File size: 35,392 Bytes
f238a34
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
// jpge.cpp - C++ class for JPEG compression.
// Public domain, Rich Geldreich <[email protected]>
// v1.01, Dec. 18, 2010 - Initial release
// v1.02, Apr. 6, 2011 - Removed 2x2 ordered dither in H2V1 chroma subsampling method load_block_16_8_8(). (The rounding factor was 2, when it should have been 1. Either way, it wasn't helping.)
// v1.03, Apr. 16, 2011 - Added support for optimized Huffman code tables, optimized dynamic memory allocation down to only 1 alloc.
//                        Also from Alex Evans: Added RGBA support, linear memory allocator (no longer needed in v1.03).
// v1.04, May. 19, 2012: Forgot to set m_pFile ptr to NULL in cfile_stream::close(). Thanks to Owen Kaluza for reporting this bug.
//                       Code tweaks to fix VS2008 static code analysis warnings (all looked harmless).
//                       Code review revealed method load_block_16_8_8() (used for the non-default H2V1 sampling mode to downsample chroma) somehow didn't get the rounding factor fix from v1.02.

#include "jpge.h"

#include <stdlib.h>
#include <string.h>
#if PLATFORM_WINDOWS
#include <malloc.h>
#endif

#define JPGE_MAX(a,b) (((a)>(b))?(a):(b))
#define JPGE_MIN(a,b) (((a)<(b))?(a):(b))

namespace jpge {

static inline void *jpge_malloc(size_t nSize) { return FMemory::Malloc(nSize); }
static inline void jpge_free(void *p) { FMemory::Free(p);; }

// Various JPEG enums and tables.
enum { M_SOF0 = 0xC0, M_DHT = 0xC4, M_SOI = 0xD8, M_EOI = 0xD9, M_SOS = 0xDA, M_DQT = 0xDB, M_APP0 = 0xE0 };
enum { DC_LUM_CODES = 12, AC_LUM_CODES = 256, DC_CHROMA_CODES = 12, AC_CHROMA_CODES = 256, MAX_HUFF_SYMBOLS = 257, MAX_HUFF_CODESIZE = 32 };

static uint8 s_zag[64] = { 0,1,8,16,9,2,3,10,17,24,32,25,18,11,4,5,12,19,26,33,40,48,41,34,27,20,13,6,7,14,21,28,35,42,49,56,57,50,43,36,29,22,15,23,30,37,44,51,58,59,52,45,38,31,39,46,53,60,61,54,47,55,62,63 };
static int16 s_std_lum_quant[64] = { 16,11,12,14,12,10,16,14,13,14,18,17,16,19,24,40,26,24,22,22,24,49,35,37,29,40,58,51,61,60,57,51,56,55,64,72,92,78,64,68,87,69,55,56,80,109,81,87,95,98,103,104,103,62,77,113,121,112,100,120,92,101,103,99 };
static int16 s_std_croma_quant[64] = { 17,18,18,24,21,24,47,26,26,47,99,66,56,66,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99 };
static uint8 s_dc_lum_bits[17] = { 0,0,1,5,1,1,1,1,1,1,0,0,0,0,0,0,0 };
static uint8 s_dc_lum_val[DC_LUM_CODES] = { 0,1,2,3,4,5,6,7,8,9,10,11 };
static uint8 s_ac_lum_bits[17] = { 0,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0x7d };
static uint8 s_ac_lum_val[AC_LUM_CODES]  =
{
  0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,0x22,0x71,0x14,0x32,0x81,0x91,0xa1,0x08,0x23,0x42,0xb1,0xc1,0x15,0x52,0xd1,0xf0,
  0x24,0x33,0x62,0x72,0x82,0x09,0x0a,0x16,0x17,0x18,0x19,0x1a,0x25,0x26,0x27,0x28,0x29,0x2a,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x43,0x44,0x45,0x46,0x47,0x48,0x49,
  0x4a,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x83,0x84,0x85,0x86,0x87,0x88,0x89,
  0x8a,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xc2,0xc3,0xc4,0xc5,
  0xc6,0xc7,0xc8,0xc9,0xca,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,
  0xf9,0xfa
};
static uint8 s_dc_chroma_bits[17] = { 0,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0 };
static uint8 s_dc_chroma_val[DC_CHROMA_CODES]  = { 0,1,2,3,4,5,6,7,8,9,10,11 };
static uint8 s_ac_chroma_bits[17] = { 0,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0x77 };
static uint8 s_ac_chroma_val[AC_CHROMA_CODES] =
{
  0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71,0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,0xa1,0xb1,0xc1,0x09,0x23,0x33,0x52,0xf0,
  0x15,0x62,0x72,0xd1,0x0a,0x16,0x24,0x34,0xe1,0x25,0xf1,0x17,0x18,0x19,0x1a,0x26,0x27,0x28,0x29,0x2a,0x35,0x36,0x37,0x38,0x39,0x3a,0x43,0x44,0x45,0x46,0x47,0x48,
  0x49,0x4a,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x82,0x83,0x84,0x85,0x86,0x87,
  0x88,0x89,0x8a,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xc2,0xc3,
  0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,
  0xf9,0xfa
};

// Low-level helper functions.
template <class T> inline void clear_obj(T &obj) { memset(&obj, 0, sizeof(obj)); }

const int YR = 19595, YG = 38470, YB = 7471, CB_R = -11059, CB_G = -21709, CB_B = 32768, CR_R = 32768, CR_G = -27439, CR_B = -5329;
static inline uint8 clamp(int i) { if (static_cast<uint>(i) > 255U) { if (i < 0) i = 0; else if (i > 255) i = 255; } return static_cast<uint8>(i); }

static void RGB_to_YCC(uint8* pDst, const uint8 *pSrc, int num_pixels)
{
  for ( ; num_pixels; pDst += 3, pSrc += 3, num_pixels--)
  {
    const int r = pSrc[0], g = pSrc[1], b = pSrc[2];
    pDst[0] = static_cast<uint8>((r * YR + g * YG + b * YB + 32768) >> 16);
    pDst[1] = clamp(128 + ((r * CB_R + g * CB_G + b * CB_B + 32768) >> 16));
    pDst[2] = clamp(128 + ((r * CR_R + g * CR_G + b * CR_B + 32768) >> 16));
  }
}

static void RGB_to_Y(uint8* pDst, const uint8 *pSrc, int num_pixels)
{
  for ( ; num_pixels; pDst++, pSrc += 3, num_pixels--)
    pDst[0] = static_cast<uint8>((pSrc[0] * YR + pSrc[1] * YG + pSrc[2] * YB + 32768) >> 16);
}

static void RGBA_to_YCC(uint8* pDst, const uint8 *pSrc, int num_pixels)
{
  for ( ; num_pixels; pDst += 3, pSrc += 4, num_pixels--)
  {
    const int r = pSrc[0], g = pSrc[1], b = pSrc[2];
    pDst[0] = static_cast<uint8>((r * YR + g * YG + b * YB + 32768) >> 16);
    pDst[1] = clamp(128 + ((r * CB_R + g * CB_G + b * CB_B + 32768) >> 16));
    pDst[2] = clamp(128 + ((r * CR_R + g * CR_G + b * CR_B + 32768) >> 16));
  }
}

static void RGBA_to_Y(uint8* pDst, const uint8 *pSrc, int num_pixels)
{
  for ( ; num_pixels; pDst++, pSrc += 4, num_pixels--)
    pDst[0] = static_cast<uint8>((pSrc[0] * YR + pSrc[1] * YG + pSrc[2] * YB + 32768) >> 16);
}

static void Y_to_YCC(uint8* pDst, const uint8* pSrc, int num_pixels)
{
  for( ; num_pixels; pDst += 3, pSrc++, num_pixels--) { pDst[0] = pSrc[0]; pDst[1] = 128; pDst[2] = 128; }
}

// Forward DCT - DCT derived from jfdctint.
#define CONST_BITS  13
#define ROW_BITS    2
#define DCT_DESCALE(x, n) (((x) + (((int32)1) << ((n) - 1))) >> (n))
#define DCT_MUL(var, c) (static_cast<int16>(var) * static_cast<int32>(c))
#define DCT1D(s0, s1, s2, s3, s4, s5, s6, s7) \
  int32 t0 = s0 + s7, t7 = s0 - s7, t1 = s1 + s6, t6 = s1 - s6, t2 = s2 + s5, t5 = s2 - s5, t3 = s3 + s4, t4 = s3 - s4; \
  int32 t10 = t0 + t3, t13 = t0 - t3, t11 = t1 + t2, t12 = t1 - t2; \
  int32 u1 = DCT_MUL(t12 + t13, 4433); \
  s2 = u1 + DCT_MUL(t13, 6270); \
  s6 = u1 + DCT_MUL(t12, -15137); \
  u1 = t4 + t7; \
  int32 u2 = t5 + t6, u3 = t4 + t6, u4 = t5 + t7; \
  int32 z5 = DCT_MUL(u3 + u4, 9633); \
  t4 = DCT_MUL(t4, 2446); t5 = DCT_MUL(t5, 16819); \
  t6 = DCT_MUL(t6, 25172); t7 = DCT_MUL(t7, 12299); \
  u1 = DCT_MUL(u1, -7373); u2 = DCT_MUL(u2, -20995); \
  u3 = DCT_MUL(u3, -16069); u4 = DCT_MUL(u4, -3196); \
  u3 += z5; u4 += z5; \
  s0 = t10 + t11; s1 = t7 + u1 + u4; s3 = t6 + u2 + u3; s4 = t10 - t11; s5 = t5 + u2 + u4; s7 = t4 + u1 + u3;

static void DCT2D(int32 *p)
{
  int32 c, *q = p;
  for (c = 7; c >= 0; c--, q += 8)
  {
    int32 s0 = q[0], s1 = q[1], s2 = q[2], s3 = q[3], s4 = q[4], s5 = q[5], s6 = q[6], s7 = q[7];
    DCT1D(s0, s1, s2, s3, s4, s5, s6, s7);
    q[0] = s0 << ROW_BITS; q[1] = DCT_DESCALE(s1, CONST_BITS-ROW_BITS); q[2] = DCT_DESCALE(s2, CONST_BITS-ROW_BITS); q[3] = DCT_DESCALE(s3, CONST_BITS-ROW_BITS);
    q[4] = s4 << ROW_BITS; q[5] = DCT_DESCALE(s5, CONST_BITS-ROW_BITS); q[6] = DCT_DESCALE(s6, CONST_BITS-ROW_BITS); q[7] = DCT_DESCALE(s7, CONST_BITS-ROW_BITS);
  }
  for (q = p, c = 7; c >= 0; c--, q++)
  {
    int32 s0 = q[0*8], s1 = q[1*8], s2 = q[2*8], s3 = q[3*8], s4 = q[4*8], s5 = q[5*8], s6 = q[6*8], s7 = q[7*8];
    DCT1D(s0, s1, s2, s3, s4, s5, s6, s7);
    q[0*8] = DCT_DESCALE(s0, ROW_BITS+3); q[1*8] = DCT_DESCALE(s1, CONST_BITS+ROW_BITS+3); q[2*8] = DCT_DESCALE(s2, CONST_BITS+ROW_BITS+3); q[3*8] = DCT_DESCALE(s3, CONST_BITS+ROW_BITS+3);
    q[4*8] = DCT_DESCALE(s4, ROW_BITS+3); q[5*8] = DCT_DESCALE(s5, CONST_BITS+ROW_BITS+3); q[6*8] = DCT_DESCALE(s6, CONST_BITS+ROW_BITS+3); q[7*8] = DCT_DESCALE(s7, CONST_BITS+ROW_BITS+3);
  }
}

struct sym_freq { uint m_key, m_sym_index; };

// Radix sorts sym_freq[] array by 32-bit key m_key. Returns ptr to sorted values.
static inline sym_freq* radix_sort_syms(uint num_syms, sym_freq* pSyms0, sym_freq* pSyms1)
{
  const uint cMaxPasses = 4;
  uint32 hist[256 * cMaxPasses]; clear_obj(hist);
  for (uint i = 0; i < num_syms; i++) { uint freq = pSyms0[i].m_key; hist[freq & 0xFF]++; hist[256 + ((freq >> 8) & 0xFF)]++; hist[256*2 + ((freq >> 16) & 0xFF)]++; hist[256*3 + ((freq >> 24) & 0xFF)]++; }
  sym_freq* pCur_syms = pSyms0, *pNew_syms = pSyms1;
  uint total_passes = cMaxPasses; while ((total_passes > 1) && (num_syms == hist[(total_passes - 1) * 256])) total_passes--;
  for (uint pass_shift = 0, pass = 0; pass < total_passes; pass++, pass_shift += 8)
  {
    const uint32* pHist = &hist[pass << 8];
    uint offsets[256], cur_ofs = 0;
    for (uint i = 0; i < 256; i++) { offsets[i] = cur_ofs; cur_ofs += pHist[i]; }
    for (uint i = 0; i < num_syms; i++)
      pNew_syms[offsets[(pCur_syms[i].m_key >> pass_shift) & 0xFF]++] = pCur_syms[i];
    sym_freq* t = pCur_syms; pCur_syms = pNew_syms; pNew_syms = t;
  }
  return pCur_syms;
}

// calculate_minimum_redundancy() originally written by: Alistair Moffat, [email protected], Jyrki Katajainen, [email protected], November 1996.
static void calculate_minimum_redundancy(sym_freq *A, int n)
{
  int root, leaf, next, avbl, used, dpth;
  if (n==0) return; else if (n==1) { A[0].m_key = 1; return; }
  A[0].m_key += A[1].m_key; root = 0; leaf = 2;
  for (next=1; next < n-1; next++)
  {
    if (leaf>=n || A[root].m_key<A[leaf].m_key) { A[next].m_key = A[root].m_key; A[root++].m_key = next; } else A[next].m_key = A[leaf++].m_key;
    if (leaf>=n || (root<next && A[root].m_key<A[leaf].m_key)) { A[next].m_key += A[root].m_key; A[root++].m_key = next; } else A[next].m_key += A[leaf++].m_key;
  }
  A[n-2].m_key = 0;
  for (next=n-3; next>=0; next--) A[next].m_key = A[A[next].m_key].m_key+1;
  avbl = 1; used = dpth = 0; root = n-2; next = n-1;
  while (avbl>0)
  {
    while (root>=0 && (int)A[root].m_key==dpth) { used++; root--; }
    while (avbl>used) { A[next--].m_key = dpth; avbl--; }
    avbl = 2*used; dpth++; used = 0;
  }
}

// Limits canonical Huffman code table's max code size to max_code_size.
static void huffman_enforce_max_code_size(int *pNum_codes, int code_list_len, int max_code_size)
{
  if (code_list_len <= 1) return;

  for (int i = max_code_size + 1; i <= MAX_HUFF_CODESIZE; i++) pNum_codes[max_code_size] += pNum_codes[i];

  uint32 total = 0;
  for (int i = max_code_size; i > 0; i--)
    total += (((uint32)pNum_codes[i]) << (max_code_size - i));

  while (total != (1UL << max_code_size))
  {
    pNum_codes[max_code_size]--;
    for (int i = max_code_size - 1; i > 0; i--)
    {
      if (pNum_codes[i]) { pNum_codes[i]--; pNum_codes[i + 1] += 2; break; }
    }
    total--;
  }
}

// Generates an optimized offman table.
void jpeg_encoder::optimize_huffman_table(int table_num, int table_len)
{
  sym_freq syms0[MAX_HUFF_SYMBOLS], syms1[MAX_HUFF_SYMBOLS];
  syms0[0].m_key = 1; syms0[0].m_sym_index = 0;  // dummy symbol, assures that no valid code contains all 1's
  int num_used_syms = 1;
  const uint32 *pSym_count = &m_huff_count[table_num][0];
  for (int i = 0; i < table_len; i++)
    if (pSym_count[i]) { syms0[num_used_syms].m_key = pSym_count[i]; syms0[num_used_syms++].m_sym_index = i + 1; }
  sym_freq* pSyms = radix_sort_syms(num_used_syms, syms0, syms1);
  calculate_minimum_redundancy(pSyms, num_used_syms);

  // Count the # of symbols of each code size.
  int num_codes[1 + MAX_HUFF_CODESIZE]; clear_obj(num_codes);
  for (int i = 0; i < num_used_syms; i++)
    num_codes[pSyms[i].m_key]++;

  const uint JPGE_CODE_SIZE_LIMIT = 16; // the maximum possible size of a JPEG Huffman code (valid range is [9,16] - 9 vs. 8 because of the dummy symbol)
  huffman_enforce_max_code_size(num_codes, num_used_syms, JPGE_CODE_SIZE_LIMIT);

  // Compute m_huff_bits array, which contains the # of symbols per code size.
  clear_obj(m_huff_bits[table_num]);
  for (int i = 1; i <= (int)JPGE_CODE_SIZE_LIMIT; i++)
    m_huff_bits[table_num][i] = static_cast<uint8>(num_codes[i]);

  // Remove the dummy symbol added above, which must be in largest bucket.
  for (int i = JPGE_CODE_SIZE_LIMIT; i >= 1; i--)
  {
    if (m_huff_bits[table_num][i]) { m_huff_bits[table_num][i]--; break; }
  }

  // Compute the m_huff_val array, which contains the symbol indices sorted by code size (smallest to largest).
  for (int i = num_used_syms - 1; i >= 1; i--)
    m_huff_val[table_num][num_used_syms - 1 - i] = static_cast<uint8>(pSyms[i].m_sym_index - 1);
}

// JPEG marker generation.
void jpeg_encoder::emit_byte(uint8 i)
{
  m_all_stream_writes_succeeded = m_all_stream_writes_succeeded && m_pStream->put_obj(i);
}

void jpeg_encoder::emit_word(uint i)
{
  emit_byte(uint8(i >> 8)); emit_byte(uint8(i & 0xFF));
}

void jpeg_encoder::emit_marker(int marker)
{
  emit_byte(uint8(0xFF)); emit_byte(uint8(marker));
}

// Emit JFIF marker
void jpeg_encoder::emit_jfif_app0()
{
  emit_marker(M_APP0);
  emit_word(2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1);
  emit_byte(0x4A); emit_byte(0x46); emit_byte(0x49); emit_byte(0x46); /* Identifier: ASCII "JFIF" */
  emit_byte(0);
  emit_byte(1);      /* Major version */
  emit_byte(1);      /* Minor version */
  emit_byte(0);      /* Density unit */
  emit_word(1);
  emit_word(1);
  emit_byte(0);      /* No thumbnail image */
  emit_byte(0);
}

// Emit quantization tables
void jpeg_encoder::emit_dqt()
{
  for (int i = 0; i < ((m_num_components == 3) ? 2 : 1); i++)
  {
    emit_marker(M_DQT);
    emit_word(64 + 1 + 2);
    emit_byte(static_cast<uint8>(i));
    for (int j = 0; j < 64; j++)
      emit_byte(static_cast<uint8>(m_quantization_tables[i][j]));
  }
}

// Emit start of frame marker
void jpeg_encoder::emit_sof()
{
  emit_marker(M_SOF0);                           /* baseline */
  emit_word(3 * m_num_components + 2 + 5 + 1);
  emit_byte(8);                                  /* precision */
  emit_word(m_image_y);
  emit_word(m_image_x);
  emit_byte(m_num_components);
  for (int i = 0; i < m_num_components; i++)
  {
    emit_byte(static_cast<uint8>(i + 1));                                   /* component ID     */
    emit_byte((m_comp_h_samp[i] << 4) + m_comp_v_samp[i]);  /* h and v sampling */
    emit_byte(i > 0);                                   /* quant. table num */
  }
}

// Emit Huffman table.
void jpeg_encoder::emit_dht(uint8 *bits, uint8 *val, int index, bool ac_flag)
{
  emit_marker(M_DHT);

  int length = 0;
  for (int i = 1; i <= 16; i++)
    length += bits[i];

  emit_word(length + 2 + 1 + 16);
  emit_byte(static_cast<uint8>(index + (ac_flag << 4)));

  for (int i = 1; i <= 16; i++)
    emit_byte(bits[i]);

  for (int i = 0; i < length; i++)
    emit_byte(val[i]);
}

// Emit all Huffman tables.
void jpeg_encoder::emit_dhts()
{
  emit_dht(m_huff_bits[0+0], m_huff_val[0+0], 0, false);
  emit_dht(m_huff_bits[2+0], m_huff_val[2+0], 0, true);
  if (m_num_components == 3)
  {
    emit_dht(m_huff_bits[0+1], m_huff_val[0+1], 1, false);
    emit_dht(m_huff_bits[2+1], m_huff_val[2+1], 1, true);
  }
}

// emit start of scan
void jpeg_encoder::emit_sos()
{
  emit_marker(M_SOS);
  emit_word(2 * m_num_components + 2 + 1 + 3);
  emit_byte(m_num_components);
  for (int i = 0; i < m_num_components; i++)
  {
    emit_byte(static_cast<uint8>(i + 1));
    if (i == 0)
      emit_byte((0 << 4) + 0);
    else
      emit_byte((1 << 4) + 1);
  }
  emit_byte(0);     /* spectral selection */
  emit_byte(63);
  emit_byte(0);
}

// Emit all markers at beginning of image file.
void jpeg_encoder::emit_markers()
{
  emit_marker(M_SOI);
  emit_jfif_app0();
  emit_dqt();
  emit_sof();
  emit_dhts();
  emit_sos();
}

// Compute the actual canonical Huffman codes/code sizes given the JPEG huff bits and val arrays.
void jpeg_encoder::compute_huffman_table(uint *codes, uint8 *code_sizes, uint8 *bits, uint8 *val)
{
  int i, l, last_p, si;
  uint8 huff_size[257];
  uint huff_code[257];
  uint code;

  int p = 0;
  for (l = 1; l <= 16; l++)
    for (i = 1; i <= bits[l]; i++)
      huff_size[p++] = (char)l;

  huff_size[p] = 0; last_p = p; // write sentinel

  code = 0; si = huff_size[0]; p = 0;

  while (huff_size[p])
  {
    while (huff_size[p] == si)
      huff_code[p++] = code++;
    code <<= 1;
    si++;
  }

  memset(codes, 0, sizeof(codes[0])*256);
  memset(code_sizes, 0, sizeof(code_sizes[0])*256);
  for (p = 0; p < last_p; p++)
  {
    codes[val[p]]      = huff_code[p];
    code_sizes[val[p]] = huff_size[p];
  }
}

// Quantization table generation.
void jpeg_encoder::compute_quant_table(int32 *pDst, int16 *pSrc)
{
  int32 q;
  if (m_params.m_quality < 50)
    q = 5000 / m_params.m_quality;
  else
    q = 200 - m_params.m_quality * 2;
  for (int i = 0; i < 64; i++)
  {
    int32 j = *pSrc++; j = (j * q + 50L) / 100L;
    *pDst++ = JPGE_MIN(JPGE_MAX(j, 1), 255);
  }
}

// Higher-level methods.
void jpeg_encoder::first_pass_init()
{
  m_bit_buffer = 0; m_bits_in = 0;
  memset(m_last_dc_val, 0, 3 * sizeof(m_last_dc_val[0]));
  m_mcu_y_ofs = 0;
  m_pass_num = 1;
}

bool jpeg_encoder::second_pass_init()
{
  compute_huffman_table(&m_huff_codes[0+0][0], &m_huff_code_sizes[0+0][0], m_huff_bits[0+0], m_huff_val[0+0]);
  compute_huffman_table(&m_huff_codes[2+0][0], &m_huff_code_sizes[2+0][0], m_huff_bits[2+0], m_huff_val[2+0]);
  if (m_num_components > 1)
  {
    compute_huffman_table(&m_huff_codes[0+1][0], &m_huff_code_sizes[0+1][0], m_huff_bits[0+1], m_huff_val[0+1]);
    compute_huffman_table(&m_huff_codes[2+1][0], &m_huff_code_sizes[2+1][0], m_huff_bits[2+1], m_huff_val[2+1]);
  }
  first_pass_init();
  emit_markers();
  m_pass_num = 2;
  return true;
}

bool jpeg_encoder::jpg_open(int p_x_res, int p_y_res, int src_channels)
{
  m_num_components = 3;
  switch (m_params.m_subsampling)
  {
    case Y_ONLY:
    {
      m_num_components = 1;
      m_comp_h_samp[0] = 1; m_comp_v_samp[0] = 1;
      m_mcu_x          = 8; m_mcu_y          = 8;
      break;
    }
    case H1V1:
    {
      m_comp_h_samp[0] = 1; m_comp_v_samp[0] = 1;
      m_comp_h_samp[1] = 1; m_comp_v_samp[1] = 1;
      m_comp_h_samp[2] = 1; m_comp_v_samp[2] = 1;
      m_mcu_x          = 8; m_mcu_y          = 8;
      break;
    }
    case H2V1:
    {
      m_comp_h_samp[0] = 2; m_comp_v_samp[0] = 1;
      m_comp_h_samp[1] = 1; m_comp_v_samp[1] = 1;
      m_comp_h_samp[2] = 1; m_comp_v_samp[2] = 1;
      m_mcu_x          = 16; m_mcu_y         = 8;
      break;
    }
    case H2V2:
    {
      m_comp_h_samp[0] = 2; m_comp_v_samp[0] = 2;
      m_comp_h_samp[1] = 1; m_comp_v_samp[1] = 1;
      m_comp_h_samp[2] = 1; m_comp_v_samp[2] = 1;
      m_mcu_x          = 16; m_mcu_y         = 16;
    }
  }

  m_image_x        = p_x_res; m_image_y = p_y_res;
  m_image_bpp      = src_channels;
  m_image_bpl      = m_image_x * src_channels;
  m_image_x_mcu    = (m_image_x + m_mcu_x - 1) & (~(m_mcu_x - 1));
  m_image_y_mcu    = (m_image_y + m_mcu_y - 1) & (~(m_mcu_y - 1));
  m_image_bpl_xlt  = m_image_x * m_num_components;
  m_image_bpl_mcu  = m_image_x_mcu * m_num_components;
  m_mcus_per_row   = m_image_x_mcu / m_mcu_x;

  if ((m_mcu_lines[0] = static_cast<uint8*>(jpge_malloc(m_image_bpl_mcu * m_mcu_y))) == NULL) return false;
  for (int i = 1; i < m_mcu_y; i++)
    m_mcu_lines[i] = m_mcu_lines[i-1] + m_image_bpl_mcu;

  compute_quant_table(m_quantization_tables[0], s_std_lum_quant);
  compute_quant_table(m_quantization_tables[1], m_params.m_no_chroma_discrim_flag ? s_std_lum_quant : s_std_croma_quant);

  m_out_buf_left = JPGE_OUT_BUF_SIZE;
  m_pOut_buf = m_out_buf;

  if (m_params.m_two_pass_flag)
  {
    clear_obj(m_huff_count);
    first_pass_init();
  }
  else
  {
    memcpy(m_huff_bits[0+0], s_dc_lum_bits, 17);    memcpy(m_huff_val [0+0], s_dc_lum_val, DC_LUM_CODES);
    memcpy(m_huff_bits[2+0], s_ac_lum_bits, 17);    memcpy(m_huff_val [2+0], s_ac_lum_val, AC_LUM_CODES);
    memcpy(m_huff_bits[0+1], s_dc_chroma_bits, 17); memcpy(m_huff_val [0+1], s_dc_chroma_val, DC_CHROMA_CODES);
    memcpy(m_huff_bits[2+1], s_ac_chroma_bits, 17); memcpy(m_huff_val [2+1], s_ac_chroma_val, AC_CHROMA_CODES);
    if (!second_pass_init()) return false;   // in effect, skip over the first pass
  }
  return m_all_stream_writes_succeeded;
}

void jpeg_encoder::load_block_8_8_grey(int x)
{
  uint8 *pSrc;
  sample_array_t *pDst = m_sample_array;
  x <<= 3;
  for (int i = 0; i < 8; i++, pDst += 8)
  {
    pSrc = m_mcu_lines[i] + x;
    pDst[0] = pSrc[0] - 128; pDst[1] = pSrc[1] - 128; pDst[2] = pSrc[2] - 128; pDst[3] = pSrc[3] - 128;
    pDst[4] = pSrc[4] - 128; pDst[5] = pSrc[5] - 128; pDst[6] = pSrc[6] - 128; pDst[7] = pSrc[7] - 128;
  }
}

void jpeg_encoder::load_block_8_8(int x, int y, int c)
{
  uint8 *pSrc;
  sample_array_t *pDst = m_sample_array;
  x = (x * (8 * 3)) + c;
  y <<= 3;
  for (int i = 0; i < 8; i++, pDst += 8)
  {
    pSrc = m_mcu_lines[y + i] + x;
    pDst[0] = pSrc[0 * 3] - 128; pDst[1] = pSrc[1 * 3] - 128; pDst[2] = pSrc[2 * 3] - 128; pDst[3] = pSrc[3 * 3] - 128;
    pDst[4] = pSrc[4 * 3] - 128; pDst[5] = pSrc[5 * 3] - 128; pDst[6] = pSrc[6 * 3] - 128; pDst[7] = pSrc[7 * 3] - 128;
  }
}

void jpeg_encoder::load_block_16_8(int x, int c)
{
  uint8 *pSrc1, *pSrc2;
  sample_array_t *pDst = m_sample_array;
  x = (x * (16 * 3)) + c;
  int a = 0, b = 2;
  for (int i = 0; i < 16; i += 2, pDst += 8)
  {
    pSrc1 = m_mcu_lines[i + 0] + x;
    pSrc2 = m_mcu_lines[i + 1] + x;
    pDst[0] = ((pSrc1[ 0 * 3] + pSrc1[ 1 * 3] + pSrc2[ 0 * 3] + pSrc2[ 1 * 3] + a) >> 2) - 128; pDst[1] = ((pSrc1[ 2 * 3] + pSrc1[ 3 * 3] + pSrc2[ 2 * 3] + pSrc2[ 3 * 3] + b) >> 2) - 128;
    pDst[2] = ((pSrc1[ 4 * 3] + pSrc1[ 5 * 3] + pSrc2[ 4 * 3] + pSrc2[ 5 * 3] + a) >> 2) - 128; pDst[3] = ((pSrc1[ 6 * 3] + pSrc1[ 7 * 3] + pSrc2[ 6 * 3] + pSrc2[ 7 * 3] + b) >> 2) - 128;
    pDst[4] = ((pSrc1[ 8 * 3] + pSrc1[ 9 * 3] + pSrc2[ 8 * 3] + pSrc2[ 9 * 3] + a) >> 2) - 128; pDst[5] = ((pSrc1[10 * 3] + pSrc1[11 * 3] + pSrc2[10 * 3] + pSrc2[11 * 3] + b) >> 2) - 128;
    pDst[6] = ((pSrc1[12 * 3] + pSrc1[13 * 3] + pSrc2[12 * 3] + pSrc2[13 * 3] + a) >> 2) - 128; pDst[7] = ((pSrc1[14 * 3] + pSrc1[15 * 3] + pSrc2[14 * 3] + pSrc2[15 * 3] + b) >> 2) - 128;
    int temp = a; a = b; b = temp;
  }
}

void jpeg_encoder::load_block_16_8_8(int x, int c)
{
  uint8 *pSrc1;
  sample_array_t *pDst = m_sample_array;
  x = (x * (16 * 3)) + c;
  for (int i = 0; i < 8; i++, pDst += 8)
  {
    pSrc1 = m_mcu_lines[i + 0] + x;
    pDst[0] = ((pSrc1[ 0 * 3] + pSrc1[ 1 * 3]) >> 1) - 128; pDst[1] = ((pSrc1[ 2 * 3] + pSrc1[ 3 * 3]) >> 1) - 128;
    pDst[2] = ((pSrc1[ 4 * 3] + pSrc1[ 5 * 3]) >> 1) - 128; pDst[3] = ((pSrc1[ 6 * 3] + pSrc1[ 7 * 3]) >> 1) - 128;
    pDst[4] = ((pSrc1[ 8 * 3] + pSrc1[ 9 * 3]) >> 1) - 128; pDst[5] = ((pSrc1[10 * 3] + pSrc1[11 * 3]) >> 1) - 128;
    pDst[6] = ((pSrc1[12 * 3] + pSrc1[13 * 3]) >> 1) - 128; pDst[7] = ((pSrc1[14 * 3] + pSrc1[15 * 3]) >> 1) - 128;
  }
}

void jpeg_encoder::load_quantized_coefficients(int component_num)
{
  int32 *q = m_quantization_tables[component_num > 0];
  int16 *pDst = m_coefficient_array;
  for (int i = 0; i < 64; i++)
  {
    sample_array_t j = m_sample_array[s_zag[i]];
    if (j < 0)
    {
      if ((j = -j + (*q >> 1)) < *q)
        *pDst++ = 0;
      else
        *pDst++ = static_cast<int16>(-(j / *q));
    }
    else
    {
      if ((j = j + (*q >> 1)) < *q)
        *pDst++ = 0;
      else
        *pDst++ = static_cast<int16>((j / *q));
    }
    q++;
  }
}

void jpeg_encoder::flush_output_buffer()
{
  if (m_out_buf_left != JPGE_OUT_BUF_SIZE)
    m_all_stream_writes_succeeded = m_all_stream_writes_succeeded && m_pStream->put_buf(m_out_buf, JPGE_OUT_BUF_SIZE - m_out_buf_left);
  m_pOut_buf = m_out_buf;
  m_out_buf_left = JPGE_OUT_BUF_SIZE;
}

void jpeg_encoder::put_bits(uint bits, uint len)
{
  m_bit_buffer |= ((uint32)bits << (24 - (m_bits_in += len)));
  while (m_bits_in >= 8)
  {
    uint8 c;
    #define JPGE_PUT_BYTE(c) { *m_pOut_buf++ = (c); if (--m_out_buf_left == 0) flush_output_buffer(); }
    JPGE_PUT_BYTE(c = (uint8)((m_bit_buffer >> 16) & 0xFF));
    if (c == 0xFF) JPGE_PUT_BYTE(0);
    m_bit_buffer <<= 8;
    m_bits_in -= 8;
  }
}

void jpeg_encoder::code_coefficients_pass_one(int component_num)
{
  if (component_num >= 3) return; // just to shut up static analysis
  int i, run_len, nbits, temp1;
  int16 *src = m_coefficient_array;
  uint32 *dc_count = component_num ? m_huff_count[0 + 1] : m_huff_count[0 + 0], *ac_count = component_num ? m_huff_count[2 + 1] : m_huff_count[2 + 0];

  temp1 = src[0] - m_last_dc_val[component_num];
  m_last_dc_val[component_num] = src[0];
  if (temp1 < 0) temp1 = -temp1;

  nbits = 0;
  while (temp1)
  {
    nbits++; temp1 >>= 1;
  }

  dc_count[nbits]++;
  for (run_len = 0, i = 1; i < 64; i++)
  {
    if ((temp1 = m_coefficient_array[i]) == 0)
      run_len++;
    else
    {
      while (run_len >= 16)
      {
        ac_count[0xF0]++;
        run_len -= 16;
      }
      if (temp1 < 0) temp1 = -temp1;
      nbits = 1;
      while (temp1 >>= 1) nbits++;
      ac_count[(run_len << 4) + nbits]++;
      run_len = 0;
    }
  }
  if (run_len) ac_count[0]++;
}

void jpeg_encoder::code_coefficients_pass_two(int component_num)
{
  int i, j, run_len, nbits, temp1, temp2;
  int16 *pSrc = m_coefficient_array;
  uint *codes[2];
  uint8 *code_sizes[2];

  if (component_num == 0)
  {
    codes[0] = m_huff_codes[0 + 0]; codes[1] = m_huff_codes[2 + 0];
    code_sizes[0] = m_huff_code_sizes[0 + 0]; code_sizes[1] = m_huff_code_sizes[2 + 0];
  }
  else
  {
    codes[0] = m_huff_codes[0 + 1]; codes[1] = m_huff_codes[2 + 1];
    code_sizes[0] = m_huff_code_sizes[0 + 1]; code_sizes[1] = m_huff_code_sizes[2 + 1];
  }

  temp1 = temp2 = pSrc[0] - m_last_dc_val[component_num];
  m_last_dc_val[component_num] = pSrc[0];

  if (temp1 < 0)
  {
    temp1 = -temp1; temp2--;
  }

  nbits = 0;
  while (temp1)
  {
    nbits++; temp1 >>= 1;
  }

  put_bits(codes[0][nbits], code_sizes[0][nbits]);
  if (nbits) put_bits(temp2 & ((1 << nbits) - 1), nbits);

  for (run_len = 0, i = 1; i < 64; i++)
  {
    if ((temp1 = m_coefficient_array[i]) == 0)
      run_len++;
    else
    {
      while (run_len >= 16)
      {
        put_bits(codes[1][0xF0], code_sizes[1][0xF0]);
        run_len -= 16;
      }
      if ((temp2 = temp1) < 0)
      {
        temp1 = -temp1;
        temp2--;
      }
      nbits = 1;
      while (temp1 >>= 1)
        nbits++;
      j = (run_len << 4) + nbits;
      put_bits(codes[1][j], code_sizes[1][j]);
      put_bits(temp2 & ((1 << nbits) - 1), nbits);
      run_len = 0;
    }
  }
  if (run_len)
    put_bits(codes[1][0], code_sizes[1][0]);
}

void jpeg_encoder::code_block(int component_num)
{
  DCT2D(m_sample_array);
  load_quantized_coefficients(component_num);
  if (m_pass_num == 1)
    code_coefficients_pass_one(component_num);
  else
    code_coefficients_pass_two(component_num);
}

void jpeg_encoder::process_mcu_row()
{
  if (m_num_components == 1)
  {
    for (int i = 0; i < m_mcus_per_row; i++)
    {
      load_block_8_8_grey(i); code_block(0);
    }
  }
  else if ((m_comp_h_samp[0] == 1) && (m_comp_v_samp[0] == 1))
  {
    for (int i = 0; i < m_mcus_per_row; i++)
    {
      load_block_8_8(i, 0, 0); code_block(0); load_block_8_8(i, 0, 1); code_block(1); load_block_8_8(i, 0, 2); code_block(2);
    }
  }
  else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 1))
  {
    for (int i = 0; i < m_mcus_per_row; i++)
    {
      load_block_8_8(i * 2 + 0, 0, 0); code_block(0); load_block_8_8(i * 2 + 1, 0, 0); code_block(0);
      load_block_16_8_8(i, 1); code_block(1); load_block_16_8_8(i, 2); code_block(2);
    }
  }
  else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 2))
  {
    for (int i = 0; i < m_mcus_per_row; i++)
    {
      load_block_8_8(i * 2 + 0, 0, 0); code_block(0); load_block_8_8(i * 2 + 1, 0, 0); code_block(0);
      load_block_8_8(i * 2 + 0, 1, 0); code_block(0); load_block_8_8(i * 2 + 1, 1, 0); code_block(0);
      load_block_16_8(i, 1); code_block(1); load_block_16_8(i, 2); code_block(2);
    }
  }
}

bool jpeg_encoder::terminate_pass_one()
{
  optimize_huffman_table(0+0, DC_LUM_CODES); optimize_huffman_table(2+0, AC_LUM_CODES);
  if (m_num_components > 1)
  {
    optimize_huffman_table(0+1, DC_CHROMA_CODES); optimize_huffman_table(2+1, AC_CHROMA_CODES);
  }
  return second_pass_init();
}

bool jpeg_encoder::terminate_pass_two()
{
  put_bits(0x7F, 7);
  flush_output_buffer();
  emit_marker(M_EOI);
  m_pass_num++; // purposely bump up m_pass_num, for debugging
  return true;
}

bool jpeg_encoder::process_end_of_image()
{
  if (m_mcu_y_ofs)
  {
    if (m_mcu_y_ofs < 16) // check here just to shut up static analysis
    {
      for (int i = m_mcu_y_ofs; i < m_mcu_y; i++)
        memcpy(m_mcu_lines[i], m_mcu_lines[m_mcu_y_ofs - 1], m_image_bpl_mcu);
    }

    process_mcu_row();
  }

  if (m_pass_num == 1)
    return terminate_pass_one();
  else
    return terminate_pass_two();
}

void jpeg_encoder::load_mcu(const void *pSrc)
{
  const uint8* Psrc = reinterpret_cast<const uint8*>(pSrc);

  uint8* pDst = m_mcu_lines[m_mcu_y_ofs]; // OK to write up to m_image_bpl_xlt bytes to pDst

  if (m_num_components == 1)
  {
    if (m_image_bpp == 4)
      RGBA_to_Y(pDst, Psrc, m_image_x);
    else if (m_image_bpp == 3)
      RGB_to_Y(pDst, Psrc, m_image_x);
    else
      memcpy(pDst, Psrc, m_image_x);
  }
  else
  {
    if (m_image_bpp == 4)
      RGBA_to_YCC(pDst, Psrc, m_image_x);
    else if (m_image_bpp == 3)
      RGB_to_YCC(pDst, Psrc, m_image_x);
    else
      Y_to_YCC(pDst, Psrc, m_image_x);
  }

  // Possibly duplicate pixels at end of scanline if not a multiple of 8 or 16
  if (m_num_components == 1)
    memset(m_mcu_lines[m_mcu_y_ofs] + m_image_bpl_xlt, pDst[m_image_bpl_xlt - 1], m_image_x_mcu - m_image_x);
  else
  {
    const uint8 y = pDst[m_image_bpl_xlt - 3 + 0], cb = pDst[m_image_bpl_xlt - 3 + 1], cr = pDst[m_image_bpl_xlt - 3 + 2];
    uint8 *q = m_mcu_lines[m_mcu_y_ofs] + m_image_bpl_xlt;
    for (int i = m_image_x; i < m_image_x_mcu; i++)
    {
      *q++ = y; *q++ = cb; *q++ = cr;
    }
  }

  if (++m_mcu_y_ofs == m_mcu_y)
  {
    process_mcu_row();
    m_mcu_y_ofs = 0;
  }
}

void jpeg_encoder::clear()
{
  m_mcu_lines[0] = NULL;
  m_pass_num = 0;
  m_all_stream_writes_succeeded = true;
}

jpeg_encoder::jpeg_encoder()
{
  clear();
}

jpeg_encoder::~jpeg_encoder()
{
  deinit();
}

bool jpeg_encoder::init(output_stream *pStream, int64_t width, int64_t height, int64_t src_channels, const params &comp_params)
{
  deinit();
  if (((!pStream) || (width < 1) || (height < 1)) || ((src_channels != 1) && (src_channels != 3) && (src_channels != 4)) || (!comp_params.check_valid())) return false;
  m_pStream = pStream;
  m_params = comp_params;
  return jpg_open(width, height, src_channels);
}

void jpeg_encoder::deinit()
{
  jpge_free(m_mcu_lines[0]);
  clear();
}

bool jpeg_encoder::process_scanline(const void* pScanline)
{
  if ((m_pass_num < 1) || (m_pass_num > 2)) return false;
  if (m_all_stream_writes_succeeded)
  {
    if (!pScanline)
    {
      if (!process_end_of_image()) return false;
    }
    else
    {
      load_mcu(pScanline);
    }
  }
  return m_all_stream_writes_succeeded;
}

// Higher level wrappers/examples (optional).
#include <stdio.h>

class cfile_stream : public output_stream
{
   cfile_stream(const cfile_stream &);
   cfile_stream &operator= (const cfile_stream &);

   FILE* m_pFile;
   bool m_bStatus;

public:
   cfile_stream() : m_pFile(NULL), m_bStatus(false) { }

   virtual ~cfile_stream()
   {
      close();
   }

   bool open(const char *pFilename)
   {
      close();
#if defined(_MSC_VER)
      if (fopen_s(&m_pFile, pFilename, "wb") != 0)
	  {
		  return false;
	  }
#else
      m_pFile = fopen(pFilename, "wb");
#endif
      m_bStatus = (m_pFile != NULL);
      return m_bStatus;
   }

   bool close()
   {
      if (m_pFile)
      {
         if (fclose(m_pFile) == EOF)
         {
            m_bStatus = false;
         }
         m_pFile = NULL;
      }
      return m_bStatus;
   }

   virtual bool put_buf(const void* pBuf, int64_t len)
   {
      m_bStatus = m_bStatus && (fwrite(pBuf, len, 1, m_pFile) == 1);
      return m_bStatus;
   }

   uint get_size() const
   {
      return m_pFile ? ftell(m_pFile) : 0;
   }
};

// Writes JPEG image to file.
bool compress_image_to_jpeg_file(const char *pFilename, int64_t width, int64_t height, int64_t num_channels, const uint8 *pImage_data, const params &comp_params)
{
  cfile_stream dst_stream;
  if (!dst_stream.open(pFilename))
    return false;

  jpge::jpeg_encoder dst_image;
  if (!dst_image.init(&dst_stream, width, height, num_channels, comp_params))
    return false;

  for (uint pass_index = 0; pass_index < dst_image.get_total_passes(); pass_index++)
  {
    for (int64_t i = 0; i < height; i++)
    {
		// i, width, and num_channels are all 64bit
       const uint8* pBuf = pImage_data + i * width * num_channels;
       if (!dst_image.process_scanline(pBuf))
          return false;
    }
    if (!dst_image.process_scanline(NULL))
       return false;
  }

  dst_image.deinit();

  return dst_stream.close();
}

class memory_stream : public output_stream
{
   memory_stream(const memory_stream &);
   memory_stream &operator= (const memory_stream &);

   uint8 *m_pBuf;
   uint64_t m_buf_size, m_buf_ofs;

public:
   memory_stream(void *pBuf, uint64_t buf_size) : m_pBuf(static_cast<uint8*>(pBuf)), m_buf_size(buf_size), m_buf_ofs(0) { }

   virtual ~memory_stream() { }

   virtual bool put_buf(const void* pBuf, int64_t len)
   {
      uint64_t buf_remaining = m_buf_size - m_buf_ofs;
      if ((uint64_t)len > buf_remaining)
         return false;
      memcpy(m_pBuf + m_buf_ofs, pBuf, len);
      m_buf_ofs += len;
      return true;
   }

   uint64_t get_size() const
   {
      return m_buf_ofs;
   }
};

bool compress_image_to_jpeg_file_in_memory(void *pDstBuf, int64_t &buf_size, int64_t width, int64_t height, int64_t num_channels, const uint8 *pImage_data, const params &comp_params)
{
   if ((!pDstBuf) || (!buf_size))
      return false;

   memory_stream dst_stream(pDstBuf, buf_size);

   buf_size = 0;

   jpge::jpeg_encoder dst_image;
   if (!dst_image.init(&dst_stream, width, height, num_channels, comp_params))
      return false;

   for (uint pass_index = 0; pass_index < dst_image.get_total_passes(); pass_index++)
   {
     for (int64_t i = 0; i < height; i++)
     {
        const uint8* pScanline = pImage_data + i * width * num_channels;
        if (!dst_image.process_scanline(pScanline))
           return false;
     }
     if (!dst_image.process_scanline(NULL))
        return false;
   }

   dst_image.deinit();

   buf_size = dst_stream.get_size();
   return true;
}

} // namespace jpge