/* png.c - location for general purpose libpng functions
*
- * Last changed in libpng 1.6.19 [November 12, 2015]
- * Copyright (c) 1998-2002,2004,2006-2015 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.)
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
#include "pngpriv.h"
/* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_21 Your_png_h_is_not_version_1_6_21;
+typedef png_libpng_version_1_6_36 Your_png_h_is_not_version_1_6_36;
+
+#ifdef __GNUC__
+/* The version tests may need to be added to, but the problem warning has
+ * consistently been fixed in GCC versions which obtain wide-spread release.
+ * The problem is that many versions of GCC rearrange comparison expressions in
+ * the optimizer in such a way that the results of the comparison will change
+ * if signed integer overflow occurs. Such comparisons are not permitted in
+ * ANSI C90, however GCC isn't clever enough to work out that that do not occur
+ * below in png_ascii_from_fp and png_muldiv, so it produces a warning with
+ * -Wextra. Unfortunately this is highly dependent on the optimizer and the
+ * machine architecture so the warning comes and goes unpredictably and is
+ * impossible to "fix", even were that a good idea.
+ */
+#if __GNUC__ == 7 && __GNUC_MINOR__ == 1
+#define GCC_STRICT_OVERFLOW 1
+#endif /* GNU 7.1.x */
+#endif /* GNU */
+#ifndef GCC_STRICT_OVERFLOW
+#define GCC_STRICT_OVERFLOW 0
+#endif
/* Tells libpng that we have already handled the first "num_bytes" bytes
* of the PNG file signature. If the PNG data is embedded into another
* PNG signature (this is the same behavior as strcmp, memcmp, etc).
*/
int PNGAPI
-png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
+png_sig_cmp(png_const_bytep sig, size_t start, size_t num_to_check)
{
png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
if (items >= (~(png_alloc_size_t)0)/size)
{
png_warning (png_voidcast(png_structrp, png_ptr),
- "Potential overflow in png_zalloc()");
+ "Potential overflow in png_zalloc()");
return NULL;
}
* trouble of calculating it.
*/
void /* PRIVATE */
-png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length)
+png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, size_t length)
{
int need_crc = 1;
int
png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
{
- /* Libpng versions 1.0.0 and later are binary compatible if the version
- * string matches through the second '.'; we must recompile any
- * applications that use any older library version.
- */
+ /* Libpng versions 1.0.0 and later are binary compatible if the version
+ * string matches through the second '.'; we must recompile any
+ * applications that use any older library version.
+ */
if (user_png_ver != NULL)
{
if (png_user_version_check(&create_struct, user_png_ver) != 0)
{
png_structrp png_ptr = png_voidcast(png_structrp,
- png_malloc_warn(&create_struct, (sizeof *png_ptr)));
+ png_malloc_warn(&create_struct, (sizeof *png_ptr)));
if (png_ptr != NULL)
{
* has always been done in 'example.c'.
*/
info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
- (sizeof *info_ptr)));
+ (sizeof *info_ptr)));
if (info_ptr != NULL)
memset(info_ptr, 0, (sizeof *info_ptr));
* those cases where it does anything other than a memset.
*/
PNG_FUNCTION(void,PNGAPI
-png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size),
- PNG_DEPRECATED)
+png_info_init_3,(png_infopp ptr_ptr, size_t png_info_struct_size),
+ PNG_DEPRECATED)
{
png_inforp info_ptr = *ptr_ptr;
/* The following line is why this API should not be used: */
free(info_ptr);
info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL,
- (sizeof *info_ptr)));
+ (sizeof *info_ptr)));
if (info_ptr == NULL)
return;
*ptr_ptr = info_ptr;
/* The following API is not called internally */
void PNGAPI
png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr,
- int freer, png_uint_32 mask)
+ int freer, png_uint_32 mask)
{
png_debug(1, "in png_data_freer");
void PNGAPI
png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
- int num)
+ int num)
{
png_debug(1, "in png_free_data");
#ifdef PNG_TEXT_SUPPORTED
/* Free text item num or (if num == -1) all text items */
- if (info_ptr->text != 0 &&
+ if (info_ptr->text != NULL &&
((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0)
{
if (num != -1)
png_free(png_ptr, info_ptr->text);
info_ptr->text = NULL;
info_ptr->num_text = 0;
+ info_ptr->max_text = 0;
}
}
#endif
#ifdef PNG_sPLT_SUPPORTED
/* Free a given sPLT entry, or (if num == -1) all sPLT entries */
- if (info_ptr->splt_palettes != 0 &&
+ if (info_ptr->splt_palettes != NULL &&
((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0)
{
if (num != -1)
#endif
#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- if (info_ptr->unknown_chunks != 0 &&
+ if (info_ptr->unknown_chunks != NULL &&
((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0)
{
if (num != -1)
}
#endif
+#ifdef PNG_eXIf_SUPPORTED
+ /* Free any eXIf entry */
+ if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0)
+ {
+# ifdef PNG_READ_eXIf_SUPPORTED
+ if (info_ptr->eXIf_buf)
+ {
+ png_free(png_ptr, info_ptr->eXIf_buf);
+ info_ptr->eXIf_buf = NULL;
+ }
+# endif
+ if (info_ptr->exif)
+ {
+ png_free(png_ptr, info_ptr->exif);
+ info_ptr->exif = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_eXIf;
+ }
+#endif
+
#ifdef PNG_hIST_SUPPORTED
/* Free any hIST entry */
if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0)
/* Free any image bits attached to the info structure */
if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0)
{
- if (info_ptr->row_pointers != 0)
+ if (info_ptr->row_pointers != NULL)
{
png_uint_32 row;
for (row = 0; row < info_ptr->height; row++)
void PNGAPI
png_save_int_32(png_bytep buf, png_int_32 i)
{
- png_save_uint_32(buf, i);
+ png_save_uint_32(buf, (png_uint_32)i);
}
# endif
int PNGAPI
png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime)
{
- static PNG_CONST char short_months[12][4] =
+ static const char short_months[12][4] =
{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
#ifdef PNG_STRING_COPYRIGHT
return PNG_STRING_COPYRIGHT
#else
-# ifdef __STDC__
return PNG_STRING_NEWLINE \
- "libpng version 1.6.21 - January 15, 2016" PNG_STRING_NEWLINE \
- "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \
+ "libpng version 1.6.36" PNG_STRING_NEWLINE \
+ "Copyright (c) 2018 Cosmin Truta" PNG_STRING_NEWLINE \
+ "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
PNG_STRING_NEWLINE \
"Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
"Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
PNG_STRING_NEWLINE;
-# else
- return "libpng version 1.6.21 - January 15, 2016\
- Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\
- Copyright (c) 1996-1997 Andreas Dilger\
- Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
-# endif
#endif
}
/* The code is the fifth byte after each four byte string. Historically this
* code was always searched from the end of the list, this is no longer
- * necessary because the 'set' routine handles duplicate entries correcty.
+ * necessary because the 'set' routine handles duplicate entries correctly.
*/
do /* num_chunk_list > 0, so at least one */
{
#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */
static int
png_colorspace_check_gamma(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_fixed_point gAMA, int from)
+ png_colorspacerp colorspace, png_fixed_point gAMA, int from)
/* This is called to check a new gamma value against an existing one. The
* routine returns false if the new gamma value should not be written.
*
png_fixed_point gtest;
if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
- (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 ||
+ (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 ||
png_gamma_significant(gtest) != 0))
{
/* Either this is an sRGB image, in which case the calculated gamma
if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2)
{
png_chunk_report(png_ptr, "gamma value does not match sRGB",
- PNG_CHUNK_ERROR);
+ PNG_CHUNK_ERROR);
/* Do not overwrite an sRGB value */
return from == 2;
}
else /* sRGB tag not involved */
{
png_chunk_report(png_ptr, "gamma value does not match libpng estimate",
- PNG_CHUNK_WARNING);
+ PNG_CHUNK_WARNING);
return from == 1;
}
}
void /* PRIVATE */
png_colorspace_set_gamma(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_fixed_point gAMA)
+ png_colorspacerp colorspace, png_fixed_point gAMA)
{
/* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
- * occur. Since the fixed point representation is asymetrical it is
+ * occur. Since the fixed point representation is asymmetrical it is
* possible for 1/gamma to overflow the limit of 21474 and this means the
* gamma value must be at least 5/100000 and hence at most 20000.0. For
* safety the limits here are a little narrower. The values are 0.00016 to
static int
png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
- int preferred)
+ png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
+ int preferred)
{
if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
return 0;
int /* PRIVATE */
png_colorspace_set_chromaticities(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_xy *xy, int preferred)
+ png_colorspacerp colorspace, const png_xy *xy, int preferred)
{
/* We must check the end points to ensure they are reasonable - in the past
* color management systems have crashed as a result of getting bogus
{
case 0: /* success */
return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ,
- preferred);
+ preferred);
case 1:
/* We can't invert the chromaticities so we can't produce value XYZ
int /* PRIVATE */
png_colorspace_set_endpoints(png_const_structrp png_ptr,
- png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
+ png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
{
png_XYZ XYZ = *XYZ_in;
png_xy xy;
{
case 0:
return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ,
- preferred);
+ preferred);
case 1:
/* End points are invalid. */
static int
png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_alloc_size_t value, png_const_charp reason)
+ png_const_charp name, png_alloc_size_t value, png_const_charp reason)
{
size_t pos;
char message[196]; /* see below for calculation */
char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
pos = png_safecat(message, (sizeof message), pos,
- png_format_number(number, number+(sizeof number),
- PNG_NUMBER_FORMAT_x, value));
+ png_format_number(number, number+(sizeof number),
+ PNG_NUMBER_FORMAT_x, value));
pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
}
# endif
* application errors the PNG won't be written.)
*/
png_chunk_report(png_ptr, message,
- (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
+ (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
return 0;
}
#ifdef PNG_sRGB_SUPPORTED
int /* PRIVATE */
png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
- int intent)
+ int intent)
{
/* sRGB sets known gamma, end points and (from the chunk) intent. */
/* IMPORTANT: these are not necessarily the values found in an ICC profile
*/
if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST)
return png_icc_profile_error(png_ptr, colorspace, "sRGB",
- (unsigned)intent, "invalid sRGB rendering intent");
+ (png_alloc_size_t)intent, "invalid sRGB rendering intent");
if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 &&
- colorspace->rendering_intent != intent)
+ colorspace->rendering_intent != intent)
return png_icc_profile_error(png_ptr, colorspace, "sRGB",
- (unsigned)intent, "inconsistent rendering intents");
+ (png_alloc_size_t)intent, "inconsistent rendering intents");
if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0)
{
* warn but overwrite the value with the correct one.
*/
if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 &&
- !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
- 100))
+ !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
+ 100))
png_chunk_report(png_ptr, "cHRM chunk does not match sRGB",
PNG_CHUNK_ERROR);
* returns true when the 'from' argument corresponds to sRGB (2).
*/
(void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE,
- 2/*from sRGB*/);
+ 2/*from sRGB*/);
/* intent: bugs in GCC force 'int' to be used as the parameter type. */
colorspace->rendering_intent = (png_uint_16)intent;
static const png_byte D50_nCIEXYZ[12] =
{ 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
-int /* PRIVATE */
-png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length)
+static int /* bool */
+icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length)
{
if (profile_length < 132)
return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
- "too short");
+ "too short");
+ return 1;
+}
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+int /* PRIVATE */
+png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+ png_const_charp name, png_uint_32 profile_length)
+{
+ if (!icc_check_length(png_ptr, colorspace, name, profile_length))
+ return 0;
+
+ /* This needs to be here because the 'normal' check is in
+ * png_decompress_chunk, yet this happens after the attempt to
+ * png_malloc_base the required data. We only need this on read; on write
+ * the caller supplies the profile buffer so libpng doesn't allocate it. See
+ * the call to icc_check_length below (the write case).
+ */
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ else if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < profile_length)
+ return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+ "exceeds application limits");
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+ else if (PNG_USER_CHUNK_MALLOC_MAX < profile_length)
+ return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+ "exceeds libpng limits");
+# else /* !SET_USER_LIMITS */
+ /* This will get compiled out on all 32-bit and better systems. */
+ else if (PNG_SIZE_MAX < profile_length)
+ return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+ "exceeds system limits");
+# endif /* !SET_USER_LIMITS */
return 1;
}
+#endif /* READ_iCCP */
int /* PRIVATE */
png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length,
- png_const_bytep profile/* first 132 bytes only */, int color_type)
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile/* first 132 bytes only */, int color_type)
{
png_uint_32 temp;
temp = png_get_uint_32(profile);
if (temp != profile_length)
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "length does not match profile");
+ "length does not match profile");
temp = (png_uint_32) (*(profile+8));
if (temp > 3 && (profile_length & 3))
return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
- "invalid length");
+ "invalid length");
temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
profile_length < 132+12*temp) /* truncated tag table */
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "tag count too large");
+ "tag count too large");
/* The 'intent' must be valid or we can't store it, ICC limits the intent to
* 16 bits.
temp = png_get_uint_32(profile+64);
if (temp >= 0xffff) /* The ICC limit */
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid rendering intent");
+ "invalid rendering intent");
/* This is just a warning because the profile may be valid in future
* versions.
*/
if (temp >= PNG_sRGB_INTENT_LAST)
(void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "intent outside defined range");
+ "intent outside defined range");
/* At this point the tag table can't be checked because it hasn't necessarily
* been loaded; however, various header fields can be checked. These checks
*/
/* Data checks (could be skipped). These checks must be independent of the
- * version number; however, the version number doesn't accomodate changes in
+ * version number; however, the version number doesn't accommodate changes in
* the header fields (just the known tags and the interpretation of the
* data.)
*/
temp = png_get_uint_32(profile+36); /* signature 'ascp' */
if (temp != 0x61637370)
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid signature");
+ "invalid signature");
/* Currently the PCS illuminant/adopted white point (the computational
* white point) are required to be D50,
*/
if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
(void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/,
- "PCS illuminant is not D50");
+ "PCS illuminant is not D50");
/* The PNG spec requires this:
* "If the iCCP chunk is present, the image samples conform to the colour
case 0x52474220: /* 'RGB ' */
if ((color_type & PNG_COLOR_MASK_COLOR) == 0)
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "RGB color space not permitted on grayscale PNG");
+ "RGB color space not permitted on grayscale PNG");
break;
case 0x47524159: /* 'GRAY' */
if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "Gray color space not permitted on RGB PNG");
+ "Gray color space not permitted on RGB PNG");
break;
default:
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid ICC profile color space");
+ "invalid ICC profile color space");
}
/* It is up to the application to check that the profile class matches the
case 0x61627374: /* 'abst' */
/* May not be embedded in an image */
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "invalid embedded Abstract ICC profile");
+ "invalid embedded Abstract ICC profile");
case 0x6c696e6b: /* 'link' */
/* DeviceLink profiles cannot be interpreted in a non-device specific
* PNG.
*/
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "unexpected DeviceLink ICC profile class");
+ "unexpected DeviceLink ICC profile class");
case 0x6e6d636c: /* 'nmcl' */
/* A NamedColor profile is also device specific, however it doesn't
* certainly it will fail the tests below.
*/
(void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "unexpected NamedColor ICC profile class");
+ "unexpected NamedColor ICC profile class");
break;
default:
* understood profiles.
*/
(void)png_icc_profile_error(png_ptr, NULL, name, temp,
- "unrecognized ICC profile class");
+ "unrecognized ICC profile class");
break;
}
default:
return png_icc_profile_error(png_ptr, colorspace, name, temp,
- "unexpected ICC PCS encoding");
+ "unexpected ICC PCS encoding");
}
return 1;
int /* PRIVATE */
png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length,
- png_const_bytep profile /* header plus whole tag table */)
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile /* header plus whole tag table */)
{
png_uint_32 tag_count = png_get_uint_32(profile+128);
png_uint_32 itag;
* being in range. All defined tag types have an 8 byte header - a 4 byte
* type signature then 0.
*/
+
+ /* This is a hard error; potentially it can cause read outside the
+ * profile.
+ */
+ if (tag_start > profile_length || tag_length > profile_length - tag_start)
+ return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
+ "ICC profile tag outside profile");
+
if ((tag_start & 3) != 0)
{
- /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is
+ /* CNHP730S.icc shipped with Microsoft Windows 64 violates this; it is
* only a warning here because libpng does not care about the
* alignment.
*/
(void)png_icc_profile_error(png_ptr, NULL, name, tag_id,
- "ICC profile tag start not a multiple of 4");
+ "ICC profile tag start not a multiple of 4");
}
-
- /* This is a hard error; potentially it can cause read outside the
- * profile.
- */
- if (tag_start > profile_length || tag_length > profile_length - tag_start)
- return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
- "ICC profile tag outside profile");
}
return 1; /* success, maybe with warnings */
*/
/* adler32, crc32, MD5[4], intent, date, length, file-name */
PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9,
- PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
- "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
+ PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
+ "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
/* ICC sRGB v2 perceptual no black-compensation: */
PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21,
- PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
- "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
+ PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
+ "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae,
- PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
- "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
+ PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
+ "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
/* ICC sRGB v4 perceptual */
PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812,
- PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
- "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
+ PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
+ "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
/* The following profiles have no known MD5 checksum. If there is a match
* on the (empty) MD5 the other fields are used to attempt a match and
* which suggests that they were also made by Hewlett Packard.
*/
PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
- "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
+ "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
/* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not
* match the D50 PCS illuminant in the header (it is in fact the D65 values,
* chromaticAdaptationTag.
*/
PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
- "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
+ "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d,
- PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
- "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
+ PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
+ "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
};
static int
png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
- png_const_bytep profile, uLong adler)
+ png_const_bytep profile, uLong adler)
{
/* The quick check is to verify just the MD5 signature and trust the
* rest of the data. Because the profile has already been verified for
* which is made irrelevant by this error.
*/
png_chunk_report(png_ptr, "known incorrect sRGB profile",
- PNG_CHUNK_ERROR);
+ PNG_CHUNK_ERROR);
}
/* Warn that this being done; this isn't even an error since
else if (png_sRGB_checks[i].have_md5 == 0)
{
png_chunk_report(png_ptr,
- "out-of-date sRGB profile with no signature",
- PNG_CHUNK_WARNING);
+ "out-of-date sRGB profile with no signature",
+ PNG_CHUNK_WARNING);
}
return 1+png_sRGB_checks[i].is_broken;
return 0; /* no match */
}
-#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
void /* PRIVATE */
png_icc_set_sRGB(png_const_structrp png_ptr,
- png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
+ png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
{
/* Is this profile one of the known ICC sRGB profiles? If it is, just set
* the sRGB information.
*/
-#if PNG_sRGB_PROFILE_CHECKS >= 0
if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0)
-#endif
(void)png_colorspace_set_sRGB(png_ptr, colorspace,
(int)/*already checked*/png_get_uint_32(profile+64));
}
+#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
#endif /* sRGB */
int /* PRIVATE */
png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
- png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
- int color_type)
+ png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
+ int color_type)
{
if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
return 0;
- if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
+ if (icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
- color_type) != 0 &&
+ color_type) != 0 &&
png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
- profile) != 0)
+ profile) != 0)
{
-# ifdef PNG_sRGB_SUPPORTED
+# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
/* If no sRGB support, don't try storing sRGB information */
png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
# endif
/* Check for an internal error. */
if (r+g+b != 32768)
png_error(png_ptr,
- "internal error handling cHRM coefficients");
+ "internal error handling cHRM coefficients");
else
{
static int /* PRIVATE */
png_gt(size_t a, size_t b)
{
- return a > b;
+ return a > b;
}
#else
# define png_gt(a,b) ((a) > (b))
void /* PRIVATE */
png_check_IHDR(png_const_structrp png_ptr,
- png_uint_32 width, png_uint_32 height, int bit_depth,
- int color_type, int interlace_type, int compression_type,
- int filter_type)
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
{
int error = 0;
error = 1;
}
- if (png_gt(((width + 7) & (~7)),
+ if (png_gt(((width + 7) & (~7U)),
((PNG_SIZE_MAX
- 48 /* big_row_buf hack */
- 1) /* filter byte */
#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
/* ASCII to fp functions */
-/* Check an ASCII formated floating point value, see the more detailed
+/* Check an ASCII formatted floating point value, see the more detailed
* comments in pngpriv.h
*/
/* The following is used internally to preserve the sticky flags */
#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
int /* PRIVATE */
-png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
- png_size_tp whereami)
+png_check_fp_number(png_const_charp string, size_t size, int *statep,
+ png_size_tp whereami)
{
int state = *statep;
- png_size_t i = *whereami;
+ size_t i = *whereami;
while (i < size)
{
/* The same but for a complete string. */
int
-png_check_fp_string(png_const_charp string, png_size_t size)
+png_check_fp_string(png_const_charp string, size_t size)
{
int state=0;
- png_size_t char_index=0;
+ size_t char_index=0;
if (png_check_fp_number(string, size, &state, &char_index) != 0 &&
(char_index == size || string[char_index] == 0))
if (power < 0)
{
if (power < DBL_MIN_10_EXP) return 0;
- recip = 1, power = -power;
+ recip = 1; power = -power;
}
if (power > 0)
/* Function to format a floating point value in ASCII with a given
* precision.
*/
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic push
+/* The problem arises below with exp_b10, which can never overflow because it
+ * comes, originally, from frexp and is therefore limited to a range which is
+ * typically +/-710 (log2(DBL_MAX)/log2(DBL_MIN)).
+ */
+#pragma GCC diagnostic warning "-Wstrict-overflow=2"
+#endif /* GCC_STRICT_OVERFLOW */
void /* PRIVATE */
-png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
+png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, size_t size,
double fp, unsigned int precision)
{
/* We use standard functions from math.h, but not printf because
double test = png_pow10(exp_b10+1);
if (test <= DBL_MAX)
- ++exp_b10, base = test;
+ {
+ ++exp_b10; base = test;
+ }
else
break;
* test on DBL_MAX above.
*/
fp /= base;
- while (fp >= 1) fp /= 10, ++exp_b10;
+ while (fp >= 1)
+ {
+ fp /= 10; ++exp_b10;
+ }
/* Because of the code above fp may, at this point, be
* less than .1, this is ok because the code below can
*/
if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
{
- czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */
+ czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */
exp_b10 = 0; /* Dot added below before first output. */
}
else
/* Rounding up to 10, handle that here. */
if (czero > 0)
{
- --czero, d = 1;
+ --czero; d = 1;
if (cdigits == 0) --clead;
}
else
else if (ch == 46)
{
- ch = *--ascii, ++size;
+ ch = *--ascii; ++size;
/* Advance exp_b10 to '1', so that the
* decimal point happens after the
* previous digit.
int ch = *--ascii;
if (ch == 46)
- ++size, exp_b10 = 1;
+ {
+ ++size; exp_b10 = 1;
+ }
/* Else lost a leading zero, so 'exp_b10' is
* still ok at (-1)
*/
if (exp_b10 != (-1))
{
- if (exp_b10 == 0) *ascii++ = 46, --size;
+ if (exp_b10 == 0)
+ {
+ *ascii++ = 46; --size;
+ }
/* PLUS 1: TOTAL 4 */
--exp_b10;
}
- *ascii++ = 48, --czero;
+ *ascii++ = 48; --czero;
}
if (exp_b10 != (-1))
{
if (exp_b10 == 0)
- *ascii++ = 46, --size; /* counted above */
+ {
+ *ascii++ = 46; --size; /* counted above */
+ }
--exp_b10;
}
- *ascii++ = (char)(48 + (int)d), ++cdigits;
+ *ascii++ = (char)(48 + (int)d); ++cdigits;
}
}
while (cdigits+czero < precision+clead && fp > DBL_MIN);
/* The total output count (max) is now 4+precision */
/* Check for an exponent, if we don't need one we are
- * done and just need to terminate the string. At
- * this point exp_b10==(-1) is effectively if flag - it got
- * to '-1' because of the decrement after outputting
- * the decimal point above (the exponent required is
- * *not* -1!)
+ * done and just need to terminate the string. At this
+ * point, exp_b10==(-1) is effectively a flag: it got
+ * to '-1' because of the decrement, after outputting
+ * the decimal point above. (The exponent required is
+ * *not* -1.)
*/
if (exp_b10 >= (-1) && exp_b10 <= 2)
{
* zeros were *not* output, so this doesn't increase
* the output count.
*/
- while (--exp_b10 >= 0) *ascii++ = 48;
+ while (exp_b10-- > 0) *ascii++ = 48;
*ascii = 0;
*/
size -= cdigits;
- *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */
+ *ascii++ = 69; --size; /* 'E': PLUS 1 TOTAL 2+precision */
/* The following use of an unsigned temporary avoids ambiguities in
* the signed arithmetic on exp_b10 and permits GCC at least to do
if (exp_b10 < 0)
{
- *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */
- uexp_b10 = -exp_b10;
+ *ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */
+ uexp_b10 = 0U-exp_b10;
}
else
- uexp_b10 = exp_b10;
+ uexp_b10 = 0U+exp_b10;
cdigits = 0;
/* Here on buffer too small. */
png_error(png_ptr, "ASCII conversion buffer too small");
}
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic pop
+#endif /* GCC_STRICT_OVERFLOW */
# endif /* FLOATING_POINT */
*/
void /* PRIVATE */
png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
- png_size_t size, png_fixed_point fp)
+ size_t size, png_fixed_point fp)
{
/* Require space for 10 decimal digits, a decimal point, a minus sign and a
* trailing \0, 13 characters:
/* Avoid overflow here on the minimum integer. */
if (fp < 0)
- *ascii++ = 45, num = -fp;
+ {
+ *ascii++ = 45; num = (png_uint_32)(-fp);
+ }
else
- num = fp;
+ num = (png_uint_32)fp;
if (num <= 0x80000000) /* else overflowed */
{
* then ndigits digits to first:
*/
i = 5;
- while (ndigits < i) *ascii++ = 48, --i;
+ while (ndigits < i)
+ {
+ *ascii++ = 48; --i;
+ }
while (ndigits >= first) *ascii++ = digits[--ndigits];
/* Don't output the trailing zeros! */
}
* the nearest .00001). Overflow and divide by zero are signalled in
* the result, a boolean - true on success, false on overflow.
*/
+#if GCC_STRICT_OVERFLOW /* from above */
+/* It is not obvious which comparison below gets optimized in such a way that
+ * signed overflow would change the result; looking through the code does not
+ * reveal any tests which have the form GCC complains about, so presumably the
+ * optimizer is moving an add or subtract into the 'if' somewhere.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic warning "-Wstrict-overflow=2"
+#endif /* GCC_STRICT_OVERFLOW */
int
png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
png_int_32 divisor)
return 0;
}
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic pop
+#endif /* GCC_STRICT_OVERFLOW */
#endif /* READ_GAMMA || INCH_CONVERSIONS */
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
* of getting this accuracy in practice.
*
* To deal with this the following exp() function works out the exponent of the
- * frational part of the logarithm by using an accurate 32-bit value from the
+ * fractional part of the logarithm by using an accurate 32-bit value from the
* top four fractional bits then multiplying in the remaining bits.
*/
static const png_uint_32
{
if (value > 0 && value < 65535)
{
-# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
- /* The same (unsigned int)->(double) constraints apply here as above,
- * however in this case the (unsigned int) to (int) conversion can
- * overflow on an ANSI-C90 compliant system so the cast needs to ensure
- * that this is not possible.
- */
- double r = floor(65535*pow((png_int_32)value/65535.,
- gamma_val*.00001)+.5);
- return (png_uint_16)r;
-# else
- png_int_32 lg2 = png_log16bit(value);
- png_fixed_point res;
-
- if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
- return png_exp16bit(res);
-
- /* Overflow. */
- value = 0;
-# endif
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* The same (unsigned int)->(double) constraints apply here as above,
+ * however in this case the (unsigned int) to (int) conversion can
+ * overflow on an ANSI-C90 compliant system so the cast needs to ensure
+ * that this is not possible.
+ */
+ double r = floor(65535*pow((png_int_32)value/65535.,
+ gamma_val*.00001)+.5);
+ return (png_uint_16)r;
+# else
+ png_int_32 lg2 = png_log16bit(value);
+ png_fixed_point res;
+
+ if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+ return png_exp16bit(res);
+
+ /* Overflow. */
+ value = 0;
+# endif
}
return (png_uint_16)value;
*/
static void
png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable,
- PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+ unsigned int shift, png_fixed_point gamma_val)
{
/* Various values derived from 'shift': */
- PNG_CONST unsigned int num = 1U << (8U - shift);
+ unsigned int num = 1U << (8U - shift);
#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
/* CSE the division and work round wacky GCC warnings (see the comments
* in png_gamma_8bit_correct for where these come from.)
*/
- PNG_CONST double fmax = 1./(((png_int_32)1 << (16U - shift))-1);
+ double fmax = 1.0 / (((png_int_32)1 << (16U - shift)) - 1);
#endif
- PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
- PNG_CONST unsigned int max_by_2 = 1U << (15U-shift);
+ unsigned int max = (1U << (16U - shift)) - 1U;
+ unsigned int max_by_2 = 1U << (15U - shift);
unsigned int i;
png_uint_16pp table = *ptable =
*/
static void
png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
- PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+ unsigned int shift, png_fixed_point gamma_val)
{
- PNG_CONST unsigned int num = 1U << (8U - shift);
- PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+ unsigned int num = 1U << (8U - shift);
+ unsigned int max = (1U << (16U - shift))-1U;
unsigned int i;
png_uint_32 last;
*/
static void
png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable,
- PNG_CONST png_fixed_point gamma_val)
+ png_fixed_point gamma_val)
{
unsigned int i;
png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
void /* PRIVATE */
png_build_gamma_table(png_structrp png_ptr, int bit_depth)
{
- png_debug(1, "in png_build_gamma_table");
-
- /* Remove any existing table; this copes with multiple calls to
- * png_read_update_info. The warning is because building the gamma tables
- * multiple times is a performance hit - it's harmless but the ability to call
- * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible
- * to warn if the app introduces such a hit.
- */
- if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
- {
- png_warning(png_ptr, "gamma table being rebuilt");
- png_destroy_gamma_table(png_ptr);
- }
-
- if (bit_depth <= 8)
- {
- png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
- png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
+ png_debug(1, "in png_build_gamma_table");
+
+ /* Remove any existing table; this copes with multiple calls to
+ * png_read_update_info. The warning is because building the gamma tables
+ * multiple times is a performance hit - it's harmless but the ability to
+ * call png_read_update_info() multiple times is new in 1.5.6 so it seems
+ * sensible to warn if the app introduces such a hit.
+ */
+ if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
+ {
+ png_warning(png_ptr, "gamma table being rebuilt");
+ png_destroy_gamma_table(png_ptr);
+ }
+
+ if (bit_depth <= 8)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
+ png_ptr->screen_gamma > 0 ?
+ png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
- {
- png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
- png_reciprocal(png_ptr->colorspace.gamma));
-
- png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
- png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
- png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
- }
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
+ png_reciprocal(png_ptr->colorspace.gamma));
+
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
+ png_ptr->screen_gamma > 0 ?
+ png_reciprocal(png_ptr->screen_gamma) :
+ png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+ }
#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
- }
+ }
#ifdef PNG_16BIT_SUPPORTED
- else
- {
- png_byte shift, sig_bit;
-
- if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
- {
- sig_bit = png_ptr->sig_bit.red;
-
- if (png_ptr->sig_bit.green > sig_bit)
- sig_bit = png_ptr->sig_bit.green;
-
- if (png_ptr->sig_bit.blue > sig_bit)
- sig_bit = png_ptr->sig_bit.blue;
- }
- else
- sig_bit = png_ptr->sig_bit.gray;
-
- /* 16-bit gamma code uses this equation:
- *
- * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
- *
- * Where 'iv' is the input color value and 'ov' is the output value -
- * pow(iv, gamma).
- *
- * Thus the gamma table consists of up to 256 256-entry tables. The table
- * is selected by the (8-gamma_shift) most significant of the low 8 bits of
- * the color value then indexed by the upper 8 bits:
- *
- * table[low bits][high 8 bits]
- *
- * So the table 'n' corresponds to all those 'iv' of:
- *
- * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
- *
- */
- if (sig_bit > 0 && sig_bit < 16U)
- /* shift == insignificant bits */
- shift = (png_byte)((16U - sig_bit) & 0xff);
-
- else
- shift = 0; /* keep all 16 bits */
-
- if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
- {
- /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
- * the significant bits in the *input* when the output will
- * eventually be 8 bits. By default it is 11.
- */
- if (shift < (16U - PNG_MAX_GAMMA_8))
- shift = (16U - PNG_MAX_GAMMA_8);
- }
-
- if (shift > 8U)
- shift = 8U; /* Guarantees at least one table! */
-
- png_ptr->gamma_shift = shift;
-
- /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
- * PNG_COMPOSE). This effectively smashed the background calculation for
- * 16-bit output because the 8-bit table assumes the result will be reduced
- * to 8 bits.
- */
- if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
- png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
- png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
-
- else
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
- png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
- png_ptr->screen_gamma) : PNG_FP_1);
+ else
+ {
+ png_byte shift, sig_bit;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ sig_bit = png_ptr->sig_bit.red;
+
+ if (png_ptr->sig_bit.green > sig_bit)
+ sig_bit = png_ptr->sig_bit.green;
+
+ if (png_ptr->sig_bit.blue > sig_bit)
+ sig_bit = png_ptr->sig_bit.blue;
+ }
+ else
+ sig_bit = png_ptr->sig_bit.gray;
+
+ /* 16-bit gamma code uses this equation:
+ *
+ * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
+ *
+ * Where 'iv' is the input color value and 'ov' is the output value -
+ * pow(iv, gamma).
+ *
+ * Thus the gamma table consists of up to 256 256-entry tables. The table
+ * is selected by the (8-gamma_shift) most significant of the low 8 bits
+ * of the color value then indexed by the upper 8 bits:
+ *
+ * table[low bits][high 8 bits]
+ *
+ * So the table 'n' corresponds to all those 'iv' of:
+ *
+
* <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
+ *
+ */
+ if (sig_bit > 0 && sig_bit < 16U)
+ /* shift == insignificant bits */
+ shift = (png_byte)((16U - sig_bit) & 0xff);
+
+ else
+ shift = 0; /* keep all 16 bits */
+
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ {
+ /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
+ * the significant bits in the *input* when the output will
+ * eventually be 8 bits. By default it is 11.
+ */
+ if (shift < (16U - PNG_MAX_GAMMA_8))
+ shift = (16U - PNG_MAX_GAMMA_8);
+ }
+
+ if (shift > 8U)
+ shift = 8U; /* Guarantees at least one table! */
+
+ png_ptr->gamma_shift = shift;
+
+ /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+ * PNG_COMPOSE). This effectively smashed the background calculation for
+ * 16-bit output because the 8-bit table assumes the result will be
+ * reduced to 8 bits.
+ */
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
+
+ else
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
+ png_ptr->screen_gamma) : PNG_FP_1);
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
- {
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
- png_reciprocal(png_ptr->colorspace.gamma));
-
- /* Notice that the '16 from 1' table should be full precision, however
- * the lookup on this table still uses gamma_shift, so it can't be.
- * TODO: fix this.
- */
- png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
- png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
- png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
- }
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
+ png_reciprocal(png_ptr->colorspace.gamma));
+
+ /* Notice that the '16 from 1' table should be full precision, however
+ * the lookup on this table still uses gamma_shift, so it can't be.
+ * TODO: fix this.
+ */
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
+ png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
+ png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+ }
#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
- }
+ }
#endif /* 16BIT */
}
#endif /* READ_GAMMA */
if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
(option & 1) == 0)
{
- int mask = 3 << option;
- int setting = (2 + (onoff != 0)) << option;
- int current = png_ptr->options;
+ png_uint_32 mask = 3U << option;
+ png_uint_32 setting = (2U + (onoff != 0)) << option;
+ png_uint_32 current = png_ptr->options;
- png_ptr->options = (png_byte)(((current & ~mask) | setting) & 0xff);
+ png_ptr->options = (png_uint_32)((current & ~mask) | setting);
- return (current & mask) >> option;
+ return (int)(current & mask) >> option;
}
return PNG_OPTION_INVALID;
defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
/* sRGB conversion tables; these are machine generated with the code in
* contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the
- * specification (see the article at http://en.wikipedia.org/wiki/SRGB)
+ * specification (see the article at https://en.wikipedia.org/wiki/SRGB)
* is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
* The sRGB to linear table is exact (to the nearest 16-bit linear fraction).
* The inverse (linear to sRGB) table has accuracies as follows:
projects / platform / upstream / libpng.git / blobdiff