forked from CyanogenMod/android_external_libpng
/
pngwutil.c
2832 lines (2483 loc) · 83.1 KB
/
pngwutil.c
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
/* pngwutil.c - utilities to write a PNG file
*
* Last changed in libpng 1.2.43 [February 25, 2010]
* Copyright (c) 1998-2010 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
#define PNG_INTERNAL
#define PNG_NO_PEDANTIC_WARNINGS
#include "png.h"
#ifdef PNG_WRITE_SUPPORTED
/* Place a 32-bit number into a buffer in PNG byte order. We work
* with unsigned numbers for convenience, although one supported
* ancillary chunk uses signed (two's complement) numbers.
*/
void PNGAPI
png_save_uint_32(png_bytep buf, png_uint_32 i)
{
buf[0] = (png_byte)((i >> 24) & 0xff);
buf[1] = (png_byte)((i >> 16) & 0xff);
buf[2] = (png_byte)((i >> 8) & 0xff);
buf[3] = (png_byte)(i & 0xff);
}
/* The png_save_int_32 function assumes integers are stored in two's
* complement format. If this isn't the case, then this routine needs to
* be modified to write data in two's complement format.
*/
void PNGAPI
png_save_int_32(png_bytep buf, png_int_32 i)
{
buf[0] = (png_byte)((i >> 24) & 0xff);
buf[1] = (png_byte)((i >> 16) & 0xff);
buf[2] = (png_byte)((i >> 8) & 0xff);
buf[3] = (png_byte)(i & 0xff);
}
/* Place a 16-bit number into a buffer in PNG byte order.
* The parameter is declared unsigned int, not png_uint_16,
* just to avoid potential problems on pre-ANSI C compilers.
*/
void PNGAPI
png_save_uint_16(png_bytep buf, unsigned int i)
{
buf[0] = (png_byte)((i >> 8) & 0xff);
buf[1] = (png_byte)(i & 0xff);
}
/* Simple function to write the signature. If we have already written
* the magic bytes of the signature, or more likely, the PNG stream is
* being embedded into another stream and doesn't need its own signature,
* we should call png_set_sig_bytes() to tell libpng how many of the
* bytes have already been written.
*/
void /* PRIVATE */
png_write_sig(png_structp png_ptr)
{
png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
/* Write the rest of the 8 byte signature */
png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
(png_size_t)(8 - png_ptr->sig_bytes));
if (png_ptr->sig_bytes < 3)
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
/* Write a PNG chunk all at once. The type is an array of ASCII characters
* representing the chunk name. The array must be at least 4 bytes in
* length, and does not need to be null terminated. To be safe, pass the
* pre-defined chunk names here, and if you need a new one, define it
* where the others are defined. The length is the length of the data.
* All the data must be present. If that is not possible, use the
* png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
* functions instead.
*/
void PNGAPI
png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
png_bytep data, png_size_t length)
{
if (png_ptr == NULL)
return;
png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
png_write_chunk_data(png_ptr, data, (png_size_t)length);
png_write_chunk_end(png_ptr);
}
/* Write the start of a PNG chunk. The type is the chunk type.
* The total_length is the sum of the lengths of all the data you will be
* passing in png_write_chunk_data().
*/
void PNGAPI
png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
png_uint_32 length)
{
png_byte buf[8];
png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
(unsigned long)length);
if (png_ptr == NULL)
return;
/* Write the length and the chunk name */
png_save_uint_32(buf, length);
png_memcpy(buf + 4, chunk_name, 4);
png_write_data(png_ptr, buf, (png_size_t)8);
/* Put the chunk name into png_ptr->chunk_name */
png_memcpy(png_ptr->chunk_name, chunk_name, 4);
/* Reset the crc and run it over the chunk name */
png_reset_crc(png_ptr);
png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
}
/* Write the data of a PNG chunk started with png_write_chunk_start().
* Note that multiple calls to this function are allowed, and that the
* sum of the lengths from these calls *must* add up to the total_length
* given to png_write_chunk_start().
*/
void PNGAPI
png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
/* Write the data, and run the CRC over it */
if (png_ptr == NULL)
return;
if (data != NULL && length > 0)
{
png_write_data(png_ptr, data, length);
/* Update the CRC after writing the data,
* in case that the user I/O routine alters it.
*/
png_calculate_crc(png_ptr, data, length);
}
}
/* Finish a chunk started with png_write_chunk_start(). */
void PNGAPI
png_write_chunk_end(png_structp png_ptr)
{
png_byte buf[4];
if (png_ptr == NULL) return;
/* Write the crc in a single operation */
png_save_uint_32(buf, png_ptr->crc);
png_write_data(png_ptr, buf, (png_size_t)4);
}
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
/* This pair of functions encapsulates the operation of (a) compressing a
* text string, and (b) issuing it later as a series of chunk data writes.
* The compression_state structure is shared context for these functions
* set up by the caller in order to make the whole mess thread-safe.
*/
typedef struct
{
char *input; /* The uncompressed input data */
int input_len; /* Its length */
int num_output_ptr; /* Number of output pointers used */
int max_output_ptr; /* Size of output_ptr */
png_charpp output_ptr; /* Array of pointers to output */
} compression_state;
/* Compress given text into storage in the png_ptr structure */
static int /* PRIVATE */
png_text_compress(png_structp png_ptr,
png_charp text, png_size_t text_len, int compression,
compression_state *comp)
{
int ret;
comp->num_output_ptr = 0;
comp->max_output_ptr = 0;
comp->output_ptr = NULL;
comp->input = NULL;
comp->input_len = 0;
/* We may just want to pass the text right through */
if (compression == PNG_TEXT_COMPRESSION_NONE)
{
comp->input = text;
comp->input_len = text_len;
return((int)text_len);
}
if (compression >= PNG_TEXT_COMPRESSION_LAST)
{
#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
char msg[50];
png_snprintf(msg, 50, "Unknown compression type %d", compression);
png_warning(png_ptr, msg);
#else
png_warning(png_ptr, "Unknown compression type");
#endif
}
/* We can't write the chunk until we find out how much data we have,
* which means we need to run the compressor first and save the
* output. This shouldn't be a problem, as the vast majority of
* comments should be reasonable, but we will set up an array of
* malloc'd pointers to be sure.
*
* If we knew the application was well behaved, we could simplify this
* greatly by assuming we can always malloc an output buffer large
* enough to hold the compressed text ((1001 * text_len / 1000) + 12)
* and malloc this directly. The only time this would be a bad idea is
* if we can't malloc more than 64K and we have 64K of random input
* data, or if the input string is incredibly large (although this
* wouldn't cause a failure, just a slowdown due to swapping).
*/
/* Set up the compression buffers */
png_ptr->zstream.avail_in = (uInt)text_len;
png_ptr->zstream.next_in = (Bytef *)text;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
/* This is the same compression loop as in png_write_row() */
do
{
/* Compress the data */
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
if (ret != Z_OK)
{
/* Error */
if (png_ptr->zstream.msg != NULL)
png_error(png_ptr, png_ptr->zstream.msg);
else
png_error(png_ptr, "zlib error");
}
/* Check to see if we need more room */
if (!(png_ptr->zstream.avail_out))
{
/* Make sure the output array has room */
if (comp->num_output_ptr >= comp->max_output_ptr)
{
int old_max;
old_max = comp->max_output_ptr;
comp->max_output_ptr = comp->num_output_ptr + 4;
if (comp->output_ptr != NULL)
{
png_charpp old_ptr;
old_ptr = comp->output_ptr;
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
(png_uint_32)
(comp->max_output_ptr * png_sizeof(png_charpp)));
png_memcpy(comp->output_ptr, old_ptr, old_max
* png_sizeof(png_charp));
png_free(png_ptr, old_ptr);
}
else
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
(png_uint_32)
(comp->max_output_ptr * png_sizeof(png_charp)));
}
/* Save the data */
comp->output_ptr[comp->num_output_ptr] =
(png_charp)png_malloc(png_ptr,
(png_uint_32)png_ptr->zbuf_size);
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
png_ptr->zbuf_size);
comp->num_output_ptr++;
/* and reset the buffer */
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_out = png_ptr->zbuf;
}
/* Continue until we don't have any more to compress */
} while (png_ptr->zstream.avail_in);
/* Finish the compression */
do
{
/* Tell zlib we are finished */
ret = deflate(&png_ptr->zstream, Z_FINISH);
if (ret == Z_OK)
{
/* Check to see if we need more room */
if (!(png_ptr->zstream.avail_out))
{
/* Check to make sure our output array has room */
if (comp->num_output_ptr >= comp->max_output_ptr)
{
int old_max;
old_max = comp->max_output_ptr;
comp->max_output_ptr = comp->num_output_ptr + 4;
if (comp->output_ptr != NULL)
{
png_charpp old_ptr;
old_ptr = comp->output_ptr;
/* This could be optimized to realloc() */
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
(png_uint_32)(comp->max_output_ptr *
png_sizeof(png_charp)));
png_memcpy(comp->output_ptr, old_ptr,
old_max * png_sizeof(png_charp));
png_free(png_ptr, old_ptr);
}
else
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
(png_uint_32)(comp->max_output_ptr *
png_sizeof(png_charp)));
}
/* Save the data */
comp->output_ptr[comp->num_output_ptr] =
(png_charp)png_malloc(png_ptr,
(png_uint_32)png_ptr->zbuf_size);
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
png_ptr->zbuf_size);
comp->num_output_ptr++;
/* and reset the buffer pointers */
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_out = png_ptr->zbuf;
}
}
else if (ret != Z_STREAM_END)
{
/* We got an error */
if (png_ptr->zstream.msg != NULL)
png_error(png_ptr, png_ptr->zstream.msg);
else
png_error(png_ptr, "zlib error");
}
} while (ret != Z_STREAM_END);
/* Text length is number of buffers plus last buffer */
text_len = png_ptr->zbuf_size * comp->num_output_ptr;
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
return((int)text_len);
}
/* Ship the compressed text out via chunk writes */
static void /* PRIVATE */
png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
{
int i;
/* Handle the no-compression case */
if (comp->input)
{
png_write_chunk_data(png_ptr, (png_bytep)comp->input,
(png_size_t)comp->input_len);
return;
}
/* Write saved output buffers, if any */
for (i = 0; i < comp->num_output_ptr; i++)
{
png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
(png_size_t)png_ptr->zbuf_size);
png_free(png_ptr, comp->output_ptr[i]);
comp->output_ptr[i]=NULL;
}
if (comp->max_output_ptr != 0)
png_free(png_ptr, comp->output_ptr);
comp->output_ptr=NULL;
/* Write anything left in zbuf */
if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
png_write_chunk_data(png_ptr, png_ptr->zbuf,
(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
/* Reset zlib for another zTXt/iTXt or image data */
deflateReset(&png_ptr->zstream);
png_ptr->zstream.data_type = Z_BINARY;
}
#endif
/* Write the IHDR chunk, and update the png_struct with the necessary
* information. Note that the rest of this code depends upon this
* information being correct.
*/
void /* PRIVATE */
png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
int bit_depth, int color_type, int compression_type, int filter_type,
int interlace_type)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IHDR;
#endif
int ret;
png_byte buf[13]; /* Buffer to store the IHDR info */
png_debug(1, "in png_write_IHDR");
/* Check that we have valid input data from the application info */
switch (color_type)
{
case PNG_COLOR_TYPE_GRAY:
switch (bit_depth)
{
case 1:
case 2:
case 4:
case 8:
case 16: png_ptr->channels = 1; break;
default: png_error(png_ptr,
"Invalid bit depth for grayscale image");
}
break;
case PNG_COLOR_TYPE_RGB:
if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for RGB image");
png_ptr->channels = 3;
break;
case PNG_COLOR_TYPE_PALETTE:
switch (bit_depth)
{
case 1:
case 2:
case 4:
case 8: png_ptr->channels = 1; break;
default: png_error(png_ptr, "Invalid bit depth for paletted image");
}
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
png_ptr->channels = 2;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for RGBA image");
png_ptr->channels = 4;
break;
default:
png_error(png_ptr, "Invalid image color type specified");
}
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
{
png_warning(png_ptr, "Invalid compression type specified");
compression_type = PNG_COMPRESSION_TYPE_BASE;
}
/* Write filter_method 64 (intrapixel differencing) only if
* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
* 2. Libpng did not write a PNG signature (this filter_method is only
* used in PNG datastreams that are embedded in MNG datastreams) and
* 3. The application called png_permit_mng_features with a mask that
* included PNG_FLAG_MNG_FILTER_64 and
* 4. The filter_method is 64 and
* 5. The color_type is RGB or RGBA
*/
if (
#ifdef PNG_MNG_FEATURES_SUPPORTED
!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
(color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
#endif
filter_type != PNG_FILTER_TYPE_BASE)
{
png_warning(png_ptr, "Invalid filter type specified");
filter_type = PNG_FILTER_TYPE_BASE;
}
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
if (interlace_type != PNG_INTERLACE_NONE &&
interlace_type != PNG_INTERLACE_ADAM7)
{
png_warning(png_ptr, "Invalid interlace type specified");
interlace_type = PNG_INTERLACE_ADAM7;
}
#else
interlace_type=PNG_INTERLACE_NONE;
#endif
/* Save the relevent information */
png_ptr->bit_depth = (png_byte)bit_depth;
png_ptr->color_type = (png_byte)color_type;
png_ptr->interlaced = (png_byte)interlace_type;
#ifdef PNG_MNG_FEATURES_SUPPORTED
png_ptr->filter_type = (png_byte)filter_type;
#endif
png_ptr->compression_type = (png_byte)compression_type;
png_ptr->width = width;
png_ptr->height = height;
png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
/* Set the usr info, so any transformations can modify it */
png_ptr->usr_width = png_ptr->width;
png_ptr->usr_bit_depth = png_ptr->bit_depth;
png_ptr->usr_channels = png_ptr->channels;
/* Pack the header information into the buffer */
png_save_uint_32(buf, width);
png_save_uint_32(buf + 4, height);
buf[8] = (png_byte)bit_depth;
buf[9] = (png_byte)color_type;
buf[10] = (png_byte)compression_type;
buf[11] = (png_byte)filter_type;
buf[12] = (png_byte)interlace_type;
/* Write the chunk */
png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
/* Initialize zlib with PNG info */
png_ptr->zstream.zalloc = png_zalloc;
png_ptr->zstream.zfree = png_zfree;
png_ptr->zstream.opaque = (voidpf)png_ptr;
if (!(png_ptr->do_filter))
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
png_ptr->bit_depth < 8)
png_ptr->do_filter = PNG_FILTER_NONE;
else
png_ptr->do_filter = PNG_ALL_FILTERS;
}
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
{
if (png_ptr->do_filter != PNG_FILTER_NONE)
png_ptr->zlib_strategy = Z_FILTERED;
else
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
}
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
png_ptr->zlib_mem_level = 8;
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
png_ptr->zlib_window_bits = 15;
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
png_ptr->zlib_method = 8;
ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
png_ptr->zlib_method, png_ptr->zlib_window_bits,
png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
if (ret != Z_OK)
{
if (ret == Z_VERSION_ERROR) png_error(png_ptr,
"zlib failed to initialize compressor -- version error");
if (ret == Z_STREAM_ERROR) png_error(png_ptr,
"zlib failed to initialize compressor -- stream error");
if (ret == Z_MEM_ERROR) png_error(png_ptr,
"zlib failed to initialize compressor -- mem error");
png_error(png_ptr, "zlib failed to initialize compressor");
}
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
/* libpng is not interested in zstream.data_type */
/* Set it to a predefined value, to avoid its evaluation inside zlib */
png_ptr->zstream.data_type = Z_BINARY;
png_ptr->mode = PNG_HAVE_IHDR;
}
/* Write the palette. We are careful not to trust png_color to be in the
* correct order for PNG, so people can redefine it to any convenient
* structure.
*/
void /* PRIVATE */
png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_PLTE;
#endif
png_uint_32 i;
png_colorp pal_ptr;
png_byte buf[3];
png_debug(1, "in png_write_PLTE");
if ((
#ifdef PNG_MNG_FEATURES_SUPPORTED
!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
#endif
num_pal == 0) || num_pal > 256)
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
png_error(png_ptr, "Invalid number of colors in palette");
}
else
{
png_warning(png_ptr, "Invalid number of colors in palette");
return;
}
}
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
{
png_warning(png_ptr,
"Ignoring request to write a PLTE chunk in grayscale PNG");
return;
}
png_ptr->num_palette = (png_uint_16)num_pal;
png_debug1(3, "num_palette = %d", png_ptr->num_palette);
png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
(png_uint_32)(num_pal * 3));
#ifdef PNG_POINTER_INDEXING_SUPPORTED
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
{
buf[0] = pal_ptr->red;
buf[1] = pal_ptr->green;
buf[2] = pal_ptr->blue;
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
}
#else
/* This is a little slower but some buggy compilers need to do this
* instead
*/
pal_ptr=palette;
for (i = 0; i < num_pal; i++)
{
buf[0] = pal_ptr[i].red;
buf[1] = pal_ptr[i].green;
buf[2] = pal_ptr[i].blue;
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
}
#endif
png_write_chunk_end(png_ptr);
png_ptr->mode |= PNG_HAVE_PLTE;
}
/* Write an IDAT chunk */
void /* PRIVATE */
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IDAT;
#endif
png_debug(1, "in png_write_IDAT");
/* Optimize the CMF field in the zlib stream. */
/* This hack of the zlib stream is compliant to the stream specification. */
if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
{
unsigned int z_cmf = data[0]; /* zlib compression method and flags */
if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
{
/* Avoid memory underflows and multiplication overflows.
*
* The conditions below are practically always satisfied;
* however, they still must be checked.
*/
if (length >= 2 &&
png_ptr->height < 16384 && png_ptr->width < 16384)
{
png_uint_32 uncompressed_idat_size = png_ptr->height *
((png_ptr->width *
png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
unsigned int z_cinfo = z_cmf >> 4;
unsigned int half_z_window_size = 1 << (z_cinfo + 7);
while (uncompressed_idat_size <= half_z_window_size &&
half_z_window_size >= 256)
{
z_cinfo--;
half_z_window_size >>= 1;
}
z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
if (data[0] != (png_byte)z_cmf)
{
data[0] = (png_byte)z_cmf;
data[1] &= 0xe0;
data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
}
}
}
else
png_error(png_ptr,
"Invalid zlib compression method or flags in IDAT");
}
png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
png_ptr->mode |= PNG_HAVE_IDAT;
}
/* Write an IEND chunk */
void /* PRIVATE */
png_write_IEND(png_structp png_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IEND;
#endif
png_debug(1, "in png_write_IEND");
png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
(png_size_t)0);
png_ptr->mode |= PNG_HAVE_IEND;
}
#ifdef PNG_WRITE_gAMA_SUPPORTED
/* Write a gAMA chunk */
#ifdef PNG_FLOATING_POINT_SUPPORTED
void /* PRIVATE */
png_write_gAMA(png_structp png_ptr, double file_gamma)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_gAMA;
#endif
png_uint_32 igamma;
png_byte buf[4];
png_debug(1, "in png_write_gAMA");
/* file_gamma is saved in 1/100,000ths */
igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
png_save_uint_32(buf, igamma);
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
}
#endif
#ifdef PNG_FIXED_POINT_SUPPORTED
void /* PRIVATE */
png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_gAMA;
#endif
png_byte buf[4];
png_debug(1, "in png_write_gAMA");
/* file_gamma is saved in 1/100,000ths */
png_save_uint_32(buf, (png_uint_32)file_gamma);
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
}
#endif
#endif
#ifdef PNG_WRITE_sRGB_SUPPORTED
/* Write a sRGB chunk */
void /* PRIVATE */
png_write_sRGB(png_structp png_ptr, int srgb_intent)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_sRGB;
#endif
png_byte buf[1];
png_debug(1, "in png_write_sRGB");
if (srgb_intent >= PNG_sRGB_INTENT_LAST)
png_warning(png_ptr,
"Invalid sRGB rendering intent specified");
buf[0]=(png_byte)srgb_intent;
png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
}
#endif
#ifdef PNG_WRITE_iCCP_SUPPORTED
/* Write an iCCP chunk */
void /* PRIVATE */
png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
png_charp profile, int profile_len)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_iCCP;
#endif
png_size_t name_len;
png_charp new_name;
compression_state comp;
int embedded_profile_len = 0;
png_debug(1, "in png_write_iCCP");
comp.num_output_ptr = 0;
comp.max_output_ptr = 0;
comp.output_ptr = NULL;
comp.input = NULL;
comp.input_len = 0;
if ((name_len = png_check_keyword(png_ptr, name,
&new_name)) == 0)
return;
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
png_warning(png_ptr, "Unknown compression type in iCCP chunk");
if (profile == NULL)
profile_len = 0;
if (profile_len > 3)
embedded_profile_len =
((*( (png_bytep)profile ))<<24) |
((*( (png_bytep)profile + 1))<<16) |
((*( (png_bytep)profile + 2))<< 8) |
((*( (png_bytep)profile + 3)) );
if (embedded_profile_len < 0)
{
png_warning(png_ptr,
"Embedded profile length in iCCP chunk is negative");
png_free(png_ptr, new_name);
return;
}
if (profile_len < embedded_profile_len)
{
png_warning(png_ptr,
"Embedded profile length too large in iCCP chunk");
png_free(png_ptr, new_name);
return;
}
if (profile_len > embedded_profile_len)
{
png_warning(png_ptr,
"Truncating profile to actual length in iCCP chunk");
profile_len = embedded_profile_len;
}
if (profile_len)
profile_len = png_text_compress(png_ptr, profile,
(png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
/* Make sure we include the NULL after the name and the compression type */
png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
(png_uint_32)(name_len + profile_len + 2));
new_name[name_len + 1] = 0x00;
png_write_chunk_data(png_ptr, (png_bytep)new_name,
(png_size_t)(name_len + 2));
if (profile_len)
png_write_compressed_data_out(png_ptr, &comp);
png_write_chunk_end(png_ptr);
png_free(png_ptr, new_name);
}
#endif
#ifdef PNG_WRITE_sPLT_SUPPORTED
/* Write a sPLT chunk */
void /* PRIVATE */
png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_sPLT;
#endif
png_size_t name_len;
png_charp new_name;
png_byte entrybuf[10];
int entry_size = (spalette->depth == 8 ? 6 : 10);
int palette_size = entry_size * spalette->nentries;
png_sPLT_entryp ep;
#ifndef PNG_POINTER_INDEXING_SUPPORTED
int i;
#endif
png_debug(1, "in png_write_sPLT");
if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
return;
/* Make sure we include the NULL after the name */
png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
(png_uint_32)(name_len + 2 + palette_size));
png_write_chunk_data(png_ptr, (png_bytep)new_name,
(png_size_t)(name_len + 1));
png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
/* Loop through each palette entry, writing appropriately */
#ifdef PNG_POINTER_INDEXING_SUPPORTED
for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
{
if (spalette->depth == 8)
{
entrybuf[0] = (png_byte)ep->red;
entrybuf[1] = (png_byte)ep->green;
entrybuf[2] = (png_byte)ep->blue;
entrybuf[3] = (png_byte)ep->alpha;
png_save_uint_16(entrybuf + 4, ep->frequency);
}
else
{
png_save_uint_16(entrybuf + 0, ep->red);
png_save_uint_16(entrybuf + 2, ep->green);
png_save_uint_16(entrybuf + 4, ep->blue);
png_save_uint_16(entrybuf + 6, ep->alpha);
png_save_uint_16(entrybuf + 8, ep->frequency);
}
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
}
#else
ep=spalette->entries;
for (i=0; i>spalette->nentries; i++)
{
if (spalette->depth == 8)
{
entrybuf[0] = (png_byte)ep[i].red;
entrybuf[1] = (png_byte)ep[i].green;
entrybuf[2] = (png_byte)ep[i].blue;
entrybuf[3] = (png_byte)ep[i].alpha;
png_save_uint_16(entrybuf + 4, ep[i].frequency);
}
else
{
png_save_uint_16(entrybuf + 0, ep[i].red);
png_save_uint_16(entrybuf + 2, ep[i].green);
png_save_uint_16(entrybuf + 4, ep[i].blue);
png_save_uint_16(entrybuf + 6, ep[i].alpha);
png_save_uint_16(entrybuf + 8, ep[i].frequency);
}
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
}
#endif
png_write_chunk_end(png_ptr);
png_free(png_ptr, new_name);
}
#endif
#ifdef PNG_WRITE_sBIT_SUPPORTED
/* Write the sBIT chunk */
void /* PRIVATE */
png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_sBIT;
#endif
png_byte buf[4];
png_size_t size;
png_debug(1, "in png_write_sBIT");
/* Make sure we don't depend upon the order of PNG_COLOR_8 */
if (color_type & PNG_COLOR_MASK_COLOR)
{
png_byte maxbits;
maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
png_ptr->usr_bit_depth);
if (sbit->red == 0 || sbit->red > maxbits ||
sbit->green == 0 || sbit->green > maxbits ||
sbit->blue == 0 || sbit->blue > maxbits)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
buf[0] = sbit->red;
buf[1] = sbit->green;
buf[2] = sbit->blue;
size = 3;
}
else
{
if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
buf[0] = sbit->gray;
size = 1;
}
if (color_type & PNG_COLOR_MASK_ALPHA)
{
if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
buf[size++] = sbit->alpha;
}
png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
}
#endif
#ifdef PNG_WRITE_cHRM_SUPPORTED
/* Write the cHRM chunk */
#ifdef PNG_FLOATING_POINT_SUPPORTED
void /* PRIVATE */
png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
double red_x, double red_y, double green_x, double green_y,
double blue_x, double blue_y)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_cHRM;
#endif
png_byte buf[32];
png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
int_green_x, int_green_y, int_blue_x, int_blue_y;