2
/* pngpread.c - read a png file in push mode
4
* libpng 1.0.8 - July 24, 2000
5
* For conditions of distribution and use, see copyright notice in png.h
6
* Copyright (c) 1998, 1999, 2000 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
19
#define PNG_READ_IDAT_MODE 2
20
#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);
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#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");
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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)
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#if defined(PNG_READ_pCAL_SUPPORTED)
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#if defined(PNG_READ_pHYs_SUPPORTED)
169
#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)
181
#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);
225
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
227
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
229
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
231
png_push_save_buffer(png_ptr);
235
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
237
else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
239
/* If we reach an IDAT chunk, this means we have read all of the
240
* header chunks, and we can start reading the image (or if this
241
* is called after the image has been read - we have an error).
243
if (png_ptr->mode & PNG_HAVE_IDAT)
245
if (png_ptr->push_length == 0)
248
if (png_ptr->mode & PNG_AFTER_IDAT)
249
png_error(png_ptr, "Too many IDAT's found");
252
png_ptr->idat_size = png_ptr->push_length;
253
png_ptr->mode |= PNG_HAVE_IDAT;
254
png_ptr->process_mode = PNG_READ_IDAT_MODE;
255
png_push_have_info(png_ptr, info_ptr);
256
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
257
png_ptr->zstream.next_out = png_ptr->row_buf;
260
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
262
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
264
png_push_save_buffer(png_ptr);
268
png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
269
png_ptr->process_mode = PNG_READ_DONE_MODE;
270
png_push_have_end(png_ptr, info_ptr);
272
#if defined(PNG_READ_gAMA_SUPPORTED)
273
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
275
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
277
png_push_save_buffer(png_ptr);
281
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
284
#if defined(PNG_READ_sBIT_SUPPORTED)
285
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
287
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
289
png_push_save_buffer(png_ptr);
293
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
296
#if defined(PNG_READ_cHRM_SUPPORTED)
297
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
299
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
301
png_push_save_buffer(png_ptr);
305
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
308
#if defined(PNG_READ_sRGB_SUPPORTED)
309
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
311
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
313
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);
329
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
332
#if defined(PNG_READ_sPLT_SUPPORTED)
333
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
335
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
337
png_push_save_buffer(png_ptr);
341
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
344
#if defined(PNG_READ_tRNS_SUPPORTED)
345
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
347
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
349
png_push_save_buffer(png_ptr);
353
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
356
#if defined(PNG_READ_bKGD_SUPPORTED)
357
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
359
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
361
png_push_save_buffer(png_ptr);
365
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
368
#if defined(PNG_READ_hIST_SUPPORTED)
369
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
371
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
373
png_push_save_buffer(png_ptr);
377
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
380
#if defined(PNG_READ_pHYs_SUPPORTED)
381
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
383
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
385
png_push_save_buffer(png_ptr);
389
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
392
#if defined(PNG_READ_oFFs_SUPPORTED)
393
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
395
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
397
png_push_save_buffer(png_ptr);
401
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
404
#if defined(PNG_READ_pCAL_SUPPORTED)
405
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
407
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
409
png_push_save_buffer(png_ptr);
413
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
416
#if defined(PNG_READ_sCAL_SUPPORTED)
417
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
419
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
421
png_push_save_buffer(png_ptr);
425
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
428
#if defined(PNG_READ_tIME_SUPPORTED)
429
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
431
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
433
png_push_save_buffer(png_ptr);
437
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
440
#if defined(PNG_READ_tEXt_SUPPORTED)
441
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
443
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
446
#if defined(PNG_READ_zTXt_SUPPORTED)
447
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
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
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
460
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
463
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
467
png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
469
png_ptr->process_mode = PNG_SKIP_MODE;
470
png_ptr->skip_length = skip;
474
png_push_crc_finish(png_structp png_ptr)
476
if (png_ptr->skip_length && png_ptr->save_buffer_size)
478
png_size_t save_size;
480
if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
481
save_size = (png_size_t)png_ptr->skip_length;
483
save_size = png_ptr->save_buffer_size;
485
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
487
png_ptr->skip_length -= save_size;
488
png_ptr->buffer_size -= save_size;
489
png_ptr->save_buffer_size -= save_size;
490
png_ptr->save_buffer_ptr += save_size;
492
if (png_ptr->skip_length && png_ptr->current_buffer_size)
494
png_size_t save_size;
496
if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
497
save_size = (png_size_t)png_ptr->skip_length;
499
save_size = png_ptr->current_buffer_size;
501
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
503
png_ptr->skip_length -= save_size;
504
png_ptr->buffer_size -= save_size;
505
png_ptr->current_buffer_size -= save_size;
506
png_ptr->current_buffer_ptr += save_size;
508
if (!png_ptr->skip_length)
510
if (png_ptr->buffer_size < 4)
512
png_push_save_buffer(png_ptr);
516
png_crc_finish(png_ptr, 0);
517
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
522
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
527
if (png_ptr->save_buffer_size)
529
png_size_t save_size;
531
if (length < png_ptr->save_buffer_size)
534
save_size = png_ptr->save_buffer_size;
536
png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
539
png_ptr->buffer_size -= save_size;
540
png_ptr->save_buffer_size -= save_size;
541
png_ptr->save_buffer_ptr += save_size;
543
if (length && png_ptr->current_buffer_size)
545
png_size_t save_size;
547
if (length < png_ptr->current_buffer_size)
550
save_size = png_ptr->current_buffer_size;
552
png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
553
png_ptr->buffer_size -= save_size;
554
png_ptr->current_buffer_size -= save_size;
555
png_ptr->current_buffer_ptr += save_size;
560
png_push_save_buffer(png_structp png_ptr)
562
if (png_ptr->save_buffer_size)
564
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
570
istop = png_ptr->save_buffer_size;
571
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
572
i < istop; i++, sp++, dp++)
578
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
579
png_ptr->save_buffer_max)
582
png_bytep old_buffer;
584
new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
585
old_buffer = png_ptr->save_buffer;
586
png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
587
(png_uint_32)new_max);
588
png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
589
png_free(png_ptr, old_buffer);
590
png_ptr->save_buffer_max = new_max;
592
if (png_ptr->current_buffer_size)
594
png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
595
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
596
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
597
png_ptr->current_buffer_size = 0;
599
png_ptr->save_buffer_ptr = png_ptr->save_buffer;
600
png_ptr->buffer_size = 0;
604
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
605
png_size_t buffer_length)
607
png_ptr->current_buffer = buffer;
608
png_ptr->current_buffer_size = buffer_length;
609
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
610
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
614
png_push_read_IDAT(png_structp png_ptr)
616
#ifdef PNG_USE_LOCAL_ARRAYS
619
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
621
png_byte chunk_length[4];
623
if (png_ptr->buffer_size < 8)
625
png_push_save_buffer(png_ptr);
629
png_push_fill_buffer(png_ptr, chunk_length, 4);
630
png_ptr->push_length = png_get_uint_32(chunk_length);
632
png_reset_crc(png_ptr);
633
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
634
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
636
if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
638
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
639
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
640
png_error(png_ptr, "Not enough compressed data");
644
png_ptr->idat_size = png_ptr->push_length;
646
if (png_ptr->idat_size && png_ptr->save_buffer_size)
648
png_size_t save_size;
650
if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
652
save_size = (png_size_t)png_ptr->idat_size;
653
/* check for overflow */
654
if((png_uint_32)save_size != png_ptr->idat_size)
655
png_error(png_ptr, "save_size overflowed in pngpread");
658
save_size = png_ptr->save_buffer_size;
660
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
661
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
663
png_ptr->idat_size -= save_size;
664
png_ptr->buffer_size -= save_size;
665
png_ptr->save_buffer_size -= save_size;
666
png_ptr->save_buffer_ptr += save_size;
668
if (png_ptr->idat_size && png_ptr->current_buffer_size)
670
png_size_t save_size;
672
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
674
save_size = (png_size_t)png_ptr->idat_size;
675
/* check for overflow */
676
if((png_uint_32)save_size != png_ptr->idat_size)
677
png_error(png_ptr, "save_size overflowed in pngpread");
680
save_size = png_ptr->current_buffer_size;
682
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
683
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
685
png_ptr->idat_size -= save_size;
686
png_ptr->buffer_size -= save_size;
687
png_ptr->current_buffer_size -= save_size;
688
png_ptr->current_buffer_ptr += save_size;
690
if (!png_ptr->idat_size)
692
if (png_ptr->buffer_size < 4)
694
png_push_save_buffer(png_ptr);
698
png_crc_finish(png_ptr, 0);
699
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
704
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
705
png_size_t buffer_length)
709
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
710
png_error(png_ptr, "Extra compression data");
712
png_ptr->zstream.next_in = buffer;
713
png_ptr->zstream.avail_in = (uInt)buffer_length;
716
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
719
if (ret == Z_STREAM_END)
721
if (png_ptr->zstream.avail_in)
722
png_error(png_ptr, "Extra compressed data");
723
if (!(png_ptr->zstream.avail_out))
725
png_push_process_row(png_ptr);
728
png_ptr->mode |= PNG_AFTER_IDAT;
729
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
732
else if (ret == Z_BUF_ERROR)
735
png_error(png_ptr, "Decompression Error");
737
if (!(png_ptr->zstream.avail_out))
739
png_push_process_row(png_ptr);
740
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
741
png_ptr->zstream.next_out = png_ptr->row_buf;
749
png_push_process_row(png_structp png_ptr)
751
png_ptr->row_info.color_type = png_ptr->color_type;
752
png_ptr->row_info.width = png_ptr->iwidth;
753
png_ptr->row_info.channels = png_ptr->channels;
754
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
755
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
757
png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
758
(png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
760
png_read_filter_row(png_ptr, &(png_ptr->row_info),
761
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
762
(int)(png_ptr->row_buf[0]));
764
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
765
png_ptr->rowbytes + 1);
767
if (png_ptr->transformations)
768
png_do_read_transformations(png_ptr);
770
#if defined(PNG_READ_INTERLACING_SUPPORTED)
771
/* blow up interlaced rows to full size */
772
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
774
if (png_ptr->pass < 6)
775
png_do_read_interlace(&(png_ptr->row_info),
776
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
778
switch (png_ptr->pass)
783
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
785
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
786
png_read_push_finish_row(png_ptr);
793
for (i = 0; i < 8 && png_ptr->pass == 1; i++)
795
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
796
png_read_push_finish_row(png_ptr);
798
if (png_ptr->pass == 2)
800
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
802
png_push_have_row(png_ptr, NULL);
803
png_read_push_finish_row(png_ptr);
811
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
813
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
814
png_read_push_finish_row(png_ptr);
816
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
818
png_push_have_row(png_ptr, NULL);
819
png_read_push_finish_row(png_ptr);
826
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
828
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
829
png_read_push_finish_row(png_ptr);
831
if (png_ptr->pass == 4)
833
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
835
png_push_have_row(png_ptr, NULL);
836
png_read_push_finish_row(png_ptr);
844
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
846
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
847
png_read_push_finish_row(png_ptr);
849
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
851
png_push_have_row(png_ptr, NULL);
852
png_read_push_finish_row(png_ptr);
859
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
861
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
862
png_read_push_finish_row(png_ptr);
864
if (png_ptr->pass == 6)
866
png_push_have_row(png_ptr, NULL);
867
png_read_push_finish_row(png_ptr);
873
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
874
png_read_push_finish_row(png_ptr);
875
if (png_ptr->pass != 6)
877
png_push_have_row(png_ptr, NULL);
878
png_read_push_finish_row(png_ptr);
885
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
886
png_read_push_finish_row(png_ptr);
891
png_read_push_finish_row(png_structp png_ptr)
893
#ifdef PNG_USE_LOCAL_ARRAYS
894
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
896
/* start of interlace block */
897
const int png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
899
/* offset to next interlace block */
900
const int png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
902
/* start of interlace block in the y direction */
903
const int png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
905
/* offset to next interlace block in the y direction */
906
const int png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
908
/* Width of interlace block. This is not currently used - if you need
909
* it, uncomment it here and in png.h
910
const int png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
913
/* Height of interlace block. This is not currently used - if you need
914
* it, uncomment it here and in png.h
915
const int png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
919
png_ptr->row_number++;
920
if (png_ptr->row_number < png_ptr->num_rows)
923
if (png_ptr->interlaced)
925
png_ptr->row_number = 0;
926
png_memset_check(png_ptr, png_ptr->prev_row, 0,
927
png_ptr->rowbytes + 1);
931
if (png_ptr->pass >= 7)
934
png_ptr->iwidth = (png_ptr->width +
935
png_pass_inc[png_ptr->pass] - 1 -
936
png_pass_start[png_ptr->pass]) /
937
png_pass_inc[png_ptr->pass];
939
png_ptr->irowbytes = ((png_ptr->iwidth *
940
png_ptr->pixel_depth + 7) >> 3) + 1;
942
if (png_ptr->transformations & PNG_INTERLACE)
945
png_ptr->num_rows = (png_ptr->height +
946
png_pass_yinc[png_ptr->pass] - 1 -
947
png_pass_ystart[png_ptr->pass]) /
948
png_pass_yinc[png_ptr->pass];
950
} while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
954
#if defined(PNG_READ_tEXt_SUPPORTED)
956
png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
958
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
960
png_error(png_ptr, "Out of place tEXt");
961
/* to quiet some compiler warnings */
962
if(info_ptr == NULL) return;
965
#ifdef PNG_MAX_MALLOC_64K
966
png_ptr->skip_length = 0; /* This may not be necessary */
968
if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */
970
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
971
png_ptr->skip_length = length - (png_uint_32)65535L;
972
length = (png_uint_32)65535L;
976
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
977
(png_uint_32)(length+1));
978
png_ptr->current_text[length] = '\0';
979
png_ptr->current_text_ptr = png_ptr->current_text;
980
png_ptr->current_text_size = (png_size_t)length;
981
png_ptr->current_text_left = (png_size_t)length;
982
png_ptr->process_mode = PNG_READ_tEXt_MODE;
986
png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
988
if (png_ptr->buffer_size && png_ptr->current_text_left)
990
png_size_t text_size;
992
if (png_ptr->buffer_size < png_ptr->current_text_left)
993
text_size = png_ptr->buffer_size;
995
text_size = png_ptr->current_text_left;
996
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
997
png_ptr->current_text_left -= text_size;
998
png_ptr->current_text_ptr += text_size;
1000
if (!(png_ptr->current_text_left))
1006
if (png_ptr->buffer_size < 4)
1008
png_push_save_buffer(png_ptr);
1012
png_push_crc_finish(png_ptr);
1014
#if defined(PNG_MAX_MALLOC_64K)
1015
if (png_ptr->skip_length)
1019
key = png_ptr->current_text;
1020
png_ptr->current_text = 0;
1022
for (text = key; *text; text++)
1025
if (text != key + png_ptr->current_text_size)
1028
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1029
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1030
text_ptr->key = key;
1031
#ifdef PNG_iTXt_SUPPORTED
1032
text_ptr->lang = (char *)NULL;
1033
text_ptr->lang_key = (char *)NULL;
1035
text_ptr->text = text;
1037
png_set_text(png_ptr, info_ptr, text_ptr, 1);
1039
png_free(png_ptr, key);
1040
png_free(png_ptr, text_ptr);
1045
#if defined(PNG_READ_zTXt_SUPPORTED)
1047
png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1049
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1051
png_error(png_ptr, "Out of place zTXt");
1052
/* to quiet some compiler warnings */
1053
if(info_ptr == NULL) return;
1056
#ifdef PNG_MAX_MALLOC_64K
1057
/* We can't handle zTXt chunks > 64K, since we don't have enough space
1058
* to be able to store the uncompressed data. Actually, the threshold
1059
* is probably around 32K, but it isn't as definite as 64K is.
1061
if (length > (png_uint_32)65535L)
1063
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1064
png_push_crc_skip(png_ptr, length);
1069
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1070
(png_uint_32)(length+1));
1071
png_ptr->current_text[length] = '\0';
1072
png_ptr->current_text_ptr = png_ptr->current_text;
1073
png_ptr->current_text_size = (png_size_t)length;
1074
png_ptr->current_text_left = (png_size_t)length;
1075
png_ptr->process_mode = PNG_READ_zTXt_MODE;
1079
png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1081
if (png_ptr->buffer_size && png_ptr->current_text_left)
1083
png_size_t text_size;
1085
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1086
text_size = png_ptr->buffer_size;
1088
text_size = png_ptr->current_text_left;
1089
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1090
png_ptr->current_text_left -= text_size;
1091
png_ptr->current_text_ptr += text_size;
1093
if (!(png_ptr->current_text_left))
1099
png_size_t text_size, key_size;
1101
if (png_ptr->buffer_size < 4)
1103
png_push_save_buffer(png_ptr);
1107
png_push_crc_finish(png_ptr);
1109
key = png_ptr->current_text;
1110
png_ptr->current_text = 0;
1112
for (text = key; *text; text++)
1115
/* zTXt can't have zero text */
1116
if (text == key + png_ptr->current_text_size)
1118
png_free(png_ptr, key);
1124
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
1126
png_free(png_ptr, key);
1132
png_ptr->zstream.next_in = (png_bytep )text;
1133
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1135
png_ptr->zstream.next_out = png_ptr->zbuf;
1136
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1138
key_size = text - key;
1143
while (png_ptr->zstream.avail_in)
1145
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1146
if (ret != Z_OK && ret != Z_STREAM_END)
1148
inflateReset(&png_ptr->zstream);
1149
png_ptr->zstream.avail_in = 0;
1150
png_free(png_ptr, key);
1151
png_free(png_ptr, text);
1154
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1158
text = (png_charp)png_malloc(png_ptr,
1159
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out +
1161
png_memcpy(text + key_size, png_ptr->zbuf,
1162
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1163
png_memcpy(text, key, key_size);
1164
text_size = key_size + png_ptr->zbuf_size -
1165
png_ptr->zstream.avail_out;
1166
*(text + text_size) = '\0';
1173
text = (png_charp)png_malloc(png_ptr, text_size +
1174
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1176
png_memcpy(text, tmp, text_size);
1177
png_free(png_ptr, tmp);
1178
png_memcpy(text + text_size, png_ptr->zbuf,
1179
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1180
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1181
*(text + text_size) = '\0';
1183
if (ret != Z_STREAM_END)
1185
png_ptr->zstream.next_out = png_ptr->zbuf;
1186
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1194
if (ret == Z_STREAM_END)
1198
inflateReset(&png_ptr->zstream);
1199
png_ptr->zstream.avail_in = 0;
1201
if (ret != Z_STREAM_END)
1203
png_free(png_ptr, key);
1204
png_free(png_ptr, text);
1208
png_free(png_ptr, key);
1212
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1213
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1214
text_ptr->key = key;
1215
#ifdef PNG_iTXt_SUPPORTED
1216
text_ptr->lang = (char *)NULL;
1217
text_ptr->lang_key = (char *)NULL;
1219
text_ptr->text = text;
1221
png_set_text(png_ptr, info_ptr, text_ptr, 1);
1223
png_free(png_ptr, key);
1224
png_free(png_ptr, text_ptr);
1229
#if defined(PNG_READ_iTXt_SUPPORTED)
1231
png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1233
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1235
png_error(png_ptr, "Out of place iTXt");
1236
/* to quiet some compiler warnings */
1237
if(info_ptr == NULL) return;
1240
#ifdef PNG_MAX_MALLOC_64K
1241
png_ptr->skip_length = 0; /* This may not be necessary */
1243
if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */
1245
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1246
png_ptr->skip_length = length - (png_uint_32)65535L;
1247
length = (png_uint_32)65535L;
1251
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1252
(png_uint_32)(length+1));
1253
png_ptr->current_text[length] = '\0';
1254
png_ptr->current_text_ptr = png_ptr->current_text;
1255
png_ptr->current_text_size = (png_size_t)length;
1256
png_ptr->current_text_left = (png_size_t)length;
1257
png_ptr->process_mode = PNG_READ_iTXt_MODE;
1261
png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1264
if (png_ptr->buffer_size && png_ptr->current_text_left)
1266
png_size_t text_size;
1268
if (png_ptr->buffer_size < png_ptr->current_text_left)
1269
text_size = png_ptr->buffer_size;
1271
text_size = png_ptr->current_text_left;
1272
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1273
png_ptr->current_text_left -= text_size;
1274
png_ptr->current_text_ptr += text_size;
1276
if (!(png_ptr->current_text_left))
1285
if (png_ptr->buffer_size < 4)
1287
png_push_save_buffer(png_ptr);
1291
png_push_crc_finish(png_ptr);
1293
#if defined(PNG_MAX_MALLOC_64K)
1294
if (png_ptr->skip_length)
1298
key = png_ptr->current_text;
1299
png_ptr->current_text = 0;
1301
for (lang = key; *lang; lang++)
1304
if (lang != key + png_ptr->current_text_size)
1307
comp_flag = *lang++;
1308
lang++; /* skip comp_type, always zero */
1310
for (lang_key = lang; *lang_key; lang_key++)
1312
lang_key++; /* skip NUL separator */
1314
for (text = lang_key; *text; text++)
1317
if (text != key + png_ptr->current_text_size)
1320
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1321
text_ptr->compression = comp_flag + 2;
1322
text_ptr->key = key;
1323
text_ptr->lang = lang;
1324
text_ptr->lang_key = lang_key;
1325
text_ptr->text = text;
1326
text_ptr->text_length = 0;
1327
text_ptr->itxt_length = png_strlen(text);
1329
png_set_text(png_ptr, info_ptr, text_ptr, 1);
1331
png_free(png_ptr, text_ptr);
1336
/* This function is called when we haven't found a handler for this
1337
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1338
* name or a critical chunk), the chunk is (currently) silently ignored.
1341
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
1344
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
1346
if (!(png_ptr->chunk_name[0] & 0x20))
1348
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1349
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1351
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1352
&& png_ptr->read_user_chunk_fn == (png_user_chunk_ptr)NULL
1356
png_chunk_error(png_ptr, "unknown critical chunk");
1358
/* to quiet compiler warnings about unused info_ptr */
1359
if (info_ptr == NULL)
1363
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1364
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1366
png_unknown_chunk chunk;
1368
#ifdef PNG_MAX_MALLOC_64K
1369
if (length > (png_uint_32)65535L)
1371
png_warning(png_ptr, "unknown chunk too large to fit in memory");
1372
skip = length - (png_uint_32)65535L;
1373
length = (png_uint_32)65535L;
1377
strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
1378
chunk.data = (png_bytep)png_malloc(png_ptr, length);
1379
png_crc_read(png_ptr, chunk.data, length);
1380
chunk.size = length;
1381
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1382
if(png_ptr->read_user_chunk_fn != (png_user_chunk_ptr)NULL)
1384
/* callback to user unknown chunk handler */
1385
if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
1387
if (!(png_ptr->chunk_name[0] & 0x20))
1388
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1389
HANDLE_CHUNK_ALWAYS)
1390
png_chunk_error(png_ptr, "unknown critical chunk");
1392
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1396
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1397
png_free(png_ptr, chunk.data);
1402
png_push_crc_skip(png_ptr, skip);
1406
png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1408
if (png_ptr->info_fn != NULL)
1409
(*(png_ptr->info_fn))(png_ptr, info_ptr);
1413
png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1415
if (png_ptr->end_fn != NULL)
1416
(*(png_ptr->end_fn))(png_ptr, info_ptr);
1420
png_push_have_row(png_structp png_ptr, png_bytep row)
1422
if (png_ptr->row_fn != NULL)
1423
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1424
(int)png_ptr->pass);
1428
png_progressive_combine_row (png_structp png_ptr,
1429
png_bytep old_row, png_bytep new_row)
1431
#ifdef PNG_USE_LOCAL_ARRAYS
1432
const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1434
if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1435
png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1439
png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1440
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1441
png_progressive_end_ptr end_fn)
1443
png_ptr->info_fn = info_fn;
1444
png_ptr->row_fn = row_fn;
1445
png_ptr->end_fn = end_fn;
1447
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1451
png_get_progressive_ptr(png_structp png_ptr)
1453
return png_ptr->io_ptr;
1456
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */