2 /* pngrutil.c - utilities to read a PNG file
4 * Last changed in libpng 1.5.2 [March 31, 2011]
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
13 * This file contains routines that are only called from within
14 * libpng itself during the course of reading an image.
19 #ifdef PNG_READ_SUPPORTED
21 #define png_strtod(p,a,b) strtod(a,b)
24 png_get_uint_31(png_structp png_ptr
, png_const_bytep buf
)
26 png_uint_32 uval
= png_get_uint_32(buf
);
28 if (uval
> PNG_UINT_31_MAX
)
29 png_error(png_ptr
, "PNG unsigned integer out of range");
34 #if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
35 /* The following is a variation on the above for use with the fixed
36 * point values used for gAMA and cHRM. Instead of png_error it
37 * issues a warning and returns (-1) - an invalid value because both
38 * gAMA and cHRM use *unsigned* integers for fixed point values.
40 #define PNG_FIXED_ERROR (-1)
42 static png_fixed_point
/* PRIVATE */
43 png_get_fixed_point(png_structp png_ptr
, png_const_bytep buf
)
45 png_uint_32 uval
= png_get_uint_32(buf
);
47 if (uval
<= PNG_UINT_31_MAX
)
48 return (png_fixed_point
)uval
; /* known to be in range */
50 /* The caller can turn off the warning by passing NULL. */
52 png_warning(png_ptr
, "PNG fixed point integer out of range");
54 return PNG_FIXED_ERROR
;
58 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
59 /* NOTE: the read macros will obscure these definitions, so that if
60 * PNG_USE_READ_MACROS is set the library will not use them internally,
61 * but the APIs will still be available externally.
63 * The parentheses around "PNGAPI function_name" in the following three
64 * functions are necessary because they allow the macros to co-exist with
65 * these (unused but exported) functions.
68 /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
70 png_get_uint_32
)(png_const_bytep buf
)
73 ((png_uint_32
)(*(buf
)) << 24) +
74 ((png_uint_32
)(*(buf
+ 1)) << 16) +
75 ((png_uint_32
)(*(buf
+ 2)) << 8) +
76 ((png_uint_32
)(*(buf
+ 3)) ) ;
81 /* Grab a signed 32-bit integer from a buffer in big-endian format. The
82 * data is stored in the PNG file in two's complement format and there
83 * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
84 * the following code does a two's complement to native conversion.
87 png_get_int_32
)(png_const_bytep buf
)
89 png_uint_32 uval
= png_get_uint_32(buf
);
90 if ((uval
& 0x80000000L
) == 0) /* non-negative */
93 uval
= (uval
^ 0xffffffffL
) + 1; /* 2's complement: -x = ~x+1 */
94 return -(png_int_32
)uval
;
97 /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
99 png_get_uint_16
)(png_const_bytep buf
)
101 /* ANSI-C requires an int value to accomodate at least 16 bits so this
102 * works and allows the compiler not to worry about possible narrowing
103 * on 32 bit systems. (Pre-ANSI systems did not make integers smaller
104 * than 16 bits either.)
107 ((unsigned int)(*buf
) << 8) +
108 ((unsigned int)(*(buf
+ 1)));
110 return (png_uint_16
)val
;
113 #endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
115 /* Read and check the PNG file signature */
117 png_read_sig(png_structp png_ptr
, png_infop info_ptr
)
119 png_size_t num_checked
, num_to_check
;
121 /* Exit if the user application does not expect a signature. */
122 if (png_ptr
->sig_bytes
>= 8)
125 num_checked
= png_ptr
->sig_bytes
;
126 num_to_check
= 8 - num_checked
;
128 #ifdef PNG_IO_STATE_SUPPORTED
129 png_ptr
->io_state
= PNG_IO_READING
| PNG_IO_SIGNATURE
;
132 /* The signature must be serialized in a single I/O call. */
133 png_read_data(png_ptr
, &(info_ptr
->signature
[num_checked
]), num_to_check
);
134 png_ptr
->sig_bytes
= 8;
136 if (png_sig_cmp(info_ptr
->signature
, num_checked
, num_to_check
))
138 if (num_checked
< 4 &&
139 png_sig_cmp(info_ptr
->signature
, num_checked
, num_to_check
- 4))
140 png_error(png_ptr
, "Not a PNG file");
142 png_error(png_ptr
, "PNG file corrupted by ASCII conversion");
145 png_ptr
->mode
|= PNG_HAVE_PNG_SIGNATURE
;
148 /* Read the chunk header (length + type name).
149 * Put the type name into png_ptr->chunk_name, and return the length.
151 png_uint_32
/* PRIVATE */
152 png_read_chunk_header(png_structp png_ptr
)
157 #ifdef PNG_IO_STATE_SUPPORTED
158 png_ptr
->io_state
= PNG_IO_READING
| PNG_IO_CHUNK_HDR
;
161 /* Read the length and the chunk name.
162 * This must be performed in a single I/O call.
164 png_read_data(png_ptr
, buf
, 8);
165 length
= png_get_uint_31(png_ptr
, buf
);
167 /* Put the chunk name into png_ptr->chunk_name. */
168 png_memcpy(png_ptr
->chunk_name
, buf
+ 4, 4);
170 png_debug2(0, "Reading %s chunk, length = %u",
171 png_ptr
->chunk_name
, length
);
173 /* Reset the crc and run it over the chunk name. */
174 png_reset_crc(png_ptr
);
175 png_calculate_crc(png_ptr
, png_ptr
->chunk_name
, 4);
177 /* Check to see if chunk name is valid. */
178 png_check_chunk_name(png_ptr
, png_ptr
->chunk_name
);
180 #ifdef PNG_IO_STATE_SUPPORTED
181 png_ptr
->io_state
= PNG_IO_READING
| PNG_IO_CHUNK_DATA
;
187 /* Read data, and (optionally) run it through the CRC. */
189 png_crc_read(png_structp png_ptr
, png_bytep buf
, png_size_t length
)
194 png_read_data(png_ptr
, buf
, length
);
195 png_calculate_crc(png_ptr
, buf
, length
);
198 /* Optionally skip data and then check the CRC. Depending on whether we
199 * are reading a ancillary or critical chunk, and how the program has set
200 * things up, we may calculate the CRC on the data and print a message.
201 * Returns '1' if there was a CRC error, '0' otherwise.
204 png_crc_finish(png_structp png_ptr
, png_uint_32 skip
)
207 png_size_t istop
= png_ptr
->zbuf_size
;
209 for (i
= (png_size_t
)skip
; i
> istop
; i
-= istop
)
211 png_crc_read(png_ptr
, png_ptr
->zbuf
, png_ptr
->zbuf_size
);
216 png_crc_read(png_ptr
, png_ptr
->zbuf
, i
);
219 if (png_crc_error(png_ptr
))
221 if (((png_ptr
->chunk_name
[0] & 0x20) && /* Ancillary */
222 !(png_ptr
->flags
& PNG_FLAG_CRC_ANCILLARY_NOWARN
)) ||
223 (!(png_ptr
->chunk_name
[0] & 0x20) && /* Critical */
224 (png_ptr
->flags
& PNG_FLAG_CRC_CRITICAL_USE
)))
226 png_chunk_warning(png_ptr
, "CRC error");
231 png_chunk_benign_error(png_ptr
, "CRC error");
241 /* Compare the CRC stored in the PNG file with that calculated by libpng from
242 * the data it has read thus far.
245 png_crc_error(png_structp png_ptr
)
247 png_byte crc_bytes
[4];
251 if (png_ptr
->chunk_name
[0] & 0x20) /* ancillary */
253 if ((png_ptr
->flags
& PNG_FLAG_CRC_ANCILLARY_MASK
) ==
254 (PNG_FLAG_CRC_ANCILLARY_USE
| PNG_FLAG_CRC_ANCILLARY_NOWARN
))
260 if (png_ptr
->flags
& PNG_FLAG_CRC_CRITICAL_IGNORE
)
264 #ifdef PNG_IO_STATE_SUPPORTED
265 png_ptr
->io_state
= PNG_IO_READING
| PNG_IO_CHUNK_CRC
;
268 /* The chunk CRC must be serialized in a single I/O call. */
269 png_read_data(png_ptr
, crc_bytes
, 4);
273 crc
= png_get_uint_32(crc_bytes
);
274 return ((int)(crc
!= png_ptr
->crc
));
281 #if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
282 defined(PNG_READ_iCCP_SUPPORTED)
284 png_inflate(png_structp png_ptr
, png_bytep data
, png_size_t size
,
285 png_bytep output
, png_size_t output_size
)
287 png_size_t count
= 0;
289 /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't
290 * even necessarily handle 65536 bytes) because the type uInt is "16 bits or
291 * more". Consequently it is necessary to chunk the input to zlib. This
292 * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value
293 * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a
294 * lower value in pngpriv.h and this may sometimes have a performance
295 * advantage, because it forces access of the input data to be separated from
296 * at least some of the use by some period of time.
298 png_ptr
->zstream
.next_in
= data
;
299 /* avail_in is set below from 'size' */
300 png_ptr
->zstream
.avail_in
= 0;
306 /* The setting of 'avail_in' used to be outside the loop, by setting it
307 * inside it is possible to chunk the input to zlib and simply rely on
308 * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o
309 * data to be passed through zlib at the unavoidable cost of requiring a
310 * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX
313 if (png_ptr
->zstream
.avail_in
== 0 && size
> 0)
315 if (size
<= ZLIB_IO_MAX
)
317 /* The value is less than ZLIB_IO_MAX so the cast is safe: */
318 png_ptr
->zstream
.avail_in
= (uInt
)size
;
324 png_ptr
->zstream
.avail_in
= ZLIB_IO_MAX
;
329 /* Reset the output buffer each time round - we empty it
330 * after every inflate call.
332 png_ptr
->zstream
.next_out
= png_ptr
->zbuf
;
333 png_ptr
->zstream
.avail_out
= png_ptr
->zbuf_size
;
335 ret
= inflate(&png_ptr
->zstream
, Z_NO_FLUSH
);
336 avail
= png_ptr
->zbuf_size
- png_ptr
->zstream
.avail_out
;
338 /* First copy/count any new output - but only if we didn't
341 if ((ret
== Z_OK
|| ret
== Z_STREAM_END
) && avail
> 0)
343 png_size_t space
= avail
; /* > 0, see above */
345 if (output
!= 0 && output_size
> count
)
347 png_size_t copy
= output_size
- count
;
352 png_memcpy(output
+ count
, png_ptr
->zbuf
, copy
);
360 /* Termination conditions - always reset the zstream, it
361 * must be left in inflateInit state.
363 png_ptr
->zstream
.avail_in
= 0;
364 inflateReset(&png_ptr
->zstream
);
366 if (ret
== Z_STREAM_END
)
367 return count
; /* NOTE: may be zero. */
369 /* Now handle the error codes - the API always returns 0
370 * and the error message is dumped into the uncompressed
371 * buffer if available.
375 #ifdef PNG_CONSOLE_IO_SUPPORTED
378 if (png_ptr
->zstream
.msg
!= 0)
379 msg
= png_ptr
->zstream
.msg
;
383 #ifdef PNG_CONSOLE_IO_SUPPORTED
387 msg
= "Buffer error in compressed datastream in %s chunk";
391 msg
= "Data error in compressed datastream in %s chunk";
395 msg
= "Incomplete compressed datastream in %s chunk";
399 png_snprintf(umsg
, sizeof umsg
, msg
, png_ptr
->chunk_name
);
402 msg
= "Damaged compressed datastream in chunk other than IDAT";
406 png_warning(png_ptr
, msg
);
409 /* 0 means an error - notice that this code simply ignores
410 * zero length compressed chunks as a result.
417 * Decompress trailing data in a chunk. The assumption is that chunkdata
418 * points at an allocated area holding the contents of a chunk with a
419 * trailing compressed part. What we get back is an allocated area
420 * holding the original prefix part and an uncompressed version of the
421 * trailing part (the malloc area passed in is freed).
424 png_decompress_chunk(png_structp png_ptr
, int comp_type
,
425 png_size_t chunklength
,
426 png_size_t prefix_size
, png_size_t
*newlength
)
428 /* The caller should guarantee this */
429 if (prefix_size
> chunklength
)
431 /* The recovery is to delete the chunk. */
432 png_warning(png_ptr
, "invalid chunklength");
433 prefix_size
= 0; /* To delete everything */
436 else if (comp_type
== PNG_COMPRESSION_TYPE_BASE
)
438 png_size_t expanded_size
= png_inflate(png_ptr
,
439 (png_bytep
)(png_ptr
->chunkdata
+ prefix_size
),
440 chunklength
- prefix_size
,
444 /* Now check the limits on this chunk - if the limit fails the
445 * compressed data will be removed, the prefix will remain.
447 #ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
448 if (png_ptr
->user_chunk_malloc_max
&&
449 (prefix_size
+ expanded_size
>= png_ptr
->user_chunk_malloc_max
- 1))
451 # ifdef PNG_USER_CHUNK_MALLOC_MAX
452 if ((PNG_USER_CHUNK_MALLOC_MAX
> 0) &&
453 prefix_size
+ expanded_size
>= PNG_USER_CHUNK_MALLOC_MAX
- 1)
456 png_warning(png_ptr
, "Exceeded size limit while expanding chunk");
458 /* If the size is zero either there was an error and a message
459 * has already been output (warning) or the size really is zero
460 * and we have nothing to do - the code will exit through the
463 #if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
464 defined(PNG_USER_CHUNK_MALLOC_MAX)
465 else if (expanded_size
> 0)
467 if (expanded_size
> 0)
470 /* Success (maybe) - really uncompress the chunk. */
471 png_size_t new_size
= 0;
472 png_charp text
= png_malloc_warn(png_ptr
,
473 prefix_size
+ expanded_size
+ 1);
477 png_memcpy(text
, png_ptr
->chunkdata
, prefix_size
);
478 new_size
= png_inflate(png_ptr
,
479 (png_bytep
)(png_ptr
->chunkdata
+ prefix_size
),
480 chunklength
- prefix_size
,
481 (png_bytep
)(text
+ prefix_size
), expanded_size
);
482 text
[prefix_size
+ expanded_size
] = 0; /* just in case */
484 if (new_size
== expanded_size
)
486 png_free(png_ptr
, png_ptr
->chunkdata
);
487 png_ptr
->chunkdata
= text
;
488 *newlength
= prefix_size
+ expanded_size
;
489 return; /* The success return! */
492 png_warning(png_ptr
, "png_inflate logic error");
493 png_free(png_ptr
, text
);
497 png_warning(png_ptr
, "Not enough memory to decompress chunk");
501 else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
503 #ifdef PNG_STDIO_SUPPORTED
506 png_snprintf(umsg
, sizeof umsg
,
507 "Unknown zTXt compression type %d", comp_type
);
508 png_warning(png_ptr
, umsg
);
510 png_warning(png_ptr
, "Unknown zTXt compression type");
513 /* The recovery is to simply drop the data. */
516 /* Generic error return - leave the prefix, delete the compressed
517 * data, reallocate the chunkdata to remove the potentially large
518 * amount of compressed data.
521 png_charp text
= png_malloc_warn(png_ptr
, prefix_size
+ 1);
526 png_memcpy(text
, png_ptr
->chunkdata
, prefix_size
);
528 png_free(png_ptr
, png_ptr
->chunkdata
);
529 png_ptr
->chunkdata
= text
;
531 /* This is an extra zero in the 'uncompressed' part. */
532 *(png_ptr
->chunkdata
+ prefix_size
) = 0x00;
534 /* Ignore a malloc error here - it is safe. */
537 *newlength
= prefix_size
;
541 /* Read and check the IDHR chunk */
543 png_handle_IHDR(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
546 png_uint_32 width
, height
;
547 int bit_depth
, color_type
, compression_type
, filter_type
;
550 png_debug(1, "in png_handle_IHDR");
552 if (png_ptr
->mode
& PNG_HAVE_IHDR
)
553 png_error(png_ptr
, "Out of place IHDR");
555 /* Check the length */
557 png_error(png_ptr
, "Invalid IHDR chunk");
559 png_ptr
->mode
|= PNG_HAVE_IHDR
;
561 png_crc_read(png_ptr
, buf
, 13);
562 png_crc_finish(png_ptr
, 0);
564 width
= png_get_uint_31(png_ptr
, buf
);
565 height
= png_get_uint_31(png_ptr
, buf
+ 4);
568 compression_type
= buf
[10];
569 filter_type
= buf
[11];
570 interlace_type
= buf
[12];
572 /* Set internal variables */
573 png_ptr
->width
= width
;
574 png_ptr
->height
= height
;
575 png_ptr
->bit_depth
= (png_byte
)bit_depth
;
576 png_ptr
->interlaced
= (png_byte
)interlace_type
;
577 png_ptr
->color_type
= (png_byte
)color_type
;
578 #ifdef PNG_MNG_FEATURES_SUPPORTED
579 png_ptr
->filter_type
= (png_byte
)filter_type
;
581 png_ptr
->compression_type
= (png_byte
)compression_type
;
583 /* Find number of channels */
584 switch (png_ptr
->color_type
)
586 default: /* invalid, png_set_IHDR calls png_error */
587 case PNG_COLOR_TYPE_GRAY
:
588 case PNG_COLOR_TYPE_PALETTE
:
589 png_ptr
->channels
= 1;
592 case PNG_COLOR_TYPE_RGB
:
593 png_ptr
->channels
= 3;
596 case PNG_COLOR_TYPE_GRAY_ALPHA
:
597 png_ptr
->channels
= 2;
600 case PNG_COLOR_TYPE_RGB_ALPHA
:
601 png_ptr
->channels
= 4;
605 /* Set up other useful info */
606 png_ptr
->pixel_depth
= (png_byte
)(png_ptr
->bit_depth
*
608 png_ptr
->rowbytes
= PNG_ROWBYTES(png_ptr
->pixel_depth
, png_ptr
->width
);
609 png_debug1(3, "bit_depth = %d", png_ptr
->bit_depth
);
610 png_debug1(3, "channels = %d", png_ptr
->channels
);
611 png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr
->rowbytes
);
612 png_set_IHDR(png_ptr
, info_ptr
, width
, height
, bit_depth
,
613 color_type
, interlace_type
, compression_type
, filter_type
);
616 /* Read and check the palette */
618 png_handle_PLTE(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
620 png_color palette
[PNG_MAX_PALETTE_LENGTH
];
622 #ifdef PNG_POINTER_INDEXING_SUPPORTED
626 png_debug(1, "in png_handle_PLTE");
628 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
629 png_error(png_ptr
, "Missing IHDR before PLTE");
631 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
633 png_warning(png_ptr
, "Invalid PLTE after IDAT");
634 png_crc_finish(png_ptr
, length
);
638 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
639 png_error(png_ptr
, "Duplicate PLTE chunk");
641 png_ptr
->mode
|= PNG_HAVE_PLTE
;
643 if (!(png_ptr
->color_type
&PNG_COLOR_MASK_COLOR
))
646 "Ignoring PLTE chunk in grayscale PNG");
647 png_crc_finish(png_ptr
, length
);
651 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
652 if (png_ptr
->color_type
!= PNG_COLOR_TYPE_PALETTE
)
654 png_crc_finish(png_ptr
, length
);
659 if (length
> 3*PNG_MAX_PALETTE_LENGTH
|| length
% 3)
661 if (png_ptr
->color_type
!= PNG_COLOR_TYPE_PALETTE
)
663 png_warning(png_ptr
, "Invalid palette chunk");
664 png_crc_finish(png_ptr
, length
);
670 png_error(png_ptr
, "Invalid palette chunk");
674 num
= (int)length
/ 3;
676 #ifdef PNG_POINTER_INDEXING_SUPPORTED
677 for (i
= 0, pal_ptr
= palette
; i
< num
; i
++, pal_ptr
++)
681 png_crc_read(png_ptr
, buf
, 3);
682 pal_ptr
->red
= buf
[0];
683 pal_ptr
->green
= buf
[1];
684 pal_ptr
->blue
= buf
[2];
687 for (i
= 0; i
< num
; i
++)
691 png_crc_read(png_ptr
, buf
, 3);
692 /* Don't depend upon png_color being any order */
693 palette
[i
].red
= buf
[0];
694 palette
[i
].green
= buf
[1];
695 palette
[i
].blue
= buf
[2];
699 /* If we actually need the PLTE chunk (ie for a paletted image), we do
700 * whatever the normal CRC configuration tells us. However, if we
701 * have an RGB image, the PLTE can be considered ancillary, so
702 * we will act as though it is.
704 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
705 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
708 png_crc_finish(png_ptr
, 0);
711 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
712 else if (png_crc_error(png_ptr
)) /* Only if we have a CRC error */
714 /* If we don't want to use the data from an ancillary chunk,
715 * we have two options: an error abort, or a warning and we
716 * ignore the data in this chunk (which should be OK, since
717 * it's considered ancillary for a RGB or RGBA image).
719 if (!(png_ptr
->flags
& PNG_FLAG_CRC_ANCILLARY_USE
))
721 if (png_ptr
->flags
& PNG_FLAG_CRC_ANCILLARY_NOWARN
)
723 png_chunk_benign_error(png_ptr
, "CRC error");
728 png_chunk_warning(png_ptr
, "CRC error");
733 /* Otherwise, we (optionally) emit a warning and use the chunk. */
734 else if (!(png_ptr
->flags
& PNG_FLAG_CRC_ANCILLARY_NOWARN
))
736 png_chunk_warning(png_ptr
, "CRC error");
741 png_set_PLTE(png_ptr
, info_ptr
, palette
, num
);
743 #ifdef PNG_READ_tRNS_SUPPORTED
744 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
746 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_tRNS
))
748 if (png_ptr
->num_trans
> (png_uint_16
)num
)
750 png_warning(png_ptr
, "Truncating incorrect tRNS chunk length");
751 png_ptr
->num_trans
= (png_uint_16
)num
;
754 if (info_ptr
->num_trans
> (png_uint_16
)num
)
756 png_warning(png_ptr
, "Truncating incorrect info tRNS chunk length");
757 info_ptr
->num_trans
= (png_uint_16
)num
;
766 png_handle_IEND(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
768 png_debug(1, "in png_handle_IEND");
770 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
) || !(png_ptr
->mode
& PNG_HAVE_IDAT
))
772 png_error(png_ptr
, "No image in file");
775 png_ptr
->mode
|= (PNG_AFTER_IDAT
| PNG_HAVE_IEND
);
779 png_warning(png_ptr
, "Incorrect IEND chunk length");
782 png_crc_finish(png_ptr
, length
);
784 PNG_UNUSED(info_ptr
) /* Quiet compiler warnings about unused info_ptr */
787 #ifdef PNG_READ_gAMA_SUPPORTED
789 png_handle_gAMA(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
791 png_fixed_point igamma
;
794 png_debug(1, "in png_handle_gAMA");
796 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
797 png_error(png_ptr
, "Missing IHDR before gAMA");
799 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
801 png_warning(png_ptr
, "Invalid gAMA after IDAT");
802 png_crc_finish(png_ptr
, length
);
806 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
807 /* Should be an error, but we can cope with it */
808 png_warning(png_ptr
, "Out of place gAMA chunk");
810 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_gAMA
)
811 #ifdef PNG_READ_sRGB_SUPPORTED
812 && !(info_ptr
->valid
& PNG_INFO_sRGB
)
816 png_warning(png_ptr
, "Duplicate gAMA chunk");
817 png_crc_finish(png_ptr
, length
);
823 png_warning(png_ptr
, "Incorrect gAMA chunk length");
824 png_crc_finish(png_ptr
, length
);
828 png_crc_read(png_ptr
, buf
, 4);
830 if (png_crc_finish(png_ptr
, 0))
833 igamma
= png_get_fixed_point(NULL
, buf
);
835 /* Check for zero gamma or an error. */
839 "Ignoring gAMA chunk with out of range gamma");
844 # ifdef PNG_READ_sRGB_SUPPORTED
845 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_sRGB
))
847 if (PNG_OUT_OF_RANGE(igamma
, 45500L, 500))
850 "Ignoring incorrect gAMA value when sRGB is also present");
852 # ifdef PNG_CONSOLE_IO_SUPPORTED
853 fprintf(stderr
, "gamma = (%d/100000)", (int)igamma
);
858 # endif /* PNG_READ_sRGB_SUPPORTED */
860 # ifdef PNG_READ_GAMMA_SUPPORTED
861 /* Gamma correction on read is supported. */
862 png_ptr
->gamma
= igamma
;
864 /* And set the 'info' structure members. */
865 png_set_gAMA_fixed(png_ptr
, info_ptr
, igamma
);
869 #ifdef PNG_READ_sBIT_SUPPORTED
871 png_handle_sBIT(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
876 png_debug(1, "in png_handle_sBIT");
878 buf
[0] = buf
[1] = buf
[2] = buf
[3] = 0;
880 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
881 png_error(png_ptr
, "Missing IHDR before sBIT");
883 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
885 png_warning(png_ptr
, "Invalid sBIT after IDAT");
886 png_crc_finish(png_ptr
, length
);
890 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
892 /* Should be an error, but we can cope with it */
893 png_warning(png_ptr
, "Out of place sBIT chunk");
896 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_sBIT
))
898 png_warning(png_ptr
, "Duplicate sBIT chunk");
899 png_crc_finish(png_ptr
, length
);
903 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
907 truelen
= (png_size_t
)png_ptr
->channels
;
909 if (length
!= truelen
|| length
> 4)
911 png_warning(png_ptr
, "Incorrect sBIT chunk length");
912 png_crc_finish(png_ptr
, length
);
916 png_crc_read(png_ptr
, buf
, truelen
);
918 if (png_crc_finish(png_ptr
, 0))
921 if (png_ptr
->color_type
& PNG_COLOR_MASK_COLOR
)
923 png_ptr
->sig_bit
.red
= buf
[0];
924 png_ptr
->sig_bit
.green
= buf
[1];
925 png_ptr
->sig_bit
.blue
= buf
[2];
926 png_ptr
->sig_bit
.alpha
= buf
[3];
931 png_ptr
->sig_bit
.gray
= buf
[0];
932 png_ptr
->sig_bit
.red
= buf
[0];
933 png_ptr
->sig_bit
.green
= buf
[0];
934 png_ptr
->sig_bit
.blue
= buf
[0];
935 png_ptr
->sig_bit
.alpha
= buf
[1];
938 png_set_sBIT(png_ptr
, info_ptr
, &(png_ptr
->sig_bit
));
942 #ifdef PNG_READ_cHRM_SUPPORTED
944 png_handle_cHRM(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
947 png_fixed_point x_white
, y_white
, x_red
, y_red
, x_green
, y_green
, x_blue
,
950 png_debug(1, "in png_handle_cHRM");
952 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
953 png_error(png_ptr
, "Missing IHDR before cHRM");
955 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
957 png_warning(png_ptr
, "Invalid cHRM after IDAT");
958 png_crc_finish(png_ptr
, length
);
962 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
963 /* Should be an error, but we can cope with it */
964 png_warning(png_ptr
, "Missing PLTE before cHRM");
966 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_cHRM
)
967 # ifdef PNG_READ_sRGB_SUPPORTED
968 && !(info_ptr
->valid
& PNG_INFO_sRGB
)
972 png_warning(png_ptr
, "Duplicate cHRM chunk");
973 png_crc_finish(png_ptr
, length
);
979 png_warning(png_ptr
, "Incorrect cHRM chunk length");
980 png_crc_finish(png_ptr
, length
);
984 png_crc_read(png_ptr
, buf
, 32);
986 if (png_crc_finish(png_ptr
, 0))
989 x_white
= png_get_fixed_point(NULL
, buf
);
990 y_white
= png_get_fixed_point(NULL
, buf
+ 4);
991 x_red
= png_get_fixed_point(NULL
, buf
+ 8);
992 y_red
= png_get_fixed_point(NULL
, buf
+ 12);
993 x_green
= png_get_fixed_point(NULL
, buf
+ 16);
994 y_green
= png_get_fixed_point(NULL
, buf
+ 20);
995 x_blue
= png_get_fixed_point(NULL
, buf
+ 24);
996 y_blue
= png_get_fixed_point(NULL
, buf
+ 28);
998 if (x_white
== PNG_FIXED_ERROR
||
999 y_white
== PNG_FIXED_ERROR
||
1000 x_red
== PNG_FIXED_ERROR
||
1001 y_red
== PNG_FIXED_ERROR
||
1002 x_green
== PNG_FIXED_ERROR
||
1003 y_green
== PNG_FIXED_ERROR
||
1004 x_blue
== PNG_FIXED_ERROR
||
1005 y_blue
== PNG_FIXED_ERROR
)
1007 png_warning(png_ptr
, "Ignoring cHRM chunk with negative chromaticities");
1011 #ifdef PNG_READ_sRGB_SUPPORTED
1012 if ((info_ptr
!= NULL
) && (info_ptr
->valid
& PNG_INFO_sRGB
))
1014 if (PNG_OUT_OF_RANGE(x_white
, 31270, 1000) ||
1015 PNG_OUT_OF_RANGE(y_white
, 32900, 1000) ||
1016 PNG_OUT_OF_RANGE(x_red
, 64000L, 1000) ||
1017 PNG_OUT_OF_RANGE(y_red
, 33000, 1000) ||
1018 PNG_OUT_OF_RANGE(x_green
, 30000, 1000) ||
1019 PNG_OUT_OF_RANGE(y_green
, 60000L, 1000) ||
1020 PNG_OUT_OF_RANGE(x_blue
, 15000, 1000) ||
1021 PNG_OUT_OF_RANGE(y_blue
, 6000, 1000))
1023 png_warning(png_ptr
,
1024 "Ignoring incorrect cHRM value when sRGB is also present");
1026 #ifdef PNG_CONSOLE_IO_SUPPORTED
1027 fprintf(stderr
, "wx=%d, wy=%d, rx=%d, ry=%d\n",
1028 x_white
, y_white
, x_red
, y_red
);
1030 fprintf(stderr
, "gx=%d, gy=%d, bx=%d, by=%d\n",
1031 x_green
, y_green
, x_blue
, y_blue
);
1032 #endif /* PNG_CONSOLE_IO_SUPPORTED */
1036 #endif /* PNG_READ_sRGB_SUPPORTED */
1038 png_set_cHRM_fixed(png_ptr
, info_ptr
, x_white
, y_white
, x_red
, y_red
,
1039 x_green
, y_green
, x_blue
, y_blue
);
1043 #ifdef PNG_READ_sRGB_SUPPORTED
1045 png_handle_sRGB(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1050 png_debug(1, "in png_handle_sRGB");
1052 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1053 png_error(png_ptr
, "Missing IHDR before sRGB");
1055 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1057 png_warning(png_ptr
, "Invalid sRGB after IDAT");
1058 png_crc_finish(png_ptr
, length
);
1062 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
1063 /* Should be an error, but we can cope with it */
1064 png_warning(png_ptr
, "Out of place sRGB chunk");
1066 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_sRGB
))
1068 png_warning(png_ptr
, "Duplicate sRGB chunk");
1069 png_crc_finish(png_ptr
, length
);
1075 png_warning(png_ptr
, "Incorrect sRGB chunk length");
1076 png_crc_finish(png_ptr
, length
);
1080 png_crc_read(png_ptr
, buf
, 1);
1082 if (png_crc_finish(png_ptr
, 0))
1087 /* Check for bad intent */
1088 if (intent
>= PNG_sRGB_INTENT_LAST
)
1090 png_warning(png_ptr
, "Unknown sRGB intent");
1094 #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
1095 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_gAMA
))
1097 if (PNG_OUT_OF_RANGE(info_ptr
->gamma
, 45500L, 500))
1099 png_warning(png_ptr
,
1100 "Ignoring incorrect gAMA value when sRGB is also present");
1101 #ifdef PNG_CONSOLE_IO_SUPPORTED
1102 fprintf(stderr
, "incorrect gamma=(%d/100000)\n", info_ptr
->gamma
);
1106 #endif /* PNG_READ_gAMA_SUPPORTED */
1108 #ifdef PNG_READ_cHRM_SUPPORTED
1109 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_cHRM
))
1110 if (PNG_OUT_OF_RANGE(info_ptr
->x_white
, 31270, 1000) ||
1111 PNG_OUT_OF_RANGE(info_ptr
->y_white
, 32900, 1000) ||
1112 PNG_OUT_OF_RANGE(info_ptr
->x_red
, 64000L, 1000) ||
1113 PNG_OUT_OF_RANGE(info_ptr
->y_red
, 33000, 1000) ||
1114 PNG_OUT_OF_RANGE(info_ptr
->x_green
, 30000, 1000) ||
1115 PNG_OUT_OF_RANGE(info_ptr
->y_green
, 60000L, 1000) ||
1116 PNG_OUT_OF_RANGE(info_ptr
->x_blue
, 15000, 1000) ||
1117 PNG_OUT_OF_RANGE(info_ptr
->y_blue
, 6000, 1000))
1119 png_warning(png_ptr
,
1120 "Ignoring incorrect cHRM value when sRGB is also present");
1122 #endif /* PNG_READ_cHRM_SUPPORTED */
1124 png_set_sRGB_gAMA_and_cHRM(png_ptr
, info_ptr
, intent
);
1126 #endif /* PNG_READ_sRGB_SUPPORTED */
1128 #ifdef PNG_READ_iCCP_SUPPORTED
1130 png_handle_iCCP(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1131 /* Note: this does not properly handle chunks that are > 64K under DOS */
1133 png_byte compression_type
;
1136 png_uint_32 skip
= 0;
1137 png_uint_32 profile_size
;
1138 png_alloc_size_t profile_length
;
1139 png_size_t slength
, prefix_length
, data_length
;
1141 png_debug(1, "in png_handle_iCCP");
1143 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1144 png_error(png_ptr
, "Missing IHDR before iCCP");
1146 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1148 png_warning(png_ptr
, "Invalid iCCP after IDAT");
1149 png_crc_finish(png_ptr
, length
);
1153 else if (png_ptr
->mode
& PNG_HAVE_PLTE
)
1154 /* Should be an error, but we can cope with it */
1155 png_warning(png_ptr
, "Out of place iCCP chunk");
1157 if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_iCCP
))
1159 png_warning(png_ptr
, "Duplicate iCCP chunk");
1160 png_crc_finish(png_ptr
, length
);
1164 #ifdef PNG_MAX_MALLOC_64K
1165 if (length
> (png_uint_32
)65535L)
1167 png_warning(png_ptr
, "iCCP chunk too large to fit in memory");
1168 skip
= length
- (png_uint_32
)65535L;
1169 length
= (png_uint_32
)65535L;
1173 png_free(png_ptr
, png_ptr
->chunkdata
);
1174 png_ptr
->chunkdata
= (png_charp
)png_malloc(png_ptr
, length
+ 1);
1175 slength
= (png_size_t
)length
;
1176 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
1178 if (png_crc_finish(png_ptr
, skip
))
1180 png_free(png_ptr
, png_ptr
->chunkdata
);
1181 png_ptr
->chunkdata
= NULL
;
1185 png_ptr
->chunkdata
[slength
] = 0x00;
1187 for (profile
= png_ptr
->chunkdata
; *profile
; profile
++)
1188 /* Empty loop to find end of name */ ;
1192 /* There should be at least one zero (the compression type byte)
1193 * following the separator, and we should be on it
1195 if (profile
>= png_ptr
->chunkdata
+ slength
- 1)
1197 png_free(png_ptr
, png_ptr
->chunkdata
);
1198 png_ptr
->chunkdata
= NULL
;
1199 png_warning(png_ptr
, "Malformed iCCP chunk");
1203 /* Compression_type should always be zero */
1204 compression_type
= *profile
++;
1206 if (compression_type
)
1208 png_warning(png_ptr
, "Ignoring nonzero compression type in iCCP chunk");
1209 compression_type
= 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
1213 prefix_length
= profile
- png_ptr
->chunkdata
;
1214 png_decompress_chunk(png_ptr
, compression_type
,
1215 slength
, prefix_length
, &data_length
);
1217 profile_length
= data_length
- prefix_length
;
1219 if (prefix_length
> data_length
|| profile_length
< 4)
1221 png_free(png_ptr
, png_ptr
->chunkdata
);
1222 png_ptr
->chunkdata
= NULL
;
1223 png_warning(png_ptr
, "Profile size field missing from iCCP chunk");
1227 /* Check the profile_size recorded in the first 32 bits of the ICC profile */
1228 pC
= (png_bytep
)(png_ptr
->chunkdata
+ prefix_length
);
1229 profile_size
= ((*(pC
)) << 24) |
1230 ((*(pC
+ 1)) << 16) |
1231 ((*(pC
+ 2)) << 8) |
1234 /* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
1235 * because profile_size is a 32 bit value.
1237 if (profile_size
< profile_length
)
1238 profile_length
= profile_size
;
1240 /* And the following guarantees that profile_size == profile_length. */
1241 if (profile_size
> profile_length
)
1243 png_free(png_ptr
, png_ptr
->chunkdata
);
1244 png_ptr
->chunkdata
= NULL
;
1245 #ifdef PNG_STDIO_SUPPORTED
1249 png_snprintf2(umsg
, 80,
1250 "Ignoring iCCP chunk with declared size = %u "
1251 "and actual length = %u",
1252 (unsigned int) profile_size
,
1253 (unsigned int) profile_length
);
1254 png_warning(png_ptr
, umsg
);
1257 png_warning(png_ptr
,
1258 "Ignoring iCCP chunk with uncompressed size mismatch");
1263 png_set_iCCP(png_ptr
, info_ptr
, png_ptr
->chunkdata
,
1264 compression_type
, (png_bytep
)png_ptr
->chunkdata
+ prefix_length
,
1266 png_free(png_ptr
, png_ptr
->chunkdata
);
1267 png_ptr
->chunkdata
= NULL
;
1269 #endif /* PNG_READ_iCCP_SUPPORTED */
1271 #ifdef PNG_READ_sPLT_SUPPORTED
1273 png_handle_sPLT(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1274 /* Note: this does not properly handle chunks that are > 64K under DOS */
1276 png_bytep entry_start
;
1277 png_sPLT_t new_palette
;
1279 png_uint_32 data_length
;
1281 png_uint_32 skip
= 0;
1286 png_debug(1, "in png_handle_sPLT");
1288 #ifdef PNG_USER_LIMITS_SUPPORTED
1290 if (png_ptr
->user_chunk_cache_max
!= 0)
1292 if (png_ptr
->user_chunk_cache_max
== 1)
1294 png_crc_finish(png_ptr
, length
);
1298 if (--png_ptr
->user_chunk_cache_max
== 1)
1300 png_warning(png_ptr
, "No space in chunk cache for sPLT");
1301 png_crc_finish(png_ptr
, length
);
1307 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1308 png_error(png_ptr
, "Missing IHDR before sPLT");
1310 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1312 png_warning(png_ptr
, "Invalid sPLT after IDAT");
1313 png_crc_finish(png_ptr
, length
);
1317 #ifdef PNG_MAX_MALLOC_64K
1318 if (length
> (png_uint_32
)65535L)
1320 png_warning(png_ptr
, "sPLT chunk too large to fit in memory");
1321 skip
= length
- (png_uint_32
)65535L;
1322 length
= (png_uint_32
)65535L;
1326 png_free(png_ptr
, png_ptr
->chunkdata
);
1327 png_ptr
->chunkdata
= (png_charp
)png_malloc(png_ptr
, length
+ 1);
1329 /* WARNING: this may break if size_t is less than 32 bits; it is assumed
1330 * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
1331 * potential breakage point if the types in pngconf.h aren't exactly right.
1333 slength
= (png_size_t
)length
;
1334 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
1336 if (png_crc_finish(png_ptr
, skip
))
1338 png_free(png_ptr
, png_ptr
->chunkdata
);
1339 png_ptr
->chunkdata
= NULL
;
1343 png_ptr
->chunkdata
[slength
] = 0x00;
1345 for (entry_start
= (png_bytep
)png_ptr
->chunkdata
; *entry_start
;
1347 /* Empty loop to find end of name */ ;
1351 /* A sample depth should follow the separator, and we should be on it */
1352 if (entry_start
> (png_bytep
)png_ptr
->chunkdata
+ slength
- 2)
1354 png_free(png_ptr
, png_ptr
->chunkdata
);
1355 png_ptr
->chunkdata
= NULL
;
1356 png_warning(png_ptr
, "malformed sPLT chunk");
1360 new_palette
.depth
= *entry_start
++;
1361 entry_size
= (new_palette
.depth
== 8 ? 6 : 10);
1362 /* This must fit in a png_uint_32 because it is derived from the original
1363 * chunk data length (and use 'length', not 'slength' here for clarity -
1364 * they are guaranteed to be the same, see the tests above.)
1366 data_length
= length
- (png_uint_32
)(entry_start
-
1367 (png_bytep
)png_ptr
->chunkdata
);
1369 /* Integrity-check the data length */
1370 if (data_length
% entry_size
)
1372 png_free(png_ptr
, png_ptr
->chunkdata
);
1373 png_ptr
->chunkdata
= NULL
;
1374 png_warning(png_ptr
, "sPLT chunk has bad length");
1378 dl
= (png_int_32
)(data_length
/ entry_size
);
1379 max_dl
= PNG_SIZE_MAX
/ png_sizeof(png_sPLT_entry
);
1383 png_warning(png_ptr
, "sPLT chunk too long");
1387 new_palette
.nentries
= (png_int_32
)(data_length
/ entry_size
);
1389 new_palette
.entries
= (png_sPLT_entryp
)png_malloc_warn(
1390 png_ptr
, new_palette
.nentries
* png_sizeof(png_sPLT_entry
));
1392 if (new_palette
.entries
== NULL
)
1394 png_warning(png_ptr
, "sPLT chunk requires too much memory");
1398 #ifdef PNG_POINTER_INDEXING_SUPPORTED
1399 for (i
= 0; i
< new_palette
.nentries
; i
++)
1401 pp
= new_palette
.entries
+ i
;
1403 if (new_palette
.depth
== 8)
1405 pp
->red
= *entry_start
++;
1406 pp
->green
= *entry_start
++;
1407 pp
->blue
= *entry_start
++;
1408 pp
->alpha
= *entry_start
++;
1413 pp
->red
= png_get_uint_16(entry_start
); entry_start
+= 2;
1414 pp
->green
= png_get_uint_16(entry_start
); entry_start
+= 2;
1415 pp
->blue
= png_get_uint_16(entry_start
); entry_start
+= 2;
1416 pp
->alpha
= png_get_uint_16(entry_start
); entry_start
+= 2;
1419 pp
->frequency
= png_get_uint_16(entry_start
); entry_start
+= 2;
1422 pp
= new_palette
.entries
;
1424 for (i
= 0; i
< new_palette
.nentries
; i
++)
1427 if (new_palette
.depth
== 8)
1429 pp
[i
].red
= *entry_start
++;
1430 pp
[i
].green
= *entry_start
++;
1431 pp
[i
].blue
= *entry_start
++;
1432 pp
[i
].alpha
= *entry_start
++;
1437 pp
[i
].red
= png_get_uint_16(entry_start
); entry_start
+= 2;
1438 pp
[i
].green
= png_get_uint_16(entry_start
); entry_start
+= 2;
1439 pp
[i
].blue
= png_get_uint_16(entry_start
); entry_start
+= 2;
1440 pp
[i
].alpha
= png_get_uint_16(entry_start
); entry_start
+= 2;
1443 pp
[i
].frequency
= png_get_uint_16(entry_start
); entry_start
+= 2;
1447 /* Discard all chunk data except the name and stash that */
1448 new_palette
.name
= png_ptr
->chunkdata
;
1450 png_set_sPLT(png_ptr
, info_ptr
, &new_palette
, 1);
1452 png_free(png_ptr
, png_ptr
->chunkdata
);
1453 png_ptr
->chunkdata
= NULL
;
1454 png_free(png_ptr
, new_palette
.entries
);
1456 #endif /* PNG_READ_sPLT_SUPPORTED */
1458 #ifdef PNG_READ_tRNS_SUPPORTED
1460 png_handle_tRNS(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1462 png_byte readbuf
[PNG_MAX_PALETTE_LENGTH
];
1464 png_debug(1, "in png_handle_tRNS");
1466 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1467 png_error(png_ptr
, "Missing IHDR before tRNS");
1469 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1471 png_warning(png_ptr
, "Invalid tRNS after IDAT");
1472 png_crc_finish(png_ptr
, length
);
1476 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_tRNS
))
1478 png_warning(png_ptr
, "Duplicate tRNS chunk");
1479 png_crc_finish(png_ptr
, length
);
1483 if (png_ptr
->color_type
== PNG_COLOR_TYPE_GRAY
)
1489 png_warning(png_ptr
, "Incorrect tRNS chunk length");
1490 png_crc_finish(png_ptr
, length
);
1494 png_crc_read(png_ptr
, buf
, 2);
1495 png_ptr
->num_trans
= 1;
1496 png_ptr
->trans_color
.gray
= png_get_uint_16(buf
);
1499 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_RGB
)
1505 png_warning(png_ptr
, "Incorrect tRNS chunk length");
1506 png_crc_finish(png_ptr
, length
);
1510 png_crc_read(png_ptr
, buf
, (png_size_t
)length
);
1511 png_ptr
->num_trans
= 1;
1512 png_ptr
->trans_color
.red
= png_get_uint_16(buf
);
1513 png_ptr
->trans_color
.green
= png_get_uint_16(buf
+ 2);
1514 png_ptr
->trans_color
.blue
= png_get_uint_16(buf
+ 4);
1517 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
1519 if (!(png_ptr
->mode
& PNG_HAVE_PLTE
))
1521 /* Should be an error, but we can cope with it. */
1522 png_warning(png_ptr
, "Missing PLTE before tRNS");
1525 if (length
> (png_uint_32
)png_ptr
->num_palette
||
1526 length
> PNG_MAX_PALETTE_LENGTH
)
1528 png_warning(png_ptr
, "Incorrect tRNS chunk length");
1529 png_crc_finish(png_ptr
, length
);
1535 png_warning(png_ptr
, "Zero length tRNS chunk");
1536 png_crc_finish(png_ptr
, length
);
1540 png_crc_read(png_ptr
, readbuf
, (png_size_t
)length
);
1541 png_ptr
->num_trans
= (png_uint_16
)length
;
1546 png_warning(png_ptr
, "tRNS chunk not allowed with alpha channel");
1547 png_crc_finish(png_ptr
, length
);
1551 if (png_crc_finish(png_ptr
, 0))
1553 png_ptr
->num_trans
= 0;
1557 png_set_tRNS(png_ptr
, info_ptr
, readbuf
, png_ptr
->num_trans
,
1558 &(png_ptr
->trans_color
));
1562 #ifdef PNG_READ_bKGD_SUPPORTED
1564 png_handle_bKGD(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1569 png_debug(1, "in png_handle_bKGD");
1571 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1572 png_error(png_ptr
, "Missing IHDR before bKGD");
1574 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1576 png_warning(png_ptr
, "Invalid bKGD after IDAT");
1577 png_crc_finish(png_ptr
, length
);
1581 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
&&
1582 !(png_ptr
->mode
& PNG_HAVE_PLTE
))
1584 png_warning(png_ptr
, "Missing PLTE before bKGD");
1585 png_crc_finish(png_ptr
, length
);
1589 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_bKGD
))
1591 png_warning(png_ptr
, "Duplicate bKGD chunk");
1592 png_crc_finish(png_ptr
, length
);
1596 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
1599 else if (png_ptr
->color_type
& PNG_COLOR_MASK_COLOR
)
1605 if (length
!= truelen
)
1607 png_warning(png_ptr
, "Incorrect bKGD chunk length");
1608 png_crc_finish(png_ptr
, length
);
1612 png_crc_read(png_ptr
, buf
, truelen
);
1614 if (png_crc_finish(png_ptr
, 0))
1617 /* We convert the index value into RGB components so that we can allow
1618 * arbitrary RGB values for background when we have transparency, and
1619 * so it is easy to determine the RGB values of the background color
1620 * from the info_ptr struct.
1622 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
1624 png_ptr
->background
.index
= buf
[0];
1626 if (info_ptr
&& info_ptr
->num_palette
)
1628 if (buf
[0] >= info_ptr
->num_palette
)
1630 png_warning(png_ptr
, "Incorrect bKGD chunk index value");
1634 png_ptr
->background
.red
=
1635 (png_uint_16
)png_ptr
->palette
[buf
[0]].red
;
1637 png_ptr
->background
.green
=
1638 (png_uint_16
)png_ptr
->palette
[buf
[0]].green
;
1640 png_ptr
->background
.blue
=
1641 (png_uint_16
)png_ptr
->palette
[buf
[0]].blue
;
1645 else if (!(png_ptr
->color_type
& PNG_COLOR_MASK_COLOR
)) /* GRAY */
1647 png_ptr
->background
.red
=
1648 png_ptr
->background
.green
=
1649 png_ptr
->background
.blue
=
1650 png_ptr
->background
.gray
= png_get_uint_16(buf
);
1655 png_ptr
->background
.red
= png_get_uint_16(buf
);
1656 png_ptr
->background
.green
= png_get_uint_16(buf
+ 2);
1657 png_ptr
->background
.blue
= png_get_uint_16(buf
+ 4);
1660 png_set_bKGD(png_ptr
, info_ptr
, &(png_ptr
->background
));
1664 #ifdef PNG_READ_hIST_SUPPORTED
1666 png_handle_hIST(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1668 unsigned int num
, i
;
1669 png_uint_16 readbuf
[PNG_MAX_PALETTE_LENGTH
];
1671 png_debug(1, "in png_handle_hIST");
1673 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1674 png_error(png_ptr
, "Missing IHDR before hIST");
1676 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1678 png_warning(png_ptr
, "Invalid hIST after IDAT");
1679 png_crc_finish(png_ptr
, length
);
1683 else if (!(png_ptr
->mode
& PNG_HAVE_PLTE
))
1685 png_warning(png_ptr
, "Missing PLTE before hIST");
1686 png_crc_finish(png_ptr
, length
);
1690 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_hIST
))
1692 png_warning(png_ptr
, "Duplicate hIST chunk");
1693 png_crc_finish(png_ptr
, length
);
1699 if (num
!= (unsigned int)png_ptr
->num_palette
|| num
>
1700 (unsigned int)PNG_MAX_PALETTE_LENGTH
)
1702 png_warning(png_ptr
, "Incorrect hIST chunk length");
1703 png_crc_finish(png_ptr
, length
);
1707 for (i
= 0; i
< num
; i
++)
1711 png_crc_read(png_ptr
, buf
, 2);
1712 readbuf
[i
] = png_get_uint_16(buf
);
1715 if (png_crc_finish(png_ptr
, 0))
1718 png_set_hIST(png_ptr
, info_ptr
, readbuf
);
1722 #ifdef PNG_READ_pHYs_SUPPORTED
1724 png_handle_pHYs(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1727 png_uint_32 res_x
, res_y
;
1730 png_debug(1, "in png_handle_pHYs");
1732 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1733 png_error(png_ptr
, "Missing IHDR before pHYs");
1735 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1737 png_warning(png_ptr
, "Invalid pHYs after IDAT");
1738 png_crc_finish(png_ptr
, length
);
1742 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_pHYs
))
1744 png_warning(png_ptr
, "Duplicate pHYs chunk");
1745 png_crc_finish(png_ptr
, length
);
1751 png_warning(png_ptr
, "Incorrect pHYs chunk length");
1752 png_crc_finish(png_ptr
, length
);
1756 png_crc_read(png_ptr
, buf
, 9);
1758 if (png_crc_finish(png_ptr
, 0))
1761 res_x
= png_get_uint_32(buf
);
1762 res_y
= png_get_uint_32(buf
+ 4);
1764 png_set_pHYs(png_ptr
, info_ptr
, res_x
, res_y
, unit_type
);
1768 #ifdef PNG_READ_oFFs_SUPPORTED
1770 png_handle_oFFs(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1773 png_int_32 offset_x
, offset_y
;
1776 png_debug(1, "in png_handle_oFFs");
1778 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1779 png_error(png_ptr
, "Missing IHDR before oFFs");
1781 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1783 png_warning(png_ptr
, "Invalid oFFs after IDAT");
1784 png_crc_finish(png_ptr
, length
);
1788 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_oFFs
))
1790 png_warning(png_ptr
, "Duplicate oFFs chunk");
1791 png_crc_finish(png_ptr
, length
);
1797 png_warning(png_ptr
, "Incorrect oFFs chunk length");
1798 png_crc_finish(png_ptr
, length
);
1802 png_crc_read(png_ptr
, buf
, 9);
1804 if (png_crc_finish(png_ptr
, 0))
1807 offset_x
= png_get_int_32(buf
);
1808 offset_y
= png_get_int_32(buf
+ 4);
1810 png_set_oFFs(png_ptr
, info_ptr
, offset_x
, offset_y
, unit_type
);
1814 #ifdef PNG_READ_pCAL_SUPPORTED
1815 /* Read the pCAL chunk (described in the PNG Extensions document) */
1817 png_handle_pCAL(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1820 png_byte type
, nparams
;
1821 png_charp buf
, units
, endptr
;
1826 png_debug(1, "in png_handle_pCAL");
1828 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1829 png_error(png_ptr
, "Missing IHDR before pCAL");
1831 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1833 png_warning(png_ptr
, "Invalid pCAL after IDAT");
1834 png_crc_finish(png_ptr
, length
);
1838 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_pCAL
))
1840 png_warning(png_ptr
, "Duplicate pCAL chunk");
1841 png_crc_finish(png_ptr
, length
);
1845 png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
1847 png_free(png_ptr
, png_ptr
->chunkdata
);
1848 png_ptr
->chunkdata
= (png_charp
)png_malloc_warn(png_ptr
, length
+ 1);
1850 if (png_ptr
->chunkdata
== NULL
)
1852 png_warning(png_ptr
, "No memory for pCAL purpose");
1856 slength
= (png_size_t
)length
;
1857 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
1859 if (png_crc_finish(png_ptr
, 0))
1861 png_free(png_ptr
, png_ptr
->chunkdata
);
1862 png_ptr
->chunkdata
= NULL
;
1866 png_ptr
->chunkdata
[slength
] = 0x00; /* Null terminate the last string */
1868 png_debug(3, "Finding end of pCAL purpose string");
1869 for (buf
= png_ptr
->chunkdata
; *buf
; buf
++)
1872 endptr
= png_ptr
->chunkdata
+ slength
;
1874 /* We need to have at least 12 bytes after the purpose string
1875 * in order to get the parameter information.
1877 if (endptr
<= buf
+ 12)
1879 png_warning(png_ptr
, "Invalid pCAL data");
1880 png_free(png_ptr
, png_ptr
->chunkdata
);
1881 png_ptr
->chunkdata
= NULL
;
1885 png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
1886 X0
= png_get_int_32((png_bytep
)buf
+1);
1887 X1
= png_get_int_32((png_bytep
)buf
+5);
1892 png_debug(3, "Checking pCAL equation type and number of parameters");
1893 /* Check that we have the right number of parameters for known
1896 if ((type
== PNG_EQUATION_LINEAR
&& nparams
!= 2) ||
1897 (type
== PNG_EQUATION_BASE_E
&& nparams
!= 3) ||
1898 (type
== PNG_EQUATION_ARBITRARY
&& nparams
!= 3) ||
1899 (type
== PNG_EQUATION_HYPERBOLIC
&& nparams
!= 4))
1901 png_warning(png_ptr
, "Invalid pCAL parameters for equation type");
1902 png_free(png_ptr
, png_ptr
->chunkdata
);
1903 png_ptr
->chunkdata
= NULL
;
1907 else if (type
>= PNG_EQUATION_LAST
)
1909 png_warning(png_ptr
, "Unrecognized equation type for pCAL chunk");
1912 for (buf
= units
; *buf
; buf
++)
1913 /* Empty loop to move past the units string. */ ;
1915 png_debug(3, "Allocating pCAL parameters array");
1917 params
= (png_charpp
)png_malloc_warn(png_ptr
,
1918 (png_size_t
)(nparams
* png_sizeof(png_charp
)));
1922 png_free(png_ptr
, png_ptr
->chunkdata
);
1923 png_ptr
->chunkdata
= NULL
;
1924 png_warning(png_ptr
, "No memory for pCAL params");
1928 /* Get pointers to the start of each parameter string. */
1929 for (i
= 0; i
< (int)nparams
; i
++)
1931 buf
++; /* Skip the null string terminator from previous parameter. */
1933 png_debug1(3, "Reading pCAL parameter %d", i
);
1935 for (params
[i
] = buf
; buf
<= endptr
&& *buf
!= 0x00; buf
++)
1936 /* Empty loop to move past each parameter string */ ;
1938 /* Make sure we haven't run out of data yet */
1941 png_warning(png_ptr
, "Invalid pCAL data");
1942 png_free(png_ptr
, png_ptr
->chunkdata
);
1943 png_ptr
->chunkdata
= NULL
;
1944 png_free(png_ptr
, params
);
1949 png_set_pCAL(png_ptr
, info_ptr
, png_ptr
->chunkdata
, X0
, X1
, type
, nparams
,
1952 png_free(png_ptr
, png_ptr
->chunkdata
);
1953 png_ptr
->chunkdata
= NULL
;
1954 png_free(png_ptr
, params
);
1958 #ifdef PNG_READ_sCAL_SUPPORTED
1959 /* Read the sCAL chunk */
1961 png_handle_sCAL(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
1963 png_size_t slength
, i
;
1966 png_debug(1, "in png_handle_sCAL");
1968 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
1969 png_error(png_ptr
, "Missing IHDR before sCAL");
1971 else if (png_ptr
->mode
& PNG_HAVE_IDAT
)
1973 png_warning(png_ptr
, "Invalid sCAL after IDAT");
1974 png_crc_finish(png_ptr
, length
);
1978 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_sCAL
))
1980 png_warning(png_ptr
, "Duplicate sCAL chunk");
1981 png_crc_finish(png_ptr
, length
);
1985 png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
1988 png_ptr
->chunkdata
= (png_charp
)png_malloc_warn(png_ptr
, length
+ 1);
1990 if (png_ptr
->chunkdata
== NULL
)
1992 png_warning(png_ptr
, "Out of memory while processing sCAL chunk");
1993 png_crc_finish(png_ptr
, length
);
1997 slength
= (png_size_t
)length
;
1998 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
1999 png_ptr
->chunkdata
[slength
] = 0x00; /* Null terminate the last string */
2001 if (png_crc_finish(png_ptr
, 0))
2003 png_free(png_ptr
, png_ptr
->chunkdata
);
2004 png_ptr
->chunkdata
= NULL
;
2008 /* Validate the unit. */
2009 if (png_ptr
->chunkdata
[0] != 1 && png_ptr
->chunkdata
[0] != 2)
2011 png_warning(png_ptr
, "Invalid sCAL ignored: invalid unit");
2012 png_free(png_ptr
, png_ptr
->chunkdata
);
2013 png_ptr
->chunkdata
= NULL
;
2017 /* Validate the ASCII numbers, need two ASCII numbers separated by
2018 * a '\0' and they need to fit exactly in the chunk data.
2023 if (png_ptr
->chunkdata
[1] == 45 /* negative width */ ||
2024 !png_check_fp_number(png_ptr
->chunkdata
, slength
, &state
, &i
) ||
2025 i
>= slength
|| png_ptr
->chunkdata
[i
++] != 0)
2026 png_warning(png_ptr
, "Invalid sCAL chunk ignored: bad width format");
2030 png_size_t heighti
= i
;
2032 if (png_ptr
->chunkdata
[i
] == 45 /* negative height */ ||
2033 !png_check_fp_number(png_ptr
->chunkdata
, slength
, &state
, &i
) ||
2035 png_warning(png_ptr
, "Invalid sCAL chunk ignored: bad height format");
2038 /* This is the (only) success case. */
2039 png_set_sCAL_s(png_ptr
, info_ptr
, png_ptr
->chunkdata
[0],
2040 png_ptr
->chunkdata
+1, png_ptr
->chunkdata
+heighti
);
2043 /* Clean up - just free the temporarily allocated buffer. */
2044 png_free(png_ptr
, png_ptr
->chunkdata
);
2045 png_ptr
->chunkdata
= NULL
;
2049 #ifdef PNG_READ_tIME_SUPPORTED
2051 png_handle_tIME(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
2056 png_debug(1, "in png_handle_tIME");
2058 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
2059 png_error(png_ptr
, "Out of place tIME chunk");
2061 else if (info_ptr
!= NULL
&& (info_ptr
->valid
& PNG_INFO_tIME
))
2063 png_warning(png_ptr
, "Duplicate tIME chunk");
2064 png_crc_finish(png_ptr
, length
);
2068 if (png_ptr
->mode
& PNG_HAVE_IDAT
)
2069 png_ptr
->mode
|= PNG_AFTER_IDAT
;
2073 png_warning(png_ptr
, "Incorrect tIME chunk length");
2074 png_crc_finish(png_ptr
, length
);
2078 png_crc_read(png_ptr
, buf
, 7);
2080 if (png_crc_finish(png_ptr
, 0))
2083 mod_time
.second
= buf
[6];
2084 mod_time
.minute
= buf
[5];
2085 mod_time
.hour
= buf
[4];
2086 mod_time
.day
= buf
[3];
2087 mod_time
.month
= buf
[2];
2088 mod_time
.year
= png_get_uint_16(buf
);
2090 png_set_tIME(png_ptr
, info_ptr
, &mod_time
);
2094 #ifdef PNG_READ_tEXt_SUPPORTED
2095 /* Note: this does not properly handle chunks that are > 64K under DOS */
2097 png_handle_tEXt(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
2102 png_uint_32 skip
= 0;
2106 png_debug(1, "in png_handle_tEXt");
2108 #ifdef PNG_USER_LIMITS_SUPPORTED
2109 if (png_ptr
->user_chunk_cache_max
!= 0)
2111 if (png_ptr
->user_chunk_cache_max
== 1)
2113 png_crc_finish(png_ptr
, length
);
2117 if (--png_ptr
->user_chunk_cache_max
== 1)
2119 png_warning(png_ptr
, "No space in chunk cache for tEXt");
2120 png_crc_finish(png_ptr
, length
);
2126 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
2127 png_error(png_ptr
, "Missing IHDR before tEXt");
2129 if (png_ptr
->mode
& PNG_HAVE_IDAT
)
2130 png_ptr
->mode
|= PNG_AFTER_IDAT
;
2132 #ifdef PNG_MAX_MALLOC_64K
2133 if (length
> (png_uint_32
)65535L)
2135 png_warning(png_ptr
, "tEXt chunk too large to fit in memory");
2136 skip
= length
- (png_uint_32
)65535L;
2137 length
= (png_uint_32
)65535L;
2141 png_free(png_ptr
, png_ptr
->chunkdata
);
2143 png_ptr
->chunkdata
= (png_charp
)png_malloc_warn(png_ptr
, length
+ 1);
2145 if (png_ptr
->chunkdata
== NULL
)
2147 png_warning(png_ptr
, "No memory to process text chunk");
2151 slength
= (png_size_t
)length
;
2152 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
2154 if (png_crc_finish(png_ptr
, skip
))
2156 png_free(png_ptr
, png_ptr
->chunkdata
);
2157 png_ptr
->chunkdata
= NULL
;
2161 key
= png_ptr
->chunkdata
;
2163 key
[slength
] = 0x00;
2165 for (text
= key
; *text
; text
++)
2166 /* Empty loop to find end of key */ ;
2168 if (text
!= key
+ slength
)
2171 text_ptr
= (png_textp
)png_malloc_warn(png_ptr
,
2172 png_sizeof(png_text
));
2174 if (text_ptr
== NULL
)
2176 png_warning(png_ptr
, "Not enough memory to process text chunk");
2177 png_free(png_ptr
, png_ptr
->chunkdata
);
2178 png_ptr
->chunkdata
= NULL
;
2182 text_ptr
->compression
= PNG_TEXT_COMPRESSION_NONE
;
2183 text_ptr
->key
= key
;
2184 text_ptr
->lang
= NULL
;
2185 text_ptr
->lang_key
= NULL
;
2186 text_ptr
->itxt_length
= 0;
2187 text_ptr
->text
= text
;
2188 text_ptr
->text_length
= png_strlen(text
);
2190 ret
= png_set_text_2(png_ptr
, info_ptr
, text_ptr
, 1);
2192 png_free(png_ptr
, png_ptr
->chunkdata
);
2193 png_ptr
->chunkdata
= NULL
;
2194 png_free(png_ptr
, text_ptr
);
2197 png_warning(png_ptr
, "Insufficient memory to process text chunk");
2201 #ifdef PNG_READ_zTXt_SUPPORTED
2202 /* Note: this does not correctly handle chunks that are > 64K under DOS */
2204 png_handle_zTXt(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
2210 png_size_t slength
, prefix_len
, data_len
;
2212 png_debug(1, "in png_handle_zTXt");
2214 #ifdef PNG_USER_LIMITS_SUPPORTED
2215 if (png_ptr
->user_chunk_cache_max
!= 0)
2217 if (png_ptr
->user_chunk_cache_max
== 1)
2219 png_crc_finish(png_ptr
, length
);
2223 if (--png_ptr
->user_chunk_cache_max
== 1)
2225 png_warning(png_ptr
, "No space in chunk cache for zTXt");
2226 png_crc_finish(png_ptr
, length
);
2232 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
2233 png_error(png_ptr
, "Missing IHDR before zTXt");
2235 if (png_ptr
->mode
& PNG_HAVE_IDAT
)
2236 png_ptr
->mode
|= PNG_AFTER_IDAT
;
2238 #ifdef PNG_MAX_MALLOC_64K
2239 /* We will no doubt have problems with chunks even half this size, but
2240 * there is no hard and fast rule to tell us where to stop.
2242 if (length
> (png_uint_32
)65535L)
2244 png_warning(png_ptr
, "zTXt chunk too large to fit in memory");
2245 png_crc_finish(png_ptr
, length
);
2250 png_free(png_ptr
, png_ptr
->chunkdata
);
2251 png_ptr
->chunkdata
= (png_charp
)png_malloc_warn(png_ptr
, length
+ 1);
2253 if (png_ptr
->chunkdata
== NULL
)
2255 png_warning(png_ptr
, "Out of memory processing zTXt chunk");
2259 slength
= (png_size_t
)length
;
2260 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
2262 if (png_crc_finish(png_ptr
, 0))
2264 png_free(png_ptr
, png_ptr
->chunkdata
);
2265 png_ptr
->chunkdata
= NULL
;
2269 png_ptr
->chunkdata
[slength
] = 0x00;
2271 for (text
= png_ptr
->chunkdata
; *text
; text
++)
2274 /* zTXt must have some text after the chunkdataword */
2275 if (text
>= png_ptr
->chunkdata
+ slength
- 2)
2277 png_warning(png_ptr
, "Truncated zTXt chunk");
2278 png_free(png_ptr
, png_ptr
->chunkdata
);
2279 png_ptr
->chunkdata
= NULL
;
2285 comp_type
= *(++text
);
2287 if (comp_type
!= PNG_TEXT_COMPRESSION_zTXt
)
2289 png_warning(png_ptr
, "Unknown compression type in zTXt chunk");
2290 comp_type
= PNG_TEXT_COMPRESSION_zTXt
;
2293 text
++; /* Skip the compression_method byte */
2296 prefix_len
= text
- png_ptr
->chunkdata
;
2298 png_decompress_chunk(png_ptr
, comp_type
,
2299 (png_size_t
)length
, prefix_len
, &data_len
);
2301 text_ptr
= (png_textp
)png_malloc_warn(png_ptr
,
2302 png_sizeof(png_text
));
2304 if (text_ptr
== NULL
)
2306 png_warning(png_ptr
, "Not enough memory to process zTXt chunk");
2307 png_free(png_ptr
, png_ptr
->chunkdata
);
2308 png_ptr
->chunkdata
= NULL
;
2312 text_ptr
->compression
= comp_type
;
2313 text_ptr
->key
= png_ptr
->chunkdata
;
2314 text_ptr
->lang
= NULL
;
2315 text_ptr
->lang_key
= NULL
;
2316 text_ptr
->itxt_length
= 0;
2317 text_ptr
->text
= png_ptr
->chunkdata
+ prefix_len
;
2318 text_ptr
->text_length
= data_len
;
2320 ret
= png_set_text_2(png_ptr
, info_ptr
, text_ptr
, 1);
2322 png_free(png_ptr
, text_ptr
);
2323 png_free(png_ptr
, png_ptr
->chunkdata
);
2324 png_ptr
->chunkdata
= NULL
;
2327 png_error(png_ptr
, "Insufficient memory to store zTXt chunk");
2331 #ifdef PNG_READ_iTXt_SUPPORTED
2332 /* Note: this does not correctly handle chunks that are > 64K under DOS */
2334 png_handle_iTXt(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
2337 png_charp key
, lang
, text
, lang_key
;
2341 png_size_t slength
, prefix_len
, data_len
;
2343 png_debug(1, "in png_handle_iTXt");
2345 #ifdef PNG_USER_LIMITS_SUPPORTED
2346 if (png_ptr
->user_chunk_cache_max
!= 0)
2348 if (png_ptr
->user_chunk_cache_max
== 1)
2350 png_crc_finish(png_ptr
, length
);
2354 if (--png_ptr
->user_chunk_cache_max
== 1)
2356 png_warning(png_ptr
, "No space in chunk cache for iTXt");
2357 png_crc_finish(png_ptr
, length
);
2363 if (!(png_ptr
->mode
& PNG_HAVE_IHDR
))
2364 png_error(png_ptr
, "Missing IHDR before iTXt");
2366 if (png_ptr
->mode
& PNG_HAVE_IDAT
)
2367 png_ptr
->mode
|= PNG_AFTER_IDAT
;
2369 #ifdef PNG_MAX_MALLOC_64K
2370 /* We will no doubt have problems with chunks even half this size, but
2371 * there is no hard and fast rule to tell us where to stop.
2373 if (length
> (png_uint_32
)65535L)
2375 png_warning(png_ptr
, "iTXt chunk too large to fit in memory");
2376 png_crc_finish(png_ptr
, length
);
2381 png_free(png_ptr
, png_ptr
->chunkdata
);
2382 png_ptr
->chunkdata
= (png_charp
)png_malloc_warn(png_ptr
, length
+ 1);
2384 if (png_ptr
->chunkdata
== NULL
)
2386 png_warning(png_ptr
, "No memory to process iTXt chunk");
2390 slength
= (png_size_t
)length
;
2391 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->chunkdata
, slength
);
2393 if (png_crc_finish(png_ptr
, 0))
2395 png_free(png_ptr
, png_ptr
->chunkdata
);
2396 png_ptr
->chunkdata
= NULL
;
2400 png_ptr
->chunkdata
[slength
] = 0x00;
2402 for (lang
= png_ptr
->chunkdata
; *lang
; lang
++)
2405 lang
++; /* Skip NUL separator */
2407 /* iTXt must have a language tag (possibly empty), two compression bytes,
2408 * translated keyword (possibly empty), and possibly some text after the
2412 if (lang
>= png_ptr
->chunkdata
+ slength
- 3)
2414 png_warning(png_ptr
, "Truncated iTXt chunk");
2415 png_free(png_ptr
, png_ptr
->chunkdata
);
2416 png_ptr
->chunkdata
= NULL
;
2422 comp_flag
= *lang
++;
2423 comp_type
= *lang
++;
2426 for (lang_key
= lang
; *lang_key
; lang_key
++)
2429 lang_key
++; /* Skip NUL separator */
2431 if (lang_key
>= png_ptr
->chunkdata
+ slength
)
2433 png_warning(png_ptr
, "Truncated iTXt chunk");
2434 png_free(png_ptr
, png_ptr
->chunkdata
);
2435 png_ptr
->chunkdata
= NULL
;
2439 for (text
= lang_key
; *text
; text
++)
2442 text
++; /* Skip NUL separator */
2444 if (text
>= png_ptr
->chunkdata
+ slength
)
2446 png_warning(png_ptr
, "Malformed iTXt chunk");
2447 png_free(png_ptr
, png_ptr
->chunkdata
);
2448 png_ptr
->chunkdata
= NULL
;
2452 prefix_len
= text
- png_ptr
->chunkdata
;
2454 key
=png_ptr
->chunkdata
;
2457 png_decompress_chunk(png_ptr
, comp_type
,
2458 (size_t)length
, prefix_len
, &data_len
);
2461 data_len
= png_strlen(png_ptr
->chunkdata
+ prefix_len
);
2463 text_ptr
= (png_textp
)png_malloc_warn(png_ptr
,
2464 png_sizeof(png_text
));
2466 if (text_ptr
== NULL
)
2468 png_warning(png_ptr
, "Not enough memory to process iTXt chunk");
2469 png_free(png_ptr
, png_ptr
->chunkdata
);
2470 png_ptr
->chunkdata
= NULL
;
2474 text_ptr
->compression
= (int)comp_flag
+ 1;
2475 text_ptr
->lang_key
= png_ptr
->chunkdata
+ (lang_key
- key
);
2476 text_ptr
->lang
= png_ptr
->chunkdata
+ (lang
- key
);
2477 text_ptr
->itxt_length
= data_len
;
2478 text_ptr
->text_length
= 0;
2479 text_ptr
->key
= png_ptr
->chunkdata
;
2480 text_ptr
->text
= png_ptr
->chunkdata
+ prefix_len
;
2482 ret
= png_set_text_2(png_ptr
, info_ptr
, text_ptr
, 1);
2484 png_free(png_ptr
, text_ptr
);
2485 png_free(png_ptr
, png_ptr
->chunkdata
);
2486 png_ptr
->chunkdata
= NULL
;
2489 png_error(png_ptr
, "Insufficient memory to store iTXt chunk");
2493 /* This function is called when we haven't found a handler for a
2494 * chunk. If there isn't a problem with the chunk itself (ie bad
2495 * chunk name, CRC, or a critical chunk), the chunk is silently ignored
2496 * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
2497 * case it will be saved away to be written out later.
2500 png_handle_unknown(png_structp png_ptr
, png_infop info_ptr
, png_uint_32 length
)
2502 png_uint_32 skip
= 0;
2504 png_debug(1, "in png_handle_unknown");
2506 #ifdef PNG_USER_LIMITS_SUPPORTED
2507 if (png_ptr
->user_chunk_cache_max
!= 0)
2509 if (png_ptr
->user_chunk_cache_max
== 1)
2511 png_crc_finish(png_ptr
, length
);
2515 if (--png_ptr
->user_chunk_cache_max
== 1)
2517 png_warning(png_ptr
, "No space in chunk cache for unknown chunk");
2518 png_crc_finish(png_ptr
, length
);
2524 if (png_ptr
->mode
& PNG_HAVE_IDAT
)
2528 if (png_memcmp(png_ptr
->chunk_name
, png_IDAT
, 4)) /* Not an IDAT */
2529 png_ptr
->mode
|= PNG_AFTER_IDAT
;
2532 if (!(png_ptr
->chunk_name
[0] & 0x20))
2534 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2535 if (png_handle_as_unknown(png_ptr
, png_ptr
->chunk_name
) !=
2536 PNG_HANDLE_CHUNK_ALWAYS
2537 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
2538 && png_ptr
->read_user_chunk_fn
== NULL
2542 png_chunk_error(png_ptr
, "unknown critical chunk");
2545 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
2546 if ((png_ptr
->flags
& PNG_FLAG_KEEP_UNKNOWN_CHUNKS
)
2547 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
2548 || (png_ptr
->read_user_chunk_fn
!= NULL
)
2552 #ifdef PNG_MAX_MALLOC_64K
2553 if (length
> (png_uint_32
)65535L)
2555 png_warning(png_ptr
, "unknown chunk too large to fit in memory");
2556 skip
= length
- (png_uint_32
)65535L;
2557 length
= (png_uint_32
)65535L;
2561 png_memcpy((png_charp
)png_ptr
->unknown_chunk
.name
,
2562 (png_charp
)png_ptr
->chunk_name
,
2563 png_sizeof(png_ptr
->unknown_chunk
.name
));
2565 png_ptr
->unknown_chunk
.name
[png_sizeof(png_ptr
->unknown_chunk
.name
)-1]
2568 png_ptr
->unknown_chunk
.size
= (png_size_t
)length
;
2571 png_ptr
->unknown_chunk
.data
= NULL
;
2575 png_ptr
->unknown_chunk
.data
= (png_bytep
)png_malloc(png_ptr
, length
);
2576 png_crc_read(png_ptr
, (png_bytep
)png_ptr
->unknown_chunk
.data
, length
);
2579 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
2580 if (png_ptr
->read_user_chunk_fn
!= NULL
)
2582 /* Callback to user unknown chunk handler */
2585 ret
= (*(png_ptr
->read_user_chunk_fn
))
2586 (png_ptr
, &png_ptr
->unknown_chunk
);
2589 png_chunk_error(png_ptr
, "error in user chunk");
2593 if (!(png_ptr
->chunk_name
[0] & 0x20))
2595 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2596 if (png_handle_as_unknown(png_ptr
, png_ptr
->chunk_name
) !=
2597 PNG_HANDLE_CHUNK_ALWAYS
)
2599 png_chunk_error(png_ptr
, "unknown critical chunk");
2602 png_set_unknown_chunks(png_ptr
, info_ptr
,
2603 &png_ptr
->unknown_chunk
, 1);
2609 png_set_unknown_chunks(png_ptr
, info_ptr
, &png_ptr
->unknown_chunk
, 1);
2611 png_free(png_ptr
, png_ptr
->unknown_chunk
.data
);
2612 png_ptr
->unknown_chunk
.data
= NULL
;
2619 png_crc_finish(png_ptr
, skip
);
2621 #ifndef PNG_READ_USER_CHUNKS_SUPPORTED
2622 PNG_UNUSED(info_ptr
) /* Quiet compiler warnings about unused info_ptr */
2626 /* This function is called to verify that a chunk name is valid.
2627 * This function can't have the "critical chunk check" incorporated
2628 * into it, since in the future we will need to be able to call user
2629 * functions to handle unknown critical chunks after we check that
2630 * the chunk name itself is valid.
2633 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
2636 png_check_chunk_name(png_structp png_ptr
, png_const_bytep chunk_name
)
2638 png_debug(1, "in png_check_chunk_name");
2639 if (isnonalpha(chunk_name
[0]) || isnonalpha(chunk_name
[1]) ||
2640 isnonalpha(chunk_name
[2]) || isnonalpha(chunk_name
[3]))
2642 png_chunk_error(png_ptr
, "invalid chunk type");
2646 /* Combines the row recently read in with the existing pixels in the
2647 * row. This routine takes care of alpha and transparency if requested.
2648 * This routine also handles the two methods of progressive display
2649 * of interlaced images, depending on the mask value.
2650 * The mask value describes which pixels are to be combined with
2651 * the row. The pattern always repeats every 8 pixels, so just 8
2652 * bits are needed. A one indicates the pixel is to be combined,
2653 * a zero indicates the pixel is to be skipped. This is in addition
2654 * to any alpha or transparency value associated with the pixel. If
2655 * you want all pixels to be combined, pass 0xff (255) in mask.
2659 png_combine_row(png_structp png_ptr
, png_bytep row
, int mask
)
2661 png_debug(1, "in png_combine_row");
2665 png_memcpy(row
, png_ptr
->row_buf
+ 1,
2666 PNG_ROWBYTES(png_ptr
->row_info
.pixel_depth
, png_ptr
->width
));
2671 switch (png_ptr
->row_info
.pixel_depth
)
2675 png_bytep sp
= png_ptr
->row_buf
+ 1;
2677 int s_inc
, s_start
, s_end
;
2681 png_uint_32 row_width
= png_ptr
->width
;
2683 #ifdef PNG_READ_PACKSWAP_SUPPORTED
2684 if (png_ptr
->transformations
& PNG_PACKSWAP
)
2701 for (i
= 0; i
< row_width
; i
++)
2707 value
= (*sp
>> shift
) & 0x01;
2708 *dp
&= (png_byte
)((0x7f7f >> (7 - shift
)) & 0xff);
2709 *dp
|= (png_byte
)(value
<< shift
);
2733 png_bytep sp
= png_ptr
->row_buf
+ 1;
2735 int s_start
, s_end
, s_inc
;
2739 png_uint_32 row_width
= png_ptr
->width
;
2742 #ifdef PNG_READ_PACKSWAP_SUPPORTED
2743 if (png_ptr
->transformations
& PNG_PACKSWAP
)
2760 for (i
= 0; i
< row_width
; i
++)
2764 value
= (*sp
>> shift
) & 0x03;
2765 *dp
&= (png_byte
)((0x3f3f >> (6 - shift
)) & 0xff);
2766 *dp
|= (png_byte
)(value
<< shift
);
2790 png_bytep sp
= png_ptr
->row_buf
+ 1;
2792 int s_start
, s_end
, s_inc
;
2796 png_uint_32 row_width
= png_ptr
->width
;
2799 #ifdef PNG_READ_PACKSWAP_SUPPORTED
2800 if (png_ptr
->transformations
& PNG_PACKSWAP
)
2816 for (i
= 0; i
< row_width
; i
++)
2820 value
= (*sp
>> shift
) & 0xf;
2821 *dp
&= (png_byte
)((0xf0f >> (4 - shift
)) & 0xff);
2822 *dp
|= (png_byte
)(value
<< shift
);
2846 png_bytep sp
= png_ptr
->row_buf
+ 1;
2848 png_size_t pixel_bytes
= (png_ptr
->row_info
.pixel_depth
>> 3);
2850 png_uint_32 row_width
= png_ptr
->width
;
2853 for (i
= 0; i
< row_width
; i
++)
2857 png_memcpy(dp
, sp
, pixel_bytes
);
2875 #ifdef PNG_READ_INTERLACING_SUPPORTED
2877 png_do_read_interlace(png_structp png_ptr
)
2879 png_row_infop row_info
= &(png_ptr
->row_info
);
2880 png_bytep row
= png_ptr
->row_buf
+ 1;
2881 int pass
= png_ptr
->pass
;
2882 png_uint_32 transformations
= png_ptr
->transformations
;
2883 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2884 /* Offset to next interlace block */
2885 PNG_CONST
int png_pass_inc
[7] = {8, 8, 4, 4, 2, 2, 1};
2887 png_debug(1, "in png_do_read_interlace");
2888 if (row
!= NULL
&& row_info
!= NULL
)
2890 png_uint_32 final_width
;
2892 final_width
= row_info
->width
* png_pass_inc
[pass
];
2894 switch (row_info
->pixel_depth
)
2898 png_bytep sp
= row
+ (png_size_t
)((row_info
->width
- 1) >> 3);
2899 png_bytep dp
= row
+ (png_size_t
)((final_width
- 1) >> 3);
2901 int s_start
, s_end
, s_inc
;
2902 int jstop
= png_pass_inc
[pass
];
2907 #ifdef PNG_READ_PACKSWAP_SUPPORTED
2908 if (transformations
& PNG_PACKSWAP
)
2910 sshift
= (int)((row_info
->width
+ 7) & 0x07);
2911 dshift
= (int)((final_width
+ 7) & 0x07);
2920 sshift
= 7 - (int)((row_info
->width
+ 7) & 0x07);
2921 dshift
= 7 - (int)((final_width
+ 7) & 0x07);
2927 for (i
= 0; i
< row_info
->width
; i
++)
2929 v
= (png_byte
)((*sp
>> sshift
) & 0x01);
2930 for (j
= 0; j
< jstop
; j
++)
2932 *dp
&= (png_byte
)((0x7f7f >> (7 - dshift
)) & 0xff);
2933 *dp
|= (png_byte
)(v
<< dshift
);
2935 if (dshift
== s_end
)
2945 if (sshift
== s_end
)
2959 png_bytep sp
= row
+ (png_uint_32
)((row_info
->width
- 1) >> 2);
2960 png_bytep dp
= row
+ (png_uint_32
)((final_width
- 1) >> 2);
2962 int s_start
, s_end
, s_inc
;
2963 int jstop
= png_pass_inc
[pass
];
2966 #ifdef PNG_READ_PACKSWAP_SUPPORTED
2967 if (transformations
& PNG_PACKSWAP
)
2969 sshift
= (int)(((row_info
->width
+ 3) & 0x03) << 1);
2970 dshift
= (int)(((final_width
+ 3) & 0x03) << 1);
2979 sshift
= (int)((3 - ((row_info
->width
+ 3) & 0x03)) << 1);
2980 dshift
= (int)((3 - ((final_width
+ 3) & 0x03)) << 1);
2986 for (i
= 0; i
< row_info
->width
; i
++)
2991 v
= (png_byte
)((*sp
>> sshift
) & 0x03);
2992 for (j
= 0; j
< jstop
; j
++)
2994 *dp
&= (png_byte
)((0x3f3f >> (6 - dshift
)) & 0xff);
2995 *dp
|= (png_byte
)(v
<< dshift
);
2997 if (dshift
== s_end
)
3007 if (sshift
== s_end
)
3021 png_bytep sp
= row
+ (png_size_t
)((row_info
->width
- 1) >> 1);
3022 png_bytep dp
= row
+ (png_size_t
)((final_width
- 1) >> 1);
3024 int s_start
, s_end
, s_inc
;
3026 int jstop
= png_pass_inc
[pass
];
3028 #ifdef PNG_READ_PACKSWAP_SUPPORTED
3029 if (transformations
& PNG_PACKSWAP
)
3031 sshift
= (int)(((row_info
->width
+ 1) & 0x01) << 2);
3032 dshift
= (int)(((final_width
+ 1) & 0x01) << 2);
3041 sshift
= (int)((1 - ((row_info
->width
+ 1) & 0x01)) << 2);
3042 dshift
= (int)((1 - ((final_width
+ 1) & 0x01)) << 2);
3048 for (i
= 0; i
< row_info
->width
; i
++)
3050 png_byte v
= (png_byte
)((*sp
>> sshift
) & 0xf);
3053 for (j
= 0; j
< jstop
; j
++)
3055 *dp
&= (png_byte
)((0xf0f >> (4 - dshift
)) & 0xff);
3056 *dp
|= (png_byte
)(v
<< dshift
);
3058 if (dshift
== s_end
)
3068 if (sshift
== s_end
)
3081 png_size_t pixel_bytes
= (row_info
->pixel_depth
>> 3);
3083 png_bytep sp
= row
+ (png_size_t
)(row_info
->width
- 1)
3086 png_bytep dp
= row
+ (png_size_t
)(final_width
- 1) * pixel_bytes
;
3088 int jstop
= png_pass_inc
[pass
];
3091 for (i
= 0; i
< row_info
->width
; i
++)
3096 png_memcpy(v
, sp
, pixel_bytes
);
3098 for (j
= 0; j
< jstop
; j
++)
3100 png_memcpy(dp
, v
, pixel_bytes
);
3109 row_info
->width
= final_width
;
3110 row_info
->rowbytes
= PNG_ROWBYTES(row_info
->pixel_depth
, final_width
);
3112 #ifndef PNG_READ_PACKSWAP_SUPPORTED
3113 PNG_UNUSED(transformations
) /* Silence compiler warning */
3116 #endif /* PNG_READ_INTERLACING_SUPPORTED */
3119 png_read_filter_row(png_structp png_ptr
, png_row_infop row_info
, png_bytep row
,
3120 png_const_bytep prev_row
, int filter
)
3122 png_debug(1, "in png_read_filter_row");
3123 png_debug2(2, "row = %u, filter = %d", png_ptr
->row_number
, filter
);
3126 case PNG_FILTER_VALUE_NONE
:
3129 case PNG_FILTER_VALUE_SUB
:
3132 png_size_t istop
= row_info
->rowbytes
;
3133 unsigned int bpp
= (row_info
->pixel_depth
+ 7) >> 3;
3134 png_bytep rp
= row
+ bpp
;
3137 for (i
= bpp
; i
< istop
; i
++)
3139 *rp
= (png_byte
)(((int)(*rp
) + (int)(*lp
++)) & 0xff);
3144 case PNG_FILTER_VALUE_UP
:
3147 png_size_t istop
= row_info
->rowbytes
;
3149 png_const_bytep pp
= prev_row
;
3151 for (i
= 0; i
< istop
; i
++)
3153 *rp
= (png_byte
)(((int)(*rp
) + (int)(*pp
++)) & 0xff);
3158 case PNG_FILTER_VALUE_AVG
:
3162 png_const_bytep pp
= prev_row
;
3164 unsigned int bpp
= (row_info
->pixel_depth
+ 7) >> 3;
3165 png_size_t istop
= row_info
->rowbytes
- bpp
;
3167 for (i
= 0; i
< bpp
; i
++)
3169 *rp
= (png_byte
)(((int)(*rp
) +
3170 ((int)(*pp
++) / 2 )) & 0xff);
3175 for (i
= 0; i
< istop
; i
++)
3177 *rp
= (png_byte
)(((int)(*rp
) +
3178 (int)(*pp
++ + *lp
++) / 2 ) & 0xff);
3184 case PNG_FILTER_VALUE_PAETH
:
3188 png_const_bytep pp
= prev_row
;
3190 png_const_bytep cp
= prev_row
;
3191 unsigned int bpp
= (row_info
->pixel_depth
+ 7) >> 3;
3192 png_size_t istop
=row_info
->rowbytes
- bpp
;
3194 for (i
= 0; i
< bpp
; i
++)
3196 *rp
= (png_byte
)(((int)(*rp
) + (int)(*pp
++)) & 0xff);
3200 for (i
= 0; i
< istop
; i
++) /* Use leftover rp,pp */
3202 int a
, b
, c
, pa
, pb
, pc
, p
;
3216 pa
= p
< 0 ? -p
: p
;
3217 pb
= pc
< 0 ? -pc
: pc
;
3218 pc
= (p
+ pc
) < 0 ? -(p
+ pc
) : p
+ pc
;
3222 if (pa <= pb && pa <= pc)
3232 p
= (pa
<= pb
&& pa
<= pc
) ? a
: (pb
<= pc
) ? b
: c
;
3234 *rp
= (png_byte
)(((int)(*rp
) + p
) & 0xff);
3240 png_error(png_ptr
, "Ignoring bad adaptive filter type");
3246 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
3248 png_read_finish_row(png_structp png_ptr
)
3250 #ifdef PNG_READ_INTERLACING_SUPPORTED
3251 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
3253 /* Start of interlace block */
3254 PNG_CONST
int png_pass_start
[7] = {0, 4, 0, 2, 0, 1, 0};
3256 /* Offset to next interlace block */
3257 PNG_CONST
int png_pass_inc
[7] = {8, 8, 4, 4, 2, 2, 1};
3259 /* Start of interlace block in the y direction */
3260 PNG_CONST
int png_pass_ystart
[7] = {0, 0, 4, 0, 2, 0, 1};
3262 /* Offset to next interlace block in the y direction */
3263 PNG_CONST
int png_pass_yinc
[7] = {8, 8, 8, 4, 4, 2, 2};
3264 #endif /* PNG_READ_INTERLACING_SUPPORTED */
3266 png_debug(1, "in png_read_finish_row");
3267 png_ptr
->row_number
++;
3268 if (png_ptr
->row_number
< png_ptr
->num_rows
)
3271 #ifdef PNG_READ_INTERLACING_SUPPORTED
3272 if (png_ptr
->interlaced
)
3274 png_ptr
->row_number
= 0;
3276 png_memset(png_ptr
->prev_row
, 0, png_ptr
->rowbytes
+ 1);
3282 if (png_ptr
->pass
>= 7)
3285 png_ptr
->iwidth
= (png_ptr
->width
+
3286 png_pass_inc
[png_ptr
->pass
] - 1 -
3287 png_pass_start
[png_ptr
->pass
]) /
3288 png_pass_inc
[png_ptr
->pass
];
3290 if (!(png_ptr
->transformations
& PNG_INTERLACE
))
3292 png_ptr
->num_rows
= (png_ptr
->height
+
3293 png_pass_yinc
[png_ptr
->pass
] - 1 -
3294 png_pass_ystart
[png_ptr
->pass
]) /
3295 png_pass_yinc
[png_ptr
->pass
];
3298 else /* if (png_ptr->transformations & PNG_INTERLACE) */
3299 break; /* libpng deinterlacing sees every row */
3301 } while (png_ptr
->num_rows
== 0 || png_ptr
->iwidth
== 0);
3303 if (png_ptr
->pass
< 7)
3306 #endif /* PNG_READ_INTERLACING_SUPPORTED */
3308 if (!(png_ptr
->flags
& PNG_FLAG_ZLIB_FINISHED
))
3314 png_ptr
->zstream
.next_out
= (Byte
*)&extra
;
3315 png_ptr
->zstream
.avail_out
= (uInt
)1;
3319 if (!(png_ptr
->zstream
.avail_in
))
3321 while (!png_ptr
->idat_size
)
3323 png_crc_finish(png_ptr
, 0);
3324 png_ptr
->idat_size
= png_read_chunk_header(png_ptr
);
3325 if (png_memcmp(png_ptr
->chunk_name
, png_IDAT
, 4))
3326 png_error(png_ptr
, "Not enough image data");
3329 png_ptr
->zstream
.avail_in
= (uInt
)png_ptr
->zbuf_size
;
3330 png_ptr
->zstream
.next_in
= png_ptr
->zbuf
;
3332 if (png_ptr
->zbuf_size
> png_ptr
->idat_size
)
3333 png_ptr
->zstream
.avail_in
= (uInt
)png_ptr
->idat_size
;
3335 png_crc_read(png_ptr
, png_ptr
->zbuf
, png_ptr
->zstream
.avail_in
);
3336 png_ptr
->idat_size
-= png_ptr
->zstream
.avail_in
;
3339 ret
= inflate(&png_ptr
->zstream
, Z_PARTIAL_FLUSH
);
3341 if (ret
== Z_STREAM_END
)
3343 if (!(png_ptr
->zstream
.avail_out
) || png_ptr
->zstream
.avail_in
||
3345 png_warning(png_ptr
, "Extra compressed data");
3347 png_ptr
->mode
|= PNG_AFTER_IDAT
;
3348 png_ptr
->flags
|= PNG_FLAG_ZLIB_FINISHED
;
3353 png_error(png_ptr
, png_ptr
->zstream
.msg
? png_ptr
->zstream
.msg
:
3354 "Decompression Error");
3356 if (!(png_ptr
->zstream
.avail_out
))
3358 png_warning(png_ptr
, "Extra compressed data");
3359 png_ptr
->mode
|= PNG_AFTER_IDAT
;
3360 png_ptr
->flags
|= PNG_FLAG_ZLIB_FINISHED
;
3365 png_ptr
->zstream
.avail_out
= 0;
3368 if (png_ptr
->idat_size
|| png_ptr
->zstream
.avail_in
)
3369 png_warning(png_ptr
, "Extra compression data");
3371 inflateReset(&png_ptr
->zstream
);
3373 png_ptr
->mode
|= PNG_AFTER_IDAT
;
3375 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
3378 png_read_start_row(png_structp png_ptr
)
3380 #ifdef PNG_READ_INTERLACING_SUPPORTED
3381 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
3383 /* Start of interlace block */
3384 PNG_CONST
int png_pass_start
[7] = {0, 4, 0, 2, 0, 1, 0};
3386 /* Offset to next interlace block */
3387 PNG_CONST
int png_pass_inc
[7] = {8, 8, 4, 4, 2, 2, 1};
3389 /* Start of interlace block in the y direction */
3390 PNG_CONST
int png_pass_ystart
[7] = {0, 0, 4, 0, 2, 0, 1};
3392 /* Offset to next interlace block in the y direction */
3393 PNG_CONST
int png_pass_yinc
[7] = {8, 8, 8, 4, 4, 2, 2};
3396 int max_pixel_depth
;
3397 png_size_t row_bytes
;
3399 png_debug(1, "in png_read_start_row");
3400 png_ptr
->zstream
.avail_in
= 0;
3401 png_init_read_transformations(png_ptr
);
3402 #ifdef PNG_READ_INTERLACING_SUPPORTED
3403 if (png_ptr
->interlaced
)
3405 if (!(png_ptr
->transformations
& PNG_INTERLACE
))
3406 png_ptr
->num_rows
= (png_ptr
->height
+ png_pass_yinc
[0] - 1 -
3407 png_pass_ystart
[0]) / png_pass_yinc
[0];
3410 png_ptr
->num_rows
= png_ptr
->height
;
3412 png_ptr
->iwidth
= (png_ptr
->width
+
3413 png_pass_inc
[png_ptr
->pass
] - 1 -
3414 png_pass_start
[png_ptr
->pass
]) /
3415 png_pass_inc
[png_ptr
->pass
];
3419 #endif /* PNG_READ_INTERLACING_SUPPORTED */
3421 png_ptr
->num_rows
= png_ptr
->height
;
3422 png_ptr
->iwidth
= png_ptr
->width
;
3425 max_pixel_depth
= png_ptr
->pixel_depth
;
3427 #ifdef PNG_READ_PACK_SUPPORTED
3428 if ((png_ptr
->transformations
& PNG_PACK
) && png_ptr
->bit_depth
< 8)
3429 max_pixel_depth
= 8;
3432 #ifdef PNG_READ_EXPAND_SUPPORTED
3433 if (png_ptr
->transformations
& PNG_EXPAND
)
3435 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
3437 if (png_ptr
->num_trans
)
3438 max_pixel_depth
= 32;
3441 max_pixel_depth
= 24;
3444 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_GRAY
)
3446 if (max_pixel_depth
< 8)
3447 max_pixel_depth
= 8;
3449 if (png_ptr
->num_trans
)
3450 max_pixel_depth
*= 2;
3453 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_RGB
)
3455 if (png_ptr
->num_trans
)
3457 max_pixel_depth
*= 4;
3458 max_pixel_depth
/= 3;
3464 #ifdef PNG_READ_EXPAND_16_SUPPORTED
3465 if (png_ptr
->transformations
& PNG_EXPAND_16
)
3467 # ifdef PNG_READ_EXPAND_SUPPORTED
3468 /* In fact it is an error if it isn't supported, but checking is
3471 if (png_ptr
->transformations
& PNG_EXPAND
)
3473 if (png_ptr
->bit_depth
< 16)
3474 max_pixel_depth
*= 2;
3478 png_ptr
->transformations
&= ~PNG_EXPAND_16
;
3482 #ifdef PNG_READ_FILLER_SUPPORTED
3483 if (png_ptr
->transformations
& (PNG_FILLER
))
3485 if (png_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
3486 max_pixel_depth
= 32;
3488 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_GRAY
)
3490 if (max_pixel_depth
<= 8)
3491 max_pixel_depth
= 16;
3494 max_pixel_depth
= 32;
3497 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_RGB
)
3499 if (max_pixel_depth
<= 32)
3500 max_pixel_depth
= 32;
3503 max_pixel_depth
= 64;
3508 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3509 if (png_ptr
->transformations
& PNG_GRAY_TO_RGB
)
3512 #ifdef PNG_READ_EXPAND_SUPPORTED
3513 (png_ptr
->num_trans
&& (png_ptr
->transformations
& PNG_EXPAND
)) ||
3515 #ifdef PNG_READ_FILLER_SUPPORTED
3516 (png_ptr
->transformations
& (PNG_FILLER
)) ||
3518 png_ptr
->color_type
== PNG_COLOR_TYPE_GRAY_ALPHA
)
3520 if (max_pixel_depth
<= 16)
3521 max_pixel_depth
= 32;
3524 max_pixel_depth
= 64;
3529 if (max_pixel_depth
<= 8)
3531 if (png_ptr
->color_type
== PNG_COLOR_TYPE_RGB_ALPHA
)
3532 max_pixel_depth
= 32;
3535 max_pixel_depth
= 24;
3538 else if (png_ptr
->color_type
== PNG_COLOR_TYPE_RGB_ALPHA
)
3539 max_pixel_depth
= 64;
3542 max_pixel_depth
= 48;
3547 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
3548 defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
3549 if (png_ptr
->transformations
& PNG_USER_TRANSFORM
)
3551 int user_pixel_depth
= png_ptr
->user_transform_depth
*
3552 png_ptr
->user_transform_channels
;
3554 if (user_pixel_depth
> max_pixel_depth
)
3555 max_pixel_depth
=user_pixel_depth
;
3559 /* Align the width on the next larger 8 pixels. Mainly used
3562 row_bytes
= ((png_ptr
->width
+ 7) & ~((png_uint_32
)7));
3563 /* Calculate the maximum bytes needed, adding a byte and a pixel
3566 row_bytes
= PNG_ROWBYTES(max_pixel_depth
, row_bytes
) +
3567 1 + ((max_pixel_depth
+ 7) >> 3);
3569 #ifdef PNG_MAX_MALLOC_64K
3570 if (row_bytes
> (png_uint_32
)65536L)
3571 png_error(png_ptr
, "This image requires a row greater than 64KB");
3574 if (row_bytes
+ 48 > png_ptr
->old_big_row_buf_size
)
3576 png_free(png_ptr
, png_ptr
->big_row_buf
);
3578 if (png_ptr
->interlaced
)
3579 png_ptr
->big_row_buf
= (png_bytep
)png_calloc(png_ptr
,
3583 png_ptr
->big_row_buf
= (png_bytep
)png_malloc(png_ptr
,
3586 png_ptr
->old_big_row_buf_size
= row_bytes
+ 48;
3588 #ifdef PNG_ALIGNED_MEMORY_SUPPORTED
3589 /* Use 16-byte aligned memory for row_buf with at least 16 bytes
3590 * of padding before and after row_buf.
3592 png_ptr
->row_buf
= png_ptr
->big_row_buf
+ 32 -
3593 (((png_alloc_size_t
)png_ptr
->big_row_buf
+ 15) & 0x0F);
3595 png_ptr
->old_big_row_buf_size
= row_bytes
+ 48;
3597 /* Use 32 bytes of padding before and 16 bytes after row_buf. */
3598 png_ptr
->row_buf
= png_ptr
->big_row_buf
+ 32;
3600 png_ptr
->old_big_row_buf_size
= row_bytes
+ 48;
3603 #ifdef PNG_MAX_MALLOC_64K
3604 if (png_ptr
->rowbytes
> 65535)
3605 png_error(png_ptr
, "This image requires a row greater than 64KB");
3608 if (png_ptr
->rowbytes
> (PNG_SIZE_MAX
- 1))
3609 png_error(png_ptr
, "Row has too many bytes to allocate in memory");
3611 if (png_ptr
->rowbytes
+ 1 > png_ptr
->old_prev_row_size
)
3613 png_free(png_ptr
, png_ptr
->prev_row
);
3615 png_ptr
->prev_row
= (png_bytep
)png_malloc(png_ptr
, png_ptr
->rowbytes
+ 1);
3617 png_ptr
->old_prev_row_size
= png_ptr
->rowbytes
+ 1;
3620 png_memset(png_ptr
->prev_row
, 0, png_ptr
->rowbytes
+ 1);
3622 png_debug1(3, "width = %u,", png_ptr
->width
);
3623 png_debug1(3, "height = %u,", png_ptr
->height
);
3624 png_debug1(3, "iwidth = %u,", png_ptr
->iwidth
);
3625 png_debug1(3, "num_rows = %u,", png_ptr
->num_rows
);
3626 png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr
->rowbytes
);
3627 png_debug1(3, "irowbytes = %lu",
3628 (unsigned long)PNG_ROWBYTES(png_ptr
->pixel_depth
, png_ptr
->iwidth
) + 1);
3630 png_ptr
->flags
|= PNG_FLAG_ROW_INIT
;
3632 #endif /* PNG_READ_SUPPORTED */