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pngrutil.c
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/* pngrutil.c - utilities to read a PNG file
*
* Last changed in libpng 1.2.27 [April 29, 2008]
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2008 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
* This file contains routines that are only called from within
* libpng itself during the course of reading an image.
*/
#define PNG_INTERNAL
#include "png.h"
#if defined(PNG_READ_SUPPORTED)
#if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
# define WIN32_WCE_OLD
#endif
#ifdef PNG_FLOATING_POINT_SUPPORTED
# if defined(WIN32_WCE_OLD)
/* strtod() function is not supported on WindowsCE */
__inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **endptr)
{
double result = 0;
int len;
wchar_t *str, *end;
len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
str = (wchar_t *)png_malloc(png_ptr, len * sizeof(wchar_t));
if ( NULL != str )
{
MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
result = wcstod(str, &end);
len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
*endptr = (char *)nptr + (png_strlen(nptr) - len + 1);
png_free(png_ptr, str);
}
return result;
}
# else
# define png_strtod(p,a,b) strtod(a,b)
# endif
#endif
png_uint_32 PNGAPI
png_get_uint_31(png_structp png_ptr, png_bytep buf)
{
png_uint_32 i = png_get_uint_32(buf);
if (i > PNG_UINT_31_MAX)
png_error(png_ptr, "PNG unsigned integer out of range.");
return (i);
}
#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
png_uint_32 PNGAPI
png_get_uint_32(png_bytep buf)
{
png_uint_32 i = ((png_uint_32)(*buf) << 24) +
((png_uint_32)(*(buf + 1)) << 16) +
((png_uint_32)(*(buf + 2)) << 8) +
(png_uint_32)(*(buf + 3));
return (i);
}
/* Grab a signed 32-bit integer from a buffer in big-endian format. The
* data is stored in the PNG file in two's complement format, and it is
* assumed that the machine format for signed integers is the same. */
png_int_32 PNGAPI
png_get_int_32(png_bytep buf)
{
png_int_32 i = ((png_int_32)(*buf) << 24) +
((png_int_32)(*(buf + 1)) << 16) +
((png_int_32)(*(buf + 2)) << 8) +
(png_int_32)(*(buf + 3));
return (i);
}
/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
png_uint_16 PNGAPI
png_get_uint_16(png_bytep buf)
{
png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
(png_uint_16)(*(buf + 1)));
return (i);
}
#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
/* Read data, and (optionally) run it through the CRC. */
void /* PRIVATE */
png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
{
if(png_ptr == NULL) return;
png_read_data(png_ptr, buf, length);
png_calculate_crc(png_ptr, buf, length);
}
/* Optionally skip data and then check the CRC. Depending on whether we
are reading a ancillary or critical chunk, and how the program has set
things up, we may calculate the CRC on the data and print a message.
Returns '1' if there was a CRC error, '0' otherwise. */
int /* PRIVATE */
png_crc_finish(png_structp png_ptr, png_uint_32 skip)
{
png_size_t i;
png_size_t istop = png_ptr->zbuf_size;
for (i = (png_size_t)skip; i > istop; i -= istop)
{
png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
}
if (i)
{
png_crc_read(png_ptr, png_ptr->zbuf, i);
}
if (png_crc_error(png_ptr))
{
if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
(!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
{
png_chunk_warning(png_ptr, "CRC error");
}
else
{
png_chunk_error(png_ptr, "CRC error");
}
return (1);
}
return (0);
}
/* Compare the CRC stored in the PNG file with that calculated by libpng from
the data it has read thus far. */
int /* PRIVATE */
png_crc_error(png_structp png_ptr)
{
png_byte crc_bytes[4];
png_uint_32 crc;
int need_crc = 1;
if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
{
if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
need_crc = 0;
}
else /* critical */
{
if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
need_crc = 0;
}
png_read_data(png_ptr, crc_bytes, 4);
if (need_crc)
{
crc = png_get_uint_32(crc_bytes);
return ((int)(crc != png_ptr->crc));
}
else
return (0);
}
#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
defined(PNG_READ_iCCP_SUPPORTED)
/*
* Decompress trailing data in a chunk. The assumption is that chunkdata
* points at an allocated area holding the contents of a chunk with a
* trailing compressed part. What we get back is an allocated area
* holding the original prefix part and an uncompressed version of the
* trailing part (the malloc area passed in is freed).
*/
png_charp /* PRIVATE */
png_decompress_chunk(png_structp png_ptr, int comp_type,
png_charp chunkdata, png_size_t chunklength,
png_size_t prefix_size, png_size_t *newlength)
{
static PNG_CONST char msg[] = "Error decoding compressed text";
png_charp text;
png_size_t text_size;
if (comp_type == PNG_COMPRESSION_TYPE_BASE)
{
int ret = Z_OK;
png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size);
png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
text_size = 0;
text = NULL;
while (png_ptr->zstream.avail_in)
{
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END)
{
if (png_ptr->zstream.msg != NULL)
png_warning(png_ptr, png_ptr->zstream.msg);
else
png_warning(png_ptr, msg);
inflateReset(&png_ptr->zstream);
png_ptr->zstream.avail_in = 0;
if (text == NULL)
{
text_size = prefix_size + png_sizeof(msg) + 1;
text = (png_charp)png_malloc_warn(png_ptr, text_size);
if (text == NULL)
{
png_free(png_ptr,chunkdata);
png_error(png_ptr,"Not enough memory to decompress chunk");
}
png_memcpy(text, chunkdata, prefix_size);
}
text[text_size - 1] = 0x00;
/* Copy what we can of the error message into the text chunk */
text_size = (png_size_t)(chunklength - (text - chunkdata) - 1);
text_size = png_sizeof(msg) > text_size ? text_size :
png_sizeof(msg);
png_memcpy(text + prefix_size, msg, text_size);
break;
}
if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
{
if (text == NULL)
{
text_size = prefix_size +
png_ptr->zbuf_size - png_ptr->zstream.avail_out;
text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
if (text == NULL)
{
png_free(png_ptr,chunkdata);
png_error(png_ptr,"Not enough memory to decompress chunk.");
}
png_memcpy(text + prefix_size, png_ptr->zbuf,
text_size - prefix_size);
png_memcpy(text, chunkdata, prefix_size);
*(text + text_size) = 0x00;
}
else
{
png_charp tmp;
tmp = text;
text = (png_charp)png_malloc_warn(png_ptr,
(png_uint_32)(text_size +
png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
if (text == NULL)
{
png_free(png_ptr, tmp);
png_free(png_ptr, chunkdata);
png_error(png_ptr,"Not enough memory to decompress chunk..");
}
png_memcpy(text, tmp, text_size);
png_free(png_ptr, tmp);
png_memcpy(text + text_size, png_ptr->zbuf,
(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
*(text + text_size) = 0x00;
}
if (ret == Z_STREAM_END)
break;
else
{
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
}
}
}
if (ret != Z_STREAM_END)
{
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
char umsg[52];
if (ret == Z_BUF_ERROR)
png_snprintf(umsg, 52,
"Buffer error in compressed datastream in %s chunk",
png_ptr->chunk_name);
else if (ret == Z_DATA_ERROR)
png_snprintf(umsg, 52,
"Data error in compressed datastream in %s chunk",
png_ptr->chunk_name);
else
png_snprintf(umsg, 52,
"Incomplete compressed datastream in %s chunk",
png_ptr->chunk_name);
png_warning(png_ptr, umsg);
#else
png_warning(png_ptr,
"Incomplete compressed datastream in chunk other than IDAT");
#endif
text_size=prefix_size;
if (text == NULL)
{
text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
if (text == NULL)
{
png_free(png_ptr, chunkdata);
png_error(png_ptr,"Not enough memory for text.");
}
png_memcpy(text, chunkdata, prefix_size);
}
*(text + text_size) = 0x00;
}
inflateReset(&png_ptr->zstream);
png_ptr->zstream.avail_in = 0;
png_free(png_ptr, chunkdata);
chunkdata = text;
*newlength=text_size;
}
else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
{
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
char umsg[50];
png_snprintf(umsg, 50,
"Unknown zTXt compression type %d", comp_type);
png_warning(png_ptr, umsg);
#else
png_warning(png_ptr, "Unknown zTXt compression type");
#endif
*(chunkdata + prefix_size) = 0x00;
*newlength=prefix_size;
}
return chunkdata;
}
#endif
/* read and check the IDHR chunk */
void /* PRIVATE */
png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_byte buf[13];
png_uint_32 width, height;
int bit_depth, color_type, compression_type, filter_type;
int interlace_type;
png_debug(1, "in png_handle_IHDR\n");
if (png_ptr->mode & PNG_HAVE_IHDR)
png_error(png_ptr, "Out of place IHDR");
/* check the length */
if (length != 13)
png_error(png_ptr, "Invalid IHDR chunk");
png_ptr->mode |= PNG_HAVE_IHDR;
png_crc_read(png_ptr, buf, 13);
png_crc_finish(png_ptr, 0);
width = png_get_uint_31(png_ptr, buf);
height = png_get_uint_31(png_ptr, buf + 4);
bit_depth = buf[8];
color_type = buf[9];
compression_type = buf[10];
filter_type = buf[11];
interlace_type = buf[12];
/* set internal variables */
png_ptr->width = width;
png_ptr->height = height;
png_ptr->bit_depth = (png_byte)bit_depth;
png_ptr->interlaced = (png_byte)interlace_type;
png_ptr->color_type = (png_byte)color_type;
#if defined(PNG_MNG_FEATURES_SUPPORTED)
png_ptr->filter_type = (png_byte)filter_type;
#endif
png_ptr->compression_type = (png_byte)compression_type;
/* find number of channels */
switch (png_ptr->color_type)
{
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_PALETTE:
png_ptr->channels = 1;
break;
case PNG_COLOR_TYPE_RGB:
png_ptr->channels = 3;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
png_ptr->channels = 2;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
png_ptr->channels = 4;
break;
}
/* set up other useful info */
png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
png_ptr->channels);
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
png_debug1(3,"channels = %d\n", png_ptr->channels);
png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes);
png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
color_type, interlace_type, compression_type, filter_type);
}
/* read and check the palette */
void /* PRIVATE */
png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_color palette[PNG_MAX_PALETTE_LENGTH];
int num, i;
#ifndef PNG_NO_POINTER_INDEXING
png_colorp pal_ptr;
#endif
png_debug(1, "in png_handle_PLTE\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before PLTE");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid PLTE after IDAT");
png_crc_finish(png_ptr, length);
return;
}
else if (png_ptr->mode & PNG_HAVE_PLTE)
png_error(png_ptr, "Duplicate PLTE chunk");
png_ptr->mode |= PNG_HAVE_PLTE;
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
{
png_warning(png_ptr,
"Ignoring PLTE chunk in grayscale PNG");
png_crc_finish(png_ptr, length);
return;
}
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
{
png_crc_finish(png_ptr, length);
return;
}
#endif
if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
{
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
{
png_warning(png_ptr, "Invalid palette chunk");
png_crc_finish(png_ptr, length);
return;
}
else
{
png_error(png_ptr, "Invalid palette chunk");
}
}
num = (int)length / 3;
#ifndef PNG_NO_POINTER_INDEXING
for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
{
png_byte buf[3];
png_crc_read(png_ptr, buf, 3);
pal_ptr->red = buf[0];
pal_ptr->green = buf[1];
pal_ptr->blue = buf[2];
}
#else
for (i = 0; i < num; i++)
{
png_byte buf[3];
png_crc_read(png_ptr, buf, 3);
/* don't depend upon png_color being any order */
palette[i].red = buf[0];
palette[i].green = buf[1];
palette[i].blue = buf[2];
}
#endif
/* If we actually NEED the PLTE chunk (ie for a paletted image), we do
whatever the normal CRC configuration tells us. However, if we
have an RGB image, the PLTE can be considered ancillary, so
we will act as though it is. */
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
#endif
{
png_crc_finish(png_ptr, 0);
}
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
{
/* If we don't want to use the data from an ancillary chunk,
we have two options: an error abort, or a warning and we
ignore the data in this chunk (which should be OK, since
it's considered ancillary for a RGB or RGBA image). */
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
{
if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
{
png_chunk_error(png_ptr, "CRC error");
}
else
{
png_chunk_warning(png_ptr, "CRC error");
return;
}
}
/* Otherwise, we (optionally) emit a warning and use the chunk. */
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
{
png_chunk_warning(png_ptr, "CRC error");
}
}
#endif
png_set_PLTE(png_ptr, info_ptr, palette, num);
#if defined(PNG_READ_tRNS_SUPPORTED)
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
{
if (png_ptr->num_trans > (png_uint_16)num)
{
png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
png_ptr->num_trans = (png_uint_16)num;
}
if (info_ptr->num_trans > (png_uint_16)num)
{
png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
info_ptr->num_trans = (png_uint_16)num;
}
}
}
#endif
}
void /* PRIVATE */
png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_debug(1, "in png_handle_IEND\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
{
png_error(png_ptr, "No image in file");
}
png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
if (length != 0)
{
png_warning(png_ptr, "Incorrect IEND chunk length");
}
png_crc_finish(png_ptr, length);
info_ptr =info_ptr; /* quiet compiler warnings about unused info_ptr */
}
#if defined(PNG_READ_gAMA_SUPPORTED)
void /* PRIVATE */
png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_fixed_point igamma;
#ifdef PNG_FLOATING_POINT_SUPPORTED
float file_gamma;
#endif
png_byte buf[4];
png_debug(1, "in png_handle_gAMA\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before gAMA");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid gAMA after IDAT");
png_crc_finish(png_ptr, length);
return;
}
else if (png_ptr->mode & PNG_HAVE_PLTE)
/* Should be an error, but we can cope with it */
png_warning(png_ptr, "Out of place gAMA chunk");
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
#if defined(PNG_READ_sRGB_SUPPORTED)
&& !(info_ptr->valid & PNG_INFO_sRGB)
#endif
)
{
png_warning(png_ptr, "Duplicate gAMA chunk");
png_crc_finish(png_ptr, length);
return;
}
if (length != 4)
{
png_warning(png_ptr, "Incorrect gAMA chunk length");
png_crc_finish(png_ptr, length);
return;
}
png_crc_read(png_ptr, buf, 4);
if (png_crc_finish(png_ptr, 0))
return;
igamma = (png_fixed_point)png_get_uint_32(buf);
/* check for zero gamma */
if (igamma == 0)
{
png_warning(png_ptr,
"Ignoring gAMA chunk with gamma=0");
return;
}
#if defined(PNG_READ_sRGB_SUPPORTED)
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
{
png_warning(png_ptr,
"Ignoring incorrect gAMA value when sRGB is also present");
#ifndef PNG_NO_CONSOLE_IO
fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma);
#endif
return;
}
#endif /* PNG_READ_sRGB_SUPPORTED */
#ifdef PNG_FLOATING_POINT_SUPPORTED
file_gamma = (float)igamma / (float)100000.0;
# ifdef PNG_READ_GAMMA_SUPPORTED
png_ptr->gamma = file_gamma;
# endif
png_set_gAMA(png_ptr, info_ptr, file_gamma);
#endif
#ifdef PNG_FIXED_POINT_SUPPORTED
png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
#endif
}
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
void /* PRIVATE */
png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_size_t truelen;
png_byte buf[4];
png_debug(1, "in png_handle_sBIT\n");
buf[0] = buf[1] = buf[2] = buf[3] = 0;
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before sBIT");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid sBIT after IDAT");
png_crc_finish(png_ptr, length);
return;
}
else if (png_ptr->mode & PNG_HAVE_PLTE)
{
/* Should be an error, but we can cope with it */
png_warning(png_ptr, "Out of place sBIT chunk");
}
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
{
png_warning(png_ptr, "Duplicate sBIT chunk");
png_crc_finish(png_ptr, length);
return;
}
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
truelen = 3;
else
truelen = (png_size_t)png_ptr->channels;
if (length != truelen || length > 4)
{
png_warning(png_ptr, "Incorrect sBIT chunk length");
png_crc_finish(png_ptr, length);
return;
}
png_crc_read(png_ptr, buf, truelen);
if (png_crc_finish(png_ptr, 0))
return;
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
{
png_ptr->sig_bit.red = buf[0];
png_ptr->sig_bit.green = buf[1];
png_ptr->sig_bit.blue = buf[2];
png_ptr->sig_bit.alpha = buf[3];
}
else
{
png_ptr->sig_bit.gray = buf[0];
png_ptr->sig_bit.red = buf[0];
png_ptr->sig_bit.green = buf[0];
png_ptr->sig_bit.blue = buf[0];
png_ptr->sig_bit.alpha = buf[1];
}
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
}
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
void /* PRIVATE */
png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_byte buf[4];
#ifdef PNG_FLOATING_POINT_SUPPORTED
float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
#endif
png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
int_y_green, int_x_blue, int_y_blue;
png_uint_32 uint_x, uint_y;
png_debug(1, "in png_handle_cHRM\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before cHRM");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid cHRM after IDAT");
png_crc_finish(png_ptr, length);
return;
}
else if (png_ptr->mode & PNG_HAVE_PLTE)
/* Should be an error, but we can cope with it */
png_warning(png_ptr, "Missing PLTE before cHRM");
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
#if defined(PNG_READ_sRGB_SUPPORTED)
&& !(info_ptr->valid & PNG_INFO_sRGB)
#endif
)
{
png_warning(png_ptr, "Duplicate cHRM chunk");
png_crc_finish(png_ptr, length);
return;
}
if (length != 32)
{
png_warning(png_ptr, "Incorrect cHRM chunk length");
png_crc_finish(png_ptr, length);
return;
}
png_crc_read(png_ptr, buf, 4);
uint_x = png_get_uint_32(buf);
png_crc_read(png_ptr, buf, 4);
uint_y = png_get_uint_32(buf);
if (uint_x > 80000L || uint_y > 80000L ||
uint_x + uint_y > 100000L)
{
png_warning(png_ptr, "Invalid cHRM white point");
png_crc_finish(png_ptr, 24);
return;
}
int_x_white = (png_fixed_point)uint_x;
int_y_white = (png_fixed_point)uint_y;
png_crc_read(png_ptr, buf, 4);
uint_x = png_get_uint_32(buf);
png_crc_read(png_ptr, buf, 4);
uint_y = png_get_uint_32(buf);
if (uint_x + uint_y > 100000L)
{
png_warning(png_ptr, "Invalid cHRM red point");
png_crc_finish(png_ptr, 16);
return;
}
int_x_red = (png_fixed_point)uint_x;
int_y_red = (png_fixed_point)uint_y;
png_crc_read(png_ptr, buf, 4);
uint_x = png_get_uint_32(buf);
png_crc_read(png_ptr, buf, 4);
uint_y = png_get_uint_32(buf);
if (uint_x + uint_y > 100000L)
{
png_warning(png_ptr, "Invalid cHRM green point");
png_crc_finish(png_ptr, 8);
return;
}
int_x_green = (png_fixed_point)uint_x;
int_y_green = (png_fixed_point)uint_y;
png_crc_read(png_ptr, buf, 4);
uint_x = png_get_uint_32(buf);
png_crc_read(png_ptr, buf, 4);
uint_y = png_get_uint_32(buf);
if (uint_x + uint_y > 100000L)
{
png_warning(png_ptr, "Invalid cHRM blue point");
png_crc_finish(png_ptr, 0);
return;
}
int_x_blue = (png_fixed_point)uint_x;
int_y_blue = (png_fixed_point)uint_y;
#ifdef PNG_FLOATING_POINT_SUPPORTED
white_x = (float)int_x_white / (float)100000.0;
white_y = (float)int_y_white / (float)100000.0;
red_x = (float)int_x_red / (float)100000.0;
red_y = (float)int_y_red / (float)100000.0;
green_x = (float)int_x_green / (float)100000.0;
green_y = (float)int_y_green / (float)100000.0;
blue_x = (float)int_x_blue / (float)100000.0;
blue_y = (float)int_y_blue / (float)100000.0;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
{
if (PNG_OUT_OF_RANGE(int_x_white, 31270, 1000) ||
PNG_OUT_OF_RANGE(int_y_white, 32900, 1000) ||
PNG_OUT_OF_RANGE(int_x_red, 64000L, 1000) ||
PNG_OUT_OF_RANGE(int_y_red, 33000, 1000) ||
PNG_OUT_OF_RANGE(int_x_green, 30000, 1000) ||
PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
PNG_OUT_OF_RANGE(int_x_blue, 15000, 1000) ||
PNG_OUT_OF_RANGE(int_y_blue, 6000, 1000))
{
png_warning(png_ptr,
"Ignoring incorrect cHRM value when sRGB is also present");
#ifndef PNG_NO_CONSOLE_IO
#ifdef PNG_FLOATING_POINT_SUPPORTED
fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
white_x, white_y, red_x, red_y);
fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
green_x, green_y, blue_x, blue_y);
#else
fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
int_x_white, int_y_white, int_x_red, int_y_red);
fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
int_x_green, int_y_green, int_x_blue, int_y_blue);
#endif
#endif /* PNG_NO_CONSOLE_IO */
}
png_crc_finish(png_ptr, 0);
return;
}
#endif /* PNG_READ_sRGB_SUPPORTED */
#ifdef PNG_FLOATING_POINT_SUPPORTED
png_set_cHRM(png_ptr, info_ptr,
white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
#endif
#ifdef PNG_FIXED_POINT_SUPPORTED
png_set_cHRM_fixed(png_ptr, info_ptr,
int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
int_y_green, int_x_blue, int_y_blue);
#endif
if (png_crc_finish(png_ptr, 0))
return;
}
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
void /* PRIVATE */
png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
int intent;
png_byte buf[1];
png_debug(1, "in png_handle_sRGB\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before sRGB");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid sRGB after IDAT");
png_crc_finish(png_ptr, length);
return;
}
else if (png_ptr->mode & PNG_HAVE_PLTE)
/* Should be an error, but we can cope with it */
png_warning(png_ptr, "Out of place sRGB chunk");
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
{
png_warning(png_ptr, "Duplicate sRGB chunk");
png_crc_finish(png_ptr, length);
return;
}
if (length != 1)
{
png_warning(png_ptr, "Incorrect sRGB chunk length");
png_crc_finish(png_ptr, length);
return;
}
png_crc_read(png_ptr, buf, 1);
if (png_crc_finish(png_ptr, 0))
return;
intent = buf[0];
/* check for bad intent */
if (intent >= PNG_sRGB_INTENT_LAST)
{
png_warning(png_ptr, "Unknown sRGB intent");
return;
}
#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
{
png_fixed_point igamma;
#ifdef PNG_FIXED_POINT_SUPPORTED
igamma=info_ptr->int_gamma;
#else
# ifdef PNG_FLOATING_POINT_SUPPORTED
igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
# endif
#endif
if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
{
png_warning(png_ptr,
"Ignoring incorrect gAMA value when sRGB is also present");
#ifndef PNG_NO_CONSOLE_IO
# ifdef PNG_FIXED_POINT_SUPPORTED
fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma);
# else
# ifdef PNG_FLOATING_POINT_SUPPORTED
fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma);
# endif
# endif
#endif
}
}
#endif /* PNG_READ_gAMA_SUPPORTED */
#ifdef PNG_READ_cHRM_SUPPORTED
#ifdef PNG_FIXED_POINT_SUPPORTED
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_x_red, 64000L, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_y_red, 33000, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_x_blue, 15000, 1000) ||
PNG_OUT_OF_RANGE(info_ptr->int_y_blue, 6000, 1000))
{
png_warning(png_ptr,
"Ignoring incorrect cHRM value when sRGB is also present");
}
#endif /* PNG_FIXED_POINT_SUPPORTED */
#endif /* PNG_READ_cHRM_SUPPORTED */
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
}
#endif /* PNG_READ_sRGB_SUPPORTED */
#if defined(PNG_READ_iCCP_SUPPORTED)
void /* PRIVATE */
png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
/* Note: this does not properly handle chunks that are > 64K under DOS */
{
png_charp chunkdata;
png_byte compression_type;
png_bytep pC;
png_charp profile;
png_uint_32 skip = 0;
png_uint_32 profile_size, profile_length;
png_size_t slength, prefix_length, data_length;
png_debug(1, "in png_handle_iCCP\n");
if (!(png_ptr->mode & PNG_HAVE_IHDR))