2
/* pngpread.c - read a png file in push mode
4
* libpng version 1.2.7 - September 12, 2004
5
* For conditions of distribution and use, see copyright notice in png.h
6
* Copyright (c) 1998-2004 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
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/* push model modes */
17
#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
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#define PNG_READ_iTXt_MODE 7
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#define PNG_ERROR_MODE 8
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png_process_data(png_structp png_ptr, png_infop info_ptr,
29
png_bytep buffer, png_size_t buffer_size)
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png_push_restore_buffer(png_ptr, buffer, buffer_size);
33
while (png_ptr->buffer_size)
35
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
40
* doing before we ran out of data...
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png_process_some_data(png_structp png_ptr, png_infop info_ptr)
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switch (png_ptr->process_mode)
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case PNG_READ_SIG_MODE:
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png_push_read_sig(png_ptr, info_ptr);
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case PNG_READ_CHUNK_MODE:
54
png_push_read_chunk(png_ptr, info_ptr);
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case PNG_READ_IDAT_MODE:
59
png_push_read_IDAT(png_ptr);
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#if defined(PNG_READ_tEXt_SUPPORTED)
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case PNG_READ_tEXt_MODE:
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png_push_read_tEXt(png_ptr, info_ptr);
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#if defined(PNG_READ_zTXt_SUPPORTED)
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case PNG_READ_zTXt_MODE:
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png_push_read_zTXt(png_ptr, info_ptr);
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#if defined(PNG_READ_iTXt_SUPPORTED)
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case PNG_READ_iTXt_MODE:
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png_push_read_iTXt(png_ptr, info_ptr);
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png_push_crc_finish(png_ptr);
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png_ptr->buffer_size = 0;
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/* Read any remaining signature bytes from the stream and compare them with
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* the correct PNG signature. It is possible that this routine is called
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* 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)
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png_size_t num_checked = png_ptr->sig_bytes,
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num_to_check = 8 - num_checked;
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if (png_ptr->buffer_size < num_to_check)
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num_to_check = png_ptr->buffer_size;
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png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
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png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
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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;
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png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
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#ifdef PNG_USE_LOCAL_ARRAYS
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#if defined(PNG_READ_bKGD_SUPPORTED)
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#if defined(PNG_READ_cHRM_SUPPORTED)
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#if defined(PNG_READ_gAMA_SUPPORTED)
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#if defined(PNG_READ_hIST_SUPPORTED)
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#if defined(PNG_READ_iCCP_SUPPORTED)
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#if defined(PNG_READ_iTXt_SUPPORTED)
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#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)
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#if defined(PNG_READ_sBIT_SUPPORTED)
172
#if defined(PNG_READ_sCAL_SUPPORTED)
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#if defined(PNG_READ_sRGB_SUPPORTED)
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#if defined(PNG_READ_sPLT_SUPPORTED)
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#if defined(PNG_READ_tEXt_SUPPORTED)
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#if defined(PNG_READ_tIME_SUPPORTED)
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#if defined(PNG_READ_tRNS_SUPPORTED)
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#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))
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png_byte chunk_length[4];
204
if (png_ptr->buffer_size < 8)
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png_push_save_buffer(png_ptr);
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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);
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png_reset_crc(png_ptr);
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png_crc_read(png_ptr, png_ptr->chunk_name, 4);
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png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
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if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
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if (png_ptr->push_length + 4 > png_ptr->buffer_size)
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png_push_save_buffer(png_ptr);
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png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
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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)
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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
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else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
241
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
243
png_push_save_buffer(png_ptr);
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if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
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png_ptr->mode |= PNG_HAVE_IDAT;
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png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
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if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
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png_ptr->mode |= PNG_HAVE_PLTE;
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else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
253
if (!(png_ptr->mode & PNG_HAVE_IHDR))
254
png_error(png_ptr, "Missing IHDR before IDAT");
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else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
256
!(png_ptr->mode & PNG_HAVE_PLTE))
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png_error(png_ptr, "Missing PLTE before IDAT");
261
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
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if (png_ptr->push_length + 4 > png_ptr->buffer_size)
265
png_push_save_buffer(png_ptr);
268
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
270
else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
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/* If we reach an IDAT chunk, this means we have read all of the
273
* header chunks, and we can start reading the image (or if this
274
* is called after the image has been read - we have an error).
276
if (!(png_ptr->mode & PNG_HAVE_IHDR))
277
png_error(png_ptr, "Missing IHDR before IDAT");
278
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
279
!(png_ptr->mode & PNG_HAVE_PLTE))
280
png_error(png_ptr, "Missing PLTE before IDAT");
282
if (png_ptr->mode & PNG_HAVE_IDAT)
284
if (png_ptr->push_length == 0)
287
if (png_ptr->mode & PNG_AFTER_IDAT)
288
png_error(png_ptr, "Too many IDAT's found");
291
png_ptr->idat_size = png_ptr->push_length;
292
png_ptr->mode |= PNG_HAVE_IDAT;
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png_ptr->process_mode = PNG_READ_IDAT_MODE;
294
png_push_have_info(png_ptr, info_ptr);
295
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
296
png_ptr->zstream.next_out = png_ptr->row_buf;
299
#if defined(PNG_READ_gAMA_SUPPORTED)
300
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
302
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
304
png_push_save_buffer(png_ptr);
307
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
310
#if defined(PNG_READ_sBIT_SUPPORTED)
311
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
313
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
315
png_push_save_buffer(png_ptr);
318
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
321
#if defined(PNG_READ_cHRM_SUPPORTED)
322
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
324
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
326
png_push_save_buffer(png_ptr);
329
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
332
#if defined(PNG_READ_sRGB_SUPPORTED)
333
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
335
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
337
png_push_save_buffer(png_ptr);
340
png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
343
#if defined(PNG_READ_iCCP_SUPPORTED)
344
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
346
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
348
png_push_save_buffer(png_ptr);
351
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
354
#if defined(PNG_READ_sPLT_SUPPORTED)
355
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
357
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
359
png_push_save_buffer(png_ptr);
362
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
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#if defined(PNG_READ_tRNS_SUPPORTED)
366
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
368
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
370
png_push_save_buffer(png_ptr);
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png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
376
#if defined(PNG_READ_bKGD_SUPPORTED)
377
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
379
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
381
png_push_save_buffer(png_ptr);
384
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
387
#if defined(PNG_READ_hIST_SUPPORTED)
388
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
390
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
392
png_push_save_buffer(png_ptr);
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png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
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#if defined(PNG_READ_pHYs_SUPPORTED)
399
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
401
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
403
png_push_save_buffer(png_ptr);
406
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
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#if defined(PNG_READ_oFFs_SUPPORTED)
410
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
412
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
414
png_push_save_buffer(png_ptr);
417
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
420
#if defined(PNG_READ_pCAL_SUPPORTED)
421
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
423
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
425
png_push_save_buffer(png_ptr);
428
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
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#if defined(PNG_READ_sCAL_SUPPORTED)
432
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
434
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
436
png_push_save_buffer(png_ptr);
439
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
442
#if defined(PNG_READ_tIME_SUPPORTED)
443
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
445
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
447
png_push_save_buffer(png_ptr);
450
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
453
#if defined(PNG_READ_tEXt_SUPPORTED)
454
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
456
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
458
png_push_save_buffer(png_ptr);
461
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
464
#if defined(PNG_READ_zTXt_SUPPORTED)
465
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
467
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
469
png_push_save_buffer(png_ptr);
472
png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
475
#if defined(PNG_READ_iTXt_SUPPORTED)
476
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
478
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
480
png_push_save_buffer(png_ptr);
483
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
488
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
490
png_push_save_buffer(png_ptr);
493
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
496
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
500
png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
502
png_ptr->process_mode = PNG_SKIP_MODE;
503
png_ptr->skip_length = skip;
507
png_push_crc_finish(png_structp png_ptr)
509
if (png_ptr->skip_length && png_ptr->save_buffer_size)
511
png_size_t save_size;
513
if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
514
save_size = (png_size_t)png_ptr->skip_length;
516
save_size = png_ptr->save_buffer_size;
518
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
520
png_ptr->skip_length -= save_size;
521
png_ptr->buffer_size -= save_size;
522
png_ptr->save_buffer_size -= save_size;
523
png_ptr->save_buffer_ptr += save_size;
525
if (png_ptr->skip_length && png_ptr->current_buffer_size)
527
png_size_t save_size;
529
if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
530
save_size = (png_size_t)png_ptr->skip_length;
532
save_size = png_ptr->current_buffer_size;
534
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
536
png_ptr->skip_length -= save_size;
537
png_ptr->buffer_size -= save_size;
538
png_ptr->current_buffer_size -= save_size;
539
png_ptr->current_buffer_ptr += save_size;
541
if (!png_ptr->skip_length)
543
if (png_ptr->buffer_size < 4)
545
png_push_save_buffer(png_ptr);
549
png_crc_finish(png_ptr, 0);
550
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
555
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
560
if (png_ptr->save_buffer_size)
562
png_size_t save_size;
564
if (length < png_ptr->save_buffer_size)
567
save_size = png_ptr->save_buffer_size;
569
png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
572
png_ptr->buffer_size -= save_size;
573
png_ptr->save_buffer_size -= save_size;
574
png_ptr->save_buffer_ptr += save_size;
576
if (length && png_ptr->current_buffer_size)
578
png_size_t save_size;
580
if (length < png_ptr->current_buffer_size)
583
save_size = png_ptr->current_buffer_size;
585
png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
586
png_ptr->buffer_size -= save_size;
587
png_ptr->current_buffer_size -= save_size;
588
png_ptr->current_buffer_ptr += save_size;
593
png_push_save_buffer(png_structp png_ptr)
595
if (png_ptr->save_buffer_size)
597
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
603
istop = png_ptr->save_buffer_size;
604
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
605
i < istop; i++, sp++, dp++)
611
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
612
png_ptr->save_buffer_max)
615
png_bytep old_buffer;
617
if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
618
(png_ptr->current_buffer_size + 256))
620
png_error(png_ptr, "Potential overflow of save_buffer");
622
new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
623
old_buffer = png_ptr->save_buffer;
624
png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
625
(png_uint_32)new_max);
626
png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
627
png_free(png_ptr, old_buffer);
628
png_ptr->save_buffer_max = new_max;
630
if (png_ptr->current_buffer_size)
632
png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
633
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
634
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
635
png_ptr->current_buffer_size = 0;
637
png_ptr->save_buffer_ptr = png_ptr->save_buffer;
638
png_ptr->buffer_size = 0;
642
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
643
png_size_t buffer_length)
645
png_ptr->current_buffer = buffer;
646
png_ptr->current_buffer_size = buffer_length;
647
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
648
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
652
png_push_read_IDAT(png_structp png_ptr)
654
#ifdef PNG_USE_LOCAL_ARRAYS
657
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
659
png_byte chunk_length[4];
661
if (png_ptr->buffer_size < 8)
663
png_push_save_buffer(png_ptr);
667
png_push_fill_buffer(png_ptr, chunk_length, 4);
668
png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
669
png_reset_crc(png_ptr);
670
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
671
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
673
if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
675
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
676
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
677
png_error(png_ptr, "Not enough compressed data");
681
png_ptr->idat_size = png_ptr->push_length;
683
if (png_ptr->idat_size && png_ptr->save_buffer_size)
685
png_size_t save_size;
687
if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
689
save_size = (png_size_t)png_ptr->idat_size;
690
/* check for overflow */
691
if((png_uint_32)save_size != png_ptr->idat_size)
692
png_error(png_ptr, "save_size overflowed in pngpread");
695
save_size = png_ptr->save_buffer_size;
697
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
698
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
699
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
700
png_ptr->idat_size -= save_size;
701
png_ptr->buffer_size -= save_size;
702
png_ptr->save_buffer_size -= save_size;
703
png_ptr->save_buffer_ptr += save_size;
705
if (png_ptr->idat_size && png_ptr->current_buffer_size)
707
png_size_t save_size;
709
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
711
save_size = (png_size_t)png_ptr->idat_size;
712
/* check for overflow */
713
if((png_uint_32)save_size != png_ptr->idat_size)
714
png_error(png_ptr, "save_size overflowed in pngpread");
717
save_size = png_ptr->current_buffer_size;
719
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
720
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
721
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
723
png_ptr->idat_size -= save_size;
724
png_ptr->buffer_size -= save_size;
725
png_ptr->current_buffer_size -= save_size;
726
png_ptr->current_buffer_ptr += save_size;
728
if (!png_ptr->idat_size)
730
if (png_ptr->buffer_size < 4)
732
png_push_save_buffer(png_ptr);
736
png_crc_finish(png_ptr, 0);
737
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
738
png_ptr->mode |= PNG_AFTER_IDAT;
743
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
744
png_size_t buffer_length)
748
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
749
png_error(png_ptr, "Extra compression data");
751
png_ptr->zstream.next_in = buffer;
752
png_ptr->zstream.avail_in = (uInt)buffer_length;
755
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
758
if (ret == Z_STREAM_END)
760
if (png_ptr->zstream.avail_in)
761
png_error(png_ptr, "Extra compressed data");
762
if (!(png_ptr->zstream.avail_out))
764
png_push_process_row(png_ptr);
767
png_ptr->mode |= PNG_AFTER_IDAT;
768
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
771
else if (ret == Z_BUF_ERROR)
774
png_error(png_ptr, "Decompression Error");
776
if (!(png_ptr->zstream.avail_out))
779
#if defined(PNG_READ_INTERLACING_SUPPORTED)
780
png_ptr->interlaced && png_ptr->pass > 6) ||
781
(!png_ptr->interlaced &&
783
png_ptr->row_number == png_ptr->num_rows))
785
if (png_ptr->zstream.avail_in)
786
png_warning(png_ptr, "Too much data in IDAT chunks");
787
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
790
png_push_process_row(png_ptr);
791
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
792
png_ptr->zstream.next_out = png_ptr->row_buf;
800
png_push_process_row(png_structp png_ptr)
802
png_ptr->row_info.color_type = png_ptr->color_type;
803
png_ptr->row_info.width = png_ptr->iwidth;
804
png_ptr->row_info.channels = png_ptr->channels;
805
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
806
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
808
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
809
png_ptr->row_info.width);
811
png_read_filter_row(png_ptr, &(png_ptr->row_info),
812
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
813
(int)(png_ptr->row_buf[0]));
815
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
816
png_ptr->rowbytes + 1);
818
if (png_ptr->transformations)
819
png_do_read_transformations(png_ptr);
821
#if defined(PNG_READ_INTERLACING_SUPPORTED)
822
/* blow up interlaced rows to full size */
823
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
825
if (png_ptr->pass < 6)
826
/* old interface (pre-1.0.9):
827
png_do_read_interlace(&(png_ptr->row_info),
828
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
830
png_do_read_interlace(png_ptr);
832
switch (png_ptr->pass)
837
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
839
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
840
png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */
842
if (png_ptr->pass == 2) /* pass 1 might be empty */
844
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
846
png_push_have_row(png_ptr, png_bytep_NULL);
847
png_read_push_finish_row(png_ptr);
850
if (png_ptr->pass == 4 && png_ptr->height <= 4)
852
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
854
png_push_have_row(png_ptr, png_bytep_NULL);
855
png_read_push_finish_row(png_ptr);
858
if (png_ptr->pass == 6 && png_ptr->height <= 4)
860
png_push_have_row(png_ptr, png_bytep_NULL);
861
png_read_push_finish_row(png_ptr);
868
for (i = 0; i < 8 && png_ptr->pass == 1; i++)
870
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
871
png_read_push_finish_row(png_ptr);
873
if (png_ptr->pass == 2) /* skip top 4 generated rows */
875
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
877
png_push_have_row(png_ptr, png_bytep_NULL);
878
png_read_push_finish_row(png_ptr);
886
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
888
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
889
png_read_push_finish_row(png_ptr);
891
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
893
png_push_have_row(png_ptr, png_bytep_NULL);
894
png_read_push_finish_row(png_ptr);
896
if (png_ptr->pass == 4) /* pass 3 might be empty */
898
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
900
png_push_have_row(png_ptr, png_bytep_NULL);
901
png_read_push_finish_row(png_ptr);
909
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
911
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
912
png_read_push_finish_row(png_ptr);
914
if (png_ptr->pass == 4) /* skip top two generated rows */
916
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
918
png_push_have_row(png_ptr, png_bytep_NULL);
919
png_read_push_finish_row(png_ptr);
927
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
929
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
930
png_read_push_finish_row(png_ptr);
932
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
934
png_push_have_row(png_ptr, png_bytep_NULL);
935
png_read_push_finish_row(png_ptr);
937
if (png_ptr->pass == 6) /* pass 5 might be empty */
939
png_push_have_row(png_ptr, png_bytep_NULL);
940
png_read_push_finish_row(png_ptr);
947
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
949
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
950
png_read_push_finish_row(png_ptr);
952
if (png_ptr->pass == 6) /* skip top generated row */
954
png_push_have_row(png_ptr, png_bytep_NULL);
955
png_read_push_finish_row(png_ptr);
961
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
962
png_read_push_finish_row(png_ptr);
963
if (png_ptr->pass != 6)
965
png_push_have_row(png_ptr, png_bytep_NULL);
966
png_read_push_finish_row(png_ptr);
973
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
974
png_read_push_finish_row(png_ptr);
979
png_read_push_finish_row(png_structp png_ptr)
981
#ifdef PNG_USE_LOCAL_ARRAYS
982
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
984
/* start of interlace block */
985
const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
987
/* offset to next interlace block */
988
const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
990
/* start of interlace block in the y direction */
991
const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
993
/* offset to next interlace block in the y direction */
994
const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
996
/* Width of interlace block. This is not currently used - if you need
997
* it, uncomment it here and in png.h
998
const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
1001
/* Height of interlace block. This is not currently used - if you need
1002
* it, uncomment it here and in png.h
1003
const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1007
png_ptr->row_number++;
1008
if (png_ptr->row_number < png_ptr->num_rows)
1011
if (png_ptr->interlaced)
1013
png_ptr->row_number = 0;
1014
png_memset_check(png_ptr, png_ptr->prev_row, 0,
1015
png_ptr->rowbytes + 1);
1019
if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1020
(png_ptr->pass == 3 && png_ptr->width < 3) ||
1021
(png_ptr->pass == 5 && png_ptr->width < 2))
1024
if (png_ptr->pass > 7)
1026
if (png_ptr->pass >= 7)
1029
png_ptr->iwidth = (png_ptr->width +
1030
png_pass_inc[png_ptr->pass] - 1 -
1031
png_pass_start[png_ptr->pass]) /
1032
png_pass_inc[png_ptr->pass];
1034
png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
1035
png_ptr->iwidth) + 1;
1037
if (png_ptr->transformations & PNG_INTERLACE)
1040
png_ptr->num_rows = (png_ptr->height +
1041
png_pass_yinc[png_ptr->pass] - 1 -
1042
png_pass_ystart[png_ptr->pass]) /
1043
png_pass_yinc[png_ptr->pass];
1045
} while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1049
#if defined(PNG_READ_tEXt_SUPPORTED)
1051
png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1054
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1056
png_error(png_ptr, "Out of place tEXt");
1057
/* to quiet some compiler warnings */
1058
if(info_ptr == NULL) return;
1061
#ifdef PNG_MAX_MALLOC_64K
1062
png_ptr->skip_length = 0; /* This may not be necessary */
1064
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1066
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1067
png_ptr->skip_length = length - (png_uint_32)65535L;
1068
length = (png_uint_32)65535L;
1072
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1073
(png_uint_32)(length+1));
1074
png_ptr->current_text[length] = '\0';
1075
png_ptr->current_text_ptr = png_ptr->current_text;
1076
png_ptr->current_text_size = (png_size_t)length;
1077
png_ptr->current_text_left = (png_size_t)length;
1078
png_ptr->process_mode = PNG_READ_tEXt_MODE;
1082
png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1084
if (png_ptr->buffer_size && png_ptr->current_text_left)
1086
png_size_t text_size;
1088
if (png_ptr->buffer_size < png_ptr->current_text_left)
1089
text_size = png_ptr->buffer_size;
1091
text_size = png_ptr->current_text_left;
1092
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1093
png_ptr->current_text_left -= text_size;
1094
png_ptr->current_text_ptr += text_size;
1096
if (!(png_ptr->current_text_left))
1103
if (png_ptr->buffer_size < 4)
1105
png_push_save_buffer(png_ptr);
1109
png_push_crc_finish(png_ptr);
1111
#if defined(PNG_MAX_MALLOC_64K)
1112
if (png_ptr->skip_length)
1116
key = png_ptr->current_text;
1118
for (text = key; *text; text++)
1121
if (text != key + png_ptr->current_text_size)
1124
text_ptr = (png_textp)png_malloc(png_ptr,
1125
(png_uint_32)png_sizeof(png_text));
1126
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1127
text_ptr->key = key;
1128
#ifdef PNG_iTXt_SUPPORTED
1129
text_ptr->lang = NULL;
1130
text_ptr->lang_key = NULL;
1132
text_ptr->text = text;
1134
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1136
png_free(png_ptr, key);
1137
png_free(png_ptr, text_ptr);
1138
png_ptr->current_text = NULL;
1141
png_warning(png_ptr, "Insufficient memory to store text chunk.");
1146
#if defined(PNG_READ_zTXt_SUPPORTED)
1148
png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1151
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1153
png_error(png_ptr, "Out of place zTXt");
1154
/* to quiet some compiler warnings */
1155
if(info_ptr == NULL) return;
1158
#ifdef PNG_MAX_MALLOC_64K
1159
/* We can't handle zTXt chunks > 64K, since we don't have enough space
1160
* to be able to store the uncompressed data. Actually, the threshold
1161
* is probably around 32K, but it isn't as definite as 64K is.
1163
if (length > (png_uint_32)65535L)
1165
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1166
png_push_crc_skip(png_ptr, length);
1171
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1172
(png_uint_32)(length+1));
1173
png_ptr->current_text[length] = '\0';
1174
png_ptr->current_text_ptr = png_ptr->current_text;
1175
png_ptr->current_text_size = (png_size_t)length;
1176
png_ptr->current_text_left = (png_size_t)length;
1177
png_ptr->process_mode = PNG_READ_zTXt_MODE;
1181
png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1183
if (png_ptr->buffer_size && png_ptr->current_text_left)
1185
png_size_t text_size;
1187
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1188
text_size = png_ptr->buffer_size;
1190
text_size = png_ptr->current_text_left;
1191
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1192
png_ptr->current_text_left -= text_size;
1193
png_ptr->current_text_ptr += text_size;
1195
if (!(png_ptr->current_text_left))
1201
png_size_t text_size, key_size;
1203
if (png_ptr->buffer_size < 4)
1205
png_push_save_buffer(png_ptr);
1209
png_push_crc_finish(png_ptr);
1211
key = png_ptr->current_text;
1213
for (text = key; *text; text++)
1216
/* zTXt can't have zero text */
1217
if (text == key + png_ptr->current_text_size)
1219
png_ptr->current_text = NULL;
1220
png_free(png_ptr, key);
1226
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
1228
png_ptr->current_text = NULL;
1229
png_free(png_ptr, key);
1235
png_ptr->zstream.next_in = (png_bytep )text;
1236
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1238
png_ptr->zstream.next_out = png_ptr->zbuf;
1239
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1241
key_size = text - key;
1246
while (png_ptr->zstream.avail_in)
1248
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1249
if (ret != Z_OK && ret != Z_STREAM_END)
1251
inflateReset(&png_ptr->zstream);
1252
png_ptr->zstream.avail_in = 0;
1253
png_ptr->current_text = NULL;
1254
png_free(png_ptr, key);
1255
png_free(png_ptr, text);
1258
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1262
text = (png_charp)png_malloc(png_ptr,
1263
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1265
png_memcpy(text + key_size, png_ptr->zbuf,
1266
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1267
png_memcpy(text, key, key_size);
1268
text_size = key_size + png_ptr->zbuf_size -
1269
png_ptr->zstream.avail_out;
1270
*(text + text_size) = '\0';
1277
text = (png_charp)png_malloc(png_ptr, text_size +
1278
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1280
png_memcpy(text, tmp, text_size);
1281
png_free(png_ptr, tmp);
1282
png_memcpy(text + text_size, png_ptr->zbuf,
1283
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1284
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1285
*(text + text_size) = '\0';
1287
if (ret != Z_STREAM_END)
1289
png_ptr->zstream.next_out = png_ptr->zbuf;
1290
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1298
if (ret == Z_STREAM_END)
1302
inflateReset(&png_ptr->zstream);
1303
png_ptr->zstream.avail_in = 0;
1305
if (ret != Z_STREAM_END)
1307
png_ptr->current_text = NULL;
1308
png_free(png_ptr, key);
1309
png_free(png_ptr, text);
1313
png_ptr->current_text = NULL;
1314
png_free(png_ptr, key);
1318
text_ptr = (png_textp)png_malloc(png_ptr,
1319
(png_uint_32)png_sizeof(png_text));
1320
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1321
text_ptr->key = key;
1322
#ifdef PNG_iTXt_SUPPORTED
1323
text_ptr->lang = NULL;
1324
text_ptr->lang_key = NULL;
1326
text_ptr->text = text;
1328
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1330
png_free(png_ptr, key);
1331
png_free(png_ptr, text_ptr);
1334
png_warning(png_ptr, "Insufficient memory to store text chunk.");
1339
#if defined(PNG_READ_iTXt_SUPPORTED)
1341
png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1344
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1346
png_error(png_ptr, "Out of place iTXt");
1347
/* to quiet some compiler warnings */
1348
if(info_ptr == NULL) return;
1351
#ifdef PNG_MAX_MALLOC_64K
1352
png_ptr->skip_length = 0; /* This may not be necessary */
1354
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1356
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1357
png_ptr->skip_length = length - (png_uint_32)65535L;
1358
length = (png_uint_32)65535L;
1362
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1363
(png_uint_32)(length+1));
1364
png_ptr->current_text[length] = '\0';
1365
png_ptr->current_text_ptr = png_ptr->current_text;
1366
png_ptr->current_text_size = (png_size_t)length;
1367
png_ptr->current_text_left = (png_size_t)length;
1368
png_ptr->process_mode = PNG_READ_iTXt_MODE;
1372
png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1375
if (png_ptr->buffer_size && png_ptr->current_text_left)
1377
png_size_t text_size;
1379
if (png_ptr->buffer_size < png_ptr->current_text_left)
1380
text_size = png_ptr->buffer_size;
1382
text_size = png_ptr->current_text_left;
1383
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1384
png_ptr->current_text_left -= text_size;
1385
png_ptr->current_text_ptr += text_size;
1387
if (!(png_ptr->current_text_left))
1397
if (png_ptr->buffer_size < 4)
1399
png_push_save_buffer(png_ptr);
1403
png_push_crc_finish(png_ptr);
1405
#if defined(PNG_MAX_MALLOC_64K)
1406
if (png_ptr->skip_length)
1410
key = png_ptr->current_text;
1412
for (lang = key; *lang; lang++)
1415
if (lang != key + png_ptr->current_text_size)
1418
comp_flag = *lang++;
1419
lang++; /* skip comp_type, always zero */
1421
for (lang_key = lang; *lang_key; lang_key++)
1423
lang_key++; /* skip NUL separator */
1425
for (text = lang_key; *text; text++)
1428
if (text != key + png_ptr->current_text_size)
1431
text_ptr = (png_textp)png_malloc(png_ptr,
1432
(png_uint_32)png_sizeof(png_text));
1433
text_ptr->compression = comp_flag + 2;
1434
text_ptr->key = key;
1435
text_ptr->lang = lang;
1436
text_ptr->lang_key = lang_key;
1437
text_ptr->text = text;
1438
text_ptr->text_length = 0;
1439
text_ptr->itxt_length = png_strlen(text);
1441
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1443
png_ptr->current_text = NULL;
1445
png_free(png_ptr, text_ptr);
1447
png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1452
/* This function is called when we haven't found a handler for this
1453
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1454
* name or a critical chunk), the chunk is (currently) silently ignored.
1457
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1461
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
1463
if (!(png_ptr->chunk_name[0] & 0x20))
1465
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1466
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1467
PNG_HANDLE_CHUNK_ALWAYS
1468
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1469
&& png_ptr->read_user_chunk_fn == NULL
1473
png_chunk_error(png_ptr, "unknown critical chunk");
1475
/* to quiet compiler warnings about unused info_ptr */
1476
if (info_ptr == NULL)
1480
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1481
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1483
png_unknown_chunk chunk;
1485
#ifdef PNG_MAX_MALLOC_64K
1486
if (length > (png_uint_32)65535L)
1488
png_warning(png_ptr, "unknown chunk too large to fit in memory");
1489
skip = length - (png_uint_32)65535L;
1490
length = (png_uint_32)65535L;
1494
png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
1495
chunk.data = (png_bytep)png_malloc(png_ptr, length);
1496
png_crc_read(png_ptr, chunk.data, length);
1497
chunk.size = length;
1498
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1499
if(png_ptr->read_user_chunk_fn != NULL)
1501
/* callback to user unknown chunk handler */
1502
if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
1504
if (!(png_ptr->chunk_name[0] & 0x20))
1505
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1506
PNG_HANDLE_CHUNK_ALWAYS)
1507
png_chunk_error(png_ptr, "unknown critical chunk");
1509
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1513
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1514
png_free(png_ptr, chunk.data);
1519
png_push_crc_skip(png_ptr, skip);
1523
png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1525
if (png_ptr->info_fn != NULL)
1526
(*(png_ptr->info_fn))(png_ptr, info_ptr);
1530
png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1532
if (png_ptr->end_fn != NULL)
1533
(*(png_ptr->end_fn))(png_ptr, info_ptr);
1537
png_push_have_row(png_structp png_ptr, png_bytep row)
1539
if (png_ptr->row_fn != NULL)
1540
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1541
(int)png_ptr->pass);
1545
png_progressive_combine_row (png_structp png_ptr,
1546
png_bytep old_row, png_bytep new_row)
1548
#ifdef PNG_USE_LOCAL_ARRAYS
1549
const int FARDATA png_pass_dsp_mask[7] =
1550
{0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1552
if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1553
png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1557
png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1558
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1559
png_progressive_end_ptr end_fn)
1561
png_ptr->info_fn = info_fn;
1562
png_ptr->row_fn = row_fn;
1563
png_ptr->end_fn = end_fn;
1565
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1569
png_get_progressive_ptr(png_structp png_ptr)
1571
return png_ptr->io_ptr;
1573
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */