2
/* pngpread.c - read a png file in push mode
4
* Last changed in libpng 1.4.3 [June 26, 2010]
5
* Copyright (c) 1998-2010 Glenn Randers-Pehrson
6
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
11
* and license in png.h
14
#define PNG_NO_PEDANTIC_WARNINGS
16
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
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/* Push model modes */
20
#define PNG_READ_SIG_MODE 0
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#define PNG_READ_CHUNK_MODE 1
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#define PNG_READ_IDAT_MODE 2
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#define PNG_SKIP_MODE 3
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#define PNG_READ_tEXt_MODE 4
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#define PNG_READ_zTXt_MODE 5
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#define PNG_READ_DONE_MODE 6
27
#define PNG_READ_iTXt_MODE 7
28
#define PNG_ERROR_MODE 8
31
png_process_data(png_structp png_ptr, png_infop info_ptr,
32
png_bytep buffer, png_size_t buffer_size)
34
if (png_ptr == NULL || info_ptr == NULL)
37
png_push_restore_buffer(png_ptr, buffer, buffer_size);
39
while (png_ptr->buffer_size)
41
png_process_some_data(png_ptr, info_ptr);
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/* What we do with the incoming data depends on what we were previously
46
* doing before we ran out of data...
49
png_process_some_data(png_structp png_ptr, png_infop info_ptr)
54
switch (png_ptr->process_mode)
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case PNG_READ_SIG_MODE:
58
png_push_read_sig(png_ptr, info_ptr);
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case PNG_READ_CHUNK_MODE:
64
png_push_read_chunk(png_ptr, info_ptr);
68
case PNG_READ_IDAT_MODE:
70
png_push_read_IDAT(png_ptr);
74
#ifdef PNG_READ_tEXt_SUPPORTED
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case PNG_READ_tEXt_MODE:
77
png_push_read_tEXt(png_ptr, info_ptr);
82
#ifdef PNG_READ_zTXt_SUPPORTED
83
case PNG_READ_zTXt_MODE:
85
png_push_read_zTXt(png_ptr, info_ptr);
90
#ifdef PNG_READ_iTXt_SUPPORTED
91
case PNG_READ_iTXt_MODE:
93
png_push_read_iTXt(png_ptr, info_ptr);
100
png_push_crc_finish(png_ptr);
106
png_ptr->buffer_size = 0;
112
/* Read any remaining signature bytes from the stream and compare them with
113
* the correct PNG signature. It is possible that this routine is called
114
* with bytes already read from the signature, either because they have been
115
* checked by the calling application, or because of multiple calls to this
119
png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
121
png_size_t num_checked = png_ptr->sig_bytes,
122
num_to_check = 8 - num_checked;
124
if (png_ptr->buffer_size < num_to_check)
126
num_to_check = png_ptr->buffer_size;
129
png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
131
png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
133
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
135
if (num_checked < 4 &&
136
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
137
png_error(png_ptr, "Not a PNG file");
139
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
143
if (png_ptr->sig_bytes >= 8)
145
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
151
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
157
#ifdef PNG_READ_bKGD_SUPPORTED
160
#ifdef PNG_READ_cHRM_SUPPORTED
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#ifdef PNG_READ_gAMA_SUPPORTED
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#ifdef PNG_READ_hIST_SUPPORTED
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#ifdef PNG_READ_iCCP_SUPPORTED
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#ifdef PNG_READ_iTXt_SUPPORTED
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#ifdef PNG_READ_oFFs_SUPPORTED
178
#ifdef PNG_READ_pCAL_SUPPORTED
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#ifdef PNG_READ_pHYs_SUPPORTED
184
#ifdef PNG_READ_sBIT_SUPPORTED
187
#ifdef PNG_READ_sCAL_SUPPORTED
190
#ifdef PNG_READ_sRGB_SUPPORTED
193
#ifdef PNG_READ_sPLT_SUPPORTED
196
#ifdef PNG_READ_tEXt_SUPPORTED
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#ifdef PNG_READ_tIME_SUPPORTED
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#ifdef PNG_READ_tRNS_SUPPORTED
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#ifdef PNG_READ_zTXt_SUPPORTED
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/* First we make sure we have enough data for the 4 byte chunk name
210
* and the 4 byte chunk length before proceeding with decoding the
211
* chunk data. To fully decode each of these chunks, we also make
212
* sure we have enough data in the buffer for the 4 byte CRC at the
213
* end of every chunk (except IDAT, which is handled separately).
215
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
217
png_byte chunk_length[4];
219
if (png_ptr->buffer_size < 8)
221
png_push_save_buffer(png_ptr);
225
png_push_fill_buffer(png_ptr, chunk_length, 4);
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png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
227
png_reset_crc(png_ptr);
228
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
229
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
230
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
233
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
234
if (png_ptr->mode & PNG_AFTER_IDAT)
235
png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
237
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
239
if (png_ptr->push_length != 13)
240
png_error(png_ptr, "Invalid IHDR length");
242
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
244
png_push_save_buffer(png_ptr);
248
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
251
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
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if (png_ptr->push_length + 4 > png_ptr->buffer_size)
255
png_push_save_buffer(png_ptr);
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png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
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png_ptr->process_mode = PNG_READ_DONE_MODE;
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png_push_have_end(png_ptr, info_ptr);
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#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
266
else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
268
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
270
png_push_save_buffer(png_ptr);
274
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
275
png_ptr->mode |= PNG_HAVE_IDAT;
277
png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
279
if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
280
png_ptr->mode |= PNG_HAVE_PLTE;
282
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
284
if (!(png_ptr->mode & PNG_HAVE_IHDR))
285
png_error(png_ptr, "Missing IHDR before IDAT");
287
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
288
!(png_ptr->mode & PNG_HAVE_PLTE))
289
png_error(png_ptr, "Missing PLTE before IDAT");
294
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
296
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
298
png_push_save_buffer(png_ptr);
301
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
304
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
306
/* If we reach an IDAT chunk, this means we have read all of the
307
* header chunks, and we can start reading the image (or if this
308
* is called after the image has been read - we have an error).
311
if (!(png_ptr->mode & PNG_HAVE_IHDR))
312
png_error(png_ptr, "Missing IHDR before IDAT");
314
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
315
!(png_ptr->mode & PNG_HAVE_PLTE))
316
png_error(png_ptr, "Missing PLTE before IDAT");
318
if (png_ptr->mode & PNG_HAVE_IDAT)
320
if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
321
if (png_ptr->push_length == 0)
324
if (png_ptr->mode & PNG_AFTER_IDAT)
325
png_benign_error(png_ptr, "Too many IDATs found");
328
png_ptr->idat_size = png_ptr->push_length;
329
png_ptr->mode |= PNG_HAVE_IDAT;
330
png_ptr->process_mode = PNG_READ_IDAT_MODE;
331
png_push_have_info(png_ptr, info_ptr);
332
png_ptr->zstream.avail_out =
333
(uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
334
png_ptr->iwidth) + 1;
335
png_ptr->zstream.next_out = png_ptr->row_buf;
339
#ifdef PNG_READ_gAMA_SUPPORTED
340
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
342
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
344
png_push_save_buffer(png_ptr);
348
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
352
#ifdef PNG_READ_sBIT_SUPPORTED
353
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
355
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
357
png_push_save_buffer(png_ptr);
361
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
365
#ifdef PNG_READ_cHRM_SUPPORTED
366
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
368
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
370
png_push_save_buffer(png_ptr);
374
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
378
#ifdef PNG_READ_sRGB_SUPPORTED
379
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
381
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
383
png_push_save_buffer(png_ptr);
387
png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
391
#ifdef PNG_READ_iCCP_SUPPORTED
392
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
394
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
396
png_push_save_buffer(png_ptr);
400
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
404
#ifdef PNG_READ_sPLT_SUPPORTED
405
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
407
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
409
png_push_save_buffer(png_ptr);
413
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
417
#ifdef PNG_READ_tRNS_SUPPORTED
418
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
420
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
422
png_push_save_buffer(png_ptr);
426
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
430
#ifdef PNG_READ_bKGD_SUPPORTED
431
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
433
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
435
png_push_save_buffer(png_ptr);
439
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
443
#ifdef PNG_READ_hIST_SUPPORTED
444
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
446
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
448
png_push_save_buffer(png_ptr);
452
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
456
#ifdef PNG_READ_pHYs_SUPPORTED
457
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
459
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
461
png_push_save_buffer(png_ptr);
465
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
469
#ifdef PNG_READ_oFFs_SUPPORTED
470
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
472
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
474
png_push_save_buffer(png_ptr);
478
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
482
#ifdef PNG_READ_pCAL_SUPPORTED
483
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
485
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
487
png_push_save_buffer(png_ptr);
491
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
495
#ifdef PNG_READ_sCAL_SUPPORTED
496
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
498
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
500
png_push_save_buffer(png_ptr);
504
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
508
#ifdef PNG_READ_tIME_SUPPORTED
509
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
511
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
513
png_push_save_buffer(png_ptr);
517
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
521
#ifdef PNG_READ_tEXt_SUPPORTED
522
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
524
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
526
png_push_save_buffer(png_ptr);
530
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
534
#ifdef PNG_READ_zTXt_SUPPORTED
535
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
537
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
539
png_push_save_buffer(png_ptr);
543
png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
547
#ifdef PNG_READ_iTXt_SUPPORTED
548
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
550
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
552
png_push_save_buffer(png_ptr);
556
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
562
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
564
png_push_save_buffer(png_ptr);
567
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
570
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
574
png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
576
png_ptr->process_mode = PNG_SKIP_MODE;
577
png_ptr->skip_length = skip;
581
png_push_crc_finish(png_structp png_ptr)
583
if (png_ptr->skip_length && png_ptr->save_buffer_size)
585
png_size_t save_size;
587
if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
588
save_size = (png_size_t)png_ptr->skip_length;
590
save_size = png_ptr->save_buffer_size;
592
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
594
png_ptr->skip_length -= save_size;
595
png_ptr->buffer_size -= save_size;
596
png_ptr->save_buffer_size -= save_size;
597
png_ptr->save_buffer_ptr += save_size;
599
if (png_ptr->skip_length && png_ptr->current_buffer_size)
601
png_size_t save_size;
603
if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
604
save_size = (png_size_t)png_ptr->skip_length;
606
save_size = png_ptr->current_buffer_size;
608
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
610
png_ptr->skip_length -= save_size;
611
png_ptr->buffer_size -= save_size;
612
png_ptr->current_buffer_size -= save_size;
613
png_ptr->current_buffer_ptr += save_size;
615
if (!png_ptr->skip_length)
617
if (png_ptr->buffer_size < 4)
619
png_push_save_buffer(png_ptr);
623
png_crc_finish(png_ptr, 0);
624
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
629
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
637
if (png_ptr->save_buffer_size)
639
png_size_t save_size;
641
if (length < png_ptr->save_buffer_size)
644
save_size = png_ptr->save_buffer_size;
646
png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
649
png_ptr->buffer_size -= save_size;
650
png_ptr->save_buffer_size -= save_size;
651
png_ptr->save_buffer_ptr += save_size;
653
if (length && png_ptr->current_buffer_size)
655
png_size_t save_size;
657
if (length < png_ptr->current_buffer_size)
661
save_size = png_ptr->current_buffer_size;
663
png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
664
png_ptr->buffer_size -= save_size;
665
png_ptr->current_buffer_size -= save_size;
666
png_ptr->current_buffer_ptr += save_size;
671
png_push_save_buffer(png_structp png_ptr)
673
if (png_ptr->save_buffer_size)
675
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
681
istop = png_ptr->save_buffer_size;
682
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
683
i < istop; i++, sp++, dp++)
689
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
690
png_ptr->save_buffer_max)
693
png_bytep old_buffer;
695
if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
696
(png_ptr->current_buffer_size + 256))
698
png_error(png_ptr, "Potential overflow of save_buffer");
701
new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
702
old_buffer = png_ptr->save_buffer;
703
png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
704
(png_size_t)new_max);
705
if (png_ptr->save_buffer == NULL)
707
png_free(png_ptr, old_buffer);
708
png_error(png_ptr, "Insufficient memory for save_buffer");
710
png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
711
png_free(png_ptr, old_buffer);
712
png_ptr->save_buffer_max = new_max;
714
if (png_ptr->current_buffer_size)
716
png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
717
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
718
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
719
png_ptr->current_buffer_size = 0;
721
png_ptr->save_buffer_ptr = png_ptr->save_buffer;
722
png_ptr->buffer_size = 0;
726
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
727
png_size_t buffer_length)
729
png_ptr->current_buffer = buffer;
730
png_ptr->current_buffer_size = buffer_length;
731
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
732
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
736
png_push_read_IDAT(png_structp png_ptr)
739
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
741
png_byte chunk_length[4];
743
if (png_ptr->buffer_size < 8)
745
png_push_save_buffer(png_ptr);
749
png_push_fill_buffer(png_ptr, chunk_length, 4);
750
png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
751
png_reset_crc(png_ptr);
752
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
753
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
755
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
757
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
758
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
759
png_error(png_ptr, "Not enough compressed data");
763
png_ptr->idat_size = png_ptr->push_length;
765
if (png_ptr->idat_size && png_ptr->save_buffer_size)
767
png_size_t save_size;
769
if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
771
save_size = (png_size_t)png_ptr->idat_size;
773
/* Check for overflow */
774
if ((png_uint_32)save_size != png_ptr->idat_size)
775
png_error(png_ptr, "save_size overflowed in pngpread");
778
save_size = png_ptr->save_buffer_size;
780
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
782
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
784
png_ptr->idat_size -= save_size;
785
png_ptr->buffer_size -= save_size;
786
png_ptr->save_buffer_size -= save_size;
787
png_ptr->save_buffer_ptr += save_size;
789
if (png_ptr->idat_size && png_ptr->current_buffer_size)
791
png_size_t save_size;
793
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
795
save_size = (png_size_t)png_ptr->idat_size;
797
/* Check for overflow */
798
if ((png_uint_32)save_size != png_ptr->idat_size)
799
png_error(png_ptr, "save_size overflowed in pngpread");
802
save_size = png_ptr->current_buffer_size;
804
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
806
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
808
png_ptr->idat_size -= save_size;
809
png_ptr->buffer_size -= save_size;
810
png_ptr->current_buffer_size -= save_size;
811
png_ptr->current_buffer_ptr += save_size;
813
if (!png_ptr->idat_size)
815
if (png_ptr->buffer_size < 4)
817
png_push_save_buffer(png_ptr);
821
png_crc_finish(png_ptr, 0);
822
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
823
png_ptr->mode |= PNG_AFTER_IDAT;
828
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
829
png_size_t buffer_length)
831
/* The caller checks for a non-zero buffer length. */
832
if (!(buffer_length > 0) || buffer == NULL)
833
png_error(png_ptr, "No IDAT data (internal error)");
835
/* This routine must process all the data it has been given
836
* before returning, calling the row callback as required to
837
* handle the uncompressed results.
839
png_ptr->zstream.next_in = buffer;
840
png_ptr->zstream.avail_in = (uInt)buffer_length;
842
/* Keep going until the decompressed data is all processed
843
* or the stream marked as finished.
845
while (png_ptr->zstream.avail_in > 0 &&
846
!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
850
/* We have data for zlib, but we must check that zlib
851
* has somewhere to put the results. It doesn't matter
852
* if we don't expect any results -- it may be the input
853
* data is just the LZ end code.
855
if (!(png_ptr->zstream.avail_out > 0))
857
png_ptr->zstream.avail_out =
858
(uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
859
png_ptr->iwidth) + 1;
860
png_ptr->zstream.next_out = png_ptr->row_buf;
863
/* Using Z_SYNC_FLUSH here means that an unterminated
864
* LZ stream can still be handled (a stream with a missing
865
* end code), otherwise (Z_NO_FLUSH) a future zlib
866
* implementation might defer output and, therefore,
867
* change the current behavior. (See comments in inflate.c
868
* for why this doesn't happen at present with zlib 1.2.5.)
870
ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
872
/* Check for any failure before proceeding. */
873
if (ret != Z_OK && ret != Z_STREAM_END)
875
/* Terminate the decompression. */
876
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
878
/* This may be a truncated stream (missing or
879
* damaged end code). Treat that as a warning.
881
if (png_ptr->row_number >= png_ptr->num_rows ||
883
png_warning(png_ptr, "Truncated compressed data in IDAT");
885
png_error(png_ptr, "Decompression error in IDAT");
887
/* Skip the check on unprocessed input */
891
/* Did inflate output any data? */
892
if (png_ptr->zstream.next_out != png_ptr->row_buf)
894
/* Is this unexpected data after the last row?
895
* If it is, artificially terminate the LZ output
898
if (png_ptr->row_number >= png_ptr->num_rows ||
902
png_warning(png_ptr, "Extra compressed data in IDAT");
903
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
904
/* Do no more processing; skip the unprocessed
910
/* Do we have a complete row? */
911
if (png_ptr->zstream.avail_out == 0)
912
png_push_process_row(png_ptr);
915
/* And check for the end of the stream. */
916
if (ret == Z_STREAM_END)
917
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
920
/* All the data should have been processed, if anything
921
* is left at this point we have bytes of IDAT data
922
* after the zlib end code.
924
if (png_ptr->zstream.avail_in > 0)
925
png_warning(png_ptr, "Extra compression data");
929
png_push_process_row(png_structp png_ptr)
931
png_ptr->row_info.color_type = png_ptr->color_type;
932
png_ptr->row_info.width = png_ptr->iwidth;
933
png_ptr->row_info.channels = png_ptr->channels;
934
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
935
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
937
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
938
png_ptr->row_info.width);
940
png_read_filter_row(png_ptr, &(png_ptr->row_info),
941
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
942
(int)(png_ptr->row_buf[0]));
944
png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
946
if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
947
png_do_read_transformations(png_ptr);
949
#ifdef PNG_READ_INTERLACING_SUPPORTED
950
/* Blow up interlaced rows to full size */
951
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
953
if (png_ptr->pass < 6)
954
/* old interface (pre-1.0.9):
955
png_do_read_interlace(&(png_ptr->row_info),
956
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
958
png_do_read_interlace(png_ptr);
960
switch (png_ptr->pass)
965
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
967
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
968
png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
971
if (png_ptr->pass == 2) /* Pass 1 might be empty */
973
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
975
png_push_have_row(png_ptr, NULL);
976
png_read_push_finish_row(png_ptr);
980
if (png_ptr->pass == 4 && png_ptr->height <= 4)
982
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
984
png_push_have_row(png_ptr, NULL);
985
png_read_push_finish_row(png_ptr);
989
if (png_ptr->pass == 6 && png_ptr->height <= 4)
991
png_push_have_row(png_ptr, NULL);
992
png_read_push_finish_row(png_ptr);
1001
for (i = 0; i < 8 && png_ptr->pass == 1; i++)
1003
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1004
png_read_push_finish_row(png_ptr);
1007
if (png_ptr->pass == 2) /* Skip top 4 generated rows */
1009
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1011
png_push_have_row(png_ptr, NULL);
1012
png_read_push_finish_row(png_ptr);
1023
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1025
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1026
png_read_push_finish_row(png_ptr);
1029
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1031
png_push_have_row(png_ptr, NULL);
1032
png_read_push_finish_row(png_ptr);
1035
if (png_ptr->pass == 4) /* Pass 3 might be empty */
1037
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1039
png_push_have_row(png_ptr, NULL);
1040
png_read_push_finish_row(png_ptr);
1051
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
1053
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1054
png_read_push_finish_row(png_ptr);
1057
if (png_ptr->pass == 4) /* Skip top two generated rows */
1059
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1061
png_push_have_row(png_ptr, NULL);
1062
png_read_push_finish_row(png_ptr);
1073
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1075
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1076
png_read_push_finish_row(png_ptr);
1079
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1081
png_push_have_row(png_ptr, NULL);
1082
png_read_push_finish_row(png_ptr);
1085
if (png_ptr->pass == 6) /* Pass 5 might be empty */
1087
png_push_have_row(png_ptr, NULL);
1088
png_read_push_finish_row(png_ptr);
1098
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1100
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1101
png_read_push_finish_row(png_ptr);
1104
if (png_ptr->pass == 6) /* Skip top generated row */
1106
png_push_have_row(png_ptr, NULL);
1107
png_read_push_finish_row(png_ptr);
1114
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1115
png_read_push_finish_row(png_ptr);
1117
if (png_ptr->pass != 6)
1120
png_push_have_row(png_ptr, NULL);
1121
png_read_push_finish_row(png_ptr);
1128
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1129
png_read_push_finish_row(png_ptr);
1134
png_read_push_finish_row(png_structp png_ptr)
1136
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1138
/* Start of interlace block */
1139
PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1141
/* Offset to next interlace block */
1142
PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1144
/* Start of interlace block in the y direction */
1145
PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1147
/* Offset to next interlace block in the y direction */
1148
PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1150
/* Height of interlace block. This is not currently used - if you need
1151
* it, uncomment it here and in png.h
1152
PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1155
png_ptr->row_number++;
1156
if (png_ptr->row_number < png_ptr->num_rows)
1159
#ifdef PNG_READ_INTERLACING_SUPPORTED
1160
if (png_ptr->interlaced)
1162
png_ptr->row_number = 0;
1163
png_memset(png_ptr->prev_row, 0,
1164
png_ptr->rowbytes + 1);
1168
if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1169
(png_ptr->pass == 3 && png_ptr->width < 3) ||
1170
(png_ptr->pass == 5 && png_ptr->width < 2))
1173
if (png_ptr->pass > 7)
1176
if (png_ptr->pass >= 7)
1179
png_ptr->iwidth = (png_ptr->width +
1180
png_pass_inc[png_ptr->pass] - 1 -
1181
png_pass_start[png_ptr->pass]) /
1182
png_pass_inc[png_ptr->pass];
1184
if (png_ptr->transformations & PNG_INTERLACE)
1187
png_ptr->num_rows = (png_ptr->height +
1188
png_pass_yinc[png_ptr->pass] - 1 -
1189
png_pass_ystart[png_ptr->pass]) /
1190
png_pass_yinc[png_ptr->pass];
1192
} while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1194
#endif /* PNG_READ_INTERLACING_SUPPORTED */
1197
#ifdef PNG_READ_tEXt_SUPPORTED
1199
png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1202
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1204
png_error(png_ptr, "Out of place tEXt");
1205
info_ptr = info_ptr; /* To quiet some compiler warnings */
1208
#ifdef PNG_MAX_MALLOC_64K
1209
png_ptr->skip_length = 0; /* This may not be necessary */
1211
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1213
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1214
png_ptr->skip_length = length - (png_uint_32)65535L;
1215
length = (png_uint_32)65535L;
1219
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1220
(png_size_t)(length + 1));
1221
png_ptr->current_text[length] = '\0';
1222
png_ptr->current_text_ptr = png_ptr->current_text;
1223
png_ptr->current_text_size = (png_size_t)length;
1224
png_ptr->current_text_left = (png_size_t)length;
1225
png_ptr->process_mode = PNG_READ_tEXt_MODE;
1229
png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1231
if (png_ptr->buffer_size && png_ptr->current_text_left)
1233
png_size_t text_size;
1235
if (png_ptr->buffer_size < png_ptr->current_text_left)
1236
text_size = png_ptr->buffer_size;
1239
text_size = png_ptr->current_text_left;
1241
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1242
png_ptr->current_text_left -= text_size;
1243
png_ptr->current_text_ptr += text_size;
1245
if (!(png_ptr->current_text_left))
1252
if (png_ptr->buffer_size < 4)
1254
png_push_save_buffer(png_ptr);
1258
png_push_crc_finish(png_ptr);
1260
#ifdef PNG_MAX_MALLOC_64K
1261
if (png_ptr->skip_length)
1265
key = png_ptr->current_text;
1267
for (text = key; *text; text++)
1270
if (text < key + png_ptr->current_text_size)
1273
text_ptr = (png_textp)png_malloc(png_ptr,
1274
png_sizeof(png_text));
1275
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1276
text_ptr->key = key;
1277
#ifdef PNG_iTXt_SUPPORTED
1278
text_ptr->lang = NULL;
1279
text_ptr->lang_key = NULL;
1281
text_ptr->text = text;
1283
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1285
png_free(png_ptr, key);
1286
png_free(png_ptr, text_ptr);
1287
png_ptr->current_text = NULL;
1290
png_warning(png_ptr, "Insufficient memory to store text chunk");
1295
#ifdef PNG_READ_zTXt_SUPPORTED
1297
png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1300
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1302
png_error(png_ptr, "Out of place zTXt");
1303
info_ptr = info_ptr; /* To quiet some compiler warnings */
1306
#ifdef PNG_MAX_MALLOC_64K
1307
/* We can't handle zTXt chunks > 64K, since we don't have enough space
1308
* to be able to store the uncompressed data. Actually, the threshold
1309
* is probably around 32K, but it isn't as definite as 64K is.
1311
if (length > (png_uint_32)65535L)
1313
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1314
png_push_crc_skip(png_ptr, length);
1319
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1320
(png_size_t)(length + 1));
1321
png_ptr->current_text[length] = '\0';
1322
png_ptr->current_text_ptr = png_ptr->current_text;
1323
png_ptr->current_text_size = (png_size_t)length;
1324
png_ptr->current_text_left = (png_size_t)length;
1325
png_ptr->process_mode = PNG_READ_zTXt_MODE;
1329
png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1331
if (png_ptr->buffer_size && png_ptr->current_text_left)
1333
png_size_t text_size;
1335
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1336
text_size = png_ptr->buffer_size;
1339
text_size = png_ptr->current_text_left;
1341
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1342
png_ptr->current_text_left -= text_size;
1343
png_ptr->current_text_ptr += text_size;
1345
if (!(png_ptr->current_text_left))
1351
png_size_t text_size, key_size;
1353
if (png_ptr->buffer_size < 4)
1355
png_push_save_buffer(png_ptr);
1359
png_push_crc_finish(png_ptr);
1361
key = png_ptr->current_text;
1363
for (text = key; *text; text++)
1366
/* zTXt can't have zero text */
1367
if (text >= key + png_ptr->current_text_size)
1369
png_ptr->current_text = NULL;
1370
png_free(png_ptr, key);
1376
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1378
png_ptr->current_text = NULL;
1379
png_free(png_ptr, key);
1385
png_ptr->zstream.next_in = (png_bytep )text;
1386
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1388
png_ptr->zstream.next_out = png_ptr->zbuf;
1389
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1391
key_size = text - key;
1396
while (png_ptr->zstream.avail_in)
1398
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1399
if (ret != Z_OK && ret != Z_STREAM_END)
1401
inflateReset(&png_ptr->zstream);
1402
png_ptr->zstream.avail_in = 0;
1403
png_ptr->current_text = NULL;
1404
png_free(png_ptr, key);
1405
png_free(png_ptr, text);
1408
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1412
text = (png_charp)png_malloc(png_ptr,
1414
- png_ptr->zstream.avail_out + key_size + 1));
1416
png_memcpy(text + key_size, png_ptr->zbuf,
1417
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1419
png_memcpy(text, key, key_size);
1421
text_size = key_size + png_ptr->zbuf_size -
1422
png_ptr->zstream.avail_out;
1424
*(text + text_size) = '\0';
1431
text = (png_charp)png_malloc(png_ptr, text_size +
1433
- png_ptr->zstream.avail_out + 1));
1435
png_memcpy(text, tmp, text_size);
1436
png_free(png_ptr, tmp);
1438
png_memcpy(text + text_size, png_ptr->zbuf,
1439
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1441
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1442
*(text + text_size) = '\0';
1444
if (ret != Z_STREAM_END)
1446
png_ptr->zstream.next_out = png_ptr->zbuf;
1447
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1455
if (ret == Z_STREAM_END)
1459
inflateReset(&png_ptr->zstream);
1460
png_ptr->zstream.avail_in = 0;
1462
if (ret != Z_STREAM_END)
1464
png_ptr->current_text = NULL;
1465
png_free(png_ptr, key);
1466
png_free(png_ptr, text);
1470
png_ptr->current_text = NULL;
1471
png_free(png_ptr, key);
1475
text_ptr = (png_textp)png_malloc(png_ptr,
1476
png_sizeof(png_text));
1477
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1478
text_ptr->key = key;
1479
#ifdef PNG_iTXt_SUPPORTED
1480
text_ptr->lang = NULL;
1481
text_ptr->lang_key = NULL;
1483
text_ptr->text = text;
1485
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1487
png_free(png_ptr, key);
1488
png_free(png_ptr, text_ptr);
1491
png_warning(png_ptr, "Insufficient memory to store text chunk");
1496
#ifdef PNG_READ_iTXt_SUPPORTED
1498
png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1501
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1503
png_error(png_ptr, "Out of place iTXt");
1504
info_ptr = info_ptr; /* To quiet some compiler warnings */
1507
#ifdef PNG_MAX_MALLOC_64K
1508
png_ptr->skip_length = 0; /* This may not be necessary */
1510
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1512
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1513
png_ptr->skip_length = length - (png_uint_32)65535L;
1514
length = (png_uint_32)65535L;
1518
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1519
(png_size_t)(length + 1));
1520
png_ptr->current_text[length] = '\0';
1521
png_ptr->current_text_ptr = png_ptr->current_text;
1522
png_ptr->current_text_size = (png_size_t)length;
1523
png_ptr->current_text_left = (png_size_t)length;
1524
png_ptr->process_mode = PNG_READ_iTXt_MODE;
1528
png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1531
if (png_ptr->buffer_size && png_ptr->current_text_left)
1533
png_size_t text_size;
1535
if (png_ptr->buffer_size < png_ptr->current_text_left)
1536
text_size = png_ptr->buffer_size;
1539
text_size = png_ptr->current_text_left;
1541
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1542
png_ptr->current_text_left -= text_size;
1543
png_ptr->current_text_ptr += text_size;
1545
if (!(png_ptr->current_text_left))
1555
if (png_ptr->buffer_size < 4)
1557
png_push_save_buffer(png_ptr);
1561
png_push_crc_finish(png_ptr);
1563
#ifdef PNG_MAX_MALLOC_64K
1564
if (png_ptr->skip_length)
1568
key = png_ptr->current_text;
1570
for (lang = key; *lang; lang++)
1573
if (lang < key + png_ptr->current_text_size - 3)
1576
comp_flag = *lang++;
1577
lang++; /* Skip comp_type, always zero */
1579
for (lang_key = lang; *lang_key; lang_key++)
1582
lang_key++; /* Skip NUL separator */
1586
if (lang_key < key + png_ptr->current_text_size - 1)
1588
for (; *text; text++)
1592
if (text < key + png_ptr->current_text_size)
1595
text_ptr = (png_textp)png_malloc(png_ptr,
1596
png_sizeof(png_text));
1598
text_ptr->compression = comp_flag + 2;
1599
text_ptr->key = key;
1600
text_ptr->lang = lang;
1601
text_ptr->lang_key = lang_key;
1602
text_ptr->text = text;
1603
text_ptr->text_length = 0;
1604
text_ptr->itxt_length = png_strlen(text);
1606
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1608
png_ptr->current_text = NULL;
1610
png_free(png_ptr, text_ptr);
1612
png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
1617
/* This function is called when we haven't found a handler for this
1618
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1619
* name or a critical chunk), the chunk is (currently) silently ignored.
1622
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1625
png_uint_32 skip = 0;
1627
if (!(png_ptr->chunk_name[0] & 0x20))
1629
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1630
if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1631
PNG_HANDLE_CHUNK_ALWAYS
1632
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1633
&& png_ptr->read_user_chunk_fn == NULL
1637
png_chunk_error(png_ptr, "unknown critical chunk");
1639
info_ptr = info_ptr; /* To quiet some compiler warnings */
1642
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1643
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1645
#ifdef PNG_MAX_MALLOC_64K
1646
if (length > (png_uint_32)65535L)
1648
png_warning(png_ptr, "unknown chunk too large to fit in memory");
1649
skip = length - (png_uint_32)65535L;
1650
length = (png_uint_32)65535L;
1653
png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1654
(png_charp)png_ptr->chunk_name,
1655
png_sizeof(png_ptr->unknown_chunk.name));
1656
png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
1659
png_ptr->unknown_chunk.size = (png_size_t)length;
1662
png_ptr->unknown_chunk.data = NULL;
1666
png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1667
(png_size_t)length);
1668
png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1671
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1672
if (png_ptr->read_user_chunk_fn != NULL)
1674
/* Callback to user unknown chunk handler */
1676
ret = (*(png_ptr->read_user_chunk_fn))
1677
(png_ptr, &png_ptr->unknown_chunk);
1680
png_chunk_error(png_ptr, "error in user chunk");
1684
if (!(png_ptr->chunk_name[0] & 0x20))
1685
if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1686
PNG_HANDLE_CHUNK_ALWAYS)
1687
png_chunk_error(png_ptr, "unknown critical chunk");
1688
png_set_unknown_chunks(png_ptr, info_ptr,
1689
&png_ptr->unknown_chunk, 1);
1695
png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1696
png_free(png_ptr, png_ptr->unknown_chunk.data);
1697
png_ptr->unknown_chunk.data = NULL;
1703
png_push_crc_skip(png_ptr, skip);
1707
png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1709
if (png_ptr->info_fn != NULL)
1710
(*(png_ptr->info_fn))(png_ptr, info_ptr);
1714
png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1716
if (png_ptr->end_fn != NULL)
1717
(*(png_ptr->end_fn))(png_ptr, info_ptr);
1721
png_push_have_row(png_structp png_ptr, png_bytep row)
1723
if (png_ptr->row_fn != NULL)
1724
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1725
(int)png_ptr->pass);
1729
png_progressive_combine_row (png_structp png_ptr,
1730
png_bytep old_row, png_bytep new_row)
1732
PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1733
{0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1735
if (png_ptr == NULL)
1738
if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1739
png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1743
png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1744
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1745
png_progressive_end_ptr end_fn)
1747
if (png_ptr == NULL)
1750
png_ptr->info_fn = info_fn;
1751
png_ptr->row_fn = row_fn;
1752
png_ptr->end_fn = end_fn;
1754
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1758
png_get_progressive_ptr(png_structp png_ptr)
1760
if (png_ptr == NULL)
1763
return png_ptr->io_ptr;
1765
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */