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Andreas Dilger 1997-01-17 01:34:35 -06:00 committed by Glenn Randers-Pehrson
parent c21f90c334
commit 02ad0efbc8
25 changed files with 2448 additions and 2077 deletions
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25
pngchang.txt → CHANGES
View File

@ -93,11 +93,30 @@ version 0.89
fixed gamma and background correction for paletted images, so
png_correct_palette is not needed unless you are correcting an
external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
in pngconf.h)
in pngconf.h) - if nobody uses this, it may disappear in the future.
fixed bug with Borland 64K memory allocation (Alexander Lehmann)
fixed bug in interlace handling (Smaraderagd, I think)
fixed bug in interlace handling (Smarasderagd, I think)
added more error checking for writing and image to reduce invalid files
separated read and write functions so that they won't both be linked
into a binary when only reading or writing functionality is used
new pngtest image also has interlacing and zTXt
updated dcumentation to reflect new API
updated documentation to reflect new API
version 0.90
made CRC errors/warnings on critical and ancillary chunks configurable
libpng will use the zlib CRC routines by (compile-time) default
changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
added external C++ wrapper statements to png.h (Gilles Dauphin)
allow PNG file to be read when some or all of file signature has already
been read from the beginning of the stream (this affects the size of
info_struct and invalidates all programs that use a shared libpng)
fixed png_filler() declarations
fixed? background color conversions
fixed order of error function pointers to match documentation
current chunk name is now available in png_struct to reduce the number
of nearly identical error messages (will simplify multi-lingual
support when available)
try to get ready for unknown-chunk callback functions:
- previously read critical chunks are flagged, so the chunk handling
routines can determine if the chunk is in the right place
- all chunk handling routines have the same prototypes, so we will
be able to handle all chunks via a callback mechanism

168
README Normal file
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@ -0,0 +1,168 @@
readme.txt - for libpng 0.90
This is the fourth beta version of libpng 1.0. The changes from
libpng-0.89 include bug fixes, a C++ wrapper for png.h, some
additions to the API, as well as internal changes to the library.
**
Note that some of the changes to the png_info structure render
this version of the library binary incompatible with libpng-0.89
if you are using a shared library. Re-compiling the application
should be enough to remove this problem.
**
The additions to 0.89 include the ability to read from a PNG stream
which has had some (or all) of the signature bytes read by the
calling application. This also allows the reading of embedded PNG
streams that do not have the PNG file signature. As well, it is
now possible to set the library action on the detection of chunk
CRC errors. It is possible to set different actions based on
whether the error occurred in a critical or an ancillary chunk.
The callback functions for the error/warning messages have changed
since the 0.88 release because their implementation was broken,
and it was thought best to change the API itself (which was only
introduced in libpng-0.88 itself) to alert the user to the change,
rather than mislead the user into thinking their application was
OK after re-compiling. This means that calls to png_set_message_fn()
no longer exist, because the previously suggested method of calling
them before png_read_init() or png_write_init() is now ineffective.
The preferred method of setting the error and warning callbacks
has been incorporated into the allocation of the png_struct and
info_struct itself, which allow them to be safely used during the
initialization of the structure, as well as to keep the size of
the png_struct internal to the library, rather than at compile time
of the application. This will hopefully remove any problems with
dynamically linked libraries, and should be considered the preferred
method of creating these structures, although the previous
initialization API is still available for compatibility. See libpng.txt
for more information on the new API.
The changes made to the library, and bugs fixed are based on discussions
on the PNG implementation mailing list <png-implement@dworking.wustl.edu>
and not on material submitted to Guy.
For a detailed description on using libpng, read libpng.txt. For
usage information and restrictions (what little they are) on libpng,
see png.h. For a description on using zlib (the compression library
used by libpng) and zlib's restrictions, see zlib.h
I have included a general makefile, as well as several machine and compiler
specific ones, but you may have to modify one for your own needs.
You should use zlib 1.0.4 or later to run this, but it MAY work with
versions as old as zlib 0.95. Even so, there are bugs in older zlib
versions which can cause the output of invalid compression streams for
some images. You will definitely need zlib 1.0.4 or later if you are
taking advantage of the MS-DOS "far" structure allocation for the small
and medium memory models. You should also note that zlib is a
compression library that is useful for more things than just PNG files.
You can use zlib as a drop-in replacement for fread() and fwrite() if
you are so inclined.
zlib should be available at the same place that libpng is.
If not, it should be at ftp.uu.net in /graphics/png
Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib
You may also want a copy of the PNG specification. It is available
as an Internet Draft, and RFC, and a W3C Recommendation. Failing
these resources you can try ftp.uu.net in the /graphics/png directory.
This code is currently being archived at ftp.uu.net in the
/graphics/png directory, and on CompuServe, Lib 20 (PNG SUPPORT)
at GO GRAPHSUP. If you can't find it in any of those places,
e-mail me, and I'll help you find it.
If you have any code changes, requests, problems, etc., please e-mail
them to me. Also, I'd appreciate any make files or project files,
and any modifications you needed to make to get libpng to compile,
along with a #define variable to tell what compiler/system you are on.
If you needed to add transformations to libpng, or wish libpng would
provide the image in a different way, drop me a note (and code, if
possible), so I can consider supporting the transformation.
Finally, if you get any warning messages when compiling libpng
(note: not zlib), and they are easy to fix, I'd appreciate the
fix. Please mention "libpng" somewhere in the subject line. Thanks.
This release was created and will be supported by myself (of course
based in a large way on Guy's earlier work), and the PNG group.
adilger@enel.ucalgary.ca
png-implement@dworkin.wustl.edu
You can reach Guy, the original libpng author, at (internet preferred):
internet: schalnat@group42.com
CompuServe: 75501,1625
Please do not send general questions about PNG. Send them to
the address in the specification. At the same time, please do
not send libpng questions to that address, send them to me. I'll
get them in the end anyway. If you have a question about something
in the PNG specification that is related to using libpng, send it
to me. Send me any questions that start with "I was using libpng,
and ...". If in doubt, send questions to me. I'll bounce them
to others, if necessary.
Please do not send suggestions on how to change PNG. We have
been discussing PNG for a couple years now, and it is official and
finished. If you have suggestions for libpng, however, I'll
gladly listen. Even if your suggestion is not used for version
1.0, it may be used later.
Files in this distribution:
CHANGES.txt => Description of changes between libpng versions
README => This file
TODO => Things not implemented in the current library
ansi2knr.c => Converts files to K&R style function declarations
build.bat => MS-DOS batch file for Borland compiler
descrip.mms => VMS project file
example.c => Example code for using libpng functions
libpng.txt => Description of libpng and its functions
makefile => Defualt makefile
makefile.aco => ACORN makefile
makefile.ama => Amiga makefile
makefile.atr => Atari makefile
makefile.bor => Borland makefile
makefile.dj2 => DJGPP 2 makefile
makefile.elf => Unix ELF makefile
makefile.knr => Makefile which calls ansi2knr to convert files
makefile.mip => MIPS makefile
makefile.msc => Microsoft C makefile
makefile.std => Standard Unix makefile
makefile.tc => Turbo C makefile
makevms.com => VMS make program
png.c => Basic interface functions common to library
png.h => Library function and interface declarations
pngconf.h => System specific library configuration
pngerror.c => Error/warning message I/O functions
pngmem.c => Memory handling functions
pngpread.c => Progressive reading functions
pngrcb.c => Read callback (data handling) low-level functions
pngread.c => Read data/helper high-level functions
pngrio.c => Lowest-level data read I/O functions
pngrtran.c => Read data transformation functions
pngrutil.c => Read data utility functions
pngtest.c => Library test program
pngtest.png => Library test sample image
pngtrans.c => Common data transformation functions
pngwio.c => Lowest-level write I/O functions
pngwrite.c => High-level write functions
pngwtran.c => Write data transformations
pngwutil.c => Write utility functions
Good luck, and happy coding.
-Andreas Eric Dilger
University of Calgary
Internet: adilger@enel.ucalgary.ca
Web: www-mddsp.enel.ucalgary.ca/People/adilger/
-Guy Eric Schalnat
Group 42, Inc.
Internet: schalnat@group42.com
CompuServe: 75501,1625
Web: www.group42.com

12
pngtodo.txt → TODO
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@ -5,21 +5,19 @@ for 0.9
final bug fixes
cHRM transformation
better documentation
multi-lingual message support
after 1.0
overlaying one image on top of another
optional palette creation
histogram creation
text conversion between different code types
support for other chunks being defined (sCAl, the gIF series,
and others that people come up with).
support for application-defined chunk handlers
support for embedded PNG usage (MNG)
pull writer
better dithering
keep up with public chunks
other compression libraries
more exotic interlace handling
better filtering (counting huffman bits? filter type inertia?)
better filter selection (counting huffman bits? filter type inertia?)
C++ wrapper
other languages (pascal, for one)
comments of > 64K
comments of > 64K for DOS

61
example.c
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@ -14,45 +14,61 @@
#include <png.h>
/* check to see if a file is a png file using png_check_sig() */
int check_png(char * file_name)
/* Check to see if a file is a png file using png_check_sig().
If this call is successful, and you are going to keep the file
open, you should call png_set_sig_bytes_read(png_ptr, 8);
once you have created the png_ptr, so that libpng knows it
doesn't have to read the signature again. Make sure you don't
call png_set_sig_bytes_read() with more than 8 bytes read or
give it an incorrect number of bytes read, or you will either
have read too many bytes (your fault), or you are telling libpng
to read the wrong number of magic bytes (also your fault). */
int check_png(char *file_name, FILE **fp)
{
FILE *fp;
char buf[8];
int ret;
fp = fopen(file_name, "rb");
*fp = fopen(file_name, "rb");
if (!fp)
return 0;
ret = fread(buf, 1, 8, fp);
fclose(fp);
ret = fread(buf, 1, 8, *fp);
if (ret != 8)
return 0;
ret = png_check_sig(buf, 8);
/* Check the signature starting at byte 0, and check all 8 bytes */
ret = png_check_sig(buf, 0, 8);
return (ret);
}
/* read a png file. You may want to return an error code if the read
fails (depending upon the failure). */
void read_png(char *file_name)
fails (depending upon the failure). There are two "prototypes" given
here - one where we are given the filename, and we need to open the
file, and the other where we are given an open file (possibly with
some or all of the magic bytes read - see above) and an opened file
for reading. */
------- prototype 1 ----------
void read_png(char *file_name) /* We need to open the file */
{
FILE *fp;
png_structp png_ptr;
png_infop info_ptr;
FILE *fp;
/* open the file */
fp = fopen(file_name, "rb");
if (!fp)
if ((fp = fopen(file_name, "rb")) == NULL)
return;
------- prototype 2 ----------
void read_png(FILE *fp, unsigned int sig_read) /* file is already open */
{
png_structp png_ptr;
png_infop info_ptr;
------- only use one! --------
/* Create and initialize the png_struct with the desired error handler
functions. If you want to use the default stderr and longjump method,
you can supply NULL for the last three parameters. We also check that
the header file is compatible with the library version.
*/
the header file is compatible with the library version. */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
(void *)user_error_ptr, user_error_fn, user_warning_fn);
@ -88,7 +104,11 @@ void read_png(char *file_name)
png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn);
/* where user_io_ptr is a structure you want available to the callbacks */
/* read the file information */
/* if we have already read some of the signature from the beginning call */
png_set_sig_bytes_read(png_ptr, sig_read);
/* The call to png_read_info() gives us all of the information
from the PNG file before the first IDAT (image data chunk). */
png_read_info(png_ptr, info_ptr);
/* set up the transformations you want. Note that these are
@ -120,7 +140,10 @@ void read_png(char *file_name)
png_set_background(png_ptr, &my_background,
PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
/* tell libpng to handle the gamma conversion for you */
/* tell libpng to handle the gamma conversion for you. We only
need the second call if the screen_gamma isn't the usual 2.2
or if it is controllable by the user. It may also be a good
idea to allow the user to set the file gamma if it is unknown. */
if (info_ptr->valid & PNG_INFO_gAMA)
png_set_gamma(png_ptr, screen_gamma, info_ptr->gamma);
else
@ -398,10 +421,6 @@ void write_png(char *file_name, ... other image information ...)
/* set up the output control if you are using standard C streams */
png_init_io(png_ptr, fp);
/* if you are using replacement message functions, here you would call */
png_set_message_fn(png_ptr, (void *)msg_ptr, user_error_fn, user_warning_fn);
/* where msg_ptr is a structure you want available to the callbacks */
/* set the file information here */
info_ptr->width = ;
info_ptr->height = ;

73
libpng.txt
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@ -56,14 +56,14 @@ II. Structures
There are two main structures that are important to libpng, png_struct
and png_info. The first, png_struct, is an internal structure that
will not, for the most part, be used by a user except as the first
variable passed to every png function call.
variable passed to every libpng function call.
The png_info structure is designed to provide information about the
png file. All of its fields are intended to be examined or modified
by the user. See png.h for a good description of the png_info fields.
png.h is also an invaluable reference for programming with libpng.
And while I'm on the topic, make sure you include the png header file:
And while I'm on the topic, make sure you include the libpng header file:
#include <png.h>
@ -86,11 +86,13 @@ file. Libpng provides a simple check to see if a file is a PNG file.
To use it, pass in the first 1 to 8 bytes of the file, and it will
return true or false (1 or 0) depending on whether the bytes could be
part of a PNG file. Of course, the more bytes you pass in, the
greater the accuracy of the prediction. If you pass in more then
eight bytes, libpng will only look at the first eight bytes. However,
because libpng automatically checks the file header, this is not often
necessary, and you should pass a newly opened file pointer to libpng
when reading a file.
greater the accuracy of the prediction.
If you are intending to keep the file pointer open for use in libpng,
you must ensure you don't read more than 8 bytes from the beginning
of the file, and you also have to make a call to png_set_sig_bytes_read()
with the number of bytes you read from the beginning. Libpng will
then only check the bytes (if any) that your program didn't read.
(*): If you are not using the standard I/O functions, you will need
to replace them with custom functions. See the discussion under
@ -102,12 +104,11 @@ Customizing libpng.
return;
}
fread(header, 1, number, fp);
is_png = png_check_sig(header, number);
is_png = png_check_sig(header, 0, number);
if (!is_png)
{
return;
}
fclose(fp);
Next, png_struct and png_info need to be allocated and initialized.
In order to ensure that the size of these structures is correct even
@ -134,20 +135,20 @@ Changes to Libpng below regarding the old initialization functions.
return;
}
The error handling routines passed to png_create_read_struct()
are only necessary if you are not using the libpng supplied
error handling functions. When libpng encounters an error,
it expects to longjmp back to your routine. Therefore, you
will need to call setjmp and pass the jmpbuf field of your
png_struct. If you read the file from different routines, you
will need to update the jmpbuf field every time you enter a new
routine that will call a png_ function. See your documentation
of setjmp/longjmp for your compiler for more information on
setjmp/longjmp. See the discussion on libpng error handling
in the Customizing Libpng section below for more information on
the libpng error handling. If an error occurs, and libpng
longjmp's back to your setjmp, you will want to call
png_destroy_read_struct() to free any memory.
The error handling routines passed to png_create_read_struct() are only
necessary if you are not using the libpng supplied error handling
functions. When libpng encounters an error, it expects to longjmp back
to your routine. Therefore, you will need to call setjmp and pass the
jmpbuf field of your png_struct. If you read the file from different
routines, you will need to update the jmpbuf field every time you enter
a new routine that will call a png_ function.
See your documentation of setjmp/longjmp for your compiler for more
information on setjmp/longjmp. See the discussion on libpng error
handling in the Customizing Libpng section below for more information on
the libpng error handling. If an error occurs, and libpng longjmp's
back to your setjmp, you will want to call png_destroy_read_struct() to
free any memory.
if (setjmp(png_ptr->jmpbuf))
{
@ -165,10 +166,16 @@ Libpng section below.
png_init_io(png_ptr, fp);
If you had previously opened the file and read any of the signature from
the beginning in order to see if this was a PNG file, you need to let
libpng know that there are some bytes missing from the start of the file.
png_set_sig_bytes(png_ptr, number);
You are now ready to read all the file information up to the actual
image data. You do this with a call to png_read_info().
png_read_info(png_ptr, info_ptr);
png_read_info(png_ptr, info_ptr);
The png_info structure is now filled in with all the data necessary
to read the file. Some of the more important parts of the info_ptr are:
@ -183,8 +190,13 @@ to read the file. Some of the more important parts of the info_ptr are:
bit_depth times the channels
rowbytes - number of bytes needed to hold a row
interlace_type - currently 0 for none, 1 for interlaced
signature - holds the signature read from the file (if any). The
data is kept in the same offset it would be if the
whole signature were read (ie if you had already read
in 4 bytes of signature, the remaining 4 bytes would
be in signature[4] through signature[7]).
valid - this details which optional chunks were found in the
file to see if a chunk was present, AND '&' valid with
file. To see if a chunk was present, AND '&' valid with
the appropriate PNG_INFO_<chunk name> define.
These are also important, but their validity depends on whether a
@ -217,7 +229,7 @@ keyword/text pairs, one pair per chunk. While there are suggested
keywords, there is no requirement to restrict the use to these
strings. There is a requirement to have at least one character for a
keyword. It is strongly suggested that keywords be sensible to humans
(that's the point), so don't use abbreviations. See the png
(that's the point), so don't use abbreviations. See the PNG
specification for more details. There is also no requirement to have
text after the keyword.
@ -243,6 +255,13 @@ checks to see if it has data that it can do somthing with, you should
make sure to only enable a transformation if it will be valid for the
data. For example, don't swap red and blue on grayscale data.
The colors used for the background and transparency values should be
supplied in the same format/depth as the current image data. They
are stored in the same format/depth as the image data in a bKGD or tRNS
chunk, so this is what libpng expects for this data. The colors are
transformed to keep in sync with the image data when an application
calls the png_update_info() routine (see below).
Data will be decoded into the supplied row buffers packed into bytes
unless the library has been told to transform it into another format.
For example, 4 bit/pixel paletted or grayscale data will be returned
@ -747,7 +766,7 @@ Libpng section below.
You now have the option of modifying how the compression library will
run. The following functions are mainly for testing, but may be useful
in some cases, like if you need to write png files extremely fast and
in some cases, like if you need to write PNG files extremely fast and
are willing to give up some compression, or if you want to get the
maximum possible compression at the expense of slower writing. If you
have no special needs in this area, let the library do what it wants by

112
makefile.aco
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@ -1,4 +1,3 @@
# makefile for libpng on Acorn RISCOS
# Project: libpng
@ -8,108 +7,43 @@ C++flags = -c -depend !Depend -IC: -throwback
Linkflags = -aif -c++ -o $@
ObjAsmflags = -throwback -NoCache -depend !Depend
CMHGflags =
LibFileflags = -c -o $@
LibFileflags = -c -l -o $@
Squeezeflags = -o $@
# Final targets:
@.libpng-lib: @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
@.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran @.o.pngrutil \
@.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil
@.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran @.o.pngrutil @.o.pngtrans @.o.pngwrite \
@.o.pngwtran @.o.pngwutil
LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngwio \
@.o.pngmem @.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran \
@.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil
@.test: @.tests.pngtest
echo Please run "Test" in directory tests
@.tests.pngtest: @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
@.o.pngmem @.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran @.o.pngrutil @.o.pngtrans \
@.o.pngwrite @.o.pngwtran @.o.pngwutil
@.mm-libpng-lib: @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \
@.mm.pngpread @.mm.pngrcb @.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans \
@.mm.pngwrite @.mm.pngwtran @.mm.pngwutil
LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio \
@.mm.pngmem @.mm.pngpread @.mm.pngrcb @.mm.pngread @.mm.pngrtran @.mm.pngrutil \
@.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil
# User-editable dependencies:
Test: @.pngtest
<Prefix$Dir>.PngTest
@remove <Prefix$Dir>.pngout_png
#It would be nice if you could stop "make" listing from here on!
@.pngtest: @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
.SUFFIXES: .o .mm .c
.c.mm:
MemCheck.CC cc $(ccflags) -o $@ LibPng:$<
.c.o:
cc $(ccflags) -o $@ $<
# Static dependencies:
@.o.example: @.tests.c.example
cc $(ccflags) -o @.o.example @.tests.c.example
@.o.pngtest: @.tests.c.pngtest
cc $(ccflags) -o @.o.pngtest @.tests.c.pngtest
# Dynamic dependencies:
o.png: c.png
o.png: h.png
o.png: Zlib:h.zlib
o.png: Zlib:h.zconf
o.png: h.pngconf
o.pngerror: c.pngerror
o.pngerror: h.png
o.pngerror: Zlib:h.zlib
o.pngerror: Zlib:h.zconf
o.pngerror: h.pngconf
o.pngrio: c.pngrio
o.pngrio: h.png
o.pngrio: Zlib:h.zlib
o.pngrio: Zlib:h.zconf
o.pngrio: h.pngconf
o.pngwio: c.pngwio
o.pngwio: h.png
o.pngwio: Zlib:h.zlib
o.pngwio: Zlib:h.zconf
o.pngwio: h.pngconf
o.pngmem: c.pngmem
o.pngmem: h.png
o.pngmem: Zlib:h.zlib
o.pngmem: Zlib:h.zconf
o.pngmem: h.pngconf
o.pngpread: c.pngpread
o.pngpread: h.png
o.pngpread: Zlib:h.zlib
o.pngpread: Zlib:h.zconf
o.pngpread: h.pngconf
o.pngrcb: c.pngrcb
o.pngrcb: h.png
o.pngrcb: Zlib:h.zlib
o.pngrcb: Zlib:h.zconf
o.pngrcb: h.pngconf
o.pngread: c.pngread
o.pngread: h.png
o.pngread: Zlib:h.zlib
o.pngread: Zlib:h.zconf
o.pngread: h.pngconf
o.pngrtran: c.pngrtran
o.pngrtran: h.png
o.pngrtran: Zlib:h.zlib
o.pngrtran: Zlib:h.zconf
o.pngrtran: h.pngconf
o.pngrutil: c.pngrutil
o.pngrutil: h.png
o.pngrutil: Zlib:h.zlib
o.pngrutil: Zlib:h.zconf
o.pngrutil: h.pngconf
o.pngtrans: c.pngtrans
o.pngtrans: h.png
o.pngtrans: Zlib:h.zlib
o.pngtrans: Zlib:h.zconf
o.pngtrans: h.pngconf
o.pngwrite: c.pngwrite
o.pngwrite: h.png
o.pngwrite: Zlib:h.zlib
o.pngwrite: Zlib:h.zconf
o.pngwrite: h.pngconf
o.pngwtran: c.pngwtran
o.pngwtran: h.png
o.pngwtran: Zlib:h.zlib
o.pngwtran: Zlib:h.zconf
o.pngwtran: h.pngconf
o.pngwutil: c.pngwutil
o.pngwutil: h.png
o.pngwutil: Zlib:h.zlib
o.pngwutil: Zlib:h.zconf
o.pngwutil: h.pngconf
o.pngtest: tests.c.pngtest
o.pngtest: h.png
o.pngtest: Zlib:h.zlib
o.pngtest: Zlib:h.zconf
o.pngtest: h.pngconf

35
makefile.elf
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@ -1,15 +1,18 @@
# makefile for libpng on (linux) ELF
# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
# Copyright (C) 1996, 1997 Andreas Dilger
# For conditions of distribution and use, see copyright notice in png.h
CC=gcc
CFLAGS=-I../zlib -O2 -Wall -fPIC
CFLAGS=-I../zlib -Wall -Wwrite-strings -Wpointer-arith \
-Wstrict-prototypes -Wmissing-prototypes -O2 -fPIC
LDFLAGS=-L. -Wl,-rpath,. -L../zlib/ -Wl,-rpath,../zlib/ -lpng -lz -lm
RANLIB=ranlib
#RANLIB=echo
PNGVER = 0.89
PNGMAJ = 0
PNGMIN = 90
PNGVER = $(PNGMAJ).$(PNGMIN)
# where make install puts libpng.a, libpng.so*, and png.h
prefix=/usr/local
@ -24,14 +27,14 @@ libpng.a: $(OBJS)
ar rc $@ $(OBJS)
$(RANLIB) $@
libpng.so: libpng.so.1
ln -sf libpng.so.1 libpng.so
libpng.so: libpng.so.$(PNGMAJ)
ln -sf libpng.so.$(PNGMAJ) libpng.so
libpng.so.1: libpng.so.1.$(PNGVER)
ln -sf libpng.so.1.$(PNGVER) libpng.so.1
libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
libpng.so.1.$(PNGVER): $(OBJS)
gcc -shared -Wl,-soname,libpng.so.1 -o libpng.so.1.$(PNGVER) $(OBJS)
libpng.so.$(PNGVER): $(OBJS)
gcc -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) $(OBJS)
pngtest: pngtest.o libpng.so
$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
@ -39,21 +42,21 @@ pngtest: pngtest.o libpng.so
test: pngtest
./pngtest
install: libpng.so.1.$(PNGVER)
install: libpng.so.$(PNGVER)
-@mkdir $(prefix)/include
-@mkdir $(prefix)/lib
cp png.h $(prefix)/include
cp pngconf.h $(prefix)/include
chmod 644 $(prefix)/include/png.h
chmod 644 $(prefix)/include/pngconf.h
cp libpng.so.1.$(PNGVER) $(prefix)/lib
chmod 755 $(prefix)/lib/libpng.so.1.$(PNGVER)
-@/bin/rm $(prefix)/lib/libpng.so.1 $(prefix)/lib/libpng.so
(cd $(prefix)/lib; ln -sf libpng.so.1.$(PNGVER) libpng.so.1; \
ln -sf libpng.so.1 libpng.so)
cp libpng.so.$(PNGVER) $(prefix)/lib
chmod 755 $(prefix)/lib/libpng.so.$(PNGVER)
-@/bin/rm $(prefix)/lib/libpng.so.$(PNGMAJ) $(prefix)/lib/libpng.so
(cd $(prefix)/lib; ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
ln -sf libpng.so.$(PNGMAJ) libpng.so)
clean:
rm -f *.o libpng.so.1.$(PNGVER) libpng.so.1 libpng.so pngtest pngout.png
rm -f *.o libpng.a libpng.so* pngtest pngout.png
# DO NOT DELETE THIS LINE -- make depend depends on it.

146
png.c
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@ -1,10 +1,10 @@
/* png.c - location for general purpose png functions
libpng 1.0 beta 3 - version 0.89
libpng 1.0 beta 4 - version 0.90
For conditions of distribution and use, see copyright notice in png.h
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
May 25, 1996
January 10, 1997
*/
#define PNG_INTERNAL
@ -13,7 +13,7 @@
/* version information for c files. This better match the version
string defined in png.h */
char png_libpng_ver[] = "0.89";
char png_libpng_ver[] = "0.90";
/* place to hold the signiture string for a png file. */
png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
@ -70,15 +70,52 @@ int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
/* 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
* stream we can set num_bytes = 8 so that libpng will not attempt to read
* or write any of the magic bytes before it starts on the IHDR.
*/
void
png_set_sig_bytes(png_structp png_ptr, int num_bytes)
{
if (num_bytes > 8)
png_error(png_ptr, "Too many bytes for PNG signature.");
png_ptr->sig_bytes = num_bytes < 0 ? 0 : num_bytes;
}
/* Checks whether the supplied bytes match the PNG signature. We allow
* checking less than the full 8-byte signature so that those apps that
* already read the first few bytes of a file to determine the file type
* can simply check the remaining bytes for extra assurance. Returns
* an integer less than, equal to, or greater than zero if sig is found,
* respectively, to be less than, to match, or be greater than the correct
* PNG signature (this is the same behaviour as strcmp, memcmp, etc).
*/
int
png_sig_cmp(png_bytep sig, int start, int num_to_check)
{
if (num_to_check > 8)
num_to_check = 8;
else if (num_to_check < 1)
return 0;
if (start > 7 || start < 0)
return 0;
if (start + num_to_check > 8)
num_to_check = 8 - start;
return (png_memcmp(sig, &png_sig[start], (unsigned int)num_to_check));
}
/* (Obsolete) function to check signature bytes. It does not allow one
to check a partial signature. This function will be removed in the
future - use png_sig_cmp(). */
int
png_check_sig(png_bytep sig, int num)
{
if (num > 8)
num = 8;
if (num < 1)
return 0;
return (!png_memcmp(sig, png_sig, num));
return !png_sig_cmp(sig, 0, num);
}
/* Function to allocate memory for zlib. */
@ -88,7 +125,7 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
png_voidp ptr;
png_uint_32 num_bytes;
ptr = png_large_malloc((png_structp)png_ptr,
ptr = png_malloc((png_structp)png_ptr,
(png_uint_32)items * (png_uint_32)size);
num_bytes = (png_uint_32)items * (png_uint_32)size;
if (num_bytes > (png_uint_32)0x7fff)
@ -108,26 +145,27 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
void
png_zfree(voidpf png_ptr, voidpf ptr)
{
png_large_free((png_structp)png_ptr, (png_voidp)ptr);
png_free((png_structp)png_ptr, (png_voidp)ptr);
}
/* reset the crc variable to 32 bits of 1's. Care must be taken
in case crc is > 32 bits to leave the top bits 0 */
/* Reset the CRC variable to 32 bits of 1's. Care must be taken
in case CRC is > 32 bits to leave the top bits 0. */
void
png_reset_crc(png_structp png_ptr)
{
/* set crc to all 1's */
#ifdef PNG_USE_OWN_CRC
png_ptr->crc = 0xffffffffL;
#else
png_ptr->crc = crc32(0, Z_NULL, 0);
#endif
}
/* Note: the crc code below was copied from the sample code in the
PNG spec, with appropriate modifications made to ensure the
variables are large enough */
/* table of crc's of all 8-bit messages. If you wish to png_malloc this
table, turn this into a pointer, and png_malloc it in make_crc_table().
#ifdef PNG_USE_OWN_CRC
/* Table of CRC's of all 8-bit messages. If you wish to png_malloc this
table, turn this into a pointer, and png_malloc() it in make_crc_table().
You may then want to hook it into png_struct and free it with the
destroy functions. */
destroy functions. Another alternative is to pre-fill the table. */
static png_uint_32 crc_table[256];
/* Flag: has the table been computed? Initially false. */
@ -150,9 +188,9 @@ make_crc_table(void)
crc_table_computed = 1;
}
/* update a running crc with the bytes buf[0..len-1]--the crc should be
/* Update a running CRC with the bytes buf[0..len-1]--the crc should be
initialized to all 1's, and the transmitted value is the 1's complement
of the final running crc. */
of the final running CRC. */
static png_uint_32
update_crc(png_uint_32 crc, png_bytep buf, png_uint_32 len)
{
@ -176,8 +214,9 @@ update_crc(png_uint_32 crc, png_bytep buf, png_uint_32 len)
return c;
}
#endif /* PNG_USE_OWN_CRC */
/* calculate the crc over a section of data. Note that while we
/* Calculate the crc over a section of data. Note that while we
are passing in a 32 bit value for length, on 16 bit machines, you
would need to use huge pointers to access all that data. If you
need this, put huge here and above. */
@ -185,9 +224,18 @@ void
png_calculate_crc(png_structp png_ptr, png_bytep ptr,
png_uint_32 length)
{
#ifdef PNG_USE_OWN_CRC
png_ptr->crc = update_crc(png_ptr->crc, ptr, length);
#else
png_ptr->crc = crc32(png_ptr->crc, ptr, length);
#endif
}
/* Allocate the memory for an info_struct for the application. We don't
really need the png_ptr, but it could potentially be useful in the
future. This should be used in favour of malloc(sizeof(png_info))
and png_info_init() so that applications that want to use a shared
libpng don't have to be recompiled if png_info changes size. */
png_infop
png_create_info_struct(png_structp png_ptr)
{
@ -195,23 +243,65 @@ png_create_info_struct(png_structp png_ptr)
if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL)
{
png_memset(info_ptr, 0, sizeof(png_info));
png_ptr->do_free |= PNG_FREE_INFO;
png_info_init(info_ptr);
}
return info_ptr;
}
/* This function frees the memory associated with a single info struct.
Normally, one would use either png_destroy_read_struct() or
png_destroy_write_struct() to free an info struct, but this may be
useful for some applications. */
void
png_info_init(png_infop info)
png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
{
png_infop info_ptr = NULL;
if (info_ptr_ptr)
info_ptr = *info_ptr_ptr;
if (info_ptr)
{
png_info_destroy(png_ptr, info_ptr);
png_destroy_struct((png_voidp)info_ptr);
*info_ptr_ptr = (png_infop)NULL;
}
}
/* Initialize the info structure. This is now an internal function (0.89)
and applications using it are urged to use png_create_info_struct()
instead. */
void
png_info_init(png_infop info_ptr)
{
/* set everything to 0 */
png_memset(info, 0, sizeof (png_info));
png_memset(info_ptr, 0, sizeof (png_info));
}
/* This is an internal routine to free any memory that the info struct is
pointing to before re-using it or freeing the struct itself. */
void
png_info_destroy(png_structp png_ptr, png_infop info_ptr)
{
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
int i;
for (i = 0; i < info_ptr->num_text; i++)
{
png_free(png_ptr, info_ptr->text[i].key);
}
png_free(png_ptr, info_ptr->text);
#endif
png_info_init(info_ptr);
}
/* This function returns a pointer to the io_ptr associated with the user
functions. The application should free any memory associated with this
pointer before png_write_destroy and png_read_destroy are called. */
pointer before png_write_destroy() or png_read_destroy() are called. */
png_voidp
png_get_io_ptr(png_structp png_ptr)
{

467
png.h
View File

@ -1,8 +1,8 @@
/* png.h - header file for png reference library
libpng 1.0 beta 3 - version 0.89
May 25, 1996
libpng 1.0 beta 4 - version 0.90
January 10, 1997
Note: This is a beta version. It reads and writes valid files
on the platforms I have, and has had a wide testing program.
@ -10,14 +10,15 @@
your system, and you may have to supply the correct compiler
flags in the makefile, if you can't find a makefile suitable for
your operating system/compiler combination. Read the libpng.txt
for more information, and how to contact me if you have any
for more information, and how to contact the authors if you have any
problems, or if you want your compiler/platform to be supported
in the next official libpng release.
See libpng.txt for more information
See libpng.txt for more information.
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
Copyright (c) 1995, 1996, 1997 Guy Eric Schalnat, Group 42, Inc.
Contributing Authors:
Sam Bushnell
Andreas Dilger
Dave Martindale
Guy Eric Schalnat
@ -57,6 +58,10 @@
#ifndef _PNG_H
#define _PNG_H
#ifdef __cplusplus
extern "C" {
#endif
/* This is not the place to learn how to use libpng. The file libpng.txt
describes how to use libpng, and the file example.c summarizes it
with some code to build around. This file is useful for looking
@ -71,15 +76,14 @@
/* This file is arranged in several sections. The first section details
the functions most users will use. The third section describes the
stub files that users will most likely need to change. The last
section contains functions used internally by the code.
*/
section contains functions used internally by the code. */
/* version information for png.h - this should match the version
number in png.c */
#define PNG_LIBPNG_VER_STRING "0.89"
/* careful here. I wanted to use 089, but that would be octal. Version
#define PNG_LIBPNG_VER_STRING "0.90"
/* careful here. I wanted to use 090, but that would be octal. Version
1.0 will be 100 here, etc. */
#define PNG_LIBPNG_VER 89
#define PNG_LIBPNG_VER 90
/* variables defined in png.c - only it needs to define PNG_NO_EXTERN */
#ifndef PNG_NO_EXTERN
@ -154,9 +158,8 @@ typedef png_time FAR * FAR * png_timepp;
If you are reading the file, This structure will tell you what is
in the png file. If you are writing the file, fill in the information
you want to put into the png file, then call png_write_info().
The names chosen should be very close to the PNG
specification, so consult that document for information
about the meaning of each field. */
The names chosen should be very close to the PNG specification, so
consult that document for information about the meaning of each field. */
typedef struct png_info_struct
{
/* the following are necessary for every png file */
@ -177,6 +180,7 @@ typedef struct png_info_struct
png_byte channels; /* number of channels of data per pixel */
png_byte pixel_depth; /* number of bits per pixel */
png_byte spare_byte; /* To align the data, and for future use */
png_byte signature[8]; /* Signature read from start of file */
/* the rest are optional. If you are reading, check the valid
field to see if the information in these are valid. If you
@ -318,12 +322,11 @@ struct png_struct_def
png_rw_ptr read_data_fn; /* Function for reading input data */
png_voidp io_ptr; /* Pointer to user supplied struct for I/O functions */
png_byte mode; /* used to determine where we are in the png file */
png_uint_32 do_free; /* flags indicating if libpng should free memory */
png_uint_32 mode; /* used to determine where we are in the png file */
png_uint_32 flags; /* flags indicating various things to libpng */
png_uint_32 transformations; /* which transformations to perform */
z_stream * zstream; /* pointer to decompression structure (below) */
z_stream zstream; /* pointer to decompression structure (below) */
png_bytep zbuf; /* buffer for zlib */
png_uint_32 zbuf_size; /* size of zbuf */
int zlib_level; /* holds zlib compression level */
@ -340,12 +343,12 @@ struct png_struct_def
png_uint_32 iwidth; /* interlaced width */
png_uint_32 irowbytes; /* interlaced rowbytes */
png_uint_32 row_number; /* current row in pass */
png_bytep row_buf; /* row buffer */
png_bytep prev_row; /* previous row */
png_bytep sub_row; /* place to save row when filtering */
png_bytep up_row; /* place to save row when filtering */
png_bytep avg_row; /* place to save row when filtering */
png_bytep paeth_row; /* place to save row when filtering */
png_bytep prev_row; /* place to save previous (unfiltered) row */
png_bytep row_buf; /* place to save current (unfiltered) row */
png_bytep sub_row; /* place to save "sub" row when filtering */
png_bytep up_row; /* place to save "up" row when filtering */
png_bytep avg_row; /* place to save "avg" row when filtering */
png_bytep paeth_row; /* place to save "Paeth" row when filtering */
png_row_info row_info; /* used for transformation routines */
png_uint_32 idat_size; /* current idat size for read */
@ -353,17 +356,20 @@ struct png_struct_def
png_colorp palette; /* files palette */
png_uint_16 num_palette; /* number of entries in palette */
png_uint_16 num_trans; /* number of transparency values */
png_byte interlaced; /* interlace type of file */
png_byte pass; /* current pass (0 - 6) */
png_byte compression; /* compression type of file */
png_byte filter; /* filter type */
png_byte do_filter; /* non-zero if row filtering, zero if not */
png_byte chunk_name[5]; /* name of current chunk being processed + '\0' */
png_byte compression; /* file compression type (currently only '0' used) */
png_byte filter; /* file filter type (currently only '0' used) */
png_byte interlaced; /* file interlace type (currently only '0' and '1') */
png_byte pass; /* current interlace pass (0 - 6) */
png_byte do_filter; /* zero if not row filtering, non-zero if filtering */
png_byte color_type; /* color type of file */
png_byte bit_depth; /* bit depth of file */
png_byte usr_bit_depth; /* bit depth of users row */
png_byte pixel_depth; /* number of bits per pixel */
png_byte channels; /* number of channels in file */
png_byte usr_channels; /* channels at start of write */
png_byte sig_bytes; /* signature bytes read/written from start of file */
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
png_byte filler; /* filler byte to be used for 32-bit frame buffers */
@ -420,7 +426,6 @@ struct png_struct_def
png_uint_32 current_buffer_size;
int process_mode;
int cur_palette;
png_byte push_chunk_name[4];
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
png_uint_32 current_text_size;
png_uint_32 current_text_left;
@ -445,44 +450,37 @@ struct png_struct_def
typedef png_struct FAR * FAR * png_structpp;
/* flags for png_set_filter() to say which filters to use. The flags
are chosen so that they don't conflict with real filter types, in case they
are supplied instead of the #defined constants.
*/
#define PNG_NO_FILTERS 0x00
#define PNG_FILTER_NONE 0x08
#define PNG_FILTER_SUB 0x10
#define PNG_FILTER_UP 0x20
#define PNG_FILTER_AVG 0x40
#define PNG_FILTER_PAETH 0x80
#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
PNG_FILTER_AVG | PNG_FILTER_PAETH)
/* Here are the function definitions most commonly used. This is not
the place to find out how to use libpng. See libpng.txt for the
full explanation, see example.c for the summary. This just provides
a simple one line of the use of each function. */
/* check the first 1 - 8 bytes to see if it is a png file */
/* Tell lib we have already handled the first <num_bytes> magic bytes.
Handling more than 8 bytes from the beginning of the file is an error. */
extern void png_set_sig_bytes PNGARG((png_structp png_ptr, int num_bytes));
/* Check sig[start] through sig[start + num_to_check] to see if it's a PNG
file. Returns zero if the supplied bytes match the 8-byte PNG signature,
and non-zero otherwise. Having num_to_check == 0 or start > 7 will
always fail (ie return non-zero). */
extern int png_sig_cmp PNGARG((png_bytep sig, int start, int num_to_check));
/* (Obsolete) signature checking function. This is the same as calling
png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). To be removed in a
future version. */
extern int png_check_sig PNGARG((png_bytep sig, int num));
/* allocate and initialize png structure for reading, and any other memory */
/* Allocate and initialize png structure for reading, and any other memory. */
extern png_structp png_create_read_struct PNGARG((png_const_charp user_png_ver,
voidp error_ptr, png_error_ptr warn_fn, png_error_ptr error_fn));
voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn));
/* reset the png_struct to read a new image */
extern void png_reset_read_struct PNGARG((png_structpp png_ptr));
/* initialize png structure for reading, and allocate any other memory (old) */
extern void png_read_init PNGARG((png_structp png_ptr));
/* allocate and initialize png structure for reading, and any other memory */
extern png_structp png_create_write_struct
PNGARG((png_const_charp user_png_ver, voidp error_ptr,
png_error_ptr warn_fn, png_error_ptr error_fn));
/* reset the png_struct to read a new image */
extern void png_reset_write_struct PNGARG((png_structpp png_ptr));
png_error_ptr error_fn, png_error_ptr warn_fn));
/* initialize png structure for writing, and allocate any other memory (old) */
extern void png_write_init PNGARG((png_structp png_ptr));
@ -491,13 +489,13 @@ extern void png_write_init PNGARG((png_structp png_ptr));
extern png_infop png_create_info_struct PNGARG((png_structp png_ptr));
/* initialize the info structure (old interface) */
extern void png_info_init PNGARG((png_infop info));
extern void png_info_init PNGARG((png_infop info_ptr));
/* Writes all the png information before the image. */
extern void png_write_info PNGARG((png_structp png_ptr, png_infop info));
extern void png_write_info PNGARG((png_structp png_ptr, png_infop info_ptr));
/* read the information before the actual image data. */
extern void png_read_info PNGARG((png_structp png_ptr, png_infop info));
extern void png_read_info PNGARG((png_structp png_ptr, png_infop info_ptr));
#if defined(PNG_WRITE_tIME_SUPPORTED)
/* convert from a struct tm to png_time */
@ -524,15 +522,23 @@ extern void png_set_bgr PNGARG((png_structp png_ptr));
extern void png_set_gray_to_rgb PNGARG((png_structp png_ptr));
#endif
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
/* Reduce RGB to grayscale. (Not yet implemented) */
extern void png_set_rgb_to_gray PNGARG((png_structp png_ptr));
#endif
extern void png_build_grayscale_palette PNGARG((int bit_depth,
png_colorp palette));
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
#define PNG_FILLER_BEFORE 0
#define PNG_FILLER_AFTER 1
/* Add a filler byte to rgb images. */
extern void png_set_filler PNGARG((png_structp png_ptr, int filler,
extern void png_set_filler PNGARG((png_structp png_ptr, png_byte filler,
int flags));
/* old ways of doing this, still supported through 1.x for backwards
compatability, but not suggested */
/* Old way of doing this, still supported through 1.x for backwards
compatability, but should not be used in new code. */
/* Add a filler byte to rgb images after the colors. */
extern void png_set_rgbx PNGARG((png_structp png_ptr));
@ -584,11 +590,6 @@ extern void png_set_background PNGARG((png_structp png_ptr,
extern void png_set_strip_16 PNGARG((png_structp png_ptr));
#endif
#if defined(PNG_GRAY_TO_RGB_SUPPORTED)
/* convert a grayscale file into rgb. */
extern void png_set_gray_to_rgb PNGARG((png_structp png_ptr));
#endif
#if defined(PNG_READ_DITHER_SUPPORTED)
/* Turn on dithering, and reduce the palette to the number of colors available. */
extern void png_set_dither PNGARG((png_structp png_ptr, png_colorp palette,
@ -644,40 +645,74 @@ extern void png_write_rows PNGARG((png_structp png_ptr,
extern void png_write_image PNGARG((png_structp png_ptr, png_bytepp image));
/* writes the end of the png file. */
extern void png_write_end PNGARG((png_structp png_ptr, png_infop info));
extern void png_write_end PNGARG((png_structp png_ptr, png_infop info_ptr));
/* read the end of the png file. */
extern void png_read_end PNGARG((png_structp png_ptr, png_infop info));
extern void png_read_end PNGARG((png_structp png_ptr, png_infop info_ptr));
/* free the info structure */
/* free any memory associated with the info_struct */
extern void png_destroy_info_struct PNGARG((png_structp png_ptr,
png_infopp info_ptr));
png_infopp info_ptr_ptr));
/* free any memory associated with the png_struct and the info_structs */
extern void png_destroy_read_struct PNGARG((png_structpp png_ptr,
png_infopp info, png_infopp end_info));
extern void png_destroy_read_struct PNGARG((png_structpp png_ptr_ptr,
png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
/* free all memory used by the read (old method) */
extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info,
png_infop end_info));
extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
png_infop end_info_ptr));
/* free any memory associated with the png_struct and the info_structs */
extern void png_destroy_write_struct PNGARG((png_structpp png_ptr,
png_infopp info));
extern void png_destroy_write_struct PNGARG((png_structpp png_ptr_ptr,
png_infopp info_ptr_ptr));
/* free any memory used in png struct */
extern void png_write_destroy PNGARG((png_structp png_ptr));
/* These functions give the user control over the filtering and
compression libraries used by zlib. These functions are mainly
useful for testing, as the defaults should work with most users.
Those users who are tight on memory, or are wanting faster
performance at the expense of compression can modify them.
See the compression library header file for an explination
of these functions */
/* set the libpng method of handling chunk CRC errors */
extern void png_set_crc_action PNGARG((png_structp png_ptr, int crit_action,
int ancil_action));
/* Values for png_set_crc_action() to say how to handle CRC errors in
ancillary and critical chunks, and whether to use the data contained
therein. Note that it is impossible to "discard" data in a critical
chunk. For versions prior to 0.90, the action was always error/quit,
whereas in version 0.90, the action for CRC errors in ancillary
chunks is warn/discard.
value action:critical action:ancillary
*/
#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
/* These functions give the user control over the scan-line filtering
in libpng and the compression methods used by zlib. These functions are
mainly useful for testing, as the defaults should work with most users.
Those users who are tight on memory, or are wanting faster performance
at the expense of compression can modify them. See the compression
library header file for an explination of the compression functions */
/* set the filtering method(s) used by libpng */
extern void png_set_filter PNGARG((png_structp png_ptr, int method,
int filters));
/* Flags for png_set_filter() to say which filters to use. The flags
are chosen so that they don't conflict with real filter types, in case they
are supplied instead of the #defined constants.
*/
#define PNG_NO_FILTERS 0x00
#define PNG_FILTER_NONE 0x08
#define PNG_FILTER_SUB 0x10
#define PNG_FILTER_UP 0x20
#define PNG_FILTER_AVG 0x40
#define PNG_FILTER_PAETH 0x80
#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
PNG_FILTER_AVG | PNG_FILTER_PAETH)
extern void png_set_compression_level PNGARG((png_structp png_ptr,
int level));
@ -712,12 +747,12 @@ extern void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
/* Initialize the input/output for the png file to the default functions. */
extern void png_init_io PNGARG((png_structp png_ptr, FILE *fp));
/* Replace the error message and abort, and warning functions with user
supplied functions. If no messages are to be printed then you must
supply replacement message functions. The replacement error_fn should
/* Replace the (error and abort), and warning functions with user
supplied functions. If no messages are to be printed you must still
write and use replacement functions. The replacement error_fn should
still do a longjmp to the last setjmp location if you are using this
method of error handling. If error_fn or warning_fn is NULL, the
default functions will be used. */
default function will be used. */
extern void png_set_error_fn PNGARG((png_structp png_ptr, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warning_fn));
@ -748,27 +783,11 @@ extern void png_set_push_fn PNGARG((png_structp png_ptr, png_voidp push_ptr,
extern png_voidp png_get_progressive_ptr PNGARG((png_structp png_ptr));
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
extern png_voidp png_large_malloc PNGARG((png_structp png_ptr,
extern png_voidp png_malloc PNGARG((png_structp png_ptr,
png_uint_32 size));
/* free's a pointer allocated by png_large_malloc() */
extern void png_large_free PNGARG((png_structp png_ptr, png_voidp ptr));
/* Allocate memory. */
extern void * png_malloc PNGARG((png_structp png_ptr, png_uint_32 size));
/* Reallocate memory. */
extern void * png_realloc PNGARG((png_structp png_ptr, void * ptr,
png_uint_32 size, png_uint_32 old_size));
/* free's a pointer allocated by png_malloc() */
extern void png_free PNGARG((png_structp png_ptr, void * ptr));
/* allocate memory for an internal libpng struct */
extern png_voidp png_create_struct PNGARG((uInt type));
/* free memory from internal libpng struct */
extern void png_destroy_struct PNGARG((voidp struct_ptr));
extern void png_free PNGARG((png_structp png_ptr, png_voidp ptr));
/* Fatal error in libpng - can't continue */
extern void png_error PNGARG((png_structp png_ptr, png_const_charp error));
@ -786,33 +805,27 @@ extern void png_warning PNGARG((png_structp png_ptr, png_const_charp message));
#if defined(PNG_INTERNAL)
/* various modes of operation. Note that after an init, mode is set to
zero automatically */
#define PNG_BEFORE_IHDR 0x00
#define PNG_HAVE_IHDR 0x01
#define PNG_HAVE_PLTE 0x02
#define PNG_HAVE_IDAT 0x04
#define PNG_AT_LAST_IDAT 0x08
#define PNG_AFTER_IDAT 0x10
#define PNG_AFTER_IEND 0x20
/* Various modes of operation. Note that after an init, mode is set to
zero automatically when the structure is created. */
#define PNG_BEFORE_IHDR 0x00
#define PNG_HAVE_IHDR 0x01
#define PNG_HAVE_PLTE 0x02
#define PNG_HAVE_IDAT 0x04
#define PNG_AFTER_IDAT 0x08
#define PNG_HAVE_IEND 0x10
/* push model modes */
#define PNG_READ_SIG_MODE 0
#define PNG_READ_CHUNK_MODE 1
#define PNG_READ_IDAT_MODE 2
#define PNG_READ_PLTE_MODE 3
#define PNG_READ_END_MODE 4
#define PNG_SKIP_MODE 5
#define PNG_READ_tEXt_MODE 6
#define PNG_READ_zTXt_MODE 7
#define PNG_READ_DONE_MODE 8
#define PNG_ERROR_MODE 9
#define PNG_READ_END_MODE 3
#define PNG_SKIP_MODE 4
#define PNG_READ_tEXt_MODE 5
#define PNG_READ_zTXt_MODE 6
#define PNG_READ_DONE_MODE 7
#define PNG_ERROR_MODE 8
/* read modes */
#define PNG_READ_PULL_MODE 0
#define PNG_READ_PUSH_MODE 1
/* defines for the transformations the png library does on the image data */
/* defines for the transformations the PNG library does on the image data */
#define PNG_BGR 0x0001
#define PNG_INTERLACE 0x0002
#define PNG_PACK 0x0004
@ -822,7 +835,7 @@ extern void png_warning PNGARG((png_structp png_ptr, png_const_charp message));
#define PNG_DITHER 0x0040
#define PNG_BACKGROUND 0x0080
#define PNG_BACKGROUND_EXPAND 0x0100
#define PNG_XRGB 0x0200
#define PNG_RGB_TO_GRAY 0x0200
#define PNG_16_TO_8 0x0400
#define PNG_RGBA 0x0800
#define PNG_EXPAND 0x1000
@ -830,28 +843,37 @@ extern void png_warning PNGARG((png_structp png_ptr, png_const_charp message));
#define PNG_GRAY_TO_RGB 0x4000
#define PNG_FILLER 0x8000
/* flags for png_ptr->do_free to say if memory in png_info needs to be freed */
#define PNG_FREE_PALETTE 0x0001
#define PNG_FREE_HIST 0x0002
#define PNG_FREE_TRANS 0x0004
#define PNG_FREE_STRUCT 0x0008
#define PNG_FREE_INFO 0x0010
/* flags for png_create_struct */
#define PNG_STRUCT_PNG 0x0001
#define PNG_STRUCT_INFO 0x0002
/* flags for the png_ptr->flags rather than declaring a bye for each one */
#define PNG_FLAG_WROTE_tIME 0x0001
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0002
#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0004
#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0008
#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0010
#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0020
#define PNG_FLAG_ZLIB_FINISHED 0x0040
#define PNG_FLAG_ROW_INIT 0x0080
#define PNG_FLAG_FILLER_AFTER 0x0100
#define PNG_FLAG_HAVE_CHUNK_HEADER 0x0200
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
#define PNG_FLAG_ZLIB_FINISHED 0x0020
#define PNG_FLAG_ROW_INIT 0x0040
#define PNG_FLAG_FILLER_AFTER 0x0080
#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800