/* pngrutil.c - utilities to read a PNG file
*
- * libpng 1.0.1
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 15, 1998
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 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 which are only called from within
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
* libpng itself during the course of reading an image.
*/
-#define PNG_INTERNAL
-#include "../png/png.h"
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#define png_strtod(p,a,b) strtod(a,b)
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range");
+
+ return (uval);
+}
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
+/* The following is a variation on the above for use with the fixed
+ * point values used for gAMA and cHRM. Instead of png_error it
+ * issues a warning and returns (-1) - an invalid value because both
+ * gAMA and cHRM use *unsigned* integers for fixed point values.
+ */
+#define PNG_FIXED_ERROR (-1)
+
+static png_fixed_point /* PRIVATE */
+png_get_fixed_point(png_structp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval <= PNG_UINT_31_MAX)
+ return (png_fixed_point)uval; /* known to be in range */
+
+ /* The caller can turn off the warning by passing NULL. */
+ if (png_ptr != NULL)
+ png_warning(png_ptr, "PNG fixed point integer out of range");
+
+ return PNG_FIXED_ERROR;
+}
+#endif
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+ png_uint_32 uval =
+ ((png_uint_32)(*(buf )) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ ((png_uint_32)(*(buf + 3)) ) ;
+
+ return uval;
+}
-#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
-/* Grab an unsigned 32-bit integer from a buffer in big endian format. */
-png_uint_32
-png_get_uint_32(png_bytep buf)
+/* 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 there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
{
- png_uint_32 i;
+ png_uint_32 uval = png_get_uint_32(buf);
+ if ((uval & 0x80000000) == 0) /* non-negative */
+ return uval;
+
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ return -(png_int_32)uval;
+}
- i = ((png_uint_32)(*buf) << 24) +
- ((png_uint_32)(*(buf + 1)) << 16) +
- ((png_uint_32)(*(buf + 2)) << 8) +
- (png_uint_32)(*(buf + 3));
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+ /* ANSI-C requires an int value to accomodate at least 16 bits so this
+ * works and allows the compiler not to worry about possible narrowing
+ * on 32 bit systems. (Pre-ANSI systems did not make integers smaller
+ * than 16 bits either.)
+ */
+ unsigned int val =
+ ((unsigned int)(*buf) << 8) +
+ ((unsigned int)(*(buf + 1)));
- return (i);
+ return (png_uint_16)val;
}
-#if defined(PNG_READ_pCAL_SUPPORTED)
-/* 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
-png_get_int_32(png_bytep buf)
+#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
+
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structp png_ptr, png_infop info_ptr)
{
- png_int_32 i;
+ png_size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
- i = ((png_int_32)(*buf) << 24) +
- ((png_int_32)(*(buf + 1)) << 16) +
- ((png_int_32)(*(buf + 2)) << 8) +
- (png_int_32)(*(buf + 3));
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
- return (i);
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
-#endif /* PNG_READ_pCAL_SUPPORTED */
-/* Grab an unsigned 16-bit integer from a buffer in big endian format. */
-png_uint_16
-png_get_uint_16(png_bytep buf)
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structp png_ptr)
{
- png_uint_16 i;
+ png_byte buf[8];
+ png_uint_32 length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Read the length and the chunk name.
+ * This must be performed in a single I/O call.
+ */
+ png_read_data(png_ptr, buf, 8);
+ length = png_get_uint_31(png_ptr, buf);
+
+ /* Put the chunk name into png_ptr->chunk_name. */
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+
+ png_debug2(0, "Reading %lx chunk, length = %lu",
+ (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+
+ /* Reset the crc and run it over the chunk name. */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+ /* Check to see if chunk name is valid. */
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
- i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
- (png_uint_16)(*(buf + 1)));
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
- return (i);
+ return length;
}
-#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
/* Read data, and (optionally) run it through the CRC. */
-void
+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
+ * 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_uint_32 i;
+ png_size_t i;
+ png_size_t istop = png_ptr->zbuf_size;
- for (i = skip; i > (png_uint_32)png_ptr->zbuf_size; i -= 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, (png_size_t)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))
+ if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ?
+ !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
{
png_chunk_warning(png_ptr, "CRC error");
}
+
else
{
- png_chunk_error(png_ptr, "CRC error");
+ png_chunk_benign_error(png_ptr, "CRC error");
+ return (0);
}
+
return (1);
}
}
/* Compare the CRC stored in the PNG file with that calculated by libpng from
- the data it has read thus far. */
-int
+ * 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_CHUNK_ANCILLIARY(png_ptr->chunk_name))
{
if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
need_crc = 0;
}
- else /* critical */
+
+ else /* critical */
{
if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
need_crc = 0;
}
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* The chunk CRC must be serialized in a single I/O call. */
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);
}
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+static png_size_t
+png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
+ png_bytep output, png_size_t output_size)
+{
+ png_size_t count = 0;
+
+ /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't
+ * even necessarily handle 65536 bytes) because the type uInt is "16 bits or
+ * more". Consequently it is necessary to chunk the input to zlib. This
+ * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value
+ * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a
+ * lower value in pngpriv.h and this may sometimes have a performance
+ * advantage, because it forces access of the input data to be separated from
+ * at least some of the use by some period of time.
+ */
+ png_ptr->zstream.next_in = data;
+ /* avail_in is set below from 'size' */
+ png_ptr->zstream.avail_in = 0;
+
+ while (1)
+ {
+ int ret, avail;
+
+ /* The setting of 'avail_in' used to be outside the loop; by setting it
+ * inside it is possible to chunk the input to zlib and simply rely on
+ * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o
+ * data to be passed through zlib at the unavoidable cost of requiring a
+ * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX
+ * input bytes.
+ */
+ if (png_ptr->zstream.avail_in == 0 && size > 0)
+ {
+ if (size <= ZLIB_IO_MAX)
+ {
+ /* The value is less than ZLIB_IO_MAX so the cast is safe: */
+ png_ptr->zstream.avail_in = (uInt)size;
+ size = 0;
+ }
+
+ else
+ {
+ png_ptr->zstream.avail_in = ZLIB_IO_MAX;
+ size -= ZLIB_IO_MAX;
+ }
+ }
+
+ /* Reset the output buffer each time round - we empty it
+ * after every inflate call.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+
+ ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
+ avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+
+ /* First copy/count any new output - but only if we didn't
+ * get an error code.
+ */
+ if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
+ {
+ png_size_t space = avail; /* > 0, see above */
+
+ if (output != 0 && output_size > count)
+ {
+ png_size_t copy = output_size - count;
+
+ if (space < copy)
+ copy = space;
+
+ png_memcpy(output + count, png_ptr->zbuf, copy);
+ }
+ count += space;
+ }
+
+ if (ret == Z_OK)
+ continue;
+
+ /* Termination conditions - always reset the zstream, it
+ * must be left in inflateInit state.
+ */
+ png_ptr->zstream.avail_in = 0;
+ inflateReset(&png_ptr->zstream);
+
+ if (ret == Z_STREAM_END)
+ return count; /* NOTE: may be zero. */
+
+ /* Now handle the error codes - the API always returns 0
+ * and the error message is dumped into the uncompressed
+ * buffer if available.
+ */
+# ifdef PNG_WARNINGS_SUPPORTED
+ {
+ png_const_charp msg;
+
+ if (png_ptr->zstream.msg != 0)
+ msg = png_ptr->zstream.msg;
+
+ else switch (ret)
+ {
+ case Z_BUF_ERROR:
+ msg = "Buffer error in compressed datastream";
+ break;
+
+ case Z_DATA_ERROR:
+ msg = "Data error in compressed datastream";
+ break;
+
+ default:
+ msg = "Incomplete compressed datastream";
+ break;
+ }
+
+ png_chunk_warning(png_ptr, msg);
+ }
+# endif
+
+ /* 0 means an error - notice that this code simply ignores
+ * zero length compressed chunks as a result.
+ */
+ return 0;
+ }
+}
+
+/*
+ * 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).
+ */
+void /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+ png_size_t chunklength,
+ png_size_t prefix_size, png_size_t *newlength)
+{
+ /* The caller should guarantee this */
+ if (prefix_size > chunklength)
+ {
+ /* The recovery is to delete the chunk. */
+ png_warning(png_ptr, "invalid chunklength");
+ prefix_size = 0; /* To delete everything */
+ }
+
+ else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_size_t expanded_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ 0, /* output */
+ 0); /* output size */
+
+ /* Now check the limits on this chunk - if the limit fails the
+ * compressed data will be removed, the prefix will remain.
+ */
+#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max &&
+ (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
+#else
+# ifdef PNG_USER_CHUNK_MALLOC_MAX
+ if ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
+ prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
+# endif
+#endif
+ png_warning(png_ptr, "Exceeded size limit while expanding chunk");
+
+ /* If the size is zero either there was an error and a message
+ * has already been output (warning) or the size really is zero
+ * and we have nothing to do - the code will exit through the
+ * error case below.
+ */
+#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
+ defined(PNG_USER_CHUNK_MALLOC_MAX)
+ else if (expanded_size > 0)
+#else
+ if (expanded_size > 0)
+#endif
+ {
+ /* Success (maybe) - really uncompress the chunk. */
+ png_size_t new_size = 0;
+ png_charp text = (png_charp)png_malloc_warn(png_ptr,
+ prefix_size + expanded_size + 1);
+
+ if (text != NULL)
+ {
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
+ new_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ (png_bytep)(text + prefix_size), expanded_size);
+ text[prefix_size + expanded_size] = 0; /* just in case */
+
+ if (new_size == expanded_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+ *newlength = prefix_size + expanded_size;
+ return; /* The success return! */
+ }
+
+ png_warning(png_ptr, "png_inflate logic error");
+ png_free(png_ptr, text);
+ }
+
+ else
+ png_warning(png_ptr, "Not enough memory to decompress chunk");
+ }
+ }
+
+ else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+ {
+ PNG_WARNING_PARAMETERS(p)
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
+ png_formatted_warning(png_ptr, p, "Unknown compression type @1");
+
+ /* The recovery is to simply drop the data. */
+ }
+
+ /* Generic error return - leave the prefix, delete the compressed
+ * data, reallocate the chunkdata to remove the potentially large
+ * amount of compressed data.
+ */
+ {
+ png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1);
+
+ if (text != NULL)
+ {
+ if (prefix_size > 0)
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
-/* read and check the IDHR chunk */
-void
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+
+ /* This is an extra zero in the 'uncompressed' part. */
+ *(png_ptr->chunkdata + prefix_size) = 0x00;
+ }
+ /* Ignore a malloc error here - it is safe. */
+ }
+
+ *newlength = prefix_size;
+}
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
+
+/* 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];
int bit_depth, color_type, compression_type, filter_type;
int interlace_type;
- png_debug(1, "in png_handle_IHDR\n");
+ png_debug(1, "in png_handle_IHDR");
- if (png_ptr->mode != PNG_BEFORE_IHDR)
+ if (png_ptr->mode & PNG_HAVE_IHDR)
png_error(png_ptr, "Out of place IHDR");
- /* check the length */
+ /* Check the length */
if (length != 13)
png_error(png_ptr, "Invalid IHDR chunk");
png_crc_read(png_ptr, buf, 13);
png_crc_finish(png_ptr, 0);
- width = png_get_uint_32(buf);
- height = png_get_uint_32(buf + 4);
+ 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];
- /* check for width and height valid values */
- if (width == 0 || width > (png_uint_32)2147483647L || height == 0 ||
- height > (png_uint_32)2147483647L)
- png_error(png_ptr, "Invalid image size in IHDR");
-
- /* check other values */
- if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
- bit_depth != 8 && bit_depth != 16)
- png_error(png_ptr, "Invalid bit depth in IHDR");
-
- if (color_type < 0 || color_type == 1 ||
- color_type == 5 || color_type > 6)
- png_error(png_ptr, "Invalid color type in IHDR");
-
- if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 ||
- ((color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
- png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
-
- if (interlace_type >= PNG_INTERLACE_LAST)
- png_error(png_ptr, "Unknown interlace method in IHDR");
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- png_error(png_ptr, "Unknown compression method in IHDR");
-
- if (filter_type != PNG_FILTER_TYPE_BASE)
- png_error(png_ptr, "Unknown filter method in IHDR");
-
- /* set internal variables */
+ /* 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;
+#ifdef 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 */
+ /* Find number of channels */
switch (png_ptr->color_type)
{
+ default: /* invalid, png_set_IHDR calls png_error */
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 */
+ /* Set up other useful info */
png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
png_ptr->channels);
- png_ptr->rowbytes = ((png_ptr->width *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3);
- png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
- png_debug1(3,"channels = %d\n", png_ptr->channels);
- png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+ png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+ png_debug1(3, "channels = %d", png_ptr->channels);
+ png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
- color_type, interlace_type, compression_type, filter_type);
+ color_type, interlace_type, compression_type, filter_type);
}
-/* read and check the palette */
-void
+/* Read and check the palette */
+void /* PRIVATE */
png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- png_colorp palette;
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
int num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ png_colorp pal_ptr;
+#endif
- png_debug(1, "in png_handle_PLTE\n");
+ png_debug(1, "in png_handle_PLTE");
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 defined (PNG_READ_tRNS_SUPPORTED)
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
{
- if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
- {
- if (png_ptr->num_trans > png_ptr->num_palette)
- {
- png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
- png_ptr->num_trans = png_ptr->num_palette;
- }
- }
+ png_warning(png_ptr,
+ "Ignoring PLTE chunk in grayscale PNG");
+ png_crc_finish(png_ptr, length);
+ return;
}
-#endif
-#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
{
png_crc_finish(png_ptr, length);
}
#endif
- if (length % 3)
+ if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
{
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
{
png_crc_finish(png_ptr, length);
return;
}
+
else
{
png_error(png_ptr, "Invalid palette chunk");
}
num = (int)length / 3;
- palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color));
- png_ptr->flags |= PNG_FLAG_FREE_PALETTE;
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ 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 */
+ /* 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 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.
+ */
+#ifndef 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)
+
+#ifndef 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). */
+ * 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");
+ png_chunk_benign_error(png_ptr, "CRC error");
}
+
else
{
png_chunk_warning(png_ptr, "CRC error");
- png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE;
- png_zfree(png_ptr, palette);
return;
}
}
+
/* Otherwise, we (optionally) emit a warning and use the chunk. */
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
{
}
}
#endif
- png_ptr->palette = palette;
- png_ptr->num_palette = (png_uint_16)num;
+
png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+#ifdef 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
+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");
+ png_debug(1, "in png_handle_IEND");
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
{
png_error(png_ptr, "No image in file");
-
- /* to quiet compiler warnings about unused info_ptr */
- if (info_ptr == NULL)
- return;
}
- png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND;
+ 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);
+
+ PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
}
-#if defined(PNG_READ_gAMA_SUPPORTED)
-void
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- png_uint_32 igamma;
- float file_gamma;
+ png_fixed_point igamma;
png_byte buf[4];
- png_debug(1, "in png_handle_gAMA\n");
+ png_debug(1, "in png_handle_gAMA");
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");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA
-#if defined(PNG_READ_sRGB_SUPPORTED)
- && !(info_ptr->valid & PNG_INFO_sRGB)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+#ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
#endif
- )
+ )
{
png_warning(png_ptr, "Duplicate gAMA chunk");
png_crc_finish(png_ptr, length);
}
png_crc_read(png_ptr, buf, 4);
+
if (png_crc_finish(png_ptr, 0))
return;
- igamma = png_get_uint_32(buf);
- /* check for zero gamma */
- if (igamma == 0)
+ igamma = png_get_fixed_point(NULL, buf);
+
+ /* Check for zero gamma or an error. */
+ if (igamma <= 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring gAMA chunk with out of range gamma");
+
return;
+ }
-#if defined(PNG_READ_sRGB_SUPPORTED)
- if (info_ptr->valid & PNG_INFO_sRGB)
- if(igamma != (png_uint_32)45000L)
+# ifdef PNG_READ_sRGB_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ if (PNG_OUT_OF_RANGE(igamma, 45500, 500))
{
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- fprintf(stderr, "igamma = %lu\n", igamma);
-#endif
+ PNG_WARNING_PARAMETERS(p)
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect gAMA value @1 when sRGB is also present");
return;
}
-#endif /* PNG_READ_sRGB_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 /* PNG_READ_sRGB_SUPPORTED */
+
+# ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Gamma correction on read is supported. */
+ png_ptr->gamma = igamma;
+# endif
+ /* And set the 'info' structure members. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
}
#endif
-#if defined(PNG_READ_sBIT_SUPPORTED)
-void
+#ifdef 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");
+ png_debug(1, "in png_handle_sBIT");
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");
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT)
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
{
png_warning(png_ptr, "Duplicate sBIT chunk");
png_crc_finish(png_ptr, length);
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
truelen = 3;
+
else
truelen = (png_size_t)png_ptr->channels;
- if (length != truelen)
+ if (length != truelen || length > 4)
{
png_warning(png_ptr, "Incorrect sBIT chunk length");
png_crc_finish(png_ptr, length);
}
png_crc_read(png_ptr, buf, truelen);
+
if (png_crc_finish(png_ptr, 0))
return;
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
+#ifdef 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];
- png_uint_32 val;
- float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+ png_byte buf[32];
+ png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue,
+ y_blue;
- png_debug(1, "in png_handle_cHRM\n");
+ png_debug(1, "in png_handle_cHRM");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sBIT");
+ 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");
+ png_warning(png_ptr, "Out of place cHRM chunk");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM
-#if defined(PNG_READ_sRGB_SUPPORTED)
- && !(info_ptr->valid & PNG_INFO_sRGB)
-#endif
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
+# ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+# endif
)
{
png_warning(png_ptr, "Duplicate cHRM chunk");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- white_x = (float)val / (float)100000.0;
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- white_y = (float)val / (float)100000.0;
+ png_crc_read(png_ptr, buf, 32);
- if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
- white_x + white_y > 1.0)
- {
- png_warning(png_ptr, "Invalid cHRM white point");
- png_crc_finish(png_ptr, 24);
+ if (png_crc_finish(png_ptr, 0))
return;
- }
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- red_x = (float)val / (float)100000.0;
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- red_y = (float)val / (float)100000.0;
- if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
- red_x + red_y > 1.0)
+ x_white = png_get_fixed_point(NULL, buf);
+ y_white = png_get_fixed_point(NULL, buf + 4);
+ x_red = png_get_fixed_point(NULL, buf + 8);
+ y_red = png_get_fixed_point(NULL, buf + 12);
+ x_green = png_get_fixed_point(NULL, buf + 16);
+ y_green = png_get_fixed_point(NULL, buf + 20);
+ x_blue = png_get_fixed_point(NULL, buf + 24);
+ y_blue = png_get_fixed_point(NULL, buf + 28);
+
+ if (x_white == PNG_FIXED_ERROR ||
+ y_white == PNG_FIXED_ERROR ||
+ x_red == PNG_FIXED_ERROR ||
+ y_red == PNG_FIXED_ERROR ||
+ x_green == PNG_FIXED_ERROR ||
+ y_green == PNG_FIXED_ERROR ||
+ x_blue == PNG_FIXED_ERROR ||
+ y_blue == PNG_FIXED_ERROR)
{
- png_warning(png_ptr, "Invalid cHRM red point");
- png_crc_finish(png_ptr, 16);
+ png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- green_x = (float)val / (float)100000.0;
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- green_y = (float)val / (float)100000.0;
-
- if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
- green_x + green_y > 1.0)
+#ifdef PNG_READ_sRGB_SUPPORTED
+ if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
{
- png_warning(png_ptr, "Invalid cHRM green point");
- png_crc_finish(png_ptr, 8);
+ if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(x_red, 64000, 1000) ||
+ PNG_OUT_OF_RANGE(y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(y_green, 60000, 1000) ||
+ PNG_OUT_OF_RANGE(x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(y_blue, 6000, 1000))
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
+ png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
+ png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
+ png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
+ png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
+ png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
+ png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
+ png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
+
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
+ "when sRGB is also present");
+ }
return;
}
+#endif /* PNG_READ_sRGB_SUPPORTED */
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- blue_x = (float)val / (float)100000.0;
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- blue_y = (float)val / (float)100000.0;
-
- if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 ||
- blue_y > (float)0.8 || blue_x + blue_y > (float)1.0)
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Store the _white values as default coefficients for the rgb to gray
+ * operation if it is supported. Check if the transform is already set to
+ * avoid destroying the transform values.
+ */
+ if (!png_ptr->rgb_to_gray_coefficients_set)
{
- png_warning(png_ptr, "Invalid cHRM blue point");
- png_crc_finish(png_ptr, 0);
- return;
- }
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
-#if defined(PNG_READ_sRGB_SUPPORTED)
- if (info_ptr->valid & PNG_INFO_sRGB)
+ /* png_set_background has not been called and we haven't seen an sRGB
+ * chunk yet. Find the XYZ of the three end points.
+ */
+ png_XYZ XYZ;
+ png_xy xy;
+
+ xy.redx = x_red;
+ xy.redy = y_red;
+ xy.greenx = x_green;
+ xy.greeny = y_green;
+ xy.bluex = x_blue;
+ xy.bluey = y_blue;
+ xy.whitex = x_white;
+ xy.whitey = y_white;
+
+ if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
{
- if (fabs(white_x - (float).3127) > (float).001 ||
- fabs(white_y - (float).3290) > (float).001 ||
- fabs( red_x - (float).6400) > (float).001 ||
- fabs( red_y - (float).3300) > (float).001 ||
- fabs(green_x - (float).3000) > (float).001 ||
- fabs(green_y - (float).6000) > (float).001 ||
- fabs( blue_x - (float).1500) > (float).001 ||
- fabs( blue_y - (float).0600) > (float).001)
+ /* The success case, because XYZ_from_xy normalises to a reference
+ * white Y of 1.0 we just need to scale the numbers. This should
+ * always work just fine. It is an internal error if this overflows.
+ */
{
+ png_fixed_point r, g, b;
+ if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) &&
+ r >= 0 && r <= 32768 &&
+ png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) &&
+ g >= 0 && g <= 32768 &&
+ png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) &&
+ b >= 0 && b <= 32768 &&
+ r+g+b <= 32769)
+ {
+ /* We allow 0 coefficients here. r+g+b may be 32769 if two or
+ * all of the coefficients were rounded up. Handle this by
+ * reducing the *largest* coefficient by 1; this matches the
+ * approach used for the default coefficients in pngrtran.c
+ */
+ int add = 0;
+
+ if (r+g+b > 32768)
+ add = -1;
+ else if (r+g+b < 32768)
+ add = 1;
+
+ if (add != 0)
+ {
+ if (g >= r && g >= b)
+ g += add;
+ else if (r >= g && r >= b)
+ r += add;
+ else
+ b += add;
+ }
- png_warning(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- 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);
-#endif
+ /* Check for an internal error. */
+ if (r+g+b != 32768)
+ png_error(png_ptr,
+ "internal error handling cHRM coefficients");
+
+ png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r;
+ png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+ }
+
+ /* This is a png_error at present even though it could be ignored -
+ * it should never happen, but it is important that if it does, the
+ * bug is fixed.
+ */
+ else
+ png_error(png_ptr, "internal error handling cHRM->XYZ");
}
- return;
}
-#endif /* PNG_READ_sRGB_SUPPORTED */
+ }
+#endif
- png_set_cHRM(png_ptr, info_ptr,
- white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+ png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
+ x_green, y_green, x_blue, y_blue);
}
#endif
-#if defined(PNG_READ_sRGB_SUPPORTED)
-void
+#ifdef 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");
+ png_debug(1, "in png_handle_sRGB");
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");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
{
png_warning(png_ptr, "Duplicate sRGB chunk");
png_crc_finish(png_ptr, length);
}
png_crc_read(png_ptr, buf, 1);
+
if (png_crc_finish(png_ptr, 0))
return;
intent = buf[0];
- /* check for bad intent */
+
+ /* Check for bad intent */
if (intent >= PNG_sRGB_INTENT_LAST)
{
png_warning(png_ptr, "Unknown sRGB intent");
}
#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
- if ((info_ptr->valid & PNG_INFO_gAMA))
- if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+ {
+ if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500))
{
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
-#endif
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
+ info_ptr->gamma);
+
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect gAMA value @1 when sRGB is also present");
}
+ }
#endif /* PNG_READ_gAMA_SUPPORTED */
#ifdef PNG_READ_cHRM_SUPPORTED
- if (info_ptr->valid & PNG_INFO_cHRM)
- if (fabs(info_ptr->x_white - (float).3127) > (float).001 ||
- fabs(info_ptr->y_white - (float).3290) > (float).001 ||
- fabs( info_ptr->x_red - (float).6400) > (float).001 ||
- fabs( info_ptr->y_red - (float).3300) > (float).001 ||
- fabs(info_ptr->x_green - (float).3000) > (float).001 ||
- fabs(info_ptr->y_green - (float).6000) > (float).001 ||
- fabs( info_ptr->x_blue - (float).1500) > (float).001 ||
- fabs( info_ptr->y_blue - (float).0600) > (float).001)
- {
- png_warning(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
- }
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_red, 64000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_green, 60000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+ }
#endif /* PNG_READ_cHRM_SUPPORTED */
+ /* This is recorded for use when handling the cHRM chunk above. An sRGB
+ * chunk unconditionally overwrites the coefficients for grayscale conversion
+ * too.
+ */
+ png_ptr->is_sRGB = 1;
+
+# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Don't overwrite user supplied values: */
+ if (!png_ptr->rgb_to_gray_coefficients_set)
+ {
+ /* These numbers come from the sRGB specification (or, since one has to
+ * pay much money to get a copy, the wikipedia sRGB page) the
+ * chromaticity values quoted have been inverted to get the reverse
+ * transformation from RGB to XYZ and the 'Y' coefficients scaled by
+ * 32768 (then rounded).
+ *
+ * sRGB and ITU Rec-709 both truncate the values for the D65 white
+ * point to four digits and, even though it actually stores five
+ * digits, the PNG spec gives the truncated value.
+ *
+ * This means that when the chromaticities are converted back to XYZ
+ * end points we end up with (6968,23435,2366), which, as described in
+ * pngrtran.c, would overflow. If the five digit precision and up is
+ * used we get, instead:
+ *
+ * 6968*R + 23435*G + 2365*B
+ *
+ * (Notice that this rounds the blue coefficient down, rather than the
+ * choice used in pngrtran.c which is to round the green one down.)
+ */
+ png_ptr->rgb_to_gray_red_coeff = 6968; /* 0.212639005871510 */
+ png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */
+ /* png_ptr->rgb_to_gray_blue_coeff = 2366; 0.072192315360734 */
+
+ /* The following keeps the cHRM chunk from destroying the
+ * coefficients again in the event that it follows the sRGB chunk.
+ */
+ png_ptr->rgb_to_gray_coefficients_set = 1;
+ }
+# endif
+
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
}
#endif /* PNG_READ_sRGB_SUPPORTED */
-#if defined(PNG_READ_tRNS_SUPPORTED)
-void
+#ifdef 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_byte compression_type;
+ png_bytep pC;
+ png_charp profile;
+ png_uint_32 skip = 0;
+ png_uint_32 profile_size;
+ png_alloc_size_t profile_length;
+ png_size_t slength, prefix_length, data_length;
+
+ png_debug(1, "in png_handle_iCCP");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iCCP");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid iCCP 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 iCCP chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+ {
+ png_warning(png_ptr, "Duplicate iCCP chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (profile = png_ptr->chunkdata; *profile; profile++)
+ /* Empty loop to find end of name */ ;
+
+ ++profile;
+
+ /* There should be at least one zero (the compression type byte)
+ * following the separator, and we should be on it
+ */
+ if (profile >= png_ptr->chunkdata + slength - 1)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Malformed iCCP chunk");
+ return;
+ }
+
+ /* Compression_type should always be zero */
+ compression_type = *profile++;
+
+ if (compression_type)
+ {
+ png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+ compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
+ wrote nonzero) */
+ }
+
+ prefix_length = profile - png_ptr->chunkdata;
+ png_decompress_chunk(png_ptr, compression_type,
+ slength, prefix_length, &data_length);
+
+ profile_length = data_length - prefix_length;
+
+ if (prefix_length > data_length || profile_length < 4)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+ return;
+ }
+
+ /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+ pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
+ profile_size = ((*(pC )) << 24) |
+ ((*(pC + 1)) << 16) |
+ ((*(pC + 2)) << 8) |
+ ((*(pC + 3)) );
+
+ /* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
+ * because profile_size is a 32 bit value.
+ */
+ if (profile_size < profile_length)
+ profile_length = profile_size;
+
+ /* And the following guarantees that profile_size == profile_length. */
+ if (profile_size > profile_length)
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
+ png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
+ png_formatted_warning(png_ptr, p,
+ "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
+ return;
+ }
+
+ png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
+ compression_type, (png_bytep)png_ptr->chunkdata + prefix_length,
+ profile_size);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(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_bytep entry_start;
+ png_sPLT_t new_palette;
+ png_sPLT_entryp pp;
+ png_uint_32 data_length;
+ int entry_size, i;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+ png_uint_32 dl;
+ png_size_t max_dl;
+
+ png_debug(1, "in png_handle_sPLT");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for sPLT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sPLT");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sPLT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+
+ /* WARNING: this may break if size_t is less than 32 bits; it is assumed
+ * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
+ * potential breakage point if the types in pngconf.h aren't exactly right.
+ */
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start;
+ entry_start++)
+ /* Empty loop to find end of name */ ;
+
+ ++entry_start;
+
+ /* A sample depth should follow the separator, and we should be on it */
+ if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "malformed sPLT chunk");
+ return;
+ }
+
+ new_palette.depth = *entry_start++;
+ entry_size = (new_palette.depth == 8 ? 6 : 10);
+ /* This must fit in a png_uint_32 because it is derived from the original
+ * chunk data length (and use 'length', not 'slength' here for clarity -
+ * they are guaranteed to be the same, see the tests above.)
+ */
+ data_length = length - (png_uint_32)(entry_start -
+ (png_bytep)png_ptr->chunkdata);
+
+ /* Integrity-check the data length */
+ if (data_length % entry_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return;
+ }
+
+ dl = (png_int_32)(data_length / entry_size);
+ max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry);
+
+ if (dl > max_dl)
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return;
+ }
+
+ new_palette.nentries = (png_int_32)(data_length / entry_size);
+
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+ png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return;
+ }
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
+ {
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#else
+ pp = new_palette.entries;
+
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+
+ if (new_palette.depth == 8)
+ {
+ pp[i].red = *entry_start++;
+ pp[i].green = *entry_start++;
+ pp[i].blue = *entry_start++;
+ pp[i].alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#endif
+
+ /* Discard all chunk data except the name and stash that */
+ new_palette.name = png_ptr->chunkdata;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- png_debug(1, "in png_handle_tRNS\n");
+ png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_tRNS");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before tRNS");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid tRNS after IDAT");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
{
png_warning(png_ptr, "Duplicate tRNS chunk");
png_crc_finish(png_ptr, length);
return;
}
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
- if (!(png_ptr->mode & PNG_HAVE_PLTE))
- {
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Missing PLTE before tRNS");
- }
- else if (length > png_ptr->num_palette)
+ png_byte buf[2];
+
+ if (length != 2)
{
png_warning(png_ptr, "Incorrect tRNS chunk length");
png_crc_finish(png_ptr, length);
return;
}
- png_ptr->trans = (png_bytep)png_malloc(png_ptr, length);
- png_ptr->flags |= PNG_FLAG_FREE_TRANS;
- png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length);
- png_ptr->num_trans = (png_uint_16)length;
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.gray = png_get_uint_16(buf);
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
{
png_byte buf[6];
png_crc_read(png_ptr, buf, (png_size_t)length);
png_ptr->num_trans = 1;
- png_ptr->trans_values.red = png_get_uint_16(buf);
- png_ptr->trans_values.green = png_get_uint_16(buf + 2);
- png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
+ png_ptr->trans_color.red = png_get_uint_16(buf);
+ png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
}
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_byte buf[6];
+ if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ /* Should be an error, but we can cope with it. */
+ png_warning(png_ptr, "Missing PLTE before tRNS");
+ }
- if (length != 2)
+ if (length > (png_uint_32)png_ptr->num_palette ||
+ length > PNG_MAX_PALETTE_LENGTH)
{
png_warning(png_ptr, "Incorrect tRNS chunk length");
png_crc_finish(png_ptr, length);
return;
}
- png_crc_read(png_ptr, buf, 2);
- png_ptr->num_trans = 1;
- png_ptr->trans_values.gray = png_get_uint_16(buf);
+ if (length == 0)
+ {
+ png_warning(png_ptr, "Zero length tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, readbuf, (png_size_t)length);
+ png_ptr->num_trans = (png_uint_16)length;
}
+
else
{
png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
}
if (png_crc_finish(png_ptr, 0))
+ {
+ png_ptr->num_trans = 0;
return;
+ }
- png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans,
- &(png_ptr->trans_values));
+ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+ &(png_ptr->trans_color));
}
#endif
-#if defined(PNG_READ_bKGD_SUPPORTED)
-void
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_size_t truelen;
png_byte buf[6];
+ png_color_16 background;
- png_debug(1, "in png_handle_bKGD\n");
+ png_debug(1, "in png_handle_bKGD");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before bKGD");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid bKGD after IDAT");
png_crc_finish(png_ptr, length);
return;
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
+ !(png_ptr->mode & PNG_HAVE_PLTE))
{
png_warning(png_ptr, "Missing PLTE before bKGD");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_bKGD)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
{
png_warning(png_ptr, "Duplicate bKGD chunk");
png_crc_finish(png_ptr, length);
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
truelen = 1;
+
else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
truelen = 6;
+
else
truelen = 2;
}
png_crc_read(png_ptr, buf, truelen);
+
if (png_crc_finish(png_ptr, 0))
return;
/* We convert the index value into RGB components so that we can allow
* arbitrary RGB values for background when we have transparency, and
* so it is easy to determine the RGB values of the background color
- * from the info_ptr struct. */
+ * from the info_ptr struct.
+ */
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_ptr->background.index = buf[0];
- png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
- png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
- png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+ background.index = buf[0];
+
+ if (info_ptr && info_ptr->num_palette)
+ {
+ if (buf[0] >= info_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Incorrect bKGD chunk index value");
+ return;
+ }
+
+ background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+ background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+ background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+
+ else
+ background.red = background.green = background.blue = 0;
+
+ background.gray = 0;
}
+
else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
{
- png_ptr->background.red =
- png_ptr->background.green =
- png_ptr->background.blue =
- png_ptr->background.gray = png_get_uint_16(buf);
+ background.index = 0;
+ background.red =
+ background.green =
+ background.blue =
+ background.gray = png_get_uint_16(buf);
}
+
else
{
- png_ptr->background.red = png_get_uint_16(buf);
- png_ptr->background.green = png_get_uint_16(buf + 2);
- png_ptr->background.blue = png_get_uint_16(buf + 4);
+ background.index = 0;
+ background.red = png_get_uint_16(buf);
+ background.green = png_get_uint_16(buf + 2);
+ background.blue = png_get_uint_16(buf + 4);
+ background.gray = 0;
}
- png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+ png_set_bKGD(png_ptr, info_ptr, &background);
}
#endif
-#if defined(PNG_READ_hIST_SUPPORTED)
-void
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- int num, i;
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
- png_debug(1, "in png_handle_hIST\n");
+ png_debug(1, "in png_handle_hIST");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before hIST");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid hIST after IDAT");
png_crc_finish(png_ptr, length);
return;
}
+
else if (!(png_ptr->mode & PNG_HAVE_PLTE))
{
png_warning(png_ptr, "Missing PLTE before hIST");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_hIST)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
{
png_warning(png_ptr, "Duplicate hIST chunk");
png_crc_finish(png_ptr, length);
return;
}
- if (length != (png_uint_32)(2 * png_ptr->num_palette))
+ num = length / 2 ;
+
+ if (num != (unsigned int)png_ptr->num_palette || num >
+ (unsigned int)PNG_MAX_PALETTE_LENGTH)
{
png_warning(png_ptr, "Incorrect hIST chunk length");
png_crc_finish(png_ptr, length);
return;
}
- num = (int)length / 2;
- png_ptr->hist = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(num * sizeof (png_uint_16)));
- png_ptr->flags |= PNG_FLAG_FREE_HIST;
for (i = 0; i < num; i++)
{
png_byte buf[2];
png_crc_read(png_ptr, buf, 2);
- png_ptr->hist[i] = png_get_uint_16(buf);
+ readbuf[i] = png_get_uint_16(buf);
}
if (png_crc_finish(png_ptr, 0))
return;
- png_set_hIST(png_ptr, info_ptr, png_ptr->hist);
+ png_set_hIST(png_ptr, info_ptr, readbuf);
}
#endif
-#if defined(PNG_READ_pHYs_SUPPORTED)
-void
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_byte buf[9];
png_uint_32 res_x, res_y;
int unit_type;
- png_debug(1, "in png_handle_pHYs\n");
+ png_debug(1, "in png_handle_pHYs");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before pHYS");
+ png_error(png_ptr, "Missing IHDR before pHYs");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid pHYS after IDAT");
+ png_warning(png_ptr, "Invalid pHYs after IDAT");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
{
- png_warning(png_ptr, "Duplicate pHYS chunk");
+ png_warning(png_ptr, "Duplicate pHYs chunk");
png_crc_finish(png_ptr, length);
return;
}
}
png_crc_read(png_ptr, buf, 9);
+
if (png_crc_finish(png_ptr, 0))
return;
}
#endif
-#if defined(PNG_READ_oFFs_SUPPORTED)
-void
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_byte buf[9];
- png_uint_32 offset_x, offset_y;
+ png_int_32 offset_x, offset_y;
int unit_type;
- png_debug(1, "in png_handle_oFFs\n");
+ png_debug(1, "in png_handle_oFFs");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before oFFs");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid oFFs after IDAT");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_oFFs)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
{
png_warning(png_ptr, "Duplicate oFFs chunk");
png_crc_finish(png_ptr, length);
}
png_crc_read(png_ptr, buf, 9);
+
if (png_crc_finish(png_ptr, 0))
return;
- offset_x = png_get_uint_32(buf);
- offset_y = png_get_uint_32(buf + 4);
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
unit_type = buf[8];
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
}
#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-/* read the pCAL chunk (png-scivis-19970203) */
-void
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- png_charp purpose;
png_int_32 X0, X1;
png_byte type, nparams;
png_charp buf, units, endptr;
png_size_t slength;
int i;
- png_debug(1, "in png_handle_pCAL\n");
+ png_debug(1, "in png_handle_pCAL");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before pCAL");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
png_warning(png_ptr, "Invalid pCAL after IDAT");
png_crc_finish(png_ptr, length);
return;
}
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
{
png_warning(png_ptr, "Duplicate pCAL chunk");
png_crc_finish(png_ptr, length);
return;
}
- png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n",
- length + 1);
- purpose = (png_charp)png_malloc(png_ptr, length + 1);
+ png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+ length + 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory for pCAL purpose");
+ return;
+ }
+
slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)purpose, slength);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, 0))
{
- png_free(png_ptr, purpose);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
return;
}
- purpose[slength] = 0x00; /* null terminate the last string */
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
- png_debug(3, "Finding end of pCAL purpose string\n");
- for (buf = purpose; *buf != '\0'; buf++)
- /* empty loop */ ;
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = png_ptr->chunkdata; *buf; buf++)
+ /* Empty loop */ ;
- endptr = purpose + slength;
+ endptr = png_ptr->chunkdata + slength;
/* We need to have at least 12 bytes after the purpose string
- in order to get the parameter information. */
+ * in order to get the parameter information.
+ */
if (endptr <= buf + 12)
{
png_warning(png_ptr, "Invalid pCAL data");
- png_free(png_ptr, purpose);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
return;
}
- png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
X0 = png_get_int_32((png_bytep)buf+1);
X1 = png_get_int_32((png_bytep)buf+5);
type = buf[9];
nparams = buf[10];
units = buf + 11;
- png_debug(3, "Checking pCAL equation type and number of parameters\n");
+ png_debug(3, "Checking pCAL equation type and number of parameters");
/* Check that we have the right number of parameters for known
- equation types. */
+ * equation types.
+ */
if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
(type == PNG_EQUATION_BASE_E && nparams != 3) ||
(type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
(type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
{
png_warning(png_ptr, "Invalid pCAL parameters for equation type");
- png_free(png_ptr, purpose);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
return;
}
+
else if (type >= PNG_EQUATION_LAST)
{
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
}
- for (buf = units; *buf != 0x00; buf++)
+ for (buf = units; *buf; buf++)
/* Empty loop to move past the units string. */ ;
- png_debug(3, "Allocating pCAL parameters array\n");
- params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams
- *sizeof(png_charp))) ;
+ png_debug(3, "Allocating pCAL parameters array");
+
+ params = (png_charpp)png_malloc_warn(png_ptr,
+ (png_size_t)(nparams * png_sizeof(png_charp)));
+
+ if (params == NULL)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "No memory for pCAL params");
+ return;
+ }
/* Get pointers to the start of each parameter string. */
for (i = 0; i < (int)nparams; i++)
{
buf++; /* Skip the null string terminator from previous parameter. */
- png_debug1(3, "Reading pCAL parameter %d\n", i);
- for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
+ png_debug1(3, "Reading pCAL parameter %d", i);
+
+ for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
/* Empty loop to move past each parameter string */ ;
/* Make sure we haven't run out of data yet */
if (buf > endptr)
{
png_warning(png_ptr, "Invalid pCAL data");
- png_free(png_ptr, purpose);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
png_free(png_ptr, params);
return;
}
}
- png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
+ png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
units, params);
- png_free(png_ptr, purpose);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
png_free(png_ptr, params);
}
#endif
-#if defined(PNG_READ_tIME_SUPPORTED)
-void
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t slength, i;
+ int state;
+
+ png_debug(1, "in png_handle_sCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sCAL");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ png_warning(png_ptr, "Duplicate sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ /* Need unit type, width, \0, height: minimum 4 bytes */
+ else if (length < 4)
+ {
+ png_warning(png_ptr, "sCAL chunk too short");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+ length + 1);
+
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ /* Validate the unit. */
+ if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2)
+ {
+ png_warning(png_ptr, "Invalid sCAL ignored: invalid unit");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ /* Validate the ASCII numbers, need two ASCII numbers separated by
+ * a '\0' and they need to fit exactly in the chunk data.
+ */
+ i = 1;
+ state = 0;
+
+ if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+ i >= slength || png_ptr->chunkdata[i++] != 0)
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
+
+ else if (!PNG_FP_IS_POSITIVE(state))
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+
+ else
+ {
+ png_size_t heighti = i;
+
+ state = 0;
+ if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+ i != slength)
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
+
+ else if (!PNG_FP_IS_POSITIVE(state))
+ png_warning(png_ptr,
+ "Invalid sCAL chunk ignored: non-positive height");
+
+ else
+ /* This is the (only) success case. */
+ png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
+ png_ptr->chunkdata+1, png_ptr->chunkdata+heighti);
+ }
+
+ /* Clean up - just free the temporarily allocated buffer. */
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_byte buf[7];
png_time mod_time;
- png_debug(1, "in png_handle_tIME\n");
+ png_debug(1, "in png_handle_tIME");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Out of place tIME chunk");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME)
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
{
png_warning(png_ptr, "Duplicate tIME chunk");
png_crc_finish(png_ptr, length);
}
png_crc_read(png_ptr, buf, 7);
+
if (png_crc_finish(png_ptr, 0))
return;
}
#endif
-#if defined(PNG_READ_tEXt_SUPPORTED)
+#ifdef PNG_READ_tEXt_SUPPORTED
/* Note: this does not properly handle chunks that are > 64K under DOS */
-void
+void /* PRIVATE */
png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
png_textp text_ptr;
png_charp text;
png_uint_32 skip = 0;
png_size_t slength;
+ int ret;
+
+ png_debug(1, "in png_handle_tEXt");
- png_debug(1, "in png_handle_tEXt\n");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for tEXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before tEXt");
}
#endif
- key = (png_charp)png_malloc(png_ptr, length + 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process text chunk");
+ return;
+ }
+
slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)key, slength);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, skip))
{
- png_free(png_ptr, key);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
return;
}
+ key = png_ptr->chunkdata;
+
key[slength] = 0x00;
for (text = key; *text; text++)
- /* empty loop to find end of key */ ;
+ /* Empty loop to find end of key */ ;
if (text != key + slength)
text++;
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process text chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
text_ptr->key = key;
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
text_ptr->text = text;
+ text_ptr->text_length = png_strlen(text);
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
png_free(png_ptr, text_ptr);
+
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to process text chunk");
}
#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
-/* note: this does not correctly handle chunks that are > 64K under DOS */
-void
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- static char msg[] = "Error decoding zTXt chunk";
png_textp text_ptr;
- png_charp key;
png_charp text;
- int comp_type = PNG_TEXT_COMPRESSION_NONE;
- png_size_t slength;
+ int comp_type;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
- png_debug(1, "in png_handle_zTXt\n");
+ png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for zTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before zTXt");
#ifdef PNG_MAX_MALLOC_64K
/* We will no doubt have problems with chunks even half this size, but
- there is no hard and fast rule to tell us where to stop. */
+ * there is no hard and fast rule to tell us where to stop.
+ */
if (length > (png_uint_32)65535L)
{
- png_warning(png_ptr,"zTXt chunk too large to fit in memory");
- png_crc_finish(png_ptr, length);
- return;
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
}
#endif
- key = (png_charp)png_malloc(png_ptr, length + 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory processing zTXt chunk");
+ return;
+ }
+
slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)key, slength);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
if (png_crc_finish(png_ptr, 0))
{
- png_free(png_ptr, key);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
return;
}
- key[slength] = 0x00;
+ png_ptr->chunkdata[slength] = 0x00;
- for (text = key; *text; text++)
- /* empty loop */ ;
+ for (text = png_ptr->chunkdata; *text; text++)
+ /* Empty loop */ ;
- /* zTXt must have some text after the keyword */
- if (text == key + slength)
+ /* zTXt must have some text after the chunkdataword */
+ if (text >= png_ptr->chunkdata + slength - 2)
{
- png_warning(png_ptr, "Zero length zTXt chunk");
+ png_warning(png_ptr, "Truncated zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
}
- else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt)
+
+ else
{
- png_size_t text_size, key_size;
- text++;
+ comp_type = *(++text);
- png_ptr->zstream.next_in = (png_bytep)text;
- png_ptr->zstream.avail_in = (uInt)(length - (text - key));
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+ {
+ png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+ comp_type = PNG_TEXT_COMPRESSION_zTXt;
+ }
- key_size = (png_size_t)(text - key);
- text_size = 0;
- text = NULL;
+ text++; /* Skip the compression_method byte */
+ }
- while (png_ptr->zstream.avail_in)
- {
- int ret;
+ prefix_len = text - png_ptr->chunkdata;
- 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;
+ png_decompress_chunk(png_ptr, comp_type,
+ (png_size_t)length, prefix_len, &data_len);
- if (text == NULL)
- {
- text_size = key_size + sizeof(msg) + 1;
- text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size);
- png_memcpy(text, key, key_size);
- }
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
- text[text_size - 1] = 0x00;
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
- /* Copy what we can of the error message into the text chunk */
- text_size = (png_size_t)(slength - (text - key) - 1);
- text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
- png_memcpy(text + key_size, msg, text_size + 1);
- break;
- }
- if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
- {
- if (text == NULL)
- {
- text = (png_charp)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
- + key_size + 1));
- png_memcpy(text + key_size, png_ptr->zbuf,
- png_ptr->zbuf_size - png_ptr->zstream.avail_out);
- png_memcpy(text, key, key_size);
- text_size = key_size + png_ptr->zbuf_size -
- png_ptr->zstream.avail_out;
- *(text + text_size) = 0x00;
- }
- else
- {
- png_charp tmp;
-
- tmp = text;
- text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size +
- png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
- 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)
- {
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- }
- else
- {
- break;
- }
- }
+ text_ptr->compression = comp_type;
+ text_ptr->key = png_ptr->chunkdata;
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+ text_ptr->text_length = data_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store zTXt chunk");
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key, lang, text, lang_key;
+ int comp_flag;
+ int comp_type = 0;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ png_debug(1, "in png_handle_iTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
}
- inflateReset(&png_ptr->zstream);
- png_ptr->zstream.avail_in = 0;
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for iTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
- png_free(png_ptr, key);
- key = text;
- text += key_size;
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ * there is no hard and fast rule to tell us where to stop.
+ */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
}
- else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
{
- png_size_t text_size;
-#if !defined(PNG_NO_STDIO)
- char umsg[50];
+ png_warning(png_ptr, "No memory to process iTXt chunk");
+ return;
+ }
- sprintf(umsg, "Unknown zTXt compression type %d", comp_type);
- png_warning(png_ptr, umsg);
-#else
- png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
- /* Copy what we can of the error message into the text chunk */
- text_size = (png_size_t)(slength - (text - key) - 1);
- text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
- png_memcpy(text, msg, text_size + 1);
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
}
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
- text_ptr->compression = comp_type;
- text_ptr->key = key;
- text_ptr->text = text;
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (lang = png_ptr->chunkdata; *lang; lang++)
+ /* Empty loop */ ;
+
+ lang++; /* Skip NUL separator */
+
+ /* iTXt must have a language tag (possibly empty), two compression bytes,
+ * translated keyword (possibly empty), and possibly some text after the
+ * keyword
+ */
+
+ if (lang >= png_ptr->chunkdata + slength - 3)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
+ else
+ {
+ comp_flag = *lang++;
+ comp_type = *lang++;
+ }
+
+ if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt))
+ {
+ png_warning(png_ptr, "Unknown iTXt compression type or method");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* Empty loop */ ;
+
+ lang_key++; /* Skip NUL separator */
+
+ if (lang_key >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ for (text = lang_key; *text; text++)
+ /* Empty loop */ ;
+
+ text++; /* Skip NUL separator */
+
+ if (text >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Malformed iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ prefix_len = text - png_ptr->chunkdata;
+
+ key=png_ptr->chunkdata;
+
+ if (comp_flag)
+ png_decompress_chunk(png_ptr, comp_type,
+ (size_t)length, prefix_len, &data_len);
+
+ else
+ data_len = png_strlen(png_ptr->chunkdata + prefix_len);
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ text_ptr->compression = (int)comp_flag + 1;
+ text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
+ text_ptr->lang = png_ptr->chunkdata + (lang - key);
+ text_ptr->itxt_length = data_len;
+ text_ptr->text_length = 0;
+ text_ptr->key = png_ptr->chunkdata;
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store iTXt chunk");
}
#endif
/* This function is called when we haven't found a handler for a
- chunk. If there isn't a problem with the chunk itself (ie bad
- chunk name, CRC, or a critical chunk), the chunk is silently ignored. */
-void
+ * chunk. If there isn't a problem with the chunk itself (ie bad
+ * chunk name, CRC, or a critical chunk), the chunk is silently ignored
+ * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+ * case it will be saved away to be written out later.
+ */
+void /* PRIVATE */
png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
- png_debug(1, "in png_handle_unknown\n");
+ png_uint_32 skip = 0;
- /* In the future we can have code here that calls user-supplied
- * callback functions for unknown chunks before they are ignored or
- * cause an error.
- */
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ png_debug(1, "in png_handle_unknown");
- if (!(png_ptr->chunk_name[0] & 0x20))
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
{
- png_chunk_error(png_ptr, "unknown critical chunk");
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
- /* to quiet compiler warnings about unused info_ptr */
- if (info_ptr == NULL)
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for unknown chunk");
+ png_crc_finish(png_ptr, length);
return;
+ }
}
+#endif
if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
+ {
+ if (png_ptr->chunk_name != png_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
- png_crc_finish(png_ptr, length);
+ if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ || (png_ptr->read_user_chunk_fn != NULL)
+#endif
+ )
+ {
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > 65535)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - 65535;
+ length = 65535;
+ }
+#endif
+
+ /* TODO: this code is very close to the unknown handling in pngpread.c,
+ * maybe it can be put into a common utility routine?
+ * png_struct::unknown_chunk is just used as a temporary variable, along
+ * with the data into which the chunk is read. These can be eliminated.
+ */
+ PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+ png_ptr->unknown_chunk.size = (png_size_t)length;
+
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+ png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+ }
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret;
+
+ ret = (*(png_ptr->read_user_chunk_fn))
+ (png_ptr, &png_ptr->unknown_chunk);
+
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+
+ if (ret == 0)
+ {
+ if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ }
+ }
+
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+ else
+#endif
+ skip = length;
+ png_crc_finish(png_ptr, skip);
+
+#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+ PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+#endif
}
/* This function is called to verify that a chunk name is valid.
- This function can't have the "critical chunk check" incorporated
- into it, since in the future we will need to be able to call user
- functions to handle unknown critical chunks after we check that
- the chunk name itself is valid. */
+ * This function can't have the "critical chunk check" incorporated
+ * into it, since in the future we will need to be able to call user
+ * functions to handle unknown critical chunks after we check that
+ * the chunk name itself is valid.
+ */
-#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97))
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
-void
-png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
+void /* PRIVATE */
+png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name)
{
- png_debug(1, "in png_check_chunk_name\n");
- if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
- isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+ int i;
+
+ png_debug(1, "in png_check_chunk_name");
+
+ for (i=1; i<=4; ++i)
{
- png_chunk_error(png_ptr, "invalid chunk type");
+ int c = chunk_name & 0xff;
+
+ if (c < 65 || c > 122 || (c > 90 && c < 97))
+ png_chunk_error(png_ptr, "invalid chunk type");
+
+ chunk_name >>= 8;
}
}
-/* Combines the row recently read in with the previous row.
- This routine takes care of alpha and transparency if requested.
- This routine also handles the two methods of progressive display
- of interlaced images, depending on the mask value.
- The mask value describes which pixels are to be combined with
- the row. The pattern always repeats every 8 pixels, so just 8
- bits are needed. A one indicates the pixels is to be combined,
- a zero indicates the pixel is to be skipped. This is in addition
- to any alpha or transparency value associated with the pixel. If
- you want all pixels to be combined, pass 0xff (255) in mask. */
-void
-png_combine_row(png_structp png_ptr, png_bytep row,
- int mask)
+/* Combines the row recently read in with the existing pixels in the row. This
+ * routine takes care of alpha and transparency if requested. This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels. If
+ * 'display' is false only those pixels present in the pass are filled in.
+ */
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep dp, int display)
{
- png_debug(1,"in png_combine_row\n");
- if (mask == 0xff)
+ unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+ png_const_bytep sp = png_ptr->row_buf + 1;
+ png_uint_32 row_width = png_ptr->width;
+ unsigned int pass = png_ptr->pass;
+ png_bytep end_ptr = 0;
+ png_byte end_byte = 0;
+ unsigned int end_mask;
+
+ png_debug(1, "in png_combine_row");
+
+ /* Added in 1.5.6: it should not be possible to enter this routine until at
+ * least one row has been read from the PNG data and transformed.
+ */
+ if (pixel_depth == 0)
+ png_error(png_ptr, "internal row logic error");
+
+ /* Added in 1.5.4: the pixel depth should match the information returned by
+ * any call to png_read_update_info at this point. Do not continue if we got
+ * this wrong.
+ */
+ if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+ PNG_ROWBYTES(pixel_depth, row_width))
+ png_error(png_ptr, "internal row size calculation error");
+
+ /* Don't expect this to ever happen: */
+ if (row_width == 0)
+ png_error(png_ptr, "internal row width error");
+
+ /* Preserve the last byte in cases where only part of it will be overwritten,
+ * the multiply below may overflow, we don't care because ANSI-C guarantees
+ * we get the low bits.
+ */
+ end_mask = (pixel_depth * row_width) & 7;
+ if (end_mask != 0)
{
- png_memcpy(row, png_ptr->row_buf + 1,
- (png_size_t)((png_ptr->width *
- png_ptr->row_info.pixel_depth + 7) >> 3));
+ /* end_ptr == NULL is a flag to say do nothing */
+ end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+ end_byte = *end_ptr;
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */
+ end_mask = 0xff << end_mask;
+
+ else /* big-endian byte */
+# endif
+ end_mask = 0xff >> end_mask;
+ /* end_mask is now the bits to *keep* from the destination row */
}
- else
+
+ /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy()
+ * will also happen if interlacing isn't supported or if the application
+ * does not call png_set_interlace_handling(). In the latter cases the
+ * caller just gets a sequence of the unexpanded rows from each interlace
+ * pass.
+ */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) &&
+ pass < 6 && (display == 0 ||
+ /* The following copies everything for 'display' on passes 0, 2 and 4. */
+ (display == 1 && (pass & 1) != 0)))
{
- switch (png_ptr->row_info.pixel_depth)
+ /* Narrow images may have no bits in a pass; the caller should handle
+ * this, but this test is cheap:
+ */
+ if (row_width <= PNG_PASS_START_COL(pass))
+ return;
+
+ if (pixel_depth < 8)
{
- case 1:
+ /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
+ * into 32 bits, then a single loop over the bytes using the four byte
+ * values in the 32-bit mask can be used. For the 'display' option the
+ * expanded mask may also not require any masking within a byte. To
+ * make this work the PACKSWAP option must be taken into account - it
+ * simply requires the pixels to be reversed in each byte.
+ *
+ * The 'regular' case requires a mask for each of the first 6 passes,
+ * the 'display' case does a copy for the even passes in the range
+ * 0..6. This has already been handled in the test above.
+ *
+ * The masks are arranged as four bytes with the first byte to use in
+ * the lowest bits (little-endian) regardless of the order (PACKSWAP or
+ * not) of the pixels in each byte.
+ *
+ * NOTE: the whole of this logic depends on the caller of this function
+ * only calling it on rows appropriate to the pass. This function only
+ * understands the 'x' logic; the 'y' logic is handled by the caller.
+ *
+ * The following defines allow generation of compile time constant bit
+ * masks for each pixel depth and each possibility of swapped or not
+ * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
+ * is in the range 0..7; and the result is 1 if the pixel is to be
+ * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
+ * for the block method.
+ *
+ * With some compilers a compile time expression of the general form:
+ *
+ * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+ *
+ * Produces warnings with values of 'shift' in the range 33 to 63
+ * because the right hand side of the ?: expression is evaluated by
+ * the compiler even though it isn't used. Microsoft Visual C (various
+ * versions) and the Intel C compiler are known to do this. To avoid
+ * this the following macros are used in 1.5.6. This is a temporary
+ * solution to avoid destabilizing the code during the release process.
+ */
+# if PNG_USE_COMPILE_TIME_MASKS
+# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+# else
+# define PNG_LSR(x,s) ((x)>>(s))
+# define PNG_LSL(x,s) ((x)<<(s))
+# endif
+# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+
+ /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
+ * little endian - the first pixel is at bit 0 - however the extra
+ * parameter 's' can be set to cause the mask position to be swapped
+ * within each byte, to match the PNG format. This is done by XOR of
+ * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+ */
+# define PIXEL_MASK(p,x,d,s) \
+ (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+
+ /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+ */
+# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+
+ /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
+ * cases the result needs replicating, for the 4-bpp case the above
+ * generates a full 32 bits.
+ */
+# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+
+# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+ S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+ S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+
+# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+ B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+ B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+
+#if PNG_USE_COMPILE_TIME_MASKS
+ /* Utility macros to construct all the masks for a depth/swap
+ * combination. The 's' parameter says whether the format is PNG
+ * (big endian bytes) or not. Only the three odd-numbered passes are
+ * required for the display/block algorithm.
+ */
+# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
+ S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+
+# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
+
+# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+
+ /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
+ * then pass:
+ */
+ static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
{
- png_bytep sp;
- png_bytep dp;
- int s_inc, s_start, s_end;
- int m;
- int shift;
- png_uint_32 i;
-
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ /* Little-endian byte masks for PACKSWAP */
+ { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+ };
+
+ /* display_mask has only three entries for the odd passes, so index by
+ * pass>>1.
+ */
+ static PNG_CONST png_uint_32 display_mask[2][3][3] =
+ {
+ /* Little-endian byte masks for PACKSWAP */
+ { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+ };
+
+# define MASK(pass,depth,display,png)\
+ ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+ row_mask[png][DEPTH_INDEX(depth)][pass])
+
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+ /* This is the runtime alternative: it seems unlikely that this will
+ * ever be either smaller or faster than the compile time approach.
+ */
+# define MASK(pass,depth,display,png)\
+ ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !PNG_USE_COMPILE_TIME_MASKS */
+
+ /* Use the appropriate mask to copy the required bits. In some cases
+ * the byte mask will be 0 or 0xff, optimize these cases. row_width is
+ * the number of pixels, but the code copies bytes, so it is necessary
+ * to special case the end.
+ */
+ png_uint_32 pixels_per_byte = 8 / pixel_depth;
+ png_uint_32 mask;
+
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 7;
- s_inc = 1;
- }
- else
-#endif
- {
- s_start = 7;
- s_end = 0;
- s_inc = -1;
- }
+ mask = MASK(pass, pixel_depth, display, 0);
- shift = s_start;
-
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
- {
- int value;
+ else
+# endif
+ mask = MASK(pass, pixel_depth, display, 1);
- value = (*sp >> shift) & 0x1;
- *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
- }
+ for (;;)
+ {
+ png_uint_32 m;
- if (shift == s_end)
- {
- shift = s_start;
- sp++;
- dp++;
- }
- else
- shift += s_inc;
+ /* It doesn't matter in the following if png_uint_32 has more than
+ * 32 bits because the high bits always match those in m<<24; it is,
+ * however, essential to use OR here, not +, because of this.
+ */
+ m = mask;
+ mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+ m &= 0xff;
- if (m == 1)
- m = 0x80;
+ if (m != 0) /* something to copy */
+ {
+ if (m != 0xff)
+ *dp = (png_byte)((*dp & ~m) | (*sp & m));
else
- m >>= 1;
+ *dp = *sp;
}
- break;
+
+ /* NOTE: this may overwrite the last byte with garbage if the image
+ * is not an exact number of bytes wide; libpng has always done
+ * this.
+ */
+ if (row_width <= pixels_per_byte)
+ break; /* May need to restore part of the last byte */
+
+ row_width -= pixels_per_byte;
+ ++dp;
+ ++sp;
}
- case 2:
- {
- png_bytep sp;
- png_bytep dp;
- int s_start, s_end, s_inc;
- int m;
- int shift;
- png_uint_32 i;
- int value;
+ }
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 6;
- s_inc = 2;
- }
- else
-#endif
- {
- s_start = 6;
- s_end = 0;
- s_inc = -2;
- }
+ else /* pixel_depth >= 8 */
+ {
+ unsigned int bytes_to_copy, bytes_to_jump;
- shift = s_start;
+ /* Validate the depth - it must be a multiple of 8 */
+ if (pixel_depth & 7)
+ png_error(png_ptr, "invalid user transform pixel depth");
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
- {
- value = (*sp >> shift) & 0x3;
- *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
- }
+ pixel_depth >>= 3; /* now in bytes */
+ row_width *= pixel_depth;
- if (shift == s_end)
- {
- shift = s_start;
- sp++;
- dp++;
- }
- else
- shift += s_inc;
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
- }
- case 4:
+ /* Regardless of pass number the Adam 7 interlace always results in a
+ * fixed number of pixels to copy then to skip. There may be a
+ * different number of pixels to skip at the start though.
+ */
{
- png_bytep sp;
- png_bytep dp;
- int s_start, s_end, s_inc;
- int m;
- int shift;
- png_uint_32 i;
- int value;
+ unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 4;
- s_inc = 4;
- }
- else
-#endif
- {
- s_start = 4;
- s_end = 0;
- s_inc = -4;
- }
- shift = s_start;
+ row_width -= offset;
+ dp += offset;
+ sp += offset;
+ }
+
+ /* Work out the bytes to copy. */
+ if (display)
+ {
+ /* When doing the 'block' algorithm the pixel in the pass gets
+ * replicated to adjacent pixels. This is why the even (0,2,4,6)
+ * passes are skipped above - the entire expanded row is copied.
+ */
+ bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+
+ /* But don't allow this number to exceed the actual row width. */
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = row_width;
+ }
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
+ else /* normal row; Adam7 only ever gives us one pixel to copy. */
+ bytes_to_copy = pixel_depth;
+
+ /* In Adam7 there is a constant offset between where the pixels go. */
+ bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+
+ /* And simply copy these bytes. Some optimization is possible here,
+ * depending on the value of 'bytes_to_copy'. Special case the low
+ * byte counts, which we know to be frequent.
+ *
+ * Notice that these cases all 'return' rather than 'break' - this
+ * avoids an unnecessary test on whether to restore the last byte
+ * below.
+ */
+ switch (bytes_to_copy)
+ {
+ case 1:
+ for (;;)
{
- value = (*sp >> shift) & 0xf;
- *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
+ *dp = *sp;
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp += bytes_to_jump;
+ sp += bytes_to_jump;
+ row_width -= bytes_to_jump;
}
- if (shift == s_end)
+ case 2:
+ /* There is a possibility of a partial copy at the end here; this
+ * slows the code down somewhat.
+ */
+ do
{
- shift = s_start;
- sp++;
- dp++;
+ dp[0] = sp[0], dp[1] = sp[1];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
}
- else
- shift += s_inc;
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
- }
- default:
- {
- png_bytep sp;
- png_bytep dp;
- png_size_t pixel_bytes;
- png_uint_32 i;
- png_byte m;
+ while (row_width > 1);
- pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+ /* And there can only be one byte left at this point: */
+ *dp = *sp;
+ return;
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
+ case 3:
+ /* This can only be the RGB case, so each copy is exactly one
+ * pixel and it is not necessary to check for a partial copy.
+ */
+ for(;;)
+ {
+ dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+
+ default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+ /* Check for double byte alignment and, if possible, use a
+ * 16-bit copy. Don't attempt this for narrow images - ones that
+ * are less than an interlace panel wide. Don't attempt it for
+ * wide bytes_to_copy either - use the png_memcpy there.
+ */
+ if (bytes_to_copy < 16 /*else use png_memcpy*/ &&
+ png_isaligned(dp, png_uint_16) &&
+ png_isaligned(sp, png_uint_16) &&
+ bytes_to_copy % sizeof (png_uint_16) == 0 &&
+ bytes_to_jump % sizeof (png_uint_16) == 0)
{
- png_memcpy(dp, sp, pixel_bytes);
+ /* Everything is aligned for png_uint_16 copies, but try for
+ * png_uint_32 first.
+ */
+ if (png_isaligned(dp, png_uint_32) &&
+ png_isaligned(sp, png_uint_32) &&
+ bytes_to_copy % sizeof (png_uint_32) == 0 &&
+ bytes_to_jump % sizeof (png_uint_32) == 0)
+ {
+ png_uint_32p dp32 = (png_uint_32p)dp;
+ png_const_uint_32p sp32 = (png_const_uint_32p)sp;
+ unsigned int skip = (bytes_to_jump-bytes_to_copy) /
+ sizeof (png_uint_32);
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp32++ = *sp32++;
+ c -= sizeof (png_uint_32);
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp32 += skip;
+ sp32 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* Get to here when the row_width truncates the final copy.
+ * There will be 1-3 bytes left to copy, so don't try the
+ * 16-bit loop below.
+ */
+ dp = (png_bytep)dp32;
+ sp = (png_const_bytep)sp32;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+
+ /* Else do it in 16-bit quantities, but only if the size is
+ * not too large.
+ */
+ else
+ {
+ png_uint_16p dp16 = (png_uint_16p)dp;
+ png_const_uint_16p sp16 = (png_const_uint_16p)sp;
+ unsigned int skip = (bytes_to_jump-bytes_to_copy) /
+ sizeof (png_uint_16);
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp16++ = *sp16++;
+ c -= sizeof (png_uint_16);
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp16 += skip;
+ sp16 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* End of row - 1 byte left, bytes_to_copy > row_width: */
+ dp = (png_bytep)dp16;
+ sp = (png_const_bytep)sp16;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
}
+#endif /* PNG_ALIGN_ code */
- sp += pixel_bytes;
- dp += pixel_bytes;
+ /* The true default - use a png_memcpy: */
+ for (;;)
+ {
+ png_memcpy(dp, sp, bytes_to_copy);
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = row_width;
+ }
}
- }
+
+ /* NOT REACHED*/
+ } /* pixel_depth >= 8 */
+
+ /* Here if pixel_depth < 8 to check 'end_ptr' below. */
}
+ else
+#endif
+
+ /* If here then the switch above wasn't used so just png_memcpy the whole row
+ * from the temporary row buffer (notice that this overwrites the end of the
+ * destination row if it is a partial byte.)
+ */
+ png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+
+ /* Restore the overwritten bits from the last byte if necessary. */
+ if (end_ptr != NULL)
+ *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
}
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-void
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
- png_uint_32 transformations)
+ png_uint_32 transformations /* Because these may affect the byte layout */)
{
- png_debug(1,"in png_do_read_interlace\n");
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* Offset to next interlace block */
+ static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_read_interlace");
if (row != NULL && row_info != NULL)
{
png_uint_32 final_width;
{
case 1:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
int sshift, dshift;
int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
png_byte v;
png_uint_32 i;
int j;
- sp = row + (png_size_t)((row_info->width - 1) >> 3);
- dp = row + (png_size_t)((final_width - 1) >> 3);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)((row_info->width + 7) & 7);
- dshift = (int)((final_width + 7) & 7);
+ sshift = (int)((row_info->width + 7) & 0x07);
+ dshift = (int)((final_width + 7) & 0x07);
s_start = 7;
s_end = 0;
s_inc = -1;
}
+
else
#endif
{
- sshift = 7 - (int)((row_info->width + 7) & 7);
- dshift = 7 - (int)((final_width + 7) & 7);
+ sshift = 7 - (int)((row_info->width + 7) & 0x07);
+ dshift = 7 - (int)((final_width + 7) & 0x07);
s_start = 0;
s_end = 7;
s_inc = 1;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
- v = (png_byte)((*sp >> sshift) & 0x1);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ v = (png_byte)((*sp >> sshift) & 0x01);
+ for (j = 0; j < jstop; j++)
{
*dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
+
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
case 2:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
int sshift, dshift;
int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
png_uint_32 i;
- sp = row + (png_uint_32)((row_info->width - 1) >> 2);
- dp = row + (png_uint_32)((final_width - 1) >> 2);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)(((row_info->width + 3) & 3) << 1);
- dshift = (int)(((final_width + 3) & 3) << 1);
+ sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+ dshift = (int)(((final_width + 3) & 0x03) << 1);
s_start = 6;
s_end = 0;
s_inc = -2;
}
+
else
#endif
{
- sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
- dshift = (int)((3 - ((final_width + 3) & 3)) << 1);
+ sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
s_start = 0;
s_end = 6;
s_inc = 2;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
png_byte v;
int j;
- v = (png_byte)((*sp >> sshift) & 0x3);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ v = (png_byte)((*sp >> sshift) & 0x03);
+ for (j = 0; j < jstop; j++)
{
*dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
+
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
case 4:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
int sshift, dshift;
int s_start, s_end, s_inc;
png_uint_32 i;
+ int jstop = png_pass_inc[pass];
- sp = row + (png_size_t)((row_info->width - 1) >> 1);
- dp = row + (png_size_t)((final_width - 1) >> 1);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)(((row_info->width + 1) & 1) << 2);
- dshift = (int)(((final_width + 1) & 1) << 2);
+ sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+ dshift = (int)(((final_width + 1) & 0x01) << 2);
s_start = 4;
s_end = 0;
s_inc = -4;
}
+
else
#endif
{
- sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
- dshift = (int)((1 - ((final_width + 1) & 1)) << 2);
+ sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
s_start = 0;
s_end = 4;
s_inc = 4;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
- png_byte v;
+ png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
int j;
- v = (png_byte)((*sp >> sshift) & 0xf);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ for (j = 0; j < jstop; j++)
{
*dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
*dp |= (png_byte)(v << dshift);
+
if (dshift == s_end)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
default:
{
- png_bytep sp, dp;
- png_uint_32 i;
- png_size_t pixel_bytes;
+ png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+
+ png_bytep sp = row + (png_size_t)(row_info->width - 1)
+ * pixel_bytes;
- pixel_bytes = (row_info->pixel_depth >> 3);
+ png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
- sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
- dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
png_byte v[8];
int j;
png_memcpy(v, sp, pixel_bytes);
- for (j = 0; j < png_pass_inc[pass]; j++)
+
+ for (j = 0; j < jstop; j++)
{
png_memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
+
sp -= pixel_bytes;
}
break;
}
}
+
row_info->width = final_width;
- row_info->rowbytes = ((final_width *
- (png_uint_32)row_info->pixel_depth + 7) >> 3);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
}
-}
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+ PNG_UNUSED(transformations) /* Silence compiler warning */
#endif
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
-void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
- png_bytep prev_row, int filter)
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
{
- png_debug(1, "in png_read_filter_row\n");
- png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+ PNG_UNUSED(prev_row)
- switch (filter)
+ for (i = bpp; i < istop; i++)
{
- case PNG_FILTER_VALUE_NONE:
- break;
- case PNG_FILTER_VALUE_SUB:
- {
- png_uint_32 i;
- int bpp;
- png_bytep rp;
- png_bytep lp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
- i < row_info->rowbytes; i++, rp++, lp++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
- }
- break;
- }
- case PNG_FILTER_VALUE_UP:
- {
- png_uint_32 i;
- png_bytep rp;
- png_bytep pp;
+ *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+ rp++;
+ }
+}
- for (i = 0, rp = row, pp = prev_row;
- i < row_info->rowbytes; i++, rp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
- }
- break;
- }
- case PNG_FILTER_VALUE_AVG:
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_size_t istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp_end = row + row_info->rowbytes;
+ int a, c;
+
+ /* First pixel/byte */
+ c = *prev_row++;
+ a = *row + c;
+ *row++ = (png_byte)a;
+
+ /* Remainder */
+ while (row < rp_end)
+ {
+ int b, pa, pb, pc, p;
+
+ a &= 0xff; /* From previous iteration or start */
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+# ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+# else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+# endif
+
+ /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+ * ones in the case of a tie.
+ */
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ /* Calculate the current pixel in a, and move the previous row pixel to c
+ * for the next time round the loop
+ */
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp_end = row + bpp;
+
+ /* Process the first pixel in the row completely (this is the same as 'up'
+ * because there is only one candidate predictor for the first row).
+ */
+ while (row < rp_end)
+ {
+ int a = *row + *prev_row++;
+ *row++ = (png_byte)a;
+ }
+
+ /* Remainder */
+ rp_end += row_info->rowbytes - bpp;
+
+ while (row < rp_end)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ c = *(prev_row - bpp);
+ a = *(row - bpp);
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+# ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+# else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+# endif
+
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+#ifdef PNG_ARM_NEON
+
+#ifdef __linux__
+#include <stdio.h>
+#include <elf.h>
+#include <asm/hwcap.h>
+
+static int png_have_hwcap(unsigned cap)
+{
+ FILE *f = fopen("/proc/self/auxv", "r");
+ Elf32_auxv_t aux;
+ int have_cap = 0;
+
+ if (!f)
+ return 0;
+
+ while (fread(&aux, sizeof(aux), 1, f) > 0)
+ {
+ if (aux.a_type == AT_HWCAP &&
+ aux.a_un.a_val & cap)
{
- png_uint_32 i;
- int bpp;
- png_bytep rp;
- png_bytep pp;
- png_bytep lp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = 0, rp = row, pp = prev_row;
- i < (png_uint_32)bpp; i++, rp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) +
- ((int)(*pp) / 2)) & 0xff);
- }
- for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp + *lp) / 2) & 0xff);
- }
+ have_cap = 1;
break;
}
- case PNG_FILTER_VALUE_PAETH:
- {
- int bpp;
- png_uint_32 i;
- png_bytep rp;
- png_bytep pp;
- png_bytep lp;
- png_bytep cp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = 0, rp = row, pp = prev_row,
- lp = row - bpp, cp = prev_row - bpp;
- i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
- {
- int a, b, c, pa, pb, pc, p;
+ }
- b = *pp;
- if (i >= (png_uint_32)bpp)
- {
- c = *cp;
- a = *lp;
- }
- else
- {
- a = c = 0;
- }
- p = a + b - c;
- pa = abs(p - a);
- pb = abs(p - b);
- pc = abs(p - c);
-
- if (pa <= pb && pa <= pc)
- p = a;
- else if (pb <= pc)
- p = b;
- else
- p = c;
+ fclose(f);
- *rp = (png_byte)(((int)(*rp) + p) & 0xff);
- }
- break;
- }
- default:
- png_error(png_ptr, "Bad adaptive filter type");
- break;
+ return have_cap;
+}
+#endif /* __linux__ */
+
+static void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+#ifdef __linux__
+ if (!png_have_hwcap(HWCAP_NEON))
+ return;
+#endif
+
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+ if (bpp == 3)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth3_neon;
}
+
+ else if (bpp == 4)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth4_neon;
+ }
+}
+#endif /* PNG_ARM_NEON */
+
+static void
+png_init_filter_functions(png_structp pp)
+{
+ unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+ if (bpp == 1)
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_1byte_pixel;
+ else
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_multibyte_pixel;
+
+#ifdef PNG_ARM_NEON
+ png_init_filter_functions_neon(pp, bpp);
+#endif
+}
+
+void /* PRIVATE */
+png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row, int filter)
+{
+ if (pp->read_filter[0] == NULL)
+ png_init_filter_functions(pp);
+ if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+ pp->read_filter[filter-1](row_info, row, prev_row);
}
-void
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
png_read_finish_row(png_structp png_ptr)
{
- png_debug(1, "in png_read_finish_row\n");
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+ png_debug(1, "in png_read_finish_row");
png_ptr->row_number++;
if (png_ptr->row_number < png_ptr->num_rows)
return;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced)
{
png_ptr->row_number = 0;
- png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ /* TO DO: don't do this if prev_row isn't needed (requires
+ * read-ahead of the next row's filter byte.
+ */
+ png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
do
{
png_ptr->pass++;
+
if (png_ptr->pass >= 7)
break;
+
png_ptr->iwidth = (png_ptr->width +
png_pass_inc[png_ptr->pass] - 1 -
png_pass_start[png_ptr->pass]) /
png_pass_inc[png_ptr->pass];
- png_ptr->irowbytes = ((png_ptr->iwidth *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
if (!(png_ptr->transformations & PNG_INTERLACE))
{
png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
- if (!(png_ptr->num_rows))
- continue;
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
}
- if (png_ptr->transformations & PNG_INTERLACE)
- break;
- } while (png_ptr->iwidth == 0);
+
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break; /* libpng deinterlacing sees every row */
+
+ } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
if (png_ptr->pass < 7)
return;
}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
{
png_ptr->zstream.next_out = (Byte *)&extra;
png_ptr->zstream.avail_out = (uInt)1;
- for(;;)
+
+ for (;;)
{
if (!(png_ptr->zstream.avail_in))
{
while (!png_ptr->idat_size)
{
- png_byte chunk_length[4];
-
png_crc_finish(png_ptr, 0);
-
- png_read_data(png_ptr, chunk_length, 4);
- png_ptr->idat_size = png_get_uint_32(chunk_length);
-
- png_reset_crc(png_ptr);
- png_crc_read(png_ptr, png_ptr->chunk_name, 4);
- if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ if (png_ptr->chunk_name != png_IDAT)
png_error(png_ptr, "Not enough image data");
-
}
+
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_in = png_ptr->zbuf;
+
if (png_ptr->zbuf_size > png_ptr->idat_size)
png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+
png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
png_ptr->idat_size -= png_ptr->zstream.avail_in;
}
+
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+
if (ret == Z_STREAM_END)
{
if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
- png_ptr->idat_size)
- png_error(png_ptr, "Extra compressed data");
+ png_ptr->idat_size)
+ png_warning(png_ptr, "Extra compressed data");
+
png_ptr->mode |= PNG_AFTER_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
+
if (ret != Z_OK)
png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
- "Decompression Error");
+ "Decompression Error");
if (!(png_ptr->zstream.avail_out))
- png_error(png_ptr, "Extra compressed data");
+ {
+ png_warning(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
}
png_ptr->zstream.avail_out = 0;
}
if (png_ptr->idat_size || png_ptr->zstream.avail_in)
- png_error(png_ptr, "Extra compression data");
+ png_warning(png_ptr, "Extra compression data");
inflateReset(&png_ptr->zstream);
png_ptr->mode |= PNG_AFTER_IDAT;
}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-void
+void /* PRIVATE */
png_read_start_row(png_structp png_ptr)
{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
int max_pixel_depth;
- png_uint_32 rowbytes;
+ png_size_t row_bytes;
- png_debug(1, "in png_read_start_row\n");
+ png_debug(1, "in png_read_start_row");
png_ptr->zstream.avail_in = 0;
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
png_init_read_transformations(png_ptr);
+#endif
+#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced)
{
if (!(png_ptr->transformations & PNG_INTERLACE))
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
else
png_ptr->num_rows = png_ptr->height;
png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- rowbytes = ((png_ptr->iwidth *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
- png_ptr->irowbytes = (png_size_t)rowbytes;
- if((png_uint_32)png_ptr->irowbytes != rowbytes)
- png_error(png_ptr, "Rowbytes overflow in png_read_start_row");
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
}
+
else
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
{
png_ptr->num_rows = png_ptr->height;
png_ptr->iwidth = png_ptr->width;
- png_ptr->irowbytes = png_ptr->rowbytes + 1;
}
+
max_pixel_depth = png_ptr->pixel_depth;
-#if defined(PNG_READ_PACK_SUPPORTED)
+ /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of
+ * calculations to calculate the final pixel depth, then
+ * png_do_read_transforms actually does the transforms. This means that the
+ * code which effectively calculates this value is actually repeated in three
+ * separate places. They must all match. Innocent changes to the order of
+ * transformations can and will break libpng in a way that causes memory
+ * overwrites.
+ *
+ * TODO: fix this.
+ */
+#ifdef PNG_READ_PACK_SUPPORTED
if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
max_pixel_depth = 8;
#endif
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
if (png_ptr->transformations & PNG_EXPAND)
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (png_ptr->num_trans)
max_pixel_depth = 32;
+
else
max_pixel_depth = 24;
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
if (max_pixel_depth < 8)
max_pixel_depth = 8;
+
if (png_ptr->num_trans)
max_pixel_depth *= 2;
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
{
if (png_ptr->num_trans)
}
#endif
-#if defined(PNG_READ_FILLER_SUPPORTED)
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND_16)
+ {
+# ifdef PNG_READ_EXPAND_SUPPORTED
+ /* In fact it is an error if it isn't supported, but checking is
+ * the safe way.
+ */
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->bit_depth < 16)
+ max_pixel_depth *= 2;
+ }
+ else
+# endif
+ png_ptr->transformations &= ~PNG_EXPAND_16;
+ }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
if (png_ptr->transformations & (PNG_FILLER))
{
- if (max_pixel_depth < 32)
- max_pixel_depth = 32;
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+
+ else
+ max_pixel_depth = 32;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (max_pixel_depth <= 32)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 64;
+ }
}
#endif
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
{
- if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
- png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+ (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
if (max_pixel_depth <= 16)
max_pixel_depth = 32;
- else if (max_pixel_depth <= 32)
+
+ else
max_pixel_depth = 64;
}
+
else
{
if (max_pixel_depth <= 8)
- max_pixel_depth = 24;
- else if (max_pixel_depth <= 16)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+
+ else
max_pixel_depth = 48;
}
}
#endif
- /* align the width on the next larger 8 pixels. Mainly used
- for interlacing */
- rowbytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
- /* calculate the maximum bytes needed, adding a byte and a pixel
- for safety sake */
- rowbytes = ((rowbytes * (png_uint_32)max_pixel_depth + 7) >> 3) +
- 1 + ((max_pixel_depth + 7) >> 3);
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ int user_pixel_depth = png_ptr->user_transform_depth *
+ png_ptr->user_transform_channels;
+
+ if (user_pixel_depth > max_pixel_depth)
+ max_pixel_depth = user_pixel_depth;
+ }
+#endif
+
+ /* This value is stored in png_struct and double checked in the row read
+ * code.
+ */
+ png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+ png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
+ /* Align the width on the next larger 8 pixels. Mainly used
+ * for interlacing
+ */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* Calculate the maximum bytes needed, adding a byte and a pixel
+ * for safety's sake
+ */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3);
+
#ifdef PNG_MAX_MALLOC_64K
- if (rowbytes > (png_uint_32)65536L)
+ if (row_bytes > (png_uint_32)65536L)
png_error(png_ptr, "This image requires a row greater than 64KB");
#endif
- png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, rowbytes);
+
+ if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+ {
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_free(png_ptr, png_ptr->big_prev_row);
+
+ if (png_ptr->interlaced)
+ png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+ row_bytes + 48);
+
+ else
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+ png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+ /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+ * of padding before and after row_buf; treat prev_row similarly.
+ * NOTE: the alignment is to the start of the pixels, one beyond the start
+ * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
+ * was incorrect; the filter byte was aligned, which had the exact
+ * opposite effect of that intended.
+ */
+ {
+ png_bytep temp = png_ptr->big_row_buf + 32;
+ int extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+
+ temp = png_ptr->big_prev_row + 32;
+ extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+ }
+
+#else
+ /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 31;
+ png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+ }
#ifdef PNG_MAX_MALLOC_64K
- if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
+ if (png_ptr->rowbytes > 65535)
png_error(png_ptr, "This image requires a row greater than 64KB");
+
#endif
- png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
- png_ptr->rowbytes + 1));
+ if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory");
- png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+ png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
- png_debug1(3, "width = %d,\n", png_ptr->width);
- png_debug1(3, "height = %d,\n", png_ptr->height);
- png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth);
- png_debug1(3, "num_rows = %d\n", png_ptr->num_rows);
- png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes);
- png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes);
+ png_debug1(3, "width = %u,", png_ptr->width);
+ png_debug1(3, "height = %u,", png_ptr->height);
+ png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+ png_debug1(3, "irowbytes = %lu",
+ (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
png_ptr->flags |= PNG_FLAG_ROW_INIT;
}
+#endif /* PNG_READ_SUPPORTED */
projects / wxWidgets.git / blobdiff