/* pngrutil.c - utilities to read a PNG file
*
- * Last changed in libpng 1.5.2 [March 31, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.14 [January 24, 2013]
+ * Copyright (c) 1998-2013 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.)
*
png_get_int_32)(png_const_bytep buf)
{
png_uint_32 uval = png_get_uint_32(buf);
- if ((uval & 0x80000000L) == 0) /* non-negative */
+ if ((uval & 0x80000000) == 0) /* non-negative */
return uval;
- uval = (uval ^ 0xffffffffL) + 1; /* 2's complement: -x = ~x+1 */
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
return -(png_int_32)uval;
}
length = png_get_uint_31(png_ptr, buf);
/* Put the chunk name into png_ptr->chunk_name. */
- png_memcpy(png_ptr->chunk_name, buf + 4, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
- png_debug2(0, "Reading %s chunk, length = %u",
- png_ptr->chunk_name, length);
+ 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, png_ptr->chunk_name, 4);
+ 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);
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");
}
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;
return (0);
}
-#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
- defined(PNG_READ_iCCP_SUPPORTED)
+#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)
{
int ret, avail;
- /* The setting of 'avail_in' used to be outside the loop, by setting it
+ /* 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
* and the error message is dumped into the uncompressed
* buffer if available.
*/
+# ifdef PNG_WARNINGS_SUPPORTED
{
- PNG_CONST char *msg;
-#ifdef PNG_CONSOLE_IO_SUPPORTED
- char umsg[52];
-#endif
+ png_const_charp msg;
+
if (png_ptr->zstream.msg != 0)
msg = png_ptr->zstream.msg;
- else
+ else switch (ret)
{
-#ifdef PNG_CONSOLE_IO_SUPPORTED
- switch (ret)
- {
- case Z_BUF_ERROR:
- msg = "Buffer error in compressed datastream in %s chunk";
- break;
-
- case Z_DATA_ERROR:
- msg = "Data error in compressed datastream in %s chunk";
- break;
+ case Z_BUF_ERROR:
+ msg = "Buffer error in compressed datastream";
+ break;
- default:
- msg = "Incomplete compressed datastream in %s chunk";
- break;
- }
+ case Z_DATA_ERROR:
+ msg = "Data error in compressed datastream";
+ break;
- png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
- msg = umsg;
-#else
- msg = "Damaged compressed datastream in chunk other than IDAT";
-#endif
+ default:
+ msg = "Incomplete compressed datastream";
+ break;
}
- png_warning(png_ptr, msg);
+ png_chunk_warning(png_ptr, msg);
}
+# endif
/* 0 means an error - notice that this code simply ignores
* zero length compressed chunks as a result.
png_size_t expanded_size = png_inflate(png_ptr,
(png_bytep)(png_ptr->chunkdata + prefix_size),
chunklength - prefix_size,
- 0, /*output*/
- 0); /*output 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 &&
+ if (prefix_size >= (~(png_size_t)0) - 1 ||
+ expanded_size >= (~(png_size_t)0) - 1 - prefix_size
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ || (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) &&
+ || ((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
* 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_malloc_warn(png_ptr,
+ png_charp text = (png_charp)png_malloc_warn(png_ptr,
prefix_size + expanded_size + 1);
if (text != NULL)
else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
{
-#ifdef PNG_STDIO_SUPPORTED
- char umsg[50];
-
- png_snprintf(umsg, sizeof umsg,
- "Unknown zTXt compression type %d", comp_type);
- png_warning(png_ptr, umsg);
-#else
- png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+ 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. */
}
* amount of compressed data.
*/
{
- png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
+ png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1);
if (text != NULL)
{
*newlength = prefix_size;
}
-#endif
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
/* Read and check the IDHR chunk */
void /* PRIVATE */
# ifdef PNG_READ_sRGB_SUPPORTED
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
{
- if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ if (PNG_OUT_OF_RANGE(igamma, 45500, 500))
{
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-
-# ifdef PNG_CONSOLE_IO_SUPPORTED
- fprintf(stderr, "gamma = (%d/100000)", (int)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;
}
}
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");
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
# ifdef PNG_READ_sRGB_SUPPORTED
{
if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) ||
PNG_OUT_OF_RANGE(y_white, 32900, 1000) ||
- PNG_OUT_OF_RANGE(x_red, 64000L, 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, 60000L, 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(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
-
-#ifdef PNG_CONSOLE_IO_SUPPORTED
- fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n",
- x_white, y_white, x_red, y_red);
-
- fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n",
- x_green, y_green, x_blue, y_blue);
-#endif /* PNG_CONSOLE_IO_SUPPORTED */
+ 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 */
+#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_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))
+ {
+ /* 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;
+ }
+
+ /* 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");
+ }
+ }
+ }
+#endif
+
png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
x_green, y_green, x_blue, y_blue);
}
#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
{
- if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500))
+ if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500))
{
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-#ifdef PNG_CONSOLE_IO_SUPPORTED
- fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_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 */
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, 64000L, 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, 60000L, 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))
{
}
#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 */
/* 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))
+ if ((png_ptr->mode & PNG_HAVE_iCCP) || (info_ptr != NULL &&
+ (info_ptr->valid & (PNG_INFO_iCCP|PNG_INFO_sRGB))))
{
png_warning(png_ptr, "Duplicate iCCP chunk");
png_crc_finish(png_ptr, length);
return;
}
+ png_ptr->mode |= PNG_HAVE_iCCP;
+
#ifdef PNG_MAX_MALLOC_64K
if (length > (png_uint_32)65535L)
{
png_free(png_ptr, png_ptr->chunkdata);
png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, skip))
/* 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;
-#ifdef PNG_STDIO_SUPPORTED
- {
- char umsg[80];
-
- png_snprintf2(umsg, 80,
- "Ignoring iCCP chunk with declared size = %u "
- "and actual length = %u",
- (unsigned int) profile_size,
- (unsigned int) profile_length);
- png_warning(png_ptr, umsg);
- }
-#else
- png_warning(png_ptr,
- "Ignoring iCCP chunk with uncompressed size mismatch");
-#endif
+
+ 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;
}
* 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;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, skip))
{
png_size_t truelen;
png_byte buf[6];
+ png_color_16 background;
png_debug(1, "in png_handle_bKGD");
*/
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_ptr->background.index = buf[0];
+ background.index = buf[0];
if (info_ptr && info_ptr->num_palette)
{
return;
}
- png_ptr->background.red =
- (png_uint_16)png_ptr->palette[buf[0]].red;
+ 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;
+ }
- png_ptr->background.green =
- (png_uint_16)png_ptr->palette[buf[0]].green;
+ else
+ background.red = background.green = background.blue = 0;
- png_ptr->background.blue =
- (png_uint_16)png_ptr->palette[buf[0]].blue;
- }
+ 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
return;
}
- num = length / 2 ;
-
- if (num != (unsigned int)png_ptr->num_palette || num >
- (unsigned int)PNG_MAX_PALETTE_LENGTH)
+ if (length > 2*PNG_MAX_PALETTE_LENGTH ||
+ length != (unsigned int) (2*png_ptr->num_palette))
{
png_warning(png_ptr, "Incorrect hIST chunk length");
png_crc_finish(png_ptr, length);
return;
}
+ num = length / 2 ;
+
for (i = 0; i < num; i++)
{
png_byte buf[2];
return;
}
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, 0))
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);
return;
}
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
/* Validate the ASCII numbers, need two ASCII numbers separated by
* a '\0' and they need to fit exactly in the chunk data.
*/
- i = 0;
+ i = 1;
state = 0;
- if (png_ptr->chunkdata[1] == 45 /* negative width */ ||
- !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+ 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;
- if (png_ptr->chunkdata[i] == 45 /* negative height */ ||
- !png_check_fp_number(png_ptr->chunkdata, slength, &state, &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],
return;
}
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, skip))
return;
}
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, 0))
png_textp text_ptr;
png_charp key, lang, text, lang_key;
int comp_flag;
- int comp_type = 0;
+ int comp_type;
int ret;
png_size_t slength, prefix_len, data_len;
return;
}
- slength = (png_size_t)length;
+ slength = length;
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
if (png_crc_finish(png_ptr, 0))
return;
}
- else
+ comp_flag = *lang++;
+ comp_type = *lang++;
+
+ /* 1.5.14: The spec says "for uncompressed text decoders shall ignore [the
+ * compression type]". The compression flag shall be 0 (no compression) or
+ * 1 (compressed with method 0 - deflate.)
+ */
+ if (comp_flag != 0 && comp_flag != 1)
+ {
+ png_warning(png_ptr, "invalid iTXt compression flag");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ if (comp_flag/*compressed*/ && comp_type != 0)
{
- comp_flag = *lang++;
- comp_type = *lang++;
+ png_warning(png_ptr, "unknown iTXt compression type");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
}
for (lang_key = lang; *lang_key; lang_key++)
key=png_ptr->chunkdata;
- if (comp_flag)
+ if (comp_flag/*compressed*/)
png_decompress_chunk(png_ptr, comp_type,
(size_t)length, prefix_len, &data_len);
return;
}
- text_ptr->compression = (int)comp_flag + 1;
+ text_ptr->compression =
+ (comp_flag ? PNG_ITXT_COMPRESSION_zTXt : PNG_ITXT_COMPRESSION_NONE);
text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
text_ptr->lang = png_ptr->chunkdata + (lang - key);
text_ptr->itxt_length = data_len;
if (png_ptr->mode & PNG_HAVE_IDAT)
{
- PNG_IDAT;
-
- if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */
+ if (png_ptr->chunk_name != png_IDAT)
png_ptr->mode |= PNG_AFTER_IDAT;
}
- if (!(png_ptr->chunk_name[0] & 0x20))
+ if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
{
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ 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
)
{
#ifdef PNG_MAX_MALLOC_64K
- if (length > (png_uint_32)65535L)
+ if (length > 65535)
{
png_warning(png_ptr, "unknown chunk too large to fit in memory");
- skip = length - (png_uint_32)65535L;
- length = (png_uint_32)65535L;
+ skip = length - 65535;
+ length = 65535;
}
#endif
- png_memcpy((png_charp)png_ptr->unknown_chunk.name,
- (png_charp)png_ptr->chunk_name,
- png_sizeof(png_ptr->unknown_chunk.name));
-
- png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]
- = '\0';
-
+ /* 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)
else
{
png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
- png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+ png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
}
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
if (ret == 0)
{
- if (!(png_ptr->chunk_name[0] & 0x20))
+ if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
{
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
PNG_HANDLE_CHUNK_ALWAYS)
#endif
png_chunk_error(png_ptr, "unknown critical chunk");
* the chunk name itself is valid.
*/
-#define isnonalpha(c) ((c) < 65 || (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 /* PRIVATE */
-png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name)
+png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name)
{
+ int i;
+
png_debug(1, "in png_check_chunk_name");
- if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
- isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+
+ 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 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 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 pixel 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.
+/* 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 row, int mask)
+png_combine_row(png_structp png_ptr, png_bytep dp, int display)
{
+ 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");
- if (mask == 0xff)
+ /* 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_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
+ /* 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)
- {
- case 1:
- {
- png_bytep sp = png_ptr->row_buf + 1;
- png_bytep dp = row;
- int s_inc, s_start, s_end;
- int m = 0x80;
- int shift;
- png_uint_32 i;
- png_uint_32 row_width = png_ptr->width;
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 7;
- s_inc = 1;
- }
+ /* 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;
- else
-#endif
- {
- s_start = 7;
- s_end = 0;
- s_inc = -1;
- }
+ if (pixel_depth < 8)
+ {
+ /* 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))))
- shift = s_start;
+ /* 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)
- for (i = 0; i < row_width; i++)
- {
- if (m & mask)
- {
- int value;
+ /* 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)))
- value = (*sp >> shift) & 0x01;
- *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
- }
+# 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)
- if (shift == s_end)
- {
- shift = s_start;
- sp++;
- dp++;
- }
+# 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)
- else
- shift += s_inc;
+#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) }
- if (m == 1)
- m = 0x80;
+# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
- else
- m >>= 1;
- }
- break;
- }
+# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
- case 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_ptr->row_buf + 1;
- png_bytep dp = row;
- int s_start, s_end, s_inc;
- int m = 0x80;
- int shift;
- png_uint_32 i;
- png_uint_32 row_width = png_ptr->width;
- int value;
+ /* 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
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 6;
- s_inc = 2;
- }
+ mask = MASK(pass, pixel_depth, display, 0);
else
-#endif
+# endif
+ mask = MASK(pass, pixel_depth, display, 1);
+
+ for (;;)
+ {
+ png_uint_32 m;
+
+ /* 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 != 0) /* something to copy */
{
- s_start = 6;
- s_end = 0;
- s_inc = -2;
+ if (m != 0xff)
+ *dp = (png_byte)((*dp & ~m) | (*sp & m));
+ else
+ *dp = *sp;
}
- shift = s_start;
+ /* 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 */
- for (i = 0; i < row_width; i++)
- {
- if (m & mask)
- {
- value = (*sp >> shift) & 0x03;
- *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
- }
+ row_width -= pixels_per_byte;
+ ++dp;
+ ++sp;
+ }
+ }
- if (shift == s_end)
- {
- shift = s_start;
- sp++;
- dp++;
- }
+ else /* pixel_depth >= 8 */
+ {
+ unsigned int bytes_to_copy, bytes_to_jump;
- else
- shift += s_inc;
+ /* Validate the depth - it must be a multiple of 8 */
+ if (pixel_depth & 7)
+ png_error(png_ptr, "invalid user transform pixel depth");
- if (m == 1)
- m = 0x80;
+ pixel_depth >>= 3; /* now in bytes */
+ row_width *= pixel_depth;
- else
- m >>= 1;
- }
- break;
+ /* 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.
+ */
+ {
+ unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
+
+ row_width -= offset;
+ dp += offset;
+ sp += offset;
}
- case 4:
+ /* Work out the bytes to copy. */
+ if (display)
{
- png_bytep sp = png_ptr->row_buf + 1;
- png_bytep dp = row;
- int s_start, s_end, s_inc;
- int m = 0x80;
- int shift;
- png_uint_32 i;
- png_uint_32 row_width = png_ptr->width;
- int value;
+ /* 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;
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 4;
- s_inc = 4;
- }
+ /* But don't allow this number to exceed the actual row width. */
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = row_width;
+ }
- else
-#endif
- {
- s_start = 4;
- s_end = 0;
- s_inc = -4;
- }
- shift = s_start;
+ else /* normal row; Adam7 only ever gives us one pixel to copy. */
+ bytes_to_copy = pixel_depth;
- for (i = 0; i < row_width; i++)
- {
- if (m & mask)
+ /* 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;
}
+ while (row_width > 1);
- else
- shift += s_inc;
+ /* And there can only be one byte left at this point: */
+ *dp = *sp;
+ return;
- if (m == 1)
- m = 0x80;
+ 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];
- else
- m >>= 1;
- }
- break;
- }
+ if (row_width <= bytes_to_jump)
+ return;
- default:
- {
- png_bytep sp = png_ptr->row_buf + 1;
- png_bytep dp = row;
- png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
- png_uint_32 i;
- png_uint_32 row_width = png_ptr->width;
- png_byte m = 0x80;
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
- for (i = 0; i < row_width; i++)
- {
- if (m & mask)
+ 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;
+ if (row_width <= bytes_to_jump)
+ return;
- else
- m >>= 1;
- }
- break;
+ 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));
}
#ifdef PNG_READ_INTERLACING_SUPPORTED
void /* PRIVATE */
-png_do_read_interlace(png_structp png_ptr)
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+ png_uint_32 transformations /* Because these may affect the byte layout */)
{
- png_row_infop row_info = &(png_ptr->row_info);
- png_bytep row = png_ptr->row_buf + 1;
- int pass = png_ptr->pass;
- png_uint_32 transformations = png_ptr->transformations;
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Offset to next interlace block */
- PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ 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)
for (i = 0; i < row_info->width; i++)
{
- png_byte v = (png_byte)((*sp >> sshift) & 0xf);
+ png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
int j;
for (j = 0; j < jstop; j++)
}
break;
}
+
default:
{
png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
break;
}
}
+
row_info->width = final_width;
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
}
}
#endif /* PNG_READ_INTERLACING_SUPPORTED */
-void /* PRIVATE */
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
- png_const_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");
- png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter);
- switch (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)
+
+ for (i = bpp; i < istop; i++)
{
- case PNG_FILTER_VALUE_NONE:
- break;
+ *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+ rp++;
+ }
+}
- case PNG_FILTER_VALUE_SUB:
- {
- 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_bytep lp = row;
+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 = bpp; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
- rp++;
- }
- break;
- }
- case PNG_FILTER_VALUE_UP:
- {
- 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++;
+ }
+}
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
- rp++;
- }
- break;
- }
- case PNG_FILTER_VALUE_AVG:
- {
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- png_bytep lp = 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);
+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;
- rp++;
- }
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp++ + *lp++) / 2 ) & 0xff);
+ rp++;
+ }
- rp++;
- }
- break;
- }
- case PNG_FILTER_VALUE_PAETH:
- {
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- png_bytep lp = row;
- png_const_bytep cp = 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++)) & 0xff);
- rp++;
- }
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
- for (i = 0; i < istop; i++) /* Use leftover rp,pp */
- {
- int a, b, c, pa, pb, pc, p;
+ rp++;
+ }
+}
- a = *lp++;
- b = *pp++;
- c = *cp++;
+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;
- p = b - c;
- pc = a - c;
+ /* First pixel/byte */
+ c = *prev_row++;
+ a = *row + c;
+ *row++ = (png_byte)a;
-#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
+ /* Remainder */
+ while (row < rp_end)
+ {
+ int b, pa, pb, pc, p;
- /*
- if (pa <= pb && pa <= pc)
- p = a;
+ a &= 0xff; /* From previous iteration or start */
+ b = *prev_row++;
- else if (pb <= pc)
- p = b;
+ p = b - c;
+ pc = a - c;
- else
- p = 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
- p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
+ /* 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;
- *rp = (png_byte)(((int)(*rp) + p) & 0xff);
- rp++;
- }
- break;
- }
- default:
- png_error(png_ptr, "Ignoring bad adaptive filter type");
- /*NOT REACHED */
- break;
+ /* 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;
+ }
+}
+
+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_FILTER_OPTIMIZATIONS
+ /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+ * call to install hardware optimizations for the above functions; simply
+ * replace whatever elements of the pp->read_filter[] array with a hardware
+ * specific (or, for that matter, generic) optimization.
+ *
+ * To see an example of this examine what configure.ac does when
+ * --enable-arm-neon is specified on the command line.
+ */
+ PNG_FILTER_OPTIMIZATIONS(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);
+}
+
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void /* PRIVATE */
png_read_finish_row(png_structp png_ptr)
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
- PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
/* Offset to next interlace block */
- PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
/* Start of interlace block in the y direction */
- PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+ 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 */
- PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+ 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 = 0;
+ /* 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
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
{
- PNG_IDAT;
char extra;
int ret;
{
png_crc_finish(png_ptr, 0);
png_ptr->idat_size = png_read_chunk_header(png_ptr);
- if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ if (png_ptr->chunk_name != png_IDAT)
png_error(png_ptr, "Not enough image data");
}
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
- PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
/* Offset to next interlace block */
- PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
/* Start of interlace block in the y direction */
- PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+ 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 */
- PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
#endif
int max_pixel_depth;
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)
{
max_pixel_depth = png_ptr->pixel_depth;
+ /* 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;
#ifdef PNG_READ_FILLER_SUPPORTED
if (png_ptr->transformations & (PNG_FILLER))
{
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- max_pixel_depth = 32;
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
if (max_pixel_depth <= 8)
max_pixel_depth = 16;
max_pixel_depth = 32;
}
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ 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;
defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
if (png_ptr->transformations & PNG_USER_TRANSFORM)
{
- int user_pixel_depth = png_ptr->user_transform_depth*
+ 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;
+ 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
*/
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_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
- png_ptr->old_big_row_buf_size = 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.
+ * 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_ptr->row_buf = png_ptr->big_row_buf + 32 -
- (((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F);
+ {
+ 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*/;
+ }
- png_ptr->old_big_row_buf_size = row_bytes + 48;
#else
- /* Use 32 bytes of padding before and 16 bytes after row_buf. */
- png_ptr->row_buf = png_ptr->big_row_buf + 32;
+ /* 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;
}
if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
png_error(png_ptr, "Row has too many bytes to allocate in memory");
- if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size)
- {
- png_free(png_ptr, png_ptr->prev_row);
-
- png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
-
- png_ptr->old_prev_row_size = png_ptr->rowbytes + 1;
- }
-
png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
png_debug1(3, "width = %u,", png_ptr->width);
projects / reactos.git / blobdiff