2
/* pngpread.c - read a png file in push mode
4
* libpng 1.2.5 - October 3, 2002
5
* For conditions of distribution and use, see copyright notice in png.h
6
* Copyright (c) 1998-2002 Glenn Randers-Pehrson
7
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
14
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
16
/* push model modes */
17
#define PNG_READ_SIG_MODE 0
18
#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
21
#define PNG_READ_tEXt_MODE 4
22
#define PNG_READ_zTXt_MODE 5
23
#define PNG_READ_DONE_MODE 6
24
#define PNG_READ_iTXt_MODE 7
25
#define PNG_ERROR_MODE 8
28
png_process_data(png_structp png_ptr, png_infop info_ptr,
29
png_bytep buffer, png_size_t buffer_size)
31
png_push_restore_buffer(png_ptr, buffer, buffer_size);
33
while (png_ptr->buffer_size)
35
png_process_some_data(png_ptr, info_ptr);
39
/* What we do with the incoming data depends on what we were previously
40
* doing before we ran out of data...
43
png_process_some_data(png_structp png_ptr, png_infop info_ptr)
45
switch (png_ptr->process_mode)
47
case PNG_READ_SIG_MODE:
49
png_push_read_sig(png_ptr, info_ptr);
52
case PNG_READ_CHUNK_MODE:
54
png_push_read_chunk(png_ptr, info_ptr);
57
case PNG_READ_IDAT_MODE:
59
png_push_read_IDAT(png_ptr);
62
#if defined(PNG_READ_tEXt_SUPPORTED)
63
case PNG_READ_tEXt_MODE:
65
png_push_read_tEXt(png_ptr, info_ptr);
69
#if defined(PNG_READ_zTXt_SUPPORTED)
70
case PNG_READ_zTXt_MODE:
72
png_push_read_zTXt(png_ptr, info_ptr);
76
#if defined(PNG_READ_iTXt_SUPPORTED)
77
case PNG_READ_iTXt_MODE:
79
png_push_read_iTXt(png_ptr, info_ptr);
85
png_push_crc_finish(png_ptr);
90
png_ptr->buffer_size = 0;
96
/* Read any remaining signature bytes from the stream and compare them with
97
* the correct PNG signature. It is possible that this routine is called
98
* with bytes already read from the signature, either because they have been
99
* checked by the calling application, or because of multiple calls to this
103
png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
105
png_size_t num_checked = png_ptr->sig_bytes,
106
num_to_check = 8 - num_checked;
108
if (png_ptr->buffer_size < num_to_check)
110
num_to_check = png_ptr->buffer_size;
113
png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
115
png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
117
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
119
if (num_checked < 4 &&
120
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
121
png_error(png_ptr, "Not a PNG file");
123
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
127
if (png_ptr->sig_bytes >= 8)
129
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
135
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
137
#ifdef PNG_USE_LOCAL_ARRAYS
142
#if defined(PNG_READ_bKGD_SUPPORTED)
145
#if defined(PNG_READ_cHRM_SUPPORTED)
148
#if defined(PNG_READ_gAMA_SUPPORTED)
151
#if defined(PNG_READ_hIST_SUPPORTED)
154
#if defined(PNG_READ_iCCP_SUPPORTED)
157
#if defined(PNG_READ_iTXt_SUPPORTED)
160
#if defined(PNG_READ_oFFs_SUPPORTED)
163
#if defined(PNG_READ_pCAL_SUPPORTED)
166
#if defined(PNG_READ_pHYs_SUPPORTED)
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#if defined(PNG_READ_sBIT_SUPPORTED)
172
#if defined(PNG_READ_sCAL_SUPPORTED)
175
#if defined(PNG_READ_sRGB_SUPPORTED)
178
#if defined(PNG_READ_sPLT_SUPPORTED)
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#if defined(PNG_READ_tEXt_SUPPORTED)
184
#if defined(PNG_READ_tIME_SUPPORTED)
187
#if defined(PNG_READ_tRNS_SUPPORTED)
190
#if defined(PNG_READ_zTXt_SUPPORTED)
193
#endif /* PNG_USE_LOCAL_ARRAYS */
194
/* First we make sure we have enough data for the 4 byte chunk name
195
* and the 4 byte chunk length before proceeding with decoding the
196
* chunk data. To fully decode each of these chunks, we also make
197
* sure we have enough data in the buffer for the 4 byte CRC at the
198
* end of every chunk (except IDAT, which is handled separately).
200
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
202
png_byte chunk_length[4];
204
if (png_ptr->buffer_size < 8)
206
png_push_save_buffer(png_ptr);
210
png_push_fill_buffer(png_ptr, chunk_length, 4);
211
png_ptr->push_length = png_get_uint_32(chunk_length);
212
png_reset_crc(png_ptr);
213
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
214
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
217
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
219
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
221
png_push_save_buffer(png_ptr);
224
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
226
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
228
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
230
png_push_save_buffer(png_ptr);
233
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
235
else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
237
/* If we reach an IDAT chunk, this means we have read all of the
238
* header chunks, and we can start reading the image (or if this
239
* is called after the image has been read - we have an error).
241
if (!(png_ptr->mode & PNG_HAVE_IHDR))
242
png_error(png_ptr, "Missing IHDR before IDAT");
243
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
244
!(png_ptr->mode & PNG_HAVE_PLTE))
245
png_error(png_ptr, "Missing PLTE before IDAT");
247
if (png_ptr->mode & PNG_HAVE_IDAT)
249
if (png_ptr->push_length == 0)
252
if (png_ptr->mode & PNG_AFTER_IDAT)
253
png_error(png_ptr, "Too many IDAT's found");
256
png_ptr->idat_size = png_ptr->push_length;
257
png_ptr->mode |= PNG_HAVE_IDAT;
258
png_ptr->process_mode = PNG_READ_IDAT_MODE;
259
png_push_have_info(png_ptr, info_ptr);
260
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
261
png_ptr->zstream.next_out = png_ptr->row_buf;
264
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
266
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
268
png_push_save_buffer(png_ptr);
271
png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
273
png_ptr->process_mode = PNG_READ_DONE_MODE;
274
png_push_have_end(png_ptr, info_ptr);
276
#if defined(PNG_READ_gAMA_SUPPORTED)
277
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
279
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
281
png_push_save_buffer(png_ptr);
284
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
287
#if defined(PNG_READ_sBIT_SUPPORTED)
288
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
290
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
292
png_push_save_buffer(png_ptr);
295
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
298
#if defined(PNG_READ_cHRM_SUPPORTED)
299
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
301
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
303
png_push_save_buffer(png_ptr);
306
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
309
#if defined(PNG_READ_sRGB_SUPPORTED)
310
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
312
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
314
png_push_save_buffer(png_ptr);
317
png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
320
#if defined(PNG_READ_iCCP_SUPPORTED)
321
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
323
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
325
png_push_save_buffer(png_ptr);
328
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
331
#if defined(PNG_READ_sPLT_SUPPORTED)
332
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
334
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
336
png_push_save_buffer(png_ptr);
339
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
342
#if defined(PNG_READ_tRNS_SUPPORTED)
343
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
345
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
347
png_push_save_buffer(png_ptr);
350
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
353
#if defined(PNG_READ_bKGD_SUPPORTED)
354
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
356
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
358
png_push_save_buffer(png_ptr);
361
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
364
#if defined(PNG_READ_hIST_SUPPORTED)
365
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
367
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
369
png_push_save_buffer(png_ptr);
372
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
375
#if defined(PNG_READ_pHYs_SUPPORTED)
376
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
378
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
380
png_push_save_buffer(png_ptr);
383
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
386
#if defined(PNG_READ_oFFs_SUPPORTED)
387
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
389
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
391
png_push_save_buffer(png_ptr);
394
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
397
#if defined(PNG_READ_pCAL_SUPPORTED)
398
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
400
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
402
png_push_save_buffer(png_ptr);
405
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
408
#if defined(PNG_READ_sCAL_SUPPORTED)
409
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
411
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
413
png_push_save_buffer(png_ptr);
416
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
419
#if defined(PNG_READ_tIME_SUPPORTED)
420
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
422
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
424
png_push_save_buffer(png_ptr);
427
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
430
#if defined(PNG_READ_tEXt_SUPPORTED)
431
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
433
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
435
png_push_save_buffer(png_ptr);
438
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
441
#if defined(PNG_READ_zTXt_SUPPORTED)
442
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
444
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
446
png_push_save_buffer(png_ptr);
449
png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
452
#if defined(PNG_READ_iTXt_SUPPORTED)
453
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
455
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
457
png_push_save_buffer(png_ptr);
460
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
465
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
467
png_push_save_buffer(png_ptr);
470
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
473
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
477
png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
479
png_ptr->process_mode = PNG_SKIP_MODE;
480
png_ptr->skip_length = skip;
484
png_push_crc_finish(png_structp png_ptr)
486
if (png_ptr->skip_length && png_ptr->save_buffer_size)
488
png_size_t save_size;
490
if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
491
save_size = (png_size_t)png_ptr->skip_length;
493
save_size = png_ptr->save_buffer_size;
495
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
497
png_ptr->skip_length -= save_size;
498
png_ptr->buffer_size -= save_size;
499
png_ptr->save_buffer_size -= save_size;
500
png_ptr->save_buffer_ptr += save_size;
502
if (png_ptr->skip_length && png_ptr->current_buffer_size)
504
png_size_t save_size;
506
if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
507
save_size = (png_size_t)png_ptr->skip_length;
509
save_size = png_ptr->current_buffer_size;
511
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
513
png_ptr->skip_length -= save_size;
514
png_ptr->buffer_size -= save_size;
515
png_ptr->current_buffer_size -= save_size;
516
png_ptr->current_buffer_ptr += save_size;
518
if (!png_ptr->skip_length)
520
if (png_ptr->buffer_size < 4)
522
png_push_save_buffer(png_ptr);
526
png_crc_finish(png_ptr, 0);
527
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
532
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
537
if (png_ptr->save_buffer_size)
539
png_size_t save_size;
541
if (length < png_ptr->save_buffer_size)
544
save_size = png_ptr->save_buffer_size;
546
png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
549
png_ptr->buffer_size -= save_size;
550
png_ptr->save_buffer_size -= save_size;
551
png_ptr->save_buffer_ptr += save_size;
553
if (length && png_ptr->current_buffer_size)
555
png_size_t save_size;
557
if (length < png_ptr->current_buffer_size)
560
save_size = png_ptr->current_buffer_size;
562
png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
563
png_ptr->buffer_size -= save_size;
564
png_ptr->current_buffer_size -= save_size;
565
png_ptr->current_buffer_ptr += save_size;
570
png_push_save_buffer(png_structp png_ptr)
572
if (png_ptr->save_buffer_size)
574
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
580
istop = png_ptr->save_buffer_size;
581
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
582
i < istop; i++, sp++, dp++)
588
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
589
png_ptr->save_buffer_max)
592
png_bytep old_buffer;
594
new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
595
old_buffer = png_ptr->save_buffer;
596
png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
597
(png_uint_32)new_max);
598
png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
599
png_free(png_ptr, old_buffer);
600
png_ptr->save_buffer_max = new_max;
602
if (png_ptr->current_buffer_size)
604
png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
605
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
606
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
607
png_ptr->current_buffer_size = 0;
609
png_ptr->save_buffer_ptr = png_ptr->save_buffer;
610
png_ptr->buffer_size = 0;
614
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
615
png_size_t buffer_length)
617
png_ptr->current_buffer = buffer;
618
png_ptr->current_buffer_size = buffer_length;
619
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
620
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
624
png_push_read_IDAT(png_structp png_ptr)
626
#ifdef PNG_USE_LOCAL_ARRAYS
629
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
631
png_byte chunk_length[4];
633
if (png_ptr->buffer_size < 8)
635
png_push_save_buffer(png_ptr);
639
png_push_fill_buffer(png_ptr, chunk_length, 4);
640
png_ptr->push_length = png_get_uint_32(chunk_length);
642
png_reset_crc(png_ptr);
643
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
644
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
646
if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
648
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
649
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
650
png_error(png_ptr, "Not enough compressed data");
654
png_ptr->idat_size = png_ptr->push_length;
656
if (png_ptr->idat_size && png_ptr->save_buffer_size)
658
png_size_t save_size;
660
if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
662
save_size = (png_size_t)png_ptr->idat_size;
663
/* check for overflow */
664
if((png_uint_32)save_size != png_ptr->idat_size)
665
png_error(png_ptr, "save_size overflowed in pngpread");
668
save_size = png_ptr->save_buffer_size;
670
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
671
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
672
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
673
png_ptr->idat_size -= save_size;
674
png_ptr->buffer_size -= save_size;
675
png_ptr->save_buffer_size -= save_size;
676
png_ptr->save_buffer_ptr += save_size;
678
if (png_ptr->idat_size && png_ptr->current_buffer_size)
680
png_size_t save_size;
682
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
684
save_size = (png_size_t)png_ptr->idat_size;
685
/* check for overflow */
686
if((png_uint_32)save_size != png_ptr->idat_size)
687
png_error(png_ptr, "save_size overflowed in pngpread");
690
save_size = png_ptr->current_buffer_size;
692
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
693
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
694
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
696
png_ptr->idat_size -= save_size;
697
png_ptr->buffer_size -= save_size;
698
png_ptr->current_buffer_size -= save_size;
699
png_ptr->current_buffer_ptr += save_size;
701
if (!png_ptr->idat_size)
703
if (png_ptr->buffer_size < 4)
705
png_push_save_buffer(png_ptr);
709
png_crc_finish(png_ptr, 0);
710
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
711
png_ptr->mode |= PNG_AFTER_IDAT;
716
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
717
png_size_t buffer_length)
721
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
722
png_error(png_ptr, "Extra compression data");
724
png_ptr->zstream.next_in = buffer;
725
png_ptr->zstream.avail_in = (uInt)buffer_length;
728
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
731
if (ret == Z_STREAM_END)
733
if (png_ptr->zstream.avail_in)
734
png_error(png_ptr, "Extra compressed data");
735
if (!(png_ptr->zstream.avail_out))
737
png_push_process_row(png_ptr);
740
png_ptr->mode |= PNG_AFTER_IDAT;
741
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
744
else if (ret == Z_BUF_ERROR)
747
png_error(png_ptr, "Decompression Error");
749
if (!(png_ptr->zstream.avail_out))
752
#if defined(PNG_READ_INTERLACING_SUPPORTED)
753
png_ptr->interlaced && png_ptr->pass > 6) ||
754
(!png_ptr->interlaced &&
756
png_ptr->row_number == png_ptr->num_rows-1))
758
if (png_ptr->zstream.avail_in)
759
png_warning(png_ptr, "Too much data in IDAT chunks");
760
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
763
png_push_process_row(png_ptr);
764
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
765
png_ptr->zstream.next_out = png_ptr->row_buf;
773
png_push_process_row(png_structp png_ptr)
775
png_ptr->row_info.color_type = png_ptr->color_type;
776
png_ptr->row_info.width = png_ptr->iwidth;
777
png_ptr->row_info.channels = png_ptr->channels;
778
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
779
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
781
png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
782
(png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
784
png_read_filter_row(png_ptr, &(png_ptr->row_info),
785
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
786
(int)(png_ptr->row_buf[0]));
788
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
789
png_ptr->rowbytes + 1);
791
if (png_ptr->transformations)
792
png_do_read_transformations(png_ptr);
794
#if defined(PNG_READ_INTERLACING_SUPPORTED)
795
/* blow up interlaced rows to full size */
796
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
798
if (png_ptr->pass < 6)
799
/* old interface (pre-1.0.9):
800
png_do_read_interlace(&(png_ptr->row_info),
801
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
803
png_do_read_interlace(png_ptr);
805
switch (png_ptr->pass)
810
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
812
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
813
png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */
815
if (png_ptr->pass == 2) /* pass 1 might be empty */
817
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
819
png_push_have_row(png_ptr, png_bytep_NULL);
820
png_read_push_finish_row(png_ptr);
823
if (png_ptr->pass == 4 && png_ptr->height <= 4)
825
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
827
png_push_have_row(png_ptr, png_bytep_NULL);
828
png_read_push_finish_row(png_ptr);
831
if (png_ptr->pass == 6 && png_ptr->height <= 4)
833
png_push_have_row(png_ptr, png_bytep_NULL);
834
png_read_push_finish_row(png_ptr);
841
for (i = 0; i < 8 && png_ptr->pass == 1; i++)
843
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
844
png_read_push_finish_row(png_ptr);
846
if (png_ptr->pass == 2) /* skip top 4 generated rows */
848
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
850
png_push_have_row(png_ptr, png_bytep_NULL);
851
png_read_push_finish_row(png_ptr);
859
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
861
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
862
png_read_push_finish_row(png_ptr);
864
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
866
png_push_have_row(png_ptr, png_bytep_NULL);
867
png_read_push_finish_row(png_ptr);
869
if (png_ptr->pass == 4) /* pass 3 might be empty */
871
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
873
png_push_have_row(png_ptr, png_bytep_NULL);
874
png_read_push_finish_row(png_ptr);
882
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
884
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
885
png_read_push_finish_row(png_ptr);
887
if (png_ptr->pass == 4) /* skip top two generated rows */
889
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
891
png_push_have_row(png_ptr, png_bytep_NULL);
892
png_read_push_finish_row(png_ptr);
900
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
902
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
903
png_read_push_finish_row(png_ptr);
905
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
907
png_push_have_row(png_ptr, png_bytep_NULL);
908
png_read_push_finish_row(png_ptr);
910
if (png_ptr->pass == 6) /* pass 5 might be empty */
912
png_push_have_row(png_ptr, png_bytep_NULL);
913
png_read_push_finish_row(png_ptr);
920
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
922
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
923
png_read_push_finish_row(png_ptr);
925
if (png_ptr->pass == 6) /* skip top generated row */
927
png_push_have_row(png_ptr, png_bytep_NULL);
928
png_read_push_finish_row(png_ptr);
934
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
935
png_read_push_finish_row(png_ptr);
936
if (png_ptr->pass != 6)
938
png_push_have_row(png_ptr, png_bytep_NULL);
939
png_read_push_finish_row(png_ptr);
946
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
947
png_read_push_finish_row(png_ptr);
952
png_read_push_finish_row(png_structp png_ptr)
954
#ifdef PNG_USE_LOCAL_ARRAYS
955
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
957
/* start of interlace block */
958
const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
960
/* offset to next interlace block */
961
const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
963
/* start of interlace block in the y direction */
964
const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
966
/* offset to next interlace block in the y direction */
967
const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
969
/* Width of interlace block. This is not currently used - if you need
970
* it, uncomment it here and in png.h
971
const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
974
/* Height of interlace block. This is not currently used - if you need
975
* it, uncomment it here and in png.h
976
const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
980
png_ptr->row_number++;
981
if (png_ptr->row_number < png_ptr->num_rows)
984
if (png_ptr->interlaced)
986
png_ptr->row_number = 0;
987
png_memset_check(png_ptr, png_ptr->prev_row, 0,
988
png_ptr->rowbytes + 1);
992
if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
993
(png_ptr->pass == 3 && png_ptr->width < 3) ||
994
(png_ptr->pass == 5 && png_ptr->width < 2))
997
if (png_ptr->pass > 7)
999
if (png_ptr->pass >= 7)
1002
png_ptr->iwidth = (png_ptr->width +
1003
png_pass_inc[png_ptr->pass] - 1 -
1004
png_pass_start[png_ptr->pass]) /
1005
png_pass_inc[png_ptr->pass];
1007
png_ptr->irowbytes = ((png_ptr->iwidth *
1008
png_ptr->pixel_depth + 7) >> 3) + 1;
1010
if (png_ptr->transformations & PNG_INTERLACE)
1013
png_ptr->num_rows = (png_ptr->height +
1014
png_pass_yinc[png_ptr->pass] - 1 -
1015
png_pass_ystart[png_ptr->pass]) /
1016
png_pass_yinc[png_ptr->pass];
1018
} while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1022
#if defined(PNG_READ_tEXt_SUPPORTED)
1024
png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1027
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1029
png_error(png_ptr, "Out of place tEXt");
1030
/* to quiet some compiler warnings */
1031
if(info_ptr == NULL) return;
1034
#ifdef PNG_MAX_MALLOC_64K
1035
png_ptr->skip_length = 0; /* This may not be necessary */
1037
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1039
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1040
png_ptr->skip_length = length - (png_uint_32)65535L;
1041
length = (png_uint_32)65535L;
1045
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1046
(png_uint_32)(length+1));
1047
png_ptr->current_text[length] = '\0';
1048
png_ptr->current_text_ptr = png_ptr->current_text;
1049
png_ptr->current_text_size = (png_size_t)length;
1050
png_ptr->current_text_left = (png_size_t)length;
1051
png_ptr->process_mode = PNG_READ_tEXt_MODE;
1055
png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1057
if (png_ptr->buffer_size && png_ptr->current_text_left)
1059
png_size_t text_size;
1061
if (png_ptr->buffer_size < png_ptr->current_text_left)
1062
text_size = png_ptr->buffer_size;
1064
text_size = png_ptr->current_text_left;
1065
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1066
png_ptr->current_text_left -= text_size;
1067
png_ptr->current_text_ptr += text_size;
1069
if (!(png_ptr->current_text_left))
1076
if (png_ptr->buffer_size < 4)
1078
png_push_save_buffer(png_ptr);
1082
png_push_crc_finish(png_ptr);
1084
#if defined(PNG_MAX_MALLOC_64K)
1085
if (png_ptr->skip_length)
1089
key = png_ptr->current_text;
1091
for (text = key; *text; text++)
1094
if (text != key + png_ptr->current_text_size)
1097
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1098
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1099
text_ptr->key = key;
1100
#ifdef PNG_iTXt_SUPPORTED
1101
text_ptr->lang = NULL;
1102
text_ptr->lang_key = NULL;
1104
text_ptr->text = text;
1106
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1108
png_free(png_ptr, key);
1109
png_free(png_ptr, text_ptr);
1110
png_ptr->current_text = NULL;
1113
png_warning(png_ptr, "Insufficient memory to store text chunk.");
1118
#if defined(PNG_READ_zTXt_SUPPORTED)
1120
png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1123
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1125
png_error(png_ptr, "Out of place zTXt");
1126
/* to quiet some compiler warnings */
1127
if(info_ptr == NULL) return;
1130
#ifdef PNG_MAX_MALLOC_64K
1131
/* We can't handle zTXt chunks > 64K, since we don't have enough space
1132
* to be able to store the uncompressed data. Actually, the threshold
1133
* is probably around 32K, but it isn't as definite as 64K is.
1135
if (length > (png_uint_32)65535L)
1137
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1138
png_push_crc_skip(png_ptr, length);
1143
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1144
(png_uint_32)(length+1));
1145
png_ptr->current_text[length] = '\0';
1146
png_ptr->current_text_ptr = png_ptr->current_text;
1147
png_ptr->current_text_size = (png_size_t)length;
1148
png_ptr->current_text_left = (png_size_t)length;
1149
png_ptr->process_mode = PNG_READ_zTXt_MODE;
1153
png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1155
if (png_ptr->buffer_size && png_ptr->current_text_left)
1157
png_size_t text_size;
1159
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1160
text_size = png_ptr->buffer_size;
1162
text_size = png_ptr->current_text_left;
1163
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1164
png_ptr->current_text_left -= text_size;
1165
png_ptr->current_text_ptr += text_size;
1167
if (!(png_ptr->current_text_left))
1173
png_size_t text_size, key_size;
1175
if (png_ptr->buffer_size < 4)
1177
png_push_save_buffer(png_ptr);
1181
png_push_crc_finish(png_ptr);
1183
key = png_ptr->current_text;
1185
for (text = key; *text; text++)
1188
/* zTXt can't have zero text */
1189
if (text == key + png_ptr->current_text_size)
1191
png_ptr->current_text = NULL;
1192
png_free(png_ptr, key);
1198
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
1200
png_ptr->current_text = NULL;
1201
png_free(png_ptr, key);
1207
png_ptr->zstream.next_in = (png_bytep )text;
1208
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1210
png_ptr->zstream.next_out = png_ptr->zbuf;
1211
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1213
key_size = text - key;
1218
while (png_ptr->zstream.avail_in)
1220
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1221
if (ret != Z_OK && ret != Z_STREAM_END)
1223
inflateReset(&png_ptr->zstream);
1224
png_ptr->zstream.avail_in = 0;
1225
png_ptr->current_text = NULL;
1226
png_free(png_ptr, key);
1227
png_free(png_ptr, text);
1230
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1234
text = (png_charp)png_malloc(png_ptr,
1235
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1237
png_memcpy(text + key_size, png_ptr->zbuf,
1238
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1239
png_memcpy(text, key, key_size);
1240
text_size = key_size + png_ptr->zbuf_size -
1241
png_ptr->zstream.avail_out;
1242
*(text + text_size) = '\0';
1249
text = (png_charp)png_malloc(png_ptr, text_size +
1250
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1252
png_memcpy(text, tmp, text_size);
1253
png_free(png_ptr, tmp);
1254
png_memcpy(text + text_size, png_ptr->zbuf,
1255
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1256
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1257
*(text + text_size) = '\0';
1259
if (ret != Z_STREAM_END)
1261
png_ptr->zstream.next_out = png_ptr->zbuf;
1262
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1270
if (ret == Z_STREAM_END)
1274
inflateReset(&png_ptr->zstream);
1275
png_ptr->zstream.avail_in = 0;
1277
if (ret != Z_STREAM_END)
1279
png_ptr->current_text = NULL;
1280
png_free(png_ptr, key);
1281
png_free(png_ptr, text);
1285
png_ptr->current_text = NULL;
1286
png_free(png_ptr, key);
1290
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1291
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1292
text_ptr->key = key;
1293
#ifdef PNG_iTXt_SUPPORTED
1294
text_ptr->lang = NULL;
1295
text_ptr->lang_key = NULL;
1297
text_ptr->text = text;
1299
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1301
png_free(png_ptr, key);
1302
png_free(png_ptr, text_ptr);
1305
png_warning(png_ptr, "Insufficient memory to store text chunk.");
1310
#if defined(PNG_READ_iTXt_SUPPORTED)
1312
png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1315
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1317
png_error(png_ptr, "Out of place iTXt");
1318
/* to quiet some compiler warnings */
1319
if(info_ptr == NULL) return;
1322
#ifdef PNG_MAX_MALLOC_64K
1323
png_ptr->skip_length = 0; /* This may not be necessary */
1325
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1327
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1328
png_ptr->skip_length = length - (png_uint_32)65535L;
1329
length = (png_uint_32)65535L;
1333
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1334
(png_uint_32)(length+1));
1335
png_ptr->current_text[length] = '\0';
1336
png_ptr->current_text_ptr = png_ptr->current_text;
1337
png_ptr->current_text_size = (png_size_t)length;
1338
png_ptr->current_text_left = (png_size_t)length;
1339
png_ptr->process_mode = PNG_READ_iTXt_MODE;
1343
png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1346
if (png_ptr->buffer_size && png_ptr->current_text_left)
1348
png_size_t text_size;
1350
if (png_ptr->buffer_size < png_ptr->current_text_left)
1351
text_size = png_ptr->buffer_size;
1353
text_size = png_ptr->current_text_left;
1354
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1355
png_ptr->current_text_left -= text_size;
1356
png_ptr->current_text_ptr += text_size;
1358
if (!(png_ptr->current_text_left))
1368
if (png_ptr->buffer_size < 4)
1370
png_push_save_buffer(png_ptr);
1374
png_push_crc_finish(png_ptr);
1376
#if defined(PNG_MAX_MALLOC_64K)
1377
if (png_ptr->skip_length)
1381
key = png_ptr->current_text;
1383
for (lang = key; *lang; lang++)
1386
if (lang != key + png_ptr->current_text_size)
1389
comp_flag = *lang++;
1390
lang++; /* skip comp_type, always zero */
1392
for (lang_key = lang; *lang_key; lang_key++)
1394
lang_key++; /* skip NUL separator */
1396
for (text = lang_key; *text; text++)
1399
if (text != key + png_ptr->current_text_size)
1402
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1403
text_ptr->compression = comp_flag + 2;
1404
text_ptr->key = key;
1405
text_ptr->lang = lang;
1406
text_ptr->lang_key = lang_key;
1407
text_ptr->text = text;
1408
text_ptr->text_length = 0;
1409
text_ptr->itxt_length = png_strlen(text);
1411
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1413
png_ptr->current_text = NULL;
1415
png_free(png_ptr, text_ptr);
1417
png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1422
/* This function is called when we haven't found a handler for this
1423
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1424
* name or a critical chunk), the chunk is (currently) silently ignored.
1427
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1431
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
1433
if (!(png_ptr->chunk_name[0] & 0x20))
1435
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1436
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1438
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1439
&& png_ptr->read_user_chunk_fn == NULL
1443
png_chunk_error(png_ptr, "unknown critical chunk");
1445
/* to quiet compiler warnings about unused info_ptr */
1446
if (info_ptr == NULL)
1450
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1451
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1453
png_unknown_chunk chunk;
1455
#ifdef PNG_MAX_MALLOC_64K
1456
if (length > (png_uint_32)65535L)
1458
png_warning(png_ptr, "unknown chunk too large to fit in memory");
1459
skip = length - (png_uint_32)65535L;
1460
length = (png_uint_32)65535L;
1464
png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
1465
chunk.data = (png_bytep)png_malloc(png_ptr, length);
1466
png_crc_read(png_ptr, chunk.data, length);
1467
chunk.size = length;
1468
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1469
if(png_ptr->read_user_chunk_fn != NULL)
1471
/* callback to user unknown chunk handler */
1472
if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
1474
if (!(png_ptr->chunk_name[0] & 0x20))
1475
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1476
HANDLE_CHUNK_ALWAYS)
1477
png_chunk_error(png_ptr, "unknown critical chunk");
1479
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1483
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1484
png_free(png_ptr, chunk.data);
1489
png_push_crc_skip(png_ptr, skip);
1493
png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1495
if (png_ptr->info_fn != NULL)
1496
(*(png_ptr->info_fn))(png_ptr, info_ptr);
1500
png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1502
if (png_ptr->end_fn != NULL)
1503
(*(png_ptr->end_fn))(png_ptr, info_ptr);
1507
png_push_have_row(png_structp png_ptr, png_bytep row)
1509
if (png_ptr->row_fn != NULL)
1510
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1511
(int)png_ptr->pass);
1515
png_progressive_combine_row (png_structp png_ptr,
1516
png_bytep old_row, png_bytep new_row)
1518
#ifdef PNG_USE_LOCAL_ARRAYS
1519
const int FARDATA png_pass_dsp_mask[7] =
1520
{0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1522
if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1523
png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1527
png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1528
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1529
png_progressive_end_ptr end_fn)
1531
png_ptr->info_fn = info_fn;
1532
png_ptr->row_fn = row_fn;
1533
png_ptr->end_fn = end_fn;
1535
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1539
png_get_progressive_ptr(png_structp png_ptr)
1541
return png_ptr->io_ptr;
1543
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */