data_length >= 6 &&
      GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
      GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
      GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
      GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
      GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
      GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
    /* Suppress output of JFIF marker */
    dstinfo->write_JFIF_header = FALSE;
#if JPEG_LIB_VERSION >= 70
    /* Adjust Exif image parameters */
    if (dstinfo->jpeg_width != srcinfo->image_width ||
	dstinfo->jpeg_height != srcinfo->image_height)
      /* Align data segment to start of TIFF structure for parsing */
      adjust_exif_parameters(srcinfo->marker_list->data + 6,
	srcinfo->marker_list->data_length - 6,
	dstinfo->jpeg_width, dstinfo->jpeg_height);
#endif
  }

  /* Return the appropriate output data set */
  if (info->workspace_coef_arrays != NULL)
    return info->workspace_coef_arrays;
  return src_coef_arrays;
}


/* Execute the actual transformation, if any.
 *
 * This must be called *after* jpeg_write_coefficients, because it depends
 * on jpeg_write_coefficients to have computed subsidiary values such as
 * the per-component width and height fields in the destination object.
 *
 * Note that some transformations will modify the source data arrays!
 */

GLOBAL(void)
jtransform_execute_transform (j_decompress_ptr srcinfo,
			      j_compress_ptr dstinfo,
			      jvirt_barray_ptr *src_coef_arrays,
			      jpeg_transform_info *info)
{
  jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;

  /* Note: conditions tested here should match those in switch statement
   * in jtransform_request_workspace()
   */
  switch (info->transform) {
  case JXFORM_NONE:
    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
      do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
	      src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_FLIP_H:
    if (info->y_crop_offset != 0 || info->slow_hflip)
      do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
		src_coef_arrays, dst_coef_arrays);
    else
      do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
			src_coef_arrays);
    break;
  case JXFORM_FLIP_V:
    do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
	      src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_TRANSPOSE:
    do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
		 src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_TRANSVERSE:
    do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
		  src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_90:
    do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
	      src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_180:
    do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
	       src_coef_arrays, dst_coef_arrays);
    break;
  case JXFORM_ROT_270:
    do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
	       src_coef_arrays, dst_coef_arrays);
    break;
  }
}

/* jtransform_perfect_transform
 *
 * Determine whether lossless transformation is perfectly
 * possible for a specified image and transformation.
 *
 * Inputs:
 *   image_width, image_height: source image dimensions.
 *   MCU_width, MCU_height: pixel dimensions of MCU.
 *   transform: transformation identifier.
 * Parameter sources from initialized jpeg_struct
 * (after reading source header):
 *   image_width = cinfo.image_width
 *   image_height = cinfo.image_height
 *   MCU_width = cinfo.max_h_samp_factor * cinfo.block_size
 *   MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
 * Result:
 *   TRUE = perfect transformation possible
 *   FALSE = perfect transformation not possible
 *           (may use custom action then)
 */

GLOBAL(boolean)
jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
			     int MCU_width, int MCU_height,
			     JXFORM_CODE transform)
{
  boolean result = TRUE; /* initialize TRUE */

  switch (transform) {
  case JXFORM_FLIP_H:
  case JXFORM_ROT_270:
    if (image_width % (JDIMENSION) MCU_width)
      result = FALSE;
    break;
  case JXFORM_FLIP_V:
  case JXFORM_ROT_90:
    if (image_height % (JDIMENSION) MCU_height)
      result = FALSE;
    break;
  case JXFORM_TRANSVERSE:
  case JXFORM_ROT_180:
    if (image_width % (JDIMENSION) MCU_width)
      result = FALSE;
    if (image_height % (JDIMENSION) MCU_height)
      result = FALSE;
    break;
  default:
    break;
  }

  return result;
}

#endif /* TRANSFORMS_SUPPORTED */


/* Setup decompression object to save desired markers in memory.
 * This must be called before jpeg_read_header() to have the desired effect.
 */

GLOBAL(void)
jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
{
#ifdef SAVE_MARKERS_SUPPORTED
  int m;

  /* Save comments except under NONE option */
  if (option != JCOPYOPT_NONE) {
    jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
  }
  /* Save all types of APPn markers iff ALL option */
  if (option == JCOPYOPT_ALL) {
    for (m = 0; m < 16; m++)
      jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
  }
#endif /* SAVE_MARKERS_SUPPORTED */
}

/* Copy markers saved in the given source object to the destination object.
 * This should be called just after jpeg_start_compress() or
 * jpeg_write_coefficients().
 * Note that those routines will have written the SOI, and also the
 * JFIF APP0 or Adobe APP14 markers if selected.
 */

GLOBAL(void)
jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
		       JCOPY_OPTION option)
{
  jpeg_saved_marker_ptr marker;

  /* In the current implementation, we don't actually need to examine the
   * option flag here; we just copy everything that got saved.
   * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
   * if the encoder library already wrote one.
   */
  for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
    if (dstinfo->write_JFIF_header &&
	marker->marker == JPEG_APP0 &&
	marker->data_length >= 5 &&
	GETJOCTET(marker->data[0]) == 0x4A &&
	GETJOCTET(marker->data[1]) == 0x46 &&
	GETJOCTET(marker->data[2]) == 0x49 &&
	GETJOCTET(marker->data[3]) == 0x46 &&
	GETJOCTET(marker->data[4]) == 0)
      continue;			/* reject duplicate JFIF */
    if (dstinfo->write_Adobe_marker &&
	marker->marker == JPEG_APP0+14 &&
	marker->data_length >= 5 &&
	GETJOCTET(marker->data[0]) == 0x41 &&
	GETJOCTET(marker->data[1]) == 0x64 &&
	GETJOCTET(marker->data[2]) == 0x6F &&
	GETJOCTET(marker->data[3]) == 0x62 &&
	GETJOCTET(marker->data[4]) == 0x65)
      continue;			/* reject duplicate Adobe */
#ifdef NEED_FAR_POINTERS
    /* We could use jpeg_write_marker if the data weren't FAR... */
    {
      unsigned int i;
      jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
      for (i = 0; i < marker->data_length; i++)
	jpeg_write_m_byte(dstinfo, marker->data[i]);
    }
#else
    jpeg_write_marker(dstinfo, marker->marker,
		      marker->data, marker->data_length);
#endif
  }
}