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[master] Imported from libpng-1.6.10.tar

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Glenn Randers-Pehrson 2014-03-06 12:35:04 -06:00
parent a710317d2f
commit 1cc02f0395
58 changed files with 2962 additions and 566 deletions
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111
ANNOUNCE
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@ -1,5 +1,5 @@
Libpng 1.6.9 - February 6, 2014
Libpng 1.6.10 - March 6, 2014
This is a public release of libpng, intended for use in production codes.
@ -8,56 +8,80 @@ Files available for download:
Source files with LF line endings (for Unix/Linux) and with a
"configure" script
libpng-1.6.9.tar.xz (LZMA-compressed, recommended)
libpng-1.6.9.tar.gz
libpng-1.6.10.tar.xz (LZMA-compressed, recommended)
libpng-1.6.10.tar.gz
Source files with CRLF line endings (for Windows), without the
"configure" script
lpng169.7z (LZMA-compressed, recommended)
lpng169.zip
lpng1610.7z (LZMA-compressed, recommended)
lpng1610.zip
Other information:
libpng-1.6.9-README.txt
libpng-1.6.9-LICENSE.txt
Gnupg/*.asc (PGP armored detached signatures)
libpng-1.6.10-README.txt
libpng-1.6.10-LICENSE.txt
libpng-1.6.10-*.asc (armored detached GPG signatures)
Changes since the last public release (1.6.8):
Bookkeeping: Moved functions around (no changes). Moved transform
function definitions before the place where they are called so that
they can be masde static. Move the intrapixel functions and the
grayscale palette builder out of the png?tran.c files. The latter
isn't a transform function and is no longer used internally, and the
former MNG specific functions are better placed in pngread/pngwrite.c
Made transform implementation functions static. This makes the internal
functions called by png_do_{read|write}_transformations static. On an
x86-64 DLL build (Gentoo Linux) this reduces the size of the text
segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
maintenance by removing the declarations from pngpriv.h and allowing
easier changes to the internal interfaces.
Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69
in the tar distributions.
Added checks for libpng 1.5 to pngvalid.c. This supports the use of
this version of pngvalid in libpng 1.5
Merged with pngvalid.c from libpng-1.7 changes to create a single
pngvalid.c
Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner).
Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0
Merged libpng-1.7.0 changes to make no-interlace configurations work
with test programs.
Revised pngvalid.c to support libpng 1.5, which does not support the
PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in
pngvalid.c
Allow unversioned links created on install to be disabled in configure.
In configure builds 'make install' changes/adds links like png.h
and libpng.a to point to the newly installed, versioned, files (e.g.
libpng17/png.h and libpng17.a). Three new configure options and some
rearrangement of Makefile.am allow creation of these links to be disabled.
Removed potentially misleading warning from png_check_IHDR().
Updated scripts/makefile.* to use CPPFLAGS (Cosmin).
Added clang attribute support (Cosmin).
Quiet an uninitialized memory warning from VC2013 in png_get_png().
Changes since the last public release (1.6.9):
Backported changes from libpng-1.7.0beta30 and beta31:
Fixed a large number of instances where PNGCBAPI was omitted from
function definitions.
Added pngimage test program for png_read_png() and png_write_png()
with two new test scripts.
Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
png_set_packing() in png_read_png().
Fixed combination of ~alpha with shift. On read invert alpha, processing
occurred after shift processing, which causes the final values to be
outside the range that should be produced by the shift. Reversing the
order on read makes the two transforms work together correctly and mirrors
the order used on write.
Do not read invalid sBIT chunks. Previously libpng only checked sBIT
values on write, so a malicious PNG writer could therefore cause
the read code to return an invalid sBIT chunk, which might lead to
application errors or crashes. Such chunks are now skipped (with
chunk_benign_error).
Make png_read_png() and png_write_png() prototypes in png.h depend
upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
Support builds with unsupported PNG_TRANSFORM_* values. All of the
PNG_TRANSFORM_* values are always defined in png.h and, because they
are used for both read and write in some cases, it is not reliable
to #if out ones that are totally unsupported. This change adds error
detection in png_read_image() and png_write_image() to do a
png_app_error() if the app requests something that cannot be done
and it adds corresponding code to pngimage.c to handle such options
by not attempting to test them.
Moved redefines of png_error(), png_warning(), png_chunk_error(),
and png_chunk_warning() from pngpriv.h to png.h to make them visible
to libpng-calling applications.
Moved OS dependent code from arm/arm_init.c, to allow the included
implementation of the ARM NEON discovery function to be set at
build-time and provide sample implementations from the current code in the
contrib/arm-neon subdirectory. The __linux__ code has also been changed to
compile and link on Android by using /proc/cpuinfo, and the old linux code
is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux
dependencies apart from opening /proc/cpuinfo and is C90 compliant.
Check for info_ptr == NULL early in png_read_end() so we don't need to
run all the png_handle_*() and depend on them to return if info_ptr == NULL.
This improves the performance of png_read_end(png_ptr, NULL) and makes
it more robust against future programming errors.
Check for __has_extension before using it in pngconf.h, to
support older Clang versions (Jeremy Sequoia).
Treat CRC error handling with png_set_crc_action(), instead of with
png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
after recognizing the IDAT chunk, which avoids an infinite loop while
reading a datastream whose first IDAT chunk is of zero-length.
This fixes CERT VU#684412 and CVE-2014-0333.
Don't recognize known sRGB profiles as sRGB if they have been hacked,
but don't reject them and don't issue a copyright violation warning.
Moved some documentation from png.h to libpng.3 and libpng-manual.txt
Minor editing of contrib/arm-neon/README and contrib/examples/*.c
Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
and PNG_USR_CONFIG -> PNG_USER_CONFIG).
Un-deprecated png_data_freer().
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
@ -66,3 +90,4 @@ to subscribe)
or to glennrp at users.sourceforge.net
Glenn R-P
#endif

76
CHANGES
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@ -4754,7 +4754,7 @@ Version 1.6.8 [December 19, 2013]
Version 1.6.9beta01 [December 26, 2013]
Bookkeeping: Moved functions around (no changes). Moved transform
function definitions before the place where they are called so that
they can be masde static. Move the intrapixel functions and the
they can be made static. Move the intrapixel functions and the
grayscale palette builder out of the png?tran.c files. The latter
isn't a transform function and is no longer used internally, and the
former MNG specific functions are better placed in pngread/pngwrite.c
@ -4800,6 +4800,80 @@ Version 1.6.9rc02 [January 30, 2014]
Version 1.6.9 [February 6, 2014]
Version 1.6.10beta01 [February 9, 2014]
Backported changes from libpng-1.7.0beta30 and beta31:
Fixed a large number of instances where PNGCBAPI was omitted from
function definitions.
Added pngimage test program for png_read_png() and png_write_png()
with two new test scripts.
Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
png_set_packing() in png_read_png().
Fixed combination of ~alpha with shift. On read invert alpha, processing
occurred after shift processing, which causes the final values to be
outside the range that should be produced by the shift. Reversing the
order on read makes the two transforms work together correctly and mirrors
the order used on write.
Do not read invalid sBIT chunks. Previously libpng only checked sBIT
values on write, so a malicious PNG writer could therefore cause
the read code to return an invalid sBIT chunk, which might lead to
application errors or crashes. Such chunks are now skipped (with
chunk_benign_error).
Make png_read_png() and png_write_png() prototypes in png.h depend
upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
Support builds with unsupported PNG_TRANSFORM_* values. All of the
PNG_TRANSFORM_* values are always defined in png.h and, because they
are used for both read and write in some cases, it is not reliable
to #if out ones that are totally unsupported. This change adds error
detection in png_read_image() and png_write_image() to do a
png_app_error() if the app requests something that cannot be done
and it adds corresponding code to pngimage.c to handle such options
by not attempting to test them.
Version 1.6.10beta02 [February 23, 2014]
Moved redefines of png_error(), png_warning(), png_chunk_error(),
and png_chunk_warning() from pngpriv.h to png.h to make them visible
to libpng-calling applications.
Moved OS dependent code from arm/arm_init.c, to allow the included
implementation of the ARM NEON discovery function to be set at
build-time and provide sample implementations from the current code in the
contrib/arm-neon subdirectory. The __linux__ code has also been changed to
compile and link on Android by using /proc/cpuinfo, and the old linux code
is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux
dependencies apart from opening /proc/cpuinfo and is C90 compliant.
Check for info_ptr == NULL early in png_read_end() so we don't need to
run all the png_handle_*() and depend on them to return if info_ptr == NULL.
This improves the performance of png_read_end(png_ptr, NULL) and makes
it more robust against future programming errors.
Check for __has_extension before using it in pngconf.h, to
support older Clang versions (Jeremy Sequoia).
Treat CRC error handling with png_set_crc_action(), instead of with
png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
after recognizing the IDAT chunk, which avoids an infinite loop while
reading a datastream whose first IDAT chunk is of zero-length.
This fixes CERT VU#684412 and CVE-2014-0333.
Don't recognize known sRGB profiles as sRGB if they have been hacked,
but don't reject them and don't issue a copyright violation warning.
Version 1.6.10beta03 [February 25, 2014]
Moved some documentation from png.h to libpng.3 and libpng-manual.txt
Minor editing of contrib/arm-neon/README and contrib/examples/*.c
Version 1.6.10rc01 [February 27, 2014]
Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
and PNG_USR_CONFIG -> PNG_USER_CONFIG).
Version 1.6.10rc02 [February 28, 2014]
Removed unreachable return statement after png_chunk_error()
in pngrutil.c
Version 1.6.10rc03 [March 4, 2014]
Un-deprecated png_data_freer().
Version 1.6.10 [March 6, 2014]
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement

4
CMakeLists.txt
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@ -16,7 +16,7 @@ enable_testing()
set(PNGLIB_MAJOR 1)
set(PNGLIB_MINOR 6)
set(PNGLIB_RELEASE 9)
set(PNGLIB_RELEASE 10)
set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
@ -252,7 +252,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
# SET UP LINKS
if(PNG_SHARED)
set_target_properties(${PNG_LIB_NAME} PROPERTIES
# VERSION 16.${PNGLIB_RELEASE}.1.6.9
# VERSION 16.${PNGLIB_RELEASE}.1.6.10
VERSION 16.${PNGLIB_RELEASE}.0
SOVERSION 16
CLEAN_DIRECT_OUTPUT 1)

4
LICENSE
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@ -10,7 +10,7 @@ this sentence.
This code is released under the libpng license.
libpng versions 1.2.6, August 15, 2004, through 1.6.9, February 6, 2014, are
libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-1.2.5
with the following individual added to the list of Contributing Authors
@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
February 6, 2014
March 6, 2014

9
Makefile.am
View File

@ -7,7 +7,7 @@ PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
ACLOCAL_AMFLAGS = -I scripts
# test programs - run on make check, make distcheck
check_PROGRAMS= pngtest pngunknown pngstest pngvalid
check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage
# Utilities - installed
bin_PROGRAMS= pngfix png-fix-itxt
@ -34,6 +34,9 @@ pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
pngunknown_SOURCES = contrib/libtests/pngunknown.c
pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
pngimage_SOURCES = contrib/libtests/pngimage.c
pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
pngfix_SOURCES = contrib/tools/pngfix.c
pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
@ -59,7 +62,8 @@ TESTS =\
tests/pngstest-4a16 tests/pngstest-6a08 tests/pngstest-6a16\
tests/pngstest-error tests/pngunknown-IDAT\
tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg
tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
tests/pngimage-quick tests/pngimage-full
# These tests are expected, and required, to fail:
XFAIL_TESTS = tests/pngstest-error
@ -212,6 +216,7 @@ pngtest.o: pnglibconf.h
contrib/libtests/makepng.o: pnglibconf.h
contrib/libtests/pngstest.o: pnglibconf.h
contrib/libtests/pngunknown.o: pnglibconf.h
contrib/libtests/pngimage.o: pnglibconf.h
contrib/libtests/pngvalid.o: pnglibconf.h
contrib/libtests/readpng.o: pnglibconf.h
contrib/libtests/tarith.o: pnglibconf.h

2
README
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@ -1,4 +1,4 @@
README for libpng version 1.6.9 - February 6, 2014 (shared library 16.0)
README for libpng version 1.6.10 - March 6, 2014 (shared library 16.0)
See the note about version numbers near the top of png.h
See INSTALL for instructions on how to install libpng.

1
TODO
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@ -10,6 +10,7 @@ Add "grayscale->palette" transformation and "palette->grayscale" detection.
Improved dithering.
Multi-lingual error and warning message support.
Complete sRGB transformation (presently it simply uses gamma=0.45455).
Make profile checking optional via a png_set_something() call.
Man pages for function calls.
Better documentation.
Better filter selection

147
arm/arm_init.c
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@ -1,9 +1,9 @@
/* arm_init.c - NEON optimised filter functions
*
* Copyright (c) 2013 Glenn Randers-Pehrson
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by Mans Rullgard, 2011.
* Last changed in libpng 1.6.6 [September 16, 2013]
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -19,132 +19,33 @@
#ifdef PNG_READ_SUPPORTED
#if PNG_ARM_NEON_OPT > 0
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
#include <signal.h> /* for sig_atomic_t */
#ifdef __ANDROID__
/* Linux provides access to information about CPU capabilites via
* /proc/self/auxv, however Android blocks this while still claiming to be
* Linux. The Andoid NDK, however, provides appropriate support.
/* WARNING: it is strongly recommended that you do not build libpng with
* run-time checks for CPU features if at all possible. In the case of the ARM
* NEON instructions there is no processor-specific way of detecting the
* presense of the required support, therefore run-time detectioon is extremely
* OS specific.
*
* Documentation: http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
* You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
* a fragment of C source code which defines the png_have_neon function. There
* are a number of implementations in contrib/arm-neon, but the only one that
* has partial support is contrib/arm-neon/linux.c - a generic Linux
* implementation which reads /proc/cpufino.
*/
#include <cpu-features.h>
#ifndef PNG_ARM_NEON_FILE
# ifdef __linux__
# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
# endif
#endif
static int
png_have_neon(png_structp png_ptr)
{
/* This is a whole lot easier than the mess below, however it is probably
* implemented as below, therefore it is better to cache the result (these
* function calls may be slow!)
*/
PNG_UNUSED(png_ptr)
return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
(android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
}
#elif defined(__linux__)
/* The generic __linux__ implementation requires reading /proc/self/auxv and
* looking at each element for one that records NEON capabilities.
*/
#include <unistd.h> /* for POSIX 1003.1 */
#include <errno.h> /* for EINTR */
#ifdef PNG_ARM_NEON_FILE
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <elf.h>
#include <asm/hwcap.h>
#include <signal.h> /* for sig_atomic_t */
static int png_have_neon(png_structp png_ptr);
#include PNG_ARM_NEON_FILE
/* A read call may be interrupted, in which case it returns -1 and sets errno to
* EINTR if nothing was done, otherwise (if something was done) a partial read
* may result.
*/
static size_t
safe_read(png_structp png_ptr, int fd, void *buffer_in, size_t nbytes)
{
size_t ntotal = 0;
char *buffer = png_voidcast(char*, buffer_in);
while (nbytes > 0)
{
unsigned int nread;
int iread;
/* Passing nread > INT_MAX to read is implementation defined in POSIX
* 1003.1, therefore despite the unsigned argument portable code must
* limit the value to INT_MAX!
*/
if (nbytes > INT_MAX)
nread = INT_MAX;
else
nread = (unsigned int)/*SAFE*/nbytes;
iread = read(fd, buffer, nread);
if (iread == -1)
{
/* This is the devil in the details, a read can terminate early with 0
* bytes read because of EINTR, yet it still returns -1 otherwise end
* of file cannot be distinguished.
*/
if (errno != EINTR)
{
png_warning(png_ptr, "/proc read failed");
return 0; /* I.e., a permanent failure */
}
}
else if (iread < 0)
{
/* Not a valid 'read' result: */
png_warning(png_ptr, "OS /proc read bug");
return 0;
}
else if (iread > 0)
{
/* Continue reading until a permanent failure, or EOF */
buffer += iread;
nbytes -= (unsigned int)/*SAFE*/iread;
ntotal += (unsigned int)/*SAFE*/iread;
}
else
return ntotal;
}
return ntotal; /* nbytes == 0 */
}
static int
png_have_neon(png_structp png_ptr)
{
int fd = open("/proc/self/auxv", O_RDONLY);
Elf32_auxv_t aux;
/* Failsafe: failure to open means no NEON */
if (fd == -1)
{
png_warning(png_ptr, "/proc/self/auxv open failed");
return 0;
}
while (safe_read(png_ptr, fd, &aux, sizeof aux) == sizeof aux)
{
if (aux.a_type == AT_HWCAP && (aux.a_un.a_val & HWCAP_NEON) != 0)
{
close(fd);
return 1;
}
}
close(fd);
return 0;
}
#else
/* We don't know how to do a run-time check on this system */
# error "no support for run-time ARM NEON checks"
#endif /* OS checks */
#else /* PNG_ARM_NEON_FILE */
# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
#endif /* PNG_ARM_NEON_FILE */
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
#ifndef PNG_ALIGNED_MEMORY_SUPPORTED

6
configure.ac
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@ -18,7 +18,7 @@ AC_PREREQ([2.68])
dnl Version number stuff here:
AC_INIT([libpng],[1.6.9],[png-mng-implement@lists.sourceforge.net])
AC_INIT([libpng],[1.6.10],[png-mng-implement@lists.sourceforge.net])
AC_CONFIG_MACRO_DIR([scripts])
# libpng does not follow GNU file name conventions (hence 'foreign')
@ -39,10 +39,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
dnl AM_PREREQ([1.11.2])
dnl stop configure from automagically running automake
PNGLIB_VERSION=1.6.9
PNGLIB_VERSION=1.6.10
PNGLIB_MAJOR=1
PNGLIB_MINOR=6
PNGLIB_RELEASE=9
PNGLIB_RELEASE=10
dnl End of version number stuff

83
contrib/arm-neon/README Normal file
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@ -0,0 +1,83 @@
OPERATING SYSTEM SPECIFIC ARM NEON DETECTION
--------------------------------------------
Detection of the ability to exexcute ARM NEON on an ARM processor requires
operating system support. (The information is not available in user mode.)
HOW TO USE THIS
---------------
This directory contains C code fragments that can be included in arm/arm_init.c
by setting the macro PNG_ARM_NEON_FILE to the file name in "" or <> at build
time. This setting is not recorded in pnglibconf.h and can be changed simply by
rebuilding arm/arm_init.o with the required macro definition.
For any of this code to be used the ARM NEON code must be enabled and run time
checks must be supported. I.e.:
#if PNG_ARM_NEON_OPT > 0
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
This is done in a 'configure' build by passing configure the argument:
--enable-arm-neon=check
Apart from the basic Linux implementation in contrib/arm-neon/linux.c this code
is unsupported. That means that it is not even compiled on a regular basis and
may be broken in any given minor release.
FILE FORMAT
-----------
Each file documents its testing status as of the last time it was tested (which
may have been a long time ago):
STATUS: one of:
SUPPORTED: This indicates that the file is included in the regularly
performed test builds and bugs are fixed when discovered.
COMPILED: This indicates that the code did compile at least once. See the
more detailed description for the extent to which the result was
successful.
TESTED: This means the code was fully compiled into the libpng test programs
and these were run at least once.
BUG REPORTS: an email address to which to send reports of problems
The file is a fragment of C code. It should not define any 'extern' symbols;
everything should be static. It must define the function:
static int png_have_neon(png_structp png_ptr);
That function must return 1 if ARM NEON instructions are supported, 0 if not.
It must not execute png_error unless it detects a bug. A png_error will prevent
the reading of the PNG and in the future, writing too.
BUG REPORTS
-----------
If you mail a bug report for any file that is not SUPPORTED there may only be
limited response. Consider fixing it and sending a patch to fix the problem -
this is more likely to result in action.
CONTRIBUTIONS
-------------
You may send contributions of new implementations to
png-mng-implement@sourceforge.net. Please write code in strict C90 C where
possible. Obviously OS dependencies are to be expected. If you submit code you
must have the authors permission and it must have a license that is acceptable
to the current maintainer; in particular that license must permit modification
and redistribution.
Please try to make the contribution a single file and give the file a clear and
unambiguous name that identifies the target OS. If multiple files really are
required put them all in a sub-directory.
You must also be prepared to handle bug reports from users of the code, either
by joining the png-mng-implement mailing list or by providing an email for the
"BUG REPORTS" entry or both. Please make sure that the header of the file
contains the STATUS and BUG REPORTS fields as above.
Please list the OS requirements as precisely as possible. Ideally you should
also list the environment in which the code has been tested and certainly list
any environments where you suspect it might not work.

39
contrib/arm-neon/android-ndk.c Normal file
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@ -0,0 +1,39 @@
/* contrib/arm-neon/android-ndk.c
*
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by John Bowler, 2014.
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* SEE contrib/arm-neon/README before reporting bugs
*
* STATUS: COMPILED, UNTESTED
* BUG REPORTS: png-mng-implement@sourceforge.net
*
* png_have_neon implemented for the Android NDK, see:
*
* Documentation:
* http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
* http://code.google.com/p/android/issues/detail?id=49065
*
* NOTE: this requires that libpng is built against the Android NDK and linked
* with an implementation of the Android ARM 'cpu-features' library. The code
* has been compiled only, not linked: no version of the library has been found,
* only the header files exist in the NDK.
*/
#include <cpu-features.h>
static int
png_have_neon(png_structp png_ptr)
{
/* This is a whole lot easier than the linux code, however it is probably
* implemented as below, therefore it is better to cache the result (these
* function calls may be slow!)
*/
PNG_UNUSED(png_ptr)
return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
(android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
}

120
contrib/arm-neon/linux-auxv.c Normal file
View File

@ -0,0 +1,120 @@
/* contrib/arm-neon/linux-auxv.c
*
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by Mans Rullgard, 2011.
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* SEE contrib/arm-neon/README before reporting bugs
*
* STATUS: COMPILED, TESTED
* BUG REPORTS: png-mng-implement@sourceforge.net
*
* png_have_neon implemented for Linux versions which allow access to
* /proc/self/auxv. This is probably faster, cleaner and safer than the code to
* read /proc/cpuinfo in contrib/arm-neon/linux, however it is yet another piece
* of potentially untested code and has more complex dependencies than the code
* to read cpuinfo.
*
* This generic __linux__ implementation requires reading /proc/self/auxv and
* looking at each element for one that records NEON capabilities.
*/
#include <unistd.h> /* for POSIX 1003.1 */
#include <errno.h> /* for EINTR */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <elf.h>
#include <asm/hwcap.h>
/* A read call may be interrupted, in which case it returns -1 and sets errno to
* EINTR if nothing was done, otherwise (if something was done) a partial read
* may result.
*/
static size_t
safe_read(png_structp png_ptr, int fd, void *buffer_in, size_t nbytes)
{
size_t ntotal = 0;
char *buffer = png_voidcast(char*, buffer_in);
while (nbytes > 0)
{
unsigned int nread;
int iread;
/* Passing nread > INT_MAX to read is implementation defined in POSIX
* 1003.1, therefore despite the unsigned argument portable code must
* limit the value to INT_MAX!
*/
if (nbytes > INT_MAX)
nread = INT_MAX;
else
nread = (unsigned int)/*SAFE*/nbytes;
iread = read(fd, buffer, nread);
if (iread == -1)
{
/* This is the devil in the details, a read can terminate early with 0
* bytes read because of EINTR, yet it still returns -1 otherwise end
* of file cannot be distinguished.
*/
if (errno != EINTR)
{
png_warning(png_ptr, "/proc read failed");
return 0; /* I.e., a permanent failure */
}
}
else if (iread < 0)
{
/* Not a valid 'read' result: */
png_warning(png_ptr, "OS /proc read bug");
return 0;
}
else if (iread > 0)
{
/* Continue reading until a permanent failure, or EOF */
buffer += iread;
nbytes -= (unsigned int)/*SAFE*/iread;
ntotal += (unsigned int)/*SAFE*/iread;
}
else
return ntotal;
}
return ntotal; /* nbytes == 0 */
}
static int
png_have_neon(png_structp png_ptr)
{
int fd = open("/proc/self/auxv", O_RDONLY);
Elf32_auxv_t aux;
/* Failsafe: failure to open means no NEON */
if (fd == -1)
{
png_warning(png_ptr, "/proc/self/auxv open failed");
return 0;
}
while (safe_read(png_ptr, fd, &aux, sizeof aux) == sizeof aux)
{
if (aux.a_type == AT_HWCAP && (aux.a_un.a_val & HWCAP_NEON) != 0)
{
close(fd);
return 1;
}
}
close(fd);
return 0;
}

159
contrib/arm-neon/linux.c Normal file
View File

@ -0,0 +1,159 @@
/* contrib/arm-neon/linux.c
*
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by John Bowler, 2014.
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* SEE contrib/arm-neon/README before reporting bugs
*
* STATUS: SUPPORTED
* BUG REPORTS: png-mng-implement@sourceforge.net
*
* png_have_neon implemented for Linux by reading the widely available
* pseudo-file /proc/cpuinfo.
*
* This code is strict ANSI-C and is probably moderately portable, it does
* however use <stdio.h> and assumes that /proc/cpuinfo is never localized.
*/
#include <stdio.h>
static int
png_have_neon(png_structp png_ptr)
{
FILE *f = fopen("/proc/cpuinfo", "rb");
if (f != NULL)
{
/* This is a simple state machine which reads the input byte-by-byte until
* it gets a match on the 'neon' feature or reaches the end of the stream.
*/
static const char ch_feature[] = { 70, 69, 65, 84, 85, 82, 69, 83 };
static const char ch_neon[] = { 78, 69, 79, 78 };
enum
{
StartLine, Feature, Colon, StartTag, Neon, HaveNeon, SkipTag, SkipLine
} state;
int counter;
for (state=StartLine, counter=0;;)
{
int ch = fgetc(f);
if (ch == EOF)
{
/* EOF means error or end-of-file, return false; neon at EOF is
* assumed to be a mistake.
*/
fclose(f);
return 0;
}
switch (state)
{
case StartLine:
/* Match spaces at the start of line */
if (ch <= 32) /* skip control characters and space */
break;
counter=0;
state = Feature;
/* FALL THROUGH */
case Feature:
/* Match 'FEATURE', ASCII case insensitive. */
if ((ch & ~0x20) == ch_feature[counter])
{
if (++counter == (sizeof ch_feature))
state = Colon;
break;
}
/* did not match 'feature' */
state = SkipLine;
/* FALL THROUGH */
case SkipLine:
skipLine:
/* Skip everything until we see linefeed or carriage return */
if (ch != 10 && ch != 13)
break;
state = StartLine;
break;
case Colon:
/* Match any number of space or tab followed by ':' */
if (ch == 32 || ch == 9)
break;
if (ch == 58) /* i.e. ':' */
{
state = StartTag;
break;
}
/* Either a bad line format or a 'feature' prefix followed by
* other characters.
*/
state = SkipLine;
goto skipLine;
case StartTag:
/* Skip space characters before a tag */
if (ch == 32 || ch == 9)
break;
state = Neon;
counter = 0;
/* FALL THROUGH */
case Neon:
/* Look for 'neon' tag */
if ((ch & ~0x20) == ch_neon[counter])
{
if (++counter == (sizeof ch_neon))
state = HaveNeon;
break;
}
state = SkipTag;
/* FALL THROUGH */
case SkipTag:
/* Skip non-space characters */
if (ch == 10 || ch == 13)
state = StartLine;
else if (ch == 32 || ch == 9)
state = StartTag;
break;
case HaveNeon:
/* Have seen a 'neon' prefix, but there must be a space or new
* line character to terminate it.
*/
if (ch == 10 || ch == 13 || ch == 32 || ch == 9)
{
fclose(f);
return 1;
}
state = SkipTag;
break;
default:
png_error(png_ptr, "png_have_neon: internal error (bug)");
}
}
}
else
png_warning(png_ptr, "/proc/cpuinfo open failed");
return 0;
}

4
contrib/examples/iccfrompng.c
View File

@ -6,9 +6,9 @@
* United States.
*
* Extract any icc profiles found in the given PNG files. This is a simple
* example of a program which extracts information from the header of a PNG file
* example of a program that extracts information from the header of a PNG file
* without processing the image. Notice that some header information may occur
* after the image data, textual data and comments are an example; the approach
* after the image data. Textual data and comments are an example; the approach
* in this file won't work reliably for such data because it only looks for the
* information in the section of the file that preceeds the image data.
*

6
contrib/examples/pngpixel.c
View File

@ -8,7 +8,7 @@
* Read a single pixel value from a PNG file.
*
* This code illustrates basic 'by-row' reading of a PNG file using libpng.
* Rows are read until a particular pixel is found, the value of this pixel is
* Rows are read until a particular pixel is found; the value of this pixel is
* then printed on stdout.
*
* The code illustrates how to do this on interlaced as well as non-interlaced
@ -56,7 +56,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
case 8: return row[0];
case 16: return (row[0] << 8) + row[1];
default:
/* This should never happen, it indicates a bug in this program or in
/* This should never happen; it indicates a bug in this program or in
* libpng itself:
*/
fprintf(stderr, "pngpixel: invalid bit depth %u\n", bit_depth);
@ -132,7 +132,7 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
return;
default:
png_error(png_ptr, "invalid color type");
png_error(png_ptr, "pngpixel: invalid color type");
}
}

9
contrib/gregbook/readpng2.c
View File

@ -69,6 +69,7 @@ static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
png_uint_32 row_num, int pass);
static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg);
@ -104,7 +105,7 @@ int readpng2_init(mainprog_info *mainprog_ptr)
/* could also replace libpng warning-handler (final NULL), but no need: */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
readpng2_error_handler, NULL);
readpng2_error_handler, readpng2_warning_handler);
if (!png_ptr)
return 4; /* out of memory */
@ -467,7 +468,11 @@ void readpng2_cleanup(mainprog_info *mainprog_ptr)
}
static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg)
{
fprintf(stderr, "readpng2 libpng warning: %s\n", msg);
fflush(stderr);
}
static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)

1618
contrib/libtests/pngimage.c Normal file
View File

File diff suppressed because it is too large Load Diff

10
contrib/libtests/pngunknown.c
View File

@ -1,8 +1,8 @@
/* pngunknown.c - test the read side unknown chunk handling
*
* Last changed in libpng 1.6.0 [February 14, 2013]
* Copyright (c) 2013 Glenn Randers-Pehrson
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by John Cunningham Bowler
*
* This code is released under the libpng license.
@ -439,7 +439,7 @@ display_rc(const display *d, int strict)
}
/* libpng error and warning callbacks */
PNG_FUNCTION(void, error, (png_structp png_ptr, const char *message),
PNG_FUNCTION(void, (PNGCBAPI error), (png_structp png_ptr, const char *message),
static PNG_NORETURN)
{
display *d = (display*)png_get_error_ptr(png_ptr);
@ -448,7 +448,7 @@ PNG_FUNCTION(void, error, (png_structp png_ptr, const char *message),
display_exit(d);
}
static void
static void PNGCBAPI
warning(png_structp png_ptr, const char *message)
{
display *d = (display*)png_get_error_ptr(png_ptr);
@ -490,7 +490,7 @@ get_valid(display *d, png_infop info_ptr)
}
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
static int
static int PNGCBAPI
read_callback(png_structp pp, png_unknown_chunkp pc)
{
/* This function mimics the behavior of png_set_keep_unknown_chunks by

37
contrib/libtests/pngvalid.c
View File

@ -1,7 +1,7 @@
/* pngvalid.c - validate libpng by constructing then reading png files.
*
* Last changed in libpng 1.5.18 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 2014 Glenn Randers-Pehrson
* Written by John Cunningham Bowler
*
@ -122,11 +122,6 @@ typedef png_byte *png_const_bytep;
# endif
#endif
/* Fixups for various minimal builds */
#ifndef PNG_ERROR_TEXT_SUPPORTED
# define png_error(a,b) png_err(a)
#endif
/***************************** EXCEPTION HANDLING *****************************/
#ifdef PNG_FREESTANDING_TESTS
# include <cexcept.h>
@ -926,7 +921,7 @@ internal_error(png_store *ps, png_const_charp message)
#endif /* PNG_READ_SUPPORTED */
/* Functions to use as PNG callbacks. */
static void
static void PNGCBAPI
store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */
{
png_const_structp pp = ppIn;
@ -942,7 +937,7 @@ store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */
}
}
static void
static void PNGCBAPI
store_warning(png_structp ppIn, png_const_charp message)
{
png_const_structp pp = ppIn;
@ -1093,7 +1088,7 @@ store_image_check(PNG_CONST png_store* ps, png_const_structp pp, int iImage)
}
#endif /* PNG_READ_SUPPORTED */
static void
static void PNGCBAPI
store_write(png_structp ppIn, png_bytep pb, png_size_t st)
{
png_const_structp pp = ppIn;
@ -1121,7 +1116,7 @@ store_write(png_structp ppIn, png_bytep pb, png_size_t st)
}
}
static void
static void PNGCBAPI
store_flush(png_structp ppIn)
{
UNUSED(ppIn) /*DOES NOTHING*/
@ -1215,7 +1210,7 @@ store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
}
}
static void
static void PNGCBAPI
store_read(png_structp ppIn, png_bytep pb, png_size_t st)
{
png_const_structp pp = ppIn;
@ -1408,7 +1403,7 @@ store_pool_delete(png_store *ps, store_pool *pool)
}
/* The memory callbacks: */
static png_voidp
static png_voidp PNGCBAPI
store_malloc(png_structp ppIn, png_alloc_size_t cb)
{
png_const_structp pp = ppIn;
@ -1457,7 +1452,7 @@ store_malloc(png_structp ppIn, png_alloc_size_t cb)
return new;
}
static void
static void PNGCBAPI
store_free(png_structp ppIn, png_voidp memory)
{
png_const_structp pp = ppIn;
@ -2676,7 +2671,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
}
/* The callback: */
static void
static void PNGCBAPI
modifier_read(png_structp ppIn, png_bytep pb, png_size_t st)
{
png_const_structp pp = ppIn;
@ -4680,7 +4675,7 @@ standard_info_imp(standard_display *dp, png_structp pp, png_infop pi,
standard_info_part2(dp, pp, pi, nImages);
}
static void
static void PNGCBAPI
standard_info(png_structp pp, png_infop pi)
{
standard_display *dp = voidcast(standard_display*,
@ -4692,7 +4687,7 @@ standard_info(png_structp pp, png_infop pi)
standard_info_imp(dp, pp, pi, 1 /*only one image*/);
}
static void
static void PNGCBAPI
progressive_row(png_structp ppIn, png_bytep new_row, png_uint_32 y, int pass)
{
png_const_structp pp = ppIn;
@ -5006,7 +5001,7 @@ standard_image_validate(standard_display *dp, png_const_structp pp, int iImage,
dp->ps->validated = 1;
}
static void
static void PNGCBAPI
standard_end(png_structp ppIn, png_infop pi)
{
png_const_structp pp = ppIn;
@ -5841,7 +5836,7 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
}
}
static void
static void PNGCBAPI
transform_info(png_structp pp, png_infop pi)
{
transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)),
@ -6048,7 +6043,7 @@ transform_image_validate(transform_display *dp, png_const_structp pp,
dp->this.ps->validated = 1;
}
static void
static void PNGCBAPI
transform_end(png_structp ppIn, png_infop pi)
{
png_const_structp pp = ppIn;
@ -7865,7 +7860,7 @@ gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
standard_info_part2(&dp->this, pp, pi, 1 /*images*/);
}
static void
static void PNGCBAPI
gamma_info(png_structp pp, png_infop pi)
{
gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp,
@ -8829,7 +8824,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
dp->this.ps->validated = 1;
}
static void
static void PNGCBAPI
gamma_end(png_structp ppIn, png_infop pi)
{
png_const_structp pp = ppIn;

1
contrib/pngminim/decoder/pngusr.h
View File

@ -18,7 +18,6 @@
* affect the API (so are not recorded in pnglibconf.h)
*/
#define PNG_NO_WARNINGS
#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
#endif /* MINRDPNGCONF_H */

1
contrib/pngminim/encoder/pngusr.h
View File

@ -18,7 +18,6 @@
* affect the API (so are not recorded in pnglibconf.h)
*/
#define PNG_NO_WARNINGS
#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
#endif /* MINWRPNGCONF_H */

1
contrib/pngminim/preader/pngusr.h
View File

@ -18,7 +18,6 @@
* affect the API (so are not recorded in pnglibconf.h)
*/
#define PNG_NO_WARNINGS
#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
#endif /* MINPRDPNGCONF_H */

8
contrib/tools/pngfix.c
View File

@ -2,7 +2,7 @@
*
* Copyright (c) 2014 John Cunningham Bowler
*
* Last changed in libpng 1.6.9 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -3159,13 +3159,13 @@ read_chunk(struct file *file)
/* This returns a file* from a png_struct in an implementation specific way. */
static struct file *get_control(png_const_structrp png_ptr);
static void
static void PNGCBAPI
error_handler(png_structp png_ptr, png_const_charp message)
{
stop(get_control(png_ptr), LIBPNG_ERROR_CODE, message);
}
static void
static void PNGCBAPI
warning_handler(png_structp png_ptr, png_const_charp message)
{
struct file *file = get_control(png_ptr);
@ -3177,7 +3177,7 @@ warning_handler(png_structp png_ptr, png_const_charp message)
/* Read callback - this is where the work gets done to check the stream before
* passing it to libpng
*/
static void
static void PNGCBAPI
read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
/* Return 'count' bytes to libpng in 'buffer' */
{

258
libpng-manual.txt
View File

@ -1,6 +1,6 @@
libpng-manual.txt - A description on how to use and modify libpng
libpng version 1.6.9 - February 6, 2014
libpng version 1.6.10 - March 6, 2014
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
Based on:
libpng versions 0.97, January 1998, through 1.6.9 - February 6, 2014
libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -274,10 +274,10 @@ This method of building a customized pnglibconf.h is illustrated in
contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and
pngusr.dfa in these directories.
C. Configuration using PNG_USR_CONFIG
C. Configuration using PNG_USER_CONFIG
If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
pngusr.h will automatically be included before the options in
If -DPNG_USER_CONFIG is added to the CPPFLAGS when pnglibconf.h is built,
the file pngusr.h will automatically be included before the options in
scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only
macro definitions turning features on or off or setting settings.
@ -712,12 +712,12 @@ value. You can also specify a default encoding for the PNG file in
case the required information is missing from the file. By default libpng
assumes that the PNG data matches your system, to keep this default call:
png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
png_set_gamma(png_ptr, screen_gamma, output_gamma);
or you can use the fixed point equivalent:
png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma,
PNG_FP_1/screen_gamma);
PNG_FP_1*output_gamma);
If you don't know the gamma for your system it is probably 2.2 - a good
approximation to the IEC standard for display systems (sRGB). If images are
@ -745,6 +745,70 @@ component value whenever arithmetic is performed. A lot of graphics software
uses linear values for this reason, often with higher precision component values
to preserve overall accuracy.
The output_gamma value expresses how to decode the output values, not how
they are encoded. The values used correspond to the normal numbers used to
describe the overall gamma of a computer display system; for example 2.2 for
an sRGB conformant system. The values are scaled by 100000 in the _fixed
version of the API (so 220000 for sRGB.)
The inverse of the value is always used to provide a default for the PNG file
encoding if it has no gAMA chunk and if png_set_gamma() has not been called
to override the PNG gamma information.
When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
opaque pixels however pixels with lower alpha values are not encoded,
regardless of the output gamma setting.
When the standard Porter Duff handling is requested with mode 1 the output
encoding is set to be linear and the output_gamma value is only relevant
as a default for input data that has no gamma information. The linear output
encoding will be overridden if png_set_gamma() is called - the results may be
highly unexpected!
The following numbers are derived from the sRGB standard and the research
behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
correction required to take account of any differences in the color
environment of the original scene and the intended display environment; the
value expresses how to *decode* the image for display, not how the original
data was *encoded*.
sRGB provides a peg for the PNG standard by defining a viewing environment.
sRGB itself, and earlier TV standards, actually use a more complex transform
(a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
limited to simple power laws.) By saying that an image for direct display on
an sRGB conformant system should be stored with a gAMA chunk value of 45455
(11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
makes it possible to derive values for other display systems and
environments.
The Mac value is deduced from the sRGB based on an assumption that the actual
extra viewing correction used in early Mac display systems was implemented as
a power 1.45 lookup table.
Any system where a programmable lookup table is used or where the behavior of
the final display device characteristics can be changed requires system
specific code to obtain the current characteristic. However this can be
difficult and most PNG gamma correction only requires an approximate value.
By default, if png_set_alpha_mode() is not called, libpng assumes that all
values are unencoded, linear, values and that the output device also has a
linear characteristic. This is only very rarely correct - it is invariably
better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
default if you don't know what the right answer is!
The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
10.6) which used a correction table to implement a somewhat lower gamma on an
otherwise sRGB system.
Both these values are reserved (not simple gamma values) in order to allow
more precise correction internally in the future.
NOTE: the values can be passed to either the fixed or floating
point APIs, but the floating point API will also accept floating point
values.
The second thing you may need to tell libpng about is how your system handles
alpha channel information. Some, but not all, PNG files contain an alpha
channel. To display these files correctly you need to compose the data onto a
@ -769,11 +833,11 @@ by png_set_alpha_mode().
The mode is as follows:
PNG_ALPHA_PNG: The data is encoded according to the PNG specification. Red,
green and blue, or gray, components are gamma encoded color
values and are not premultiplied by the alpha value. The
alpha value is a linear measure of the contribution of the
pixel to the corresponding final output pixel.
PNG_ALPHA_PNG: The data is encoded according to the PNG
specification. Red, green and blue, or gray, components are
gamma encoded color values and are not premultiplied by the
alpha value. The alpha value is a linear measure of the
contribution of the pixel to the corresponding final output pixel.
You should normally use this format if you intend to perform
color correction on the color values; most, maybe all, color
@ -790,11 +854,35 @@ be used!
The remaining modes assume you don't need to do any further color correction or
that if you do, your color correction software knows all about alpha (it
probably doesn't!)
probably doesn't!). They 'associate' the alpha with the color information by
storing color channel values that have been scaled by the alpha. The
advantage is that the color channels can be resampled (the image can be
scaled) in this form. The disadvantage is that normal practice is to store
linear, not (gamma) encoded, values and this requires 16-bit channels for
still images rather than the 8-bit channels that are just about sufficient if
gamma encoding is used. In addition all non-transparent pixel values,
including completely opaque ones, must be gamma encoded to produce the final
image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
described below (the latter being the two common names for associated alpha
color channels). Note that PNG files always contain non-associated color
channels; png_set_alpha_mode() with one of the modes causes the decoder to
convert the pixels to an associated form before returning them to your
application.
PNG_ALPHA_STANDARD: The data libpng produces
is encoded in the standard way
assumed by most correctly written graphics software.
Since it is not necessary to perform arithmetic on opaque color values so
long as they are not to be resampled and are in the final color space it is
possible to optimize the handling of alpha by storing the opaque pixels in
the PNG format (adjusted for the output color space) while storing partially
opaque pixels in the standard, linear, format. The accuracy required for
standard alpha composition is relatively low, because the pixels are
isolated, therefore typically the accuracy loss in storing 8-bit linear
values is acceptable. (This is not true if the alpha channel is used to
simulate transparency over large areas - use 16 bits or the PNG mode in
this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
treated as opaque only if the alpha value is equal to the maximum value.
PNG_ALPHA_STANDARD: The data libpng produces is encoded in the
standard way assumed by most correctly written graphics software.
The gamma encoding will be removed by libpng and the
linear component values will be pre-multiplied by the
alpha channel.
@ -823,9 +911,8 @@ dynamic range. To avoid problems, and if your software
supports it, use png_set_expand_16() to force all
components to 16 bits.
PNG_ALPHA_OPTIMIZED: This mode is the same
as PNG_ALPHA_STANDARD except that
completely opaque pixels are gamma encoded according to
PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD
except that completely opaque pixels are gamma encoded according to
the screen_gamma value. Pixels with alpha less than 1.0
will still have linear components.
@ -844,18 +931,16 @@ representation of non-opaque pixels are irrelevant.
You can also try this format if your software is broken;
it might look better.
PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD;
however, all component values,
including the alpha channel are gamma encoded. This is
an appropriate format to try if your software, or more
likely hardware, is totally broken, i.e., if it performs
linear arithmetic directly on gamma encoded values.
In most cases of broken software or hardware the bug in the final display
manifests as a subtle halo around composited parts of the image. You may not
even perceive this as a halo; the composited part of the image may simply appear
separate from the background, as though it had been cut out of paper and pasted
on afterward.
PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; however, all component
values, including the alpha channel are gamma encoded. This is
broken because, in practice, no implementation that uses this choice
correctly undoes the encoding before handling alpha composition. Use this
choice only if other serious errors in the software or hardware you use
mandate it. In most cases of broken software or hardware the bug in the
final display manifests as a subtle halo around composited parts of the
image. You may not even perceive this as a halo; the composited part of
the image may simply appear separate from the background, as though it had
been cut out of paper and pasted on afterward.
If you don't have to deal with bugs in software or hardware, or if you can fix
them, there are three recommended ways of using png_set_alpha_mode():
@ -886,6 +971,89 @@ All you can do is compose the result onto a matching output. Since this
mode is libpng-specific you also need to write your own composition
software.
The following are examples of calls to png_set_alpha_mode to achieve the
required overall gamma correction and, where necessary, alpha
premultiplication.
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
This is the default libpng handling of the alpha channel - it is not
pre-multiplied into the color components. In addition the call states
that the output is for a sRGB system and causes all PNG files without gAMA
chunks to be assumed to be encoded using sRGB.
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
In this case the output is assumed to be something like an sRGB conformant
display preceeded by a power-law lookup table of power 1.45. This is how
early Mac systems behaved.
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
This is the classic Jim Blinn approach and will work in academic
environments where everything is done by the book. It has the shortcoming
of assuming that input PNG data with no gamma information is linear - this
is unlikely to be correct unless the PNG files where generated locally.
Most of the time the output precision will be so low as to show
significant banding in dark areas of the image.
png_set_expand_16(pp);
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
This is a somewhat more realistic Jim Blinn inspired approach. PNG files
are assumed to have the sRGB encoding if not marked with a gamma value and
the output is always 16 bits per component. This permits accurate scaling
and processing of the data. If you know that your input PNG files were
generated locally you might need to replace PNG_DEFAULT_sRGB with the
correct value for your system.
png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
If you just need to composite the PNG image onto an existing background
and if you control the code that does this you can use the optimization
setting. In this case you just copy completely opaque pixels to the
output. For pixels that are not completely transparent (you just skip
those) you do the composition math using png_composite or png_composite_16
below then encode the resultant 8-bit or 16-bit values to match the output
encoding.
Other cases
If neither the PNG nor the standard linear encoding work for you because
of the software or hardware you use then you have a big problem. The PNG
case will probably result in halos around the image. The linear encoding
will probably result in a washed out, too bright, image (it's actually too
contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
substantially reduce the halos. Alternatively try:
png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
This option will also reduce the halos, but there will be slight dark
halos round the opaque parts of the image where the background is light.
In the OPTIMIZED mode the halos will be light halos where the background
is dark. Take your pick - the halos are unavoidable unless you can get
your hardware/software fixed! (The OPTIMIZED approach is slightly
faster.)
When the default gamma of PNG files doesn't match the output gamma.
If you have PNG files with no gamma information png_set_alpha_mode allows
you to provide a default gamma, but it also sets the ouput gamma to the
matching value. If you know your PNG files have a gamma that doesn't
match the output you can take advantage of the fact that
png_set_alpha_mode always sets the output gamma but only sets the PNG
default if it is not already set:
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
The first call sets both the default and the output gamma values, the
second call overrides the output gamma without changing the default. This
is easier than achieving the same effect with png_set_gamma. You must use
PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
fire if more than one call to png_set_alpha_mode and png_set_background is
made in the same read operation, however multiple calls with PNG_ALPHA_PNG
are ignored.
If you don't need, or can't handle, the alpha channel you can call
png_set_background() to remove it by compositing against a fixed color. Don't
call png_set_strip_alpha() to do this - it will leave spurious pixel values in
@ -1216,7 +1384,7 @@ png_set_rgb_to_gray()).
png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
file_srgb_intent - the rendering intent (PNG_INFO_sRGB)
srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk
means that the pixel data is in the
sRGB color space. This chunk also
@ -2166,10 +2334,15 @@ how pngvalid.c does it.
Finishing a sequential read
After you are finished reading the image through the
low-level interface, you can finish reading the file. If you are
interested in comments or time, which may be stored either before or
after the image data, you should pass the separate png_info struct if
you want to keep the comments from before and after the image
low-level interface, you can finish reading the file.
If you want to use a different crc action for handling CRC errors in
chunks after the image data, you can call png_set_crc_action()
again at this point.
If you are interested in comments or time, which may be stored either
before or after the image data, you should pass the separate png_info
struct if you want to keep the comments from before and after the image
separate.
png_infop end_info = png_create_info_struct(png_ptr);
@ -2185,6 +2358,9 @@ separate.
If you are not interested, you should still call png_read_end()
but you can pass NULL, avoiding the need to create an end_info structure.
If you do this, libpng will not process any chunks after IDAT other than
skipping over them and perhaps (depending on whether you have called
png_set_crc_action) checking their CRCs while looking for the IEND chunk.
png_read_end(png_ptr, (png_infop)NULL);
@ -4941,7 +5117,7 @@ pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
build of pnglibconf.h and it is never included in an application build.
The rarely used alternative of adding a list of feature macros to the
CFLAGS setting in the build also still works; however, the macros will be
CPPFLAGS setting in the build also still works; however, the macros will be
copied to pnglibconf.h and this may produce macro redefinition warnings
when the individual C files are compiled.
@ -4998,7 +5174,6 @@ The following API are now DEPRECATED:
png_info_init_3()
png_convert_to_rfc1123() which has been replaced
with png_convert_to_rfc1123_buffer()
png_data_freer()
png_malloc_default()
png_free_default()
png_reset_zstream()
@ -5174,6 +5349,9 @@ exported functions are marked with PNGAPI:
body;
}
The return type and decorations are placed on a separate line
ahead of the function name, as illustrated above.
The prototypes for all exported functions appear in png.h,
above the comment that says
@ -5238,13 +5416,13 @@ Other rules can be inferred by inspecting the libpng source.
XVI. Y2K Compliance in libpng
February 6, 2014
March 6, 2014
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
upward through 1.6.9 are Y2K compliant. It is my belief that earlier
upward through 1.6.10 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has two year fields. One is a 2-byte unsigned integer

271
libpng.3
View File

@ -1,6 +1,6 @@
.TH LIBPNG 3 "February 6, 2014"
.TH LIBPNG 3 "March 6, 2014"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.9
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.10
.SH SYNOPSIS
\fB
#include <png.h>\fP
@ -504,7 +504,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
.SH LIBPNG.TXT
libpng-manual.txt - A description on how to use and modify libpng
libpng version 1.6.9 - February 6, 2014
libpng version 1.6.10 - March 6, 2014
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -515,7 +515,7 @@ libpng-manual.txt - A description on how to use and modify libpng
Based on:
libpng versions 0.97, January 1998, through 1.6.9 - February 6, 2014
libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -778,10 +778,10 @@ This method of building a customized pnglibconf.h is illustrated in
contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and
pngusr.dfa in these directories.
C. Configuration using PNG_USR_CONFIG
C. Configuration using PNG_USER_CONFIG
If \-DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
pngusr.h will automatically be included before the options in
If \-DPNG_USER_CONFIG is added to the CPPFLAGS when pnglibconf.h is built,
the file pngusr.h will automatically be included before the options in
scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only
macro definitions turning features on or off or setting settings.
@ -1216,12 +1216,12 @@ value. You can also specify a default encoding for the PNG file in
case the required information is missing from the file. By default libpng
assumes that the PNG data matches your system, to keep this default call:
png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
png_set_gamma(png_ptr, screen_gamma, output_gamma);
or you can use the fixed point equivalent:
png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma,
PNG_FP_1/screen_gamma);
PNG_FP_1*output_gamma);
If you don't know the gamma for your system it is probably 2.2 - a good
approximation to the IEC standard for display systems (sRGB). If images are
@ -1249,6 +1249,70 @@ component value whenever arithmetic is performed. A lot of graphics software
uses linear values for this reason, often with higher precision component values
to preserve overall accuracy.
The output_gamma value expresses how to decode the output values, not how
they are encoded. The values used correspond to the normal numbers used to
describe the overall gamma of a computer display system; for example 2.2 for
an sRGB conformant system. The values are scaled by 100000 in the _fixed
version of the API (so 220000 for sRGB.)
The inverse of the value is always used to provide a default for the PNG file
encoding if it has no gAMA chunk and if png_set_gamma() has not been called
to override the PNG gamma information.
When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
opaque pixels however pixels with lower alpha values are not encoded,
regardless of the output gamma setting.
When the standard Porter Duff handling is requested with mode 1 the output
encoding is set to be linear and the output_gamma value is only relevant
as a default for input data that has no gamma information. The linear output
encoding will be overridden if png_set_gamma() is called - the results may be
highly unexpected!
The following numbers are derived from the sRGB standard and the research
behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
correction required to take account of any differences in the color
environment of the original scene and the intended display environment; the
value expresses how to *decode* the image for display, not how the original
data was *encoded*.
sRGB provides a peg for the PNG standard by defining a viewing environment.
sRGB itself, and earlier TV standards, actually use a more complex transform
(a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
limited to simple power laws.) By saying that an image for direct display on
an sRGB conformant system should be stored with a gAMA chunk value of 45455
(11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
makes it possible to derive values for other display systems and
environments.
The Mac value is deduced from the sRGB based on an assumption that the actual
extra viewing correction used in early Mac display systems was implemented as
a power 1.45 lookup table.
Any system where a programmable lookup table is used or where the behavior of
the final display device characteristics can be changed requires system
specific code to obtain the current characteristic. However this can be
difficult and most PNG gamma correction only requires an approximate value.
By default, if png_set_alpha_mode() is not called, libpng assumes that all
values are unencoded, linear, values and that the output device also has a
linear characteristic. This is only very rarely correct - it is invariably
better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
default if you don't know what the right answer is!
The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
10.6) which used a correction table to implement a somewhat lower gamma on an
otherwise sRGB system.
Both these values are reserved (not simple gamma values) in order to allow
more precise correction internally in the future.
NOTE: the values can be passed to either the fixed or floating
point APIs, but the floating point API will also accept floating point
values.
The second thing you may need to tell libpng about is how your system handles
alpha channel information. Some, but not all, PNG files contain an alpha
channel. To display these files correctly you need to compose the data onto a
@ -1273,11 +1337,11 @@ by png_set_alpha_mode().
The mode is as follows:
PNG_ALPHA_PNG: The data is encoded according to the PNG specification. Red,
green and blue, or gray, components are gamma encoded color
values and are not premultiplied by the alpha value. The
alpha value is a linear measure of the contribution of the
pixel to the corresponding final output pixel.
PNG_ALPHA_PNG: The data is encoded according to the PNG
specification. Red, green and blue, or gray, components are
gamma encoded color values and are not premultiplied by the
alpha value. The alpha value is a linear measure of the
contribution of the pixel to the corresponding final output pixel.
You should normally use this format if you intend to perform
color correction on the color values; most, maybe all, color
@ -1294,11 +1358,35 @@ be used!
The remaining modes assume you don't need to do any further color correction or
that if you do, your color correction software knows all about alpha (it
probably doesn't!)
probably doesn't!). They 'associate' the alpha with the color information by
storing color channel values that have been scaled by the alpha. The
advantage is that the color channels can be resampled (the image can be
scaled) in this form. The disadvantage is that normal practice is to store
linear, not (gamma) encoded, values and this requires 16-bit channels for
still images rather than the 8-bit channels that are just about sufficient if
gamma encoding is used. In addition all non-transparent pixel values,
including completely opaque ones, must be gamma encoded to produce the final
image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
described below (the latter being the two common names for associated alpha
color channels). Note that PNG files always contain non-associated color
channels; png_set_alpha_mode() with one of the modes causes the decoder to
convert the pixels to an associated form before returning them to your
application.
PNG_ALPHA_STANDARD: The data libpng produces
is encoded in the standard way
assumed by most correctly written graphics software.
Since it is not necessary to perform arithmetic on opaque color values so
long as they are not to be resampled and are in the final color space it is
possible to optimize the handling of alpha by storing the opaque pixels in
the PNG format (adjusted for the output color space) while storing partially
opaque pixels in the standard, linear, format. The accuracy required for
standard alpha composition is relatively low, because the pixels are
isolated, therefore typically the accuracy loss in storing 8-bit linear
values is acceptable. (This is not true if the alpha channel is used to
simulate transparency over large areas - use 16 bits or the PNG mode in
this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
treated as opaque only if the alpha value is equal to the maximum value.
PNG_ALPHA_STANDARD: The data libpng produces is encoded in the
standard way assumed by most correctly written graphics software.
The gamma encoding will be removed by libpng and the
linear component values will be pre-multiplied by the
alpha channel.
@ -1327,9 +1415,8 @@ dynamic range. To avoid problems, and if your software
supports it, use png_set_expand_16() to force all
components to 16 bits.
PNG_ALPHA_OPTIMIZED: This mode is the same
as PNG_ALPHA_STANDARD except that
completely opaque pixels are gamma encoded according to
PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD
except that completely opaque pixels are gamma encoded according to
the screen_gamma value. Pixels with alpha less than 1.0
will still have linear components.
@ -1348,18 +1435,16 @@ representation of non-opaque pixels are irrelevant.
You can also try this format if your software is broken;
it might look better.
PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD;
however, all component values,
including the alpha channel are gamma encoded. This is
an appropriate format to try if your software, or more
likely hardware, is totally broken, i.e., if it performs
linear arithmetic directly on gamma encoded values.
In most cases of broken software or hardware the bug in the final display
manifests as a subtle halo around composited parts of the image. You may not
even perceive this as a halo; the composited part of the image may simply appear
separate from the background, as though it had been cut out of paper and pasted
on afterward.
PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; however, all component
values, including the alpha channel are gamma encoded. This is
broken because, in practice, no implementation that uses this choice
correctly undoes the encoding before handling alpha composition. Use this
choice only if other serious errors in the software or hardware you use
mandate it. In most cases of broken software or hardware the bug in the
final display manifests as a subtle halo around composited parts of the
image. You may not even perceive this as a halo; the composited part of
the image may simply appear separate from the background, as though it had
been cut out of paper and pasted on afterward.
If you don't have to deal with bugs in software or hardware, or if you can fix
them, there are three recommended ways of using png_set_alpha_mode():
@ -1390,6 +1475,89 @@ All you can do is compose the result onto a matching output. Since this
mode is libpng-specific you also need to write your own composition
software.
The following are examples of calls to png_set_alpha_mode to achieve the
required overall gamma correction and, where necessary, alpha
premultiplication.
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
This is the default libpng handling of the alpha channel - it is not
pre-multiplied into the color components. In addition the call states
that the output is for a sRGB system and causes all PNG files without gAMA
chunks to be assumed to be encoded using sRGB.
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
In this case the output is assumed to be something like an sRGB conformant
display preceeded by a power-law lookup table of power 1.45. This is how
early Mac systems behaved.
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
This is the classic Jim Blinn approach and will work in academic
environments where everything is done by the book. It has the shortcoming
of assuming that input PNG data with no gamma information is linear - this
is unlikely to be correct unless the PNG files where generated locally.
Most of the time the output precision will be so low as to show
significant banding in dark areas of the image.
png_set_expand_16(pp);
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
This is a somewhat more realistic Jim Blinn inspired approach. PNG files
are assumed to have the sRGB encoding if not marked with a gamma value and
the output is always 16 bits per component. This permits accurate scaling
and processing of the data. If you know that your input PNG files were
generated locally you might need to replace PNG_DEFAULT_sRGB with the
correct value for your system.
png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
If you just need to composite the PNG image onto an existing background
and if you control the code that does this you can use the optimization
setting. In this case you just copy completely opaque pixels to the
output. For pixels that are not completely transparent (you just skip
those) you do the composition math using png_composite or png_composite_16
below then encode the resultant 8-bit or 16-bit values to match the output
encoding.
Other cases
If neither the PNG nor the standard linear encoding work for you because
of the software or hardware you use then you have a big problem. The PNG
case will probably result in halos around the image. The linear encoding
will probably result in a washed out, too bright, image (it's actually too
contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
substantially reduce the halos. Alternatively try:
png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
This option will also reduce the halos, but there will be slight dark
halos round the opaque parts of the image where the background is light.
In the OPTIMIZED mode the halos will be light halos where the background
is dark. Take your pick - the halos are unavoidable unless you can get
your hardware/software fixed! (The OPTIMIZED approach is slightly
faster.)
When the default gamma of PNG files doesn't match the output gamma.
If you have PNG files with no gamma information png_set_alpha_mode allows
you to provide a default gamma, but it also sets the ouput gamma to the
matching value. If you know your PNG files have a gamma that doesn't
match the output you can take advantage of the fact that
png_set_alpha_mode always sets the output gamma but only sets the PNG
default if it is not already set:
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
The first call sets both the default and the output gamma values, the
second call overrides the output gamma without changing the default. This
is easier than achieving the same effect with png_set_gamma. You must use
PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
fire if more than one call to png_set_alpha_mode and png_set_background is
made in the same read operation, however multiple calls with PNG_ALPHA_PNG
are ignored.
If you don't need, or can't handle, the alpha channel you can call
png_set_background() to remove it by compositing against a fixed color. Don't
call png_set_strip_alpha() to do this - it will leave spurious pixel values in
@ -1720,7 +1888,7 @@ png_set_rgb_to_gray()).
png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
file_srgb_intent - the rendering intent (PNG_INFO_sRGB)
srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk
means that the pixel data is in the
sRGB color space. This chunk also
@ -2670,10 +2838,15 @@ how pngvalid.c does it.
.SS Finishing a sequential read
After you are finished reading the image through the
low-level interface, you can finish reading the file. If you are
interested in comments or time, which may be stored either before or
after the image data, you should pass the separate png_info struct if
you want to keep the comments from before and after the image
low-level interface, you can finish reading the file.
If you want to use a different crc action for handling CRC errors in
chunks after the image data, you can call png_set_crc_action()
again at this point.
If you are interested in comments or time, which may be stored either
before or after the image data, you should pass the separate png_info
struct if you want to keep the comments from before and after the image
separate.
png_infop end_info = png_create_info_struct(png_ptr);
@ -2689,6 +2862,9 @@ separate.
If you are not interested, you should still call png_read_end()
but you can pass NULL, avoiding the need to create an end_info structure.
If you do this, libpng will not process any chunks after IDAT other than
skipping over them and perhaps (depending on whether you have called
png_set_crc_action) checking their CRCs while looking for the IEND chunk.
png_read_end(png_ptr, (png_infop)NULL);
@ -5446,7 +5622,7 @@ pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
build of pnglibconf.h and it is never included in an application build.
The rarely used alternative of adding a list of feature macros to the
CFLAGS setting in the build also still works; however, the macros will be
CPPFLAGS setting in the build also still works; however, the macros will be
copied to pnglibconf.h and this may produce macro redefinition warnings
when the individual C files are compiled.
@ -5503,7 +5679,6 @@ The following API are now DEPRECATED:
png_info_init_3()
png_convert_to_rfc1123() which has been replaced
with png_convert_to_rfc1123_buffer()
png_data_freer()
png_malloc_default()
png_free_default()
png_reset_zstream()
@ -5679,6 +5854,9 @@ exported functions are marked with PNGAPI:
body;
}
The return type and decorations are placed on a separate line
ahead of the function name, as illustrated above.
The prototypes for all exported functions appear in png.h,
above the comment that says
@ -5743,13 +5921,13 @@ Other rules can be inferred by inspecting the libpng source.
.SH XVI. Y2K Compliance in libpng
February 6, 2014
March 6, 2014
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
upward through 1.6.9 are Y2K compliant. It is my belief that earlier
upward through 1.6.10 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has two year fields. One is a 2-byte unsigned integer
@ -5980,6 +6158,9 @@ the first widely used release:
1.6.9beta01-04 16 10609 16.so.16.9[.0]
1.6.9rc01-02 16 10609 16.so.16.9[.0]
1.6.9 16 10609 16.so.16.9[.0]
1.6.10beta01-03 16 10610 16.so.16.10[.0]
1.6.10rc01-04 16 10610 16.so.16.10[.0]
1.6.10 16 10610 16.so.16.10[.0]
Henceforth the source version will match the shared-library minor
and patch numbers; the shared-library major version number will be
@ -6036,7 +6217,7 @@ possible without all of you.
Thanks to Frank J. T. Wojcik for helping with the documentation.
Libpng version 1.6.9 - February 6, 2014:
Libpng version 1.6.10 - March 6, 2014:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@ -6059,7 +6240,7 @@ this sentence.
This code is released under the libpng license.
libpng versions 1.2.6, August 15, 2004, through 1.6.9, February 6, 2014, are
libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-1.2.5
with the following individual added to the list of Contributing Authors
@ -6158,7 +6339,7 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
February 6, 2014
March 6, 2014
.\" end of man page

4
libpngpf.3
View File

@ -1,6 +1,6 @@
.TH LIBPNGPF 3 "February 6, 2014"
.TH LIBPNGPF 3 "March 6, 2014"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.9
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.10
(private functions)
.SH SYNOPSIS
\fB#include \fI"pngpriv.h"

2
png.5
View File

@ -1,4 +1,4 @@
.TH PNG 5 "February 6, 2014"
.TH PNG 5 "March 6, 2014"
.SH NAME
png \- Portable Network Graphics (PNG) format
.SH DESCRIPTION

28
png.c
View File

@ -14,7 +14,7 @@
#include "pngpriv.h"
/* Generate a compiler error if there is an old png.h in the search path. */
typedef png_libpng_version_1_6_9 Your_png_h_is_not_version_1_6_9;
typedef png_libpng_version_1_6_10 Your_png_h_is_not_version_1_6_10;
/* 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
@ -773,13 +773,13 @@ png_get_copyright(png_const_structrp png_ptr)
#else
# ifdef __STDC__
return PNG_STRING_NEWLINE \
"libpng version 1.6.9 - February 6, 2014" PNG_STRING_NEWLINE \
"libpng version 1.6.10 - March 6, 2014" PNG_STRING_NEWLINE \
"Copyright (c) 1998-2014 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 1.6.9 - February 6, 2014\
return "libpng version 1.6.10 - March 6, 2014\
Copyright (c) 1998-2014 Glenn Randers-Pehrson\
Copyright (c) 1996-1997 Andreas Dilger\
Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@ -1742,7 +1742,8 @@ is_ICC_signature_char(png_alloc_size_t it)
(it >= 97 && it <= 122);
}
static int is_ICC_signature(png_alloc_size_t it)
static int
is_ICC_signature(png_alloc_size_t it)
{
return is_ICC_signature_char(it >> 24) /* checks all the top bits */ &&
is_ICC_signature_char((it >> 16) & 0xff) &&
@ -2295,15 +2296,16 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
}
}
# if PNG_sRGB_PROFILE_CHECKS > 0
/* The signature matched, but the profile had been changed in some
* way. This is an apparent violation of the ICC terms of use and,
* anyway, probably indicates a data error or uninformed hacking.
*/
if (png_sRGB_checks[i].have_md5)
png_benign_error(png_ptr,
"copyright violation: edited ICC profile ignored");
# endif
# if PNG_sRGB_PROFILE_CHECKS > 0
/* The signature matched, but the profile had been changed in some
* way. This probably indicates a data error or uninformed hacking.
* Fall through to "no match".
*/
png_chunk_report(png_ptr,
"Not recognizing known sRGB profile that has been edited",
PNG_CHUNK_WARNING);
break;
# endif
}
}

137
png.h
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@ -1,8 +1,8 @@
/* png.h - header file for PNG reference library
*
* libpng version 1.6.9 - February 6, 2014
* Copyright (c) 1998-2013 Glenn Randers-Pehrson
* libpng version 1.6.10 - March 6, 2014
* Copyright (c) 1998-2014 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.)
*
@ -11,7 +11,7 @@
* Authors and maintainers:
* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
* libpng versions 0.97, January 1998, through 1.6.9 - February 6, 2014: Glenn
* libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014: Glenn
* See also "Contributing Authors", below.
*
* Note about libpng version numbers:
@ -192,6 +192,9 @@
* 1.6.9beta01-04 16 10609 16.so.16.9[.0]
* 1.6.9rc01-02 16 10609 16.so.16.9[.0]
* 1.6.9 16 10609 16.so.16.9[.0]
* 1.6.10beta01-03 16 10610 16.so.16.10[.0]
* 1.6.10betarc01-04 16 10610 16.so.16.10[.0]
* 1.6.10beta 16 10610 16.so.16.10[.0]
*
* Henceforth the source version will match the shared-library major
* and minor numbers; the shared-library major version number will be
@ -223,7 +226,7 @@
*
* This code is released under the libpng license.
*
* libpng versions 1.2.6, August 15, 2004, through 1.6.9, February 6, 2014, are
* libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
* Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
* distributed according to the same disclaimer and license as libpng-1.2.5
* with the following individual added to the list of Contributing Authors:
@ -335,13 +338,13 @@
* Y2K compliance in libpng:
* =========================
*
* February 6, 2014
* March 6, 2014
*
* Since the PNG Development group is an ad-hoc body, we can't make
* an official declaration.
*
* This is your unofficial assurance that libpng from version 0.71 and
* upward through 1.6.9 are Y2K compliant. It is my belief that
* upward through 1.6.10 are Y2K compliant. It is my belief that
* earlier versions were also Y2K compliant.
*
* Libpng only has two year fields. One is a 2-byte unsigned integer
@ -401,9 +404,9 @@
*/
/* Version information for png.h - this should match the version in png.c */
#define PNG_LIBPNG_VER_STRING "1.6.9"
#define PNG_LIBPNG_VER_STRING "1.6.10"
#define PNG_HEADER_VERSION_STRING \
" libpng version 1.6.9 - February 6, 2014\n"
" libpng version 1.6.10 - March 6, 2014\n"
#define PNG_LIBPNG_VER_SONUM 16
#define PNG_LIBPNG_VER_DLLNUM 16
@ -411,7 +414,7 @@
/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
#define PNG_LIBPNG_VER_MAJOR 1
#define PNG_LIBPNG_VER_MINOR 6
#define PNG_LIBPNG_VER_RELEASE 9
#define PNG_LIBPNG_VER_RELEASE 10
/* This should match the numeric part of the final component of
* PNG_LIBPNG_VER_STRING, omitting any leading zero:
@ -442,7 +445,7 @@
* version 1.0.0 was mis-numbered 100 instead of 10000). From
* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
*/
#define PNG_LIBPNG_VER 10609 /* 1.6.9 */
#define PNG_LIBPNG_VER 10610 /* 1.6.10 */
/* Library configuration: these options cannot be changed after
* the library has been built.
@ -547,7 +550,7 @@ extern "C" {
/* This triggers a compiler error in png.c, if png.c and png.h
* do not agree upon the version number.
*/
typedef char* png_libpng_version_1_6_9;
typedef char* png_libpng_version_1_6_10;
/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
*
@ -1209,9 +1212,9 @@ PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
#endif
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
/* How the alpha channel is interpreted - this affects how the color channels of
* a PNG file are returned when an alpha channel, or tRNS chunk in a palette
* file, is present.
/* How the alpha channel is interpreted - this affects how the color channels
* of a PNG file are returned to the calling application when an alpha channel,
* or a tRNS chunk in a palette file, is present.
*
* This has no effect on the way pixels are written into a PNG output
* datastream. The color samples in a PNG datastream are never premultiplied
@ -1219,33 +1222,19 @@ PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
*
* The default is to return data according to the PNG specification: the alpha
* channel is a linear measure of the contribution of the pixel to the
* corresponding composited pixel. The gamma encoded color channels must be
* scaled according to the contribution and to do this it is necessary to undo
* corresponding composited pixel, and the color channels are unassociated
* (not premultiplied). The gamma encoded color channels must be scaled
* according to the contribution and to do this it is necessary to undo
* the encoding, scale the color values, perform the composition and reencode
* the values. This is the 'PNG' mode.
*
* The alternative is to 'associate' the alpha with the color information by
* storing color channel values that have been scaled by the alpha. The
* advantage is that the color channels can be resampled (the image can be
* scaled) in this form. The disadvantage is that normal practice is to store
* linear, not (gamma) encoded, values and this requires 16-bit channels for
* still images rather than the 8-bit channels that are just about sufficient if
* gamma encoding is used. In addition all non-transparent pixel values,
* including completely opaque ones, must be gamma encoded to produce the final
* image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
* latter being the two common names for associated alpha color channels.)
* storing color channel values that have been scaled by the alpha.
* image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
* (the latter being the two common names for associated alpha color channels).
*
* Since it is not necessary to perform arithmetic on opaque color values so
* long as they are not to be resampled and are in the final color space it is
* possible to optimize the handling of alpha by storing the opaque pixels in
* the PNG format (adjusted for the output color space) while storing partially
* opaque pixels in the standard, linear, format. The accuracy required for
* standard alpha composition is relatively low, because the pixels are
* isolated, therefore typically the accuracy loss in storing 8-bit linear
* values is acceptable. (This is not true if the alpha channel is used to
* simulate transparency over large areas - use 16 bits or the PNG mode in
* this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
* treated as opaque only if the alpha value is equal to the maximum value.
* For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
* value is equal to the maximum value.
*
* The final choice is to gamma encode the alpha channel as well. This is
* broken because, in practice, no implementation that uses this choice
@ -1272,68 +1261,7 @@ PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
/* The output_gamma value is a screen gamma in libpng terminology: it expresses
* how to decode the output values, not how they are encoded. The values used
* correspond to the normal numbers used to describe the overall gamma of a
* computer display system; for example 2.2 for an sRGB conformant system. The
* values are scaled by 100000 in the _fixed version of the API (so 220000 for
* sRGB.)
*
* The inverse of the value is always used to provide a default for the PNG file
* encoding if it has no gAMA chunk and if png_set_gamma() has not been called
* to override the PNG gamma information.
*
* When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
* opaque pixels however pixels with lower alpha values are not encoded,
* regardless of the output gamma setting.
*
* When the standard Porter Duff handling is requested with mode 1 the output
* encoding is set to be linear and the output_gamma value is only relevant
* as a default for input data that has no gamma information. The linear output
* encoding will be overridden if png_set_gamma() is called - the results may be
* highly unexpected!
*
* The following numbers are derived from the sRGB standard and the research
* behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
* 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
* correction required to take account of any differences in the color
* environment of the original scene and the intended display environment; the
* value expresses how to *decode* the image for display, not how the original
* data was *encoded*.
*
* sRGB provides a peg for the PNG standard by defining a viewing environment.
* sRGB itself, and earlier TV standards, actually use a more complex transform
* (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
* limited to simple power laws.) By saying that an image for direct display on
* an sRGB conformant system should be stored with a gAMA chunk value of 45455
* (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
* makes it possible to derive values for other display systems and
* environments.
*
* The Mac value is deduced from the sRGB based on an assumption that the actual
* extra viewing correction used in early Mac display systems was implemented as
* a power 1.45 lookup table.
*
* Any system where a programmable lookup table is used or where the behavior of
* the final display device characteristics can be changed requires system
* specific code to obtain the current characteristic. However this can be
* difficult and most PNG gamma correction only requires an approximate value.
*
* By default, if png_set_alpha_mode() is not called, libpng assumes that all
* values are unencoded, linear, values and that the output device also has a
* linear characteristic. This is only very rarely correct - it is invariably
* better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
* default if you don't know what the right answer is!
*
* The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
* 10.6) which used a correction table to implement a somewhat lower gamma on an
* otherwise sRGB system.
*
* Both these values are reserved (not simple gamma values) in order to allow
* more precise correction internally in the future.
*
* NOTE: the following values can be passed to either the fixed or floating
* point APIs, but the floating point API will also accept floating point
* values.
* how to decode the output values, not how they are encoded.
*/
#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
@ -1956,8 +1884,8 @@ PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
* It is unlikely that this function works correctly as of 1.6.0 and using it
* may result either in memory leaks or double free of allocated data.
*/
PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr,
png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED);
PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
png_inforp info_ptr, int freer, png_uint_32 mask));
/* Assignments for png_data_freer */
#define PNG_DESTROY_WILL_FREE_DATA 1
@ -1999,6 +1927,8 @@ PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
#else
/* Fatal error in PNG image of libpng - can't continue */
PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
# define png_error(s1,s2) png_err(s1)
# define png_chunk_error(s1,s2) png_err(s1)
#endif
#ifdef PNG_WARNINGS_SUPPORTED
@ -2009,6 +1939,9 @@ PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
/* Non-fatal error in libpng, chunk name is prepended to message. */
PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
png_const_charp warning_message));
#else
# define png_warning(s1,s2) ((void)(s1))
# define png_chunk_warning(s1,s2) ((void)(s1))
#endif
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
@ -2519,11 +2452,15 @@ PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
#ifdef PNG_INFO_IMAGE_SUPPORTED
/* The "params" pointer is currently not used and is for future expansion. */
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
int transforms, png_voidp params));
#endif
#ifdef PNG_WRITE_SUPPORTED
PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
int transforms, png_voidp params));
#endif
#endif
PNG_EXPORT(180, png_const_charp, png_get_copyright,
(png_const_structrp png_ptr));

10
pngconf.h
View File

@ -1,7 +1,7 @@
/* pngconf.h - machine configurable file for libpng
*
* libpng version 1.6.9 - February 6, 2014
* libpng version 1.6.10 - March 6, 2014
*
* Copyright (c) 1998-2013 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@ -376,9 +376,11 @@
# define PNG_DEPRECATED __attribute__((__deprecated__))
# endif
# if !defined(PNG_PRIVATE)
# if __has_extension(attribute_unavailable_with_message)
# define PNG_PRIVATE __attribute__((__unavailable__(\
"This function is not exported by libpng.")))
# ifdef __has_extension
# if __has_extension(attribute_unavailable_with_message)
# define PNG_PRIVATE __attribute__((__unavailable__(\
"This function is not exported by libpng.")))
# endif
# endif
# endif
# ifndef PNG_RESTRICT

10
pngerror.c
View File

@ -1,8 +1,8 @@
/* pngerror.c - stub functions for i/o and memory allocation
*
* Last changed in libpng 1.6.8 [December 19, 2013]
* Copyright (c) 1998-2013 Glenn Randers-Pehrson
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
*
@ -876,8 +876,8 @@ png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
* possible to implement without setjmp support just so long as there is some
* way to handle the error return here:
*/
PNG_FUNCTION(void /* PRIVATE */,
png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
PNG_NORETURN)
{
const png_const_structrp png_ptr = png_nonconst_ptr;
@ -912,7 +912,7 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
}
#ifdef PNG_WARNINGS_SUPPORTED
void /* PRIVATE */
void /* PRIVATE */ PNGCBAPI
png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
{
const png_const_structrp png_ptr = png_nonconst_ptr;

5
pngpread.c
View File

@ -1,8 +1,8 @@
/* pngpread.c - read a png file in push mode
*
* Last changed in libpng 1.6.8 [December 19, 2013]
* Copyright (c) 1998-2013 Glenn Randers-Pehrson
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
*
@ -234,6 +234,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
png_error(png_ptr, "Missing PLTE before IDAT");
png_ptr->mode |= PNG_HAVE_IDAT;
png_ptr->process_mode = PNG_READ_IDAT_MODE;
if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
if (png_ptr->push_length == 0)

15
pngpriv.h
View File

@ -6,7 +6,7 @@
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
* Last changed in libpng 1.6.9 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
@ -254,6 +254,11 @@
extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
#endif
#ifndef PNG_INTERNAL_CALLBACK
# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
extern PNG_FUNCTION(type, (PNGCBAPI name), args, PNG_EMPTY attributes)
#endif
/* If floating or fixed point APIs are disabled they may still be compiled
* internally. To handle this make sure they are declared as the appropriate
* internal extern function (otherwise the symbol prefixing stuff won't work and
@ -373,8 +378,6 @@
#ifdef PNG_WARNINGS_SUPPORTED
# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
#else
# define png_warning(s1,s2) ((void)(s1))
# define png_chunk_warning(s1,s2) ((void)(s1))
# define png_warning_parameter(p,number,string) ((void)0)
# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
# define png_warning_parameter_signed(p,number,format,value) ((void)0)
@ -382,8 +385,6 @@
# define PNG_WARNING_PARAMETERS(p)
#endif
#ifndef PNG_ERROR_TEXT_SUPPORTED
# define png_error(s1,s2) png_err(s1)
# define png_chunk_error(s1,s2) png_err(s1)
# define png_fixed_error(s1,s2) png_err(s1)
#endif
@ -1883,11 +1884,11 @@ typedef struct png_control
* errors that might occur. Returns true on success, false on failure (either
* of the function or as a result of a png_error.)
*/
PNG_INTERNAL_FUNCTION(void,png_safe_error,(png_structp png_ptr,
PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
png_const_charp error_message),PNG_NORETURN);
#ifdef PNG_WARNINGS_SUPPORTED
PNG_INTERNAL_FUNCTION(void,png_safe_warning,(png_structp png_ptr,
PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
png_const_charp warning_message),PNG_EMPTY);
#else
# define png_safe_warning 0/*dummy argument*/

99
pngread.c
View File

@ -1,7 +1,7 @@
/* pngread.c - read a PNG file
*
* Last changed in libpng 1.6.9 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
@ -781,11 +781,14 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
png_uint_32 length = png_read_chunk_header(png_ptr);
png_uint_32 chunk_name = png_ptr->chunk_name;
if (chunk_name == png_IHDR)
if (chunk_name == png_IEND)
png_handle_IEND(png_ptr, info_ptr, length);
else if (chunk_name == png_IHDR)
png_handle_IHDR(png_ptr, info_ptr, length);
else if (chunk_name == png_IEND)
png_handle_IEND(png_ptr, info_ptr, length);
else if (info_ptr == NULL)
png_crc_finish(png_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
@ -1001,8 +1004,6 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
int transforms,
voidp params)
{
int row;
if (png_ptr == NULL || info_ptr == NULL)
return;
@ -1014,120 +1015,149 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
png_error(png_ptr, "Image is too high to process with png_read_png()");
/* -------------- image transformations start here ------------------- */
/* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM
* is not implemented. This will only happen in de-configured (non-default)
* libpng builds. The results can be unexpected - png_read_png may return
* short or mal-formed rows because the transform is skipped.
*/
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
/* Tell libpng to strip 16-bit/color files down to 8 bits per color.
*/
if (transforms & PNG_TRANSFORM_SCALE_16)
{
/* Added at libpng-1.5.4. "strip_16" produces the same result that it
* did in earlier versions, while "scale_16" is now more accurate.
*/
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
png_set_scale_16(png_ptr);
}
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported");
#endif
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
/* If both SCALE and STRIP are required pngrtran will effectively cancel the
* latter by doing SCALE first. This is ok and allows apps not to check for
* which is supported to get the right answer.
*/
if (transforms & PNG_TRANSFORM_STRIP_16)
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
png_set_strip_16(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported");
#endif
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
/* Strip alpha bytes from the input data without combining with
* the background (not recommended).
*/
if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
png_set_strip_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported");
#endif
#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
/* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
* byte into separate bytes (useful for paletted and grayscale images).
*/
if (transforms & PNG_TRANSFORM_PACKING)
#ifdef PNG_READ_PACK_SUPPORTED
png_set_packing(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
#endif
#ifdef PNG_READ_PACKSWAP_SUPPORTED
/* Change the order of packed pixels to least significant bit first
* (not useful if you are using png_set_packing).
*/
if (transforms & PNG_TRANSFORM_PACKSWAP)
#ifdef PNG_READ_PACKSWAP_SUPPORTED
png_set_packswap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
#endif
#ifdef PNG_READ_EXPAND_SUPPORTED
/* Expand paletted colors into true RGB triplets
* Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
* Expand paletted or RGB images with transparency to full alpha
* channels so the data will be available as RGBA quartets.
*/
if (transforms & PNG_TRANSFORM_EXPAND)
if ((png_ptr->bit_depth < 8) ||
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
(info_ptr->valid & PNG_INFO_tRNS))
png_set_expand(png_ptr);
#ifdef PNG_READ_EXPAND_SUPPORTED
png_set_expand(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported");
#endif
/* We don't handle background color or gamma transformation or quantizing.
*/
#ifdef PNG_READ_INVERT_SUPPORTED
/* Invert monochrome files to have 0 as white and 1 as black
*/
if (transforms & PNG_TRANSFORM_INVERT_MONO)
#ifdef PNG_READ_INVERT_SUPPORTED
png_set_invert_mono(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
#endif
#ifdef PNG_READ_SHIFT_SUPPORTED
/* If you want to shift the pixel values from the range [0,255] or
* [0,65535] to the original [0,7] or [0,31], or whatever range the
* colors were originally in:
*/
if ((transforms & PNG_TRANSFORM_SHIFT) && (info_ptr->valid & PNG_INFO_sBIT))
png_set_shift(png_ptr, &info_ptr->sig_bit);
if (transforms & PNG_TRANSFORM_SHIFT)
#ifdef PNG_READ_SHIFT_SUPPORTED
if (info_ptr->valid & PNG_INFO_sBIT)
png_set_shift(png_ptr, &info_ptr->sig_bit);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
#endif
#ifdef PNG_READ_BGR_SUPPORTED
/* Flip the RGB pixels to BGR (or RGBA to BGRA) */
if (transforms & PNG_TRANSFORM_BGR)
#ifdef PNG_READ_BGR_SUPPORTED
png_set_bgr(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
#endif
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
/* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
png_set_swap_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
#endif
#ifdef PNG_READ_SWAP_SUPPORTED
/* Swap bytes of 16-bit files to least significant byte first */
if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
#ifdef PNG_READ_SWAP_SUPPORTED
png_set_swap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
#endif
/* Added at libpng-1.2.41 */
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
/* Invert the alpha channel from opacity to transparency */
if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
png_set_invert_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
#endif
/* Added at libpng-1.2.41 */
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
/* Expand grayscale image to RGB */
if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
png_set_gray_to_rgb(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported");
#endif
/* Added at libpng-1.5.4 */
#ifdef PNG_READ_EXPAND_16_SUPPORTED
if (transforms & PNG_TRANSFORM_EXPAND_16)
#ifdef PNG_READ_EXPAND_16_SUPPORTED
png_set_expand_16(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported");
#endif
/* We don't handle adding filler bytes */
@ -1150,16 +1180,17 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
{
png_uint_32 iptr;
info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
info_ptr->height * (sizeof (png_bytep)));
info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr,
info_ptr->height * (sizeof (png_bytep))));
for (iptr=0; iptr<info_ptr->height; iptr++)
info_ptr->row_pointers[iptr] = NULL;
info_ptr->free_me |= PNG_FREE_ROWS;
for (row = 0; row < (int)info_ptr->height; row++)
info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
png_get_rowbytes(png_ptr, info_ptr));
for (iptr = 0; iptr < info_ptr->height; iptr++)
info_ptr->row_pointers[iptr] = png_voidcast(png_bytep,
png_malloc(png_ptr, info_ptr->rowbytes));
}
png_read_image(png_ptr, info_ptr->row_pointers);
@ -1168,9 +1199,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
/* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
png_read_end(png_ptr, info_ptr);
PNG_UNUSED(transforms) /* Quiet compiler warnings */
PNG_UNUSED(params)
}
#endif /* PNG_INFO_IMAGE_SUPPORTED */
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */

24
pngrtran.c
View File

@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* Last changed in libpng 1.6.9 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
@ -1363,12 +1363,12 @@ png_init_read_transformations(png_structrp png_ptr)
* 12) PNG_EXPAND_16
* 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
* 14) PNG_INVERT_MONO
* 15) PNG_SHIFT
* 16) PNG_PACK
* 17) PNG_BGR
* 18) PNG_PACKSWAP
* 19) PNG_FILLER (includes PNG_ADD_ALPHA)
* 20) PNG_INVERT_ALPHA
* 15) PNG_INVERT_ALPHA
* 16) PNG_SHIFT
* 17) PNG_PACK
* 18) PNG_BGR
* 19) PNG_PACKSWAP
* 20) PNG_FILLER (includes PNG_ADD_ALPHA)
* 21) PNG_SWAP_ALPHA
* 22) PNG_SWAP_BYTES
* 23) PNG_USER_TRANSFORM [must be last]
@ -4907,6 +4907,11 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
png_do_invert(row_info, png_ptr->row_buf + 1);
#endif
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_ALPHA)
png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
#endif
#ifdef PNG_READ_SHIFT_SUPPORTED
if (png_ptr->transformations & PNG_SHIFT)
png_do_unshift(row_info, png_ptr->row_buf + 1,
@ -4941,11 +4946,6 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
(png_uint_32)png_ptr->filler, png_ptr->flags);
#endif
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_ALPHA)
png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
#endif
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_SWAP_ALPHA)
png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);

48
pngrutil.c
View File

@ -1,8 +1,8 @@
/* pngrutil.c - utilities to read a PNG file
*
* Last changed in libpng 1.6.8 [December 19, 2013]
* Copyright (c) 1998-2013 Glenn Randers-Pehrson
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
*
@ -227,10 +227,7 @@ png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
}
else
{
png_chunk_benign_error(png_ptr, "CRC error");
return (0);
}
png_chunk_error(png_ptr, "CRC error");
return (1);
}
@ -314,16 +311,11 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
else if (warn < 2) /* else silent */
{
#ifdef PNG_WARNINGS_SUPPORTED
if (warn)
png_chunk_warning(png_ptr, "insufficient memory to read chunk");
else
#endif
{
#ifdef PNG_ERROR_TEXT_SUPPORTED
png_chunk_error(png_ptr, "insufficient memory to read chunk");
#endif
}
}
}
@ -986,22 +978,15 @@ png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
{
if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
{
png_chunk_benign_error(png_ptr, "CRC error");
}
return;
else
{
png_chunk_warning(png_ptr, "CRC error");
return;
}
png_chunk_error(png_ptr, "CRC error");
}
/* Otherwise, we (optionally) emit a warning and use the chunk. */
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
{
png_chunk_warning(png_ptr, "CRC error");
}
}
#endif
@ -1112,13 +1097,12 @@ png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
void /* PRIVATE */
png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
unsigned int truelen;
unsigned int truelen, i;
png_byte sample_depth;
png_byte buf[4];
png_debug(1, "in png_handle_sBIT");
buf[0] = buf[1] = buf[2] = buf[3] = 0;
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_chunk_error(png_ptr, "missing IHDR");
@ -1137,10 +1121,16 @@ png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
}
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
truelen = 3;
sample_depth = 8;
}
else
{
truelen = png_ptr->channels;
sample_depth = png_ptr->bit_depth;
}
if (length != truelen || length > 4)
{
@ -1149,11 +1139,19 @@ png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
return;
}
buf[0] = buf[1] = buf[2] = buf[3] = sample_depth;
png_crc_read(png_ptr, buf, truelen);
if (png_crc_finish(png_ptr, 0))
return;
for (i=0; i<truelen; ++i)
if (buf[i] == 0 || buf[i] > sample_depth)
{
png_chunk_benign_error(png_ptr, "invalid");
return;
}
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
{
png_ptr->sig_bit.red = buf[0];
@ -1423,7 +1421,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
(sizeof local_buffer), &length,
profile + (sizeof profile_header), &size, 0);
/* Still expect a a buffer error because we expect
/* Still expect a buffer error because we expect
* there to be some tag data!
*/
if (size == 0)

6
pngtest.c
View File

@ -667,8 +667,8 @@ set_location(png_structp png_ptr, struct user_chunk_data *data, int what)
return 1; /* handled */
}
static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
png_unknown_chunkp chunk)
static int PNGCBAPI
read_user_chunk_callback(png_struct *png_ptr, png_unknown_chunkp chunk)
{
struct user_chunk_data *my_user_chunk_data =
(struct user_chunk_data*)png_get_user_chunk_ptr(png_ptr);
@ -1991,4 +1991,4 @@ main(void)
#endif
/* Generate a compiler error if there is an old png.h in the search path. */
typedef png_libpng_version_1_6_9 Your_png_h_is_not_version_1_6_9;
typedef png_libpng_version_1_6_10 Your_png_h_is_not_version_1_6_10;

78
pngwrite.c
View File

@ -1,7 +1,7 @@
/* pngwrite.c - general routines to write a PNG file
*
* Last changed in libpng 1.6.9 [February 6, 2014]
* Last changed in libpng 1.6.10 [March 6, 2014]
* Copyright (c) 1998-2014 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.)
@ -1546,81 +1546,117 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
if (png_ptr == NULL || info_ptr == NULL)
return;
if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
{
png_app_error(png_ptr, "no rows for png_write_image to write");
return;
}
/* Write the file header information. */
png_write_info(png_ptr, info_ptr);
/* ------ these transformations don't touch the info structure ------- */
#ifdef PNG_WRITE_INVERT_SUPPORTED
/* Invert monochrome pixels */
if (transforms & PNG_TRANSFORM_INVERT_MONO)
#ifdef PNG_WRITE_INVERT_SUPPORTED
png_set_invert_mono(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
#endif
#ifdef PNG_WRITE_SHIFT_SUPPORTED
/* Shift the pixels up to a legal bit depth and fill in
* as appropriate to correctly scale the image.
*/
if ((transforms & PNG_TRANSFORM_SHIFT)
&& (info_ptr->valid & PNG_INFO_sBIT))
png_set_shift(png_ptr, &info_ptr->sig_bit);
if (transforms & PNG_TRANSFORM_SHIFT)
#ifdef PNG_WRITE_SHIFT_SUPPORTED
if (info_ptr->valid & PNG_INFO_sBIT)
png_set_shift(png_ptr, &info_ptr->sig_bit);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
#endif
#ifdef PNG_WRITE_PACK_SUPPORTED
/* Pack pixels into bytes */
if (transforms & PNG_TRANSFORM_PACKING)
png_set_packing(png_ptr);
#ifdef PNG_WRITE_PACK_SUPPORTED
png_set_packing(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
#endif
#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
/* Swap location of alpha bytes from ARGB to RGBA */
if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
png_set_swap_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
#endif
/* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
* RGB, note that the code expects the input color type to be G or RGB; no
* alpha channel.
*/
if (transforms &
(PNG_TRANSFORM_STRIP_FILLER_AFTER|PNG_TRANSFORM_STRIP_FILLER_BEFORE))
{
#ifdef PNG_WRITE_FILLER_SUPPORTED
/* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
{
if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
png_app_error(png_ptr,
"PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
/* Continue if ignored - this is the pre-1.6.10 behavior */
png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
}
else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
#endif
}
#ifdef PNG_WRITE_BGR_SUPPORTED
/* Flip BGR pixels to RGB */
if (transforms & PNG_TRANSFORM_BGR)
#ifdef PNG_WRITE_BGR_SUPPORTED
png_set_bgr(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
#endif
#ifdef PNG_WRITE_SWAP_SUPPORTED
/* Swap bytes of 16-bit files to most significant byte first */
if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
#ifdef PNG_WRITE_SWAP_SUPPORTED
png_set_swap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
#endif
#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
/* Swap bits of 1, 2, 4 bit packed pixel formats */
if (transforms & PNG_TRANSFORM_PACKSWAP)
#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
png_set_packswap(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
#endif
#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
/* Invert the alpha channel from opacity to transparency */
if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
png_set_invert_alpha(png_ptr);
#else
png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
#endif
/* ----------------------- end of transformations ------------------- */
/* Write the bits */
if (info_ptr->valid & PNG_INFO_IDAT)
png_write_image(png_ptr, info_ptr->row_pointers);
png_write_image(png_ptr, info_ptr->row_pointers);
/* It is REQUIRED to call this to finish writing the rest of the file */
png_write_end(png_ptr, info_ptr);
PNG_UNUSED(transforms) /* Quiet compiler warnings */
PNG_UNUSED(params)
}
#endif

3
pngwutil.c
View File

@ -2309,7 +2309,8 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
* been specified by the application, and then writes the row out with the
* chosen filter.
*/
static void png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
static void
png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
png_size_t row_bytes);
#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)

2
projects/vstudio/readme.txt
View File

@ -1,7 +1,7 @@
VisualStudio instructions
libpng version 1.6.9 - February 6, 2014
libpng version 1.6.10 - March 6, 2014
Copyright (c) 1998-2010 Glenn Randers-Pehrson

2
projects/vstudio/zlib.props
View File

@ -2,7 +2,7 @@
<!--
* zlib.props - location of zlib source
*
* libpng version 1.6.9 - February 6, 2014
* libpng version 1.6.10 - March 6, 2014
*
* Copyright (c) 1998-2011 Glenn Randers-Pehrson
*

12
scripts/README.txt
View File

@ -1,9 +1,9 @@
Makefiles for libpng version 1.6.9 - February 6, 2014
Makefiles for libpng version 1.6.10 - March 6, 2014
pnglibconf.h.prebuilt => Stores configuration settings
makefile.linux => Linux/ELF makefile
(gcc, creates libpng16.so.16.1.6.9)
(gcc, creates libpng16.so.16.1.6.10)
makefile.gcc => Generic makefile (gcc, creates static libpng.a)
makefile.knr => Archaic UNIX Makefile that converts files with
ansi2knr (Requires ansi2knr.c from
@ -20,7 +20,7 @@ pnglibconf.h.prebuilt => Stores configuration settings
makefile.dec => DEC Alpha UNIX makefile
makefile.dj2 => DJGPP 2 makefile
makefile.elf => Linux/ELF makefile symbol versioning,
(gcc, creates libpng16.so.16.1.6.9)
(gcc, creates libpng16.so.16.1.6.10)
makefile.freebsd => FreeBSD makefile
makefile.gcc => Generic gcc makefile
makefile.hpgcc => HPUX makefile using gcc
@ -35,12 +35,12 @@ pnglibconf.h.prebuilt => Stores configuration settings
makefile.os2 => OS/2 Makefile (gcc and emx, requires libpng.def)
makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
makefile.sggcc => Silicon Graphics (gcc,
creates libpng16.so.16.1.6.9)
creates libpng16.so.16.1.6.10)
makefile.sgi => Silicon Graphics IRIX makefile (cc, creates static lib)
makefile.solaris => Solaris 2.X makefile (gcc,
creates libpng16.so.16.1.6.9)
creates libpng16.so.16.1.6.10)
makefile.so9 => Solaris 9 makefile (gcc,
creates libpng16.so.16.1.6.9)
creates libpng16.so.16.1.6.10)
makefile.std => Generic UNIX makefile (cc, creates static libpng.a)
makefile.sunos => Sun makefile
makefile.32sunu => Sun Ultra 32-bit makefile

2
scripts/def.dfn
View File

@ -21,7 +21,7 @@ PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
PNG_DFN ""
PNG_DFN "EXPORTS"
PNG_DFN ";Version 1.6.9"
PNG_DFN ";Version 1.6.10"
#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"

20
scripts/dfn.awk
View File

@ -1,9 +1,9 @@
#!/bin/awk -f
# scripts/dfn.awk - process a .dfn file
#
# last changed in libpng version 1.5.14 - February 4, 2013
# last changed in libpng version 1.5.19 - $RDATE%
#
# Copyright (c) 2013-2013 Glenn Randers-Pehrson
# Copyright (c) 2013-2014 Glenn Randers-Pehrson
#
# This code is released under the libpng license.
# For conditions of distribution and use, see the disclaimer
@ -25,7 +25,7 @@ BEGIN{
# The output file must be specified before any input:
NR==1 && out == "/dev/null" {
print "out=output.file must be given on the command line"
# but continue without setting the error code, this allows the
# but continue without setting the error code; this allows the
# script to be checked easily
}
@ -61,14 +61,14 @@ $1 ~ /^PNG_DFN_END_SORT/{
}
/^[^"]*PNG_DFN *".*"[^"]*$/{
# A definition line, apparently correctly formated, extract the
# A definition line, apparently correctly formatted; extract the
# definition then replace any doubled "" that remain with a single
# double quote. Notice that the original doubled double quotes
# may have been split by tokenization
#
# Sometimes GCC splits the PNG_DFN lines, we know this has happened
# Sometimes GCC splits the PNG_DFN lines; we know this has happened
# if the quotes aren't closed and must read another line. In this
# case it is essential to reject lines that start '#' because those
# case it is essential to reject lines that start with '#' because those
# are introduced #line directives.
orig=$0
line=$0
@ -126,13 +126,13 @@ $1 ~ /^PNG_DFN_END_SORT/{
else while (1) {
if (getline nextline) {
# If the line starts with '#' it is a preprocesor line directive
# from cc -E, skip it:
# from cc -E; skip it:
if (nextline !~ /^#/) {
line = line " " nextline
break
}
} else {
# This is end-of-input - probably a missig "@ on the first line:
# This is end-of-input - probably a missing "@ on the first line:
print "line", lineno ": unbalanced @\" ... \"@ pair"
err=1
next
@ -144,7 +144,7 @@ $1 ~ /^PNG_DFN_END_SORT/{
}
# Attempt to remove a trailing " (not preceded by '@') - if this can
# be done stop now, if not assume a split line again
# be done, stop now; if not assume a split line again
if (sub(/"[^"]*$/, "", line))
break
@ -189,7 +189,7 @@ $1 ~ /^PNG_DFN_END_SORT/{
}
/PNG_DFN/{
print "line", NR, "incorrectly formated PNG_DFN line:"
print "line", NR, "incorrectly formatted PNG_DFN line:"
print $0
err = 1
}

3
scripts/intprefix.dfn
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@ -15,5 +15,8 @@
#define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
PNG_DFN "@" name "@"
#define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
PNG_DFN "@" name "@"
#define PNGPREFIX_H /* self generation */
#include "../pngpriv.h"

2
scripts/libpng-config-head.in
View File

@ -11,7 +11,7 @@
# Modeled after libxml-config.
version=1.6.9
version=1.6.10
prefix=""
libdir=""
libs=""

2
scripts/libpng.pc.in
View File

@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
Name: libpng
Description: Loads and saves PNG files
Version: 1.6.9
Version: 1.6.10
Libs: -L${libdir} -lpng16
Cflags: -I${includedir}

2
scripts/makefile.cegcc
View File

@ -23,7 +23,7 @@
VERMAJ = 1
VERMIN = 6
VERMIC = 9
VERMIC = 10
VER = $(VERMAJ).$(VERMIN).$(VERMIC)
NAME = libpng
PACKAGE = $(NAME)-$(VER)

2
scripts/makefile.linux
View File

@ -10,7 +10,7 @@
# Library name:
LIBNAME = libpng16
PNGMAJ = 16
RELEASE = 9
RELEASE = 10
# Shared library names:
LIBSO=$(LIBNAME).so

2
scripts/makefile.msys
View File

@ -18,7 +18,7 @@ exec_prefix=$(prefix)
# Library name:
LIBNAME = libpng16
PNGMAJ = 16
RELEASE = 9
RELEASE = 10
# Shared library names:
LIBSO=$(LIBNAME).dll

2
scripts/makefile.ne12bsd
View File

@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
LIB= png16
SHLIB_MAJOR= 0
SHLIB_MINOR= 1.6.9
SHLIB_MINOR= 1.6.10
SRCS= png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
pngwtran.c pngmem.c pngerror.c pngpread.c

2
scripts/makefile.netbsd
View File

@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
LIB= png
SHLIB_MAJOR= 16
SHLIB_MINOR= 1.6.9
SHLIB_MINOR= 1.6.10
SRCS= png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
pngwtran.c pngmem.c pngerror.c pngpread.c

2
scripts/makefile.openbsd
View File

@ -11,7 +11,7 @@ LIBDIR= ${PREFIX}/lib
MANDIR= ${PREFIX}/man/cat
SHLIB_MAJOR= 16
SHLIB_MINOR= 1.6.9
SHLIB_MINOR= 1.6.10
LIB= png
SRCS= png.c pngerror.c pngget.c pngmem.c pngpread.c \

7
scripts/pnglibconf.dfa
View File

@ -164,7 +164,7 @@ logunsupported = 1
# NONE
# Note that PNG_USR_CONFIG only has an effect when building
# Note that PNG_USER_CONFIG only has an effect when building
# pnglibconf.h
setting USER_CONFIG
@ -578,8 +578,9 @@ option GAMMA disabled
option COLORSPACE enables GAMMA disabled
# When an ICC profile is read, or png_set, it will be checked for a match
# against known sRGB profiles if the sRGB handling is enabled. This
# setting controls how much work is done during the check:
# against known sRGB profiles if the sRGB handling is enabled. The
# PNG_sRGB_PROFILE_CHECKS setting controls how much work is done during the
# check:
#
# 0: Just validate the profile MD5 signature if present, otherwise use
# the checks in option 1.

4
scripts/pnglibconf.h.prebuilt
View File

@ -1,8 +1,8 @@
/* libpng 1.6.9 STANDARD API DEFINITION */
/* libpng 1.6.10 STANDARD API DEFINITION */
/* pnglibconf.h - library build configuration */
/* Libpng version 1.6.9 - February 6, 2014 */
/* Libpng version 1.6.10 - March 6, 2014 */
/* Copyright (c) 1998-2013 Glenn Randers-Pehrson */

2
scripts/symbols.def
View File

@ -1,4 +1,4 @@
;Version 1.6.9
;Version 1.6.10
;--------------------------------------------------------------
; LIBPNG symbol list as a Win32 DEF file
; Contains all the symbols that can be exported from libpng

2
tests/pngimage-full Executable file
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@ -0,0 +1,2 @@
#!/bin/sh
exec ./pngimage --exhaustive --log "${srcdir}/contrib/pngsuite/"*.png

2
tests/pngimage-quick Executable file
View File

@ -0,0 +1,2 @@
#!/bin/sh
exec ./pngimage --log "${srcdir}/contrib/pngsuite/"*.png