f24f2247c2
DM: Add a flag to use SkCodec instead of SkImageDecoder. SkCodec: Base class for codecs, allowing creation from an SkStream or an SkData. An SkCodec, on creation, knows properties of the data like its width and height. Further calls can be used to generate the image. TODO: Add scanline iterator SkPngCodec: New decoder for png. Wraps libpng. The code has been repurposed from SkImageDecoder_libpng. TODO: Handle other destination colortypes TODO: Substitute the transpose color TODO: Allow silencing warnings TODO: Use RGB instead of filler? TODO: sRGB SkSwizzler: Simplified version of SkScaledSampler. Unlike the sampler, this object does no sampling. TODO: Implement other swizzles. Requires a gclient sync to pull down libpng. BUG=skia:3257 Committed: https://skia.googlesource.com/skia/+/ca358852b4fed656d11107b2aaf28318a4518b49 (and then reverted) Review URL: https://codereview.chromium.org/930283002
173 lines
6.8 KiB
Plaintext
173 lines
6.8 KiB
Plaintext
/*
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* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
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*
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* If you modify libpng you may insert additional notices immediately following
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* this sentence.
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*
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* This code is released under the libpng license.
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*
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* libpng versions 1.2.6, August 15, 2004, through 1.6.16, December 22, 2014, are
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* Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.2.5
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* with the following individual added to the list of Contributing Authors:
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*
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* Cosmin Truta
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*
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* libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
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* Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.0.6
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* with the following individuals added to the list of Contributing Authors:
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*
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* Simon-Pierre Cadieux
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* Eric S. Raymond
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* Gilles Vollant
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*
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* and with the following additions to the disclaimer:
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*
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* There is no warranty against interference with your enjoyment of the
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* library or against infringement. There is no warranty that our
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* efforts or the library will fulfill any of your particular purposes
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* or needs. This library is provided with all faults, and the entire
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* risk of satisfactory quality, performance, accuracy, and effort is with
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* the user.
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*
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* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
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* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-0.96,
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* with the following individuals added to the list of Contributing Authors:
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*
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* Tom Lane
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* Glenn Randers-Pehrson
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* Willem van Schaik
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*
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* libpng versions 0.89, June 1996, through 0.96, May 1997, are
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* Copyright (c) 1996, 1997 Andreas Dilger
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* Distributed according to the same disclaimer and license as libpng-0.88,
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* with the following individuals added to the list of Contributing Authors:
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*
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* John Bowler
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* Kevin Bracey
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* Sam Bushell
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* Magnus Holmgren
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* Greg Roelofs
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* Tom Tanner
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*
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* libpng versions 0.5, May 1995, through 0.88, January 1996, are
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* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
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*
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* For the purposes of this copyright and license, "Contributing Authors"
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* is defined as the following set of individuals:
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*
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* Andreas Dilger
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* Dave Martindale
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* Guy Eric Schalnat
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* Paul Schmidt
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* Tim Wegner
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*
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* The PNG Reference Library is supplied "AS IS". The Contributing Authors
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* and Group 42, Inc. disclaim all warranties, expressed or implied,
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* including, without limitation, the warranties of merchantability and of
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* fitness for any purpose. The Contributing Authors and Group 42, Inc.
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* assume no liability for direct, indirect, incidental, special, exemplary,
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* or consequential damages, which may result from the use of the PNG
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* Reference Library, even if advised of the possibility of such damage.
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*
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* Permission is hereby granted to use, copy, modify, and distribute this
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* source code, or portions hereof, for any purpose, without fee, subject
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* to the following restrictions:
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*
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* 1. The origin of this source code must not be misrepresented.
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*
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* 2. Altered versions must be plainly marked as such and must not
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* be misrepresented as being the original source.
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*
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* 3. This Copyright notice may not be removed or altered from
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* any source or altered source distribution.
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*
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* The Contributing Authors and Group 42, Inc. specifically permit, without
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* fee, and encourage the use of this source code as a component to
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* supporting the PNG file format in commercial products. If you use this
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* source code in a product, acknowledgment is not required but would be
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* appreciated.
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*/
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/*
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* A "png_get_copyright" function is available, for convenient use in "about"
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* boxes and the like:
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*
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* printf("%s", png_get_copyright(NULL));
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*
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* Also, the PNG logo (in PNG format, of course) is supplied in the
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* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
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*/
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/*
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* Libpng is OSI Certified Open Source Software. OSI Certified is a
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* certification mark of the Open Source Initiative.
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*/
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/*
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* The contributing authors would like to thank all those who helped
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* with testing, bug fixes, and patience. This wouldn't have been
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* possible without all of you.
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*
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* Thanks to Frank J. T. Wojcik for helping with the documentation.
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*/
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/*
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* Y2K compliance in libpng:
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* =========================
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*
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* December 22, 2014
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*
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* Since the PNG Development group is an ad-hoc body, we can't make
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* an official declaration.
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*
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* This is your unofficial assurance that libpng from version 0.71 and
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* upward through 1.6.16 are Y2K compliant. It is my belief that
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* earlier versions were also Y2K compliant.
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*
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* Libpng only has two year fields. One is a 2-byte unsigned integer
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* that will hold years up to 65535. The other, which is deprecated,
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* holds the date in text format, and will hold years up to 9999.
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*
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* The integer is
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* "png_uint_16 year" in png_time_struct.
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*
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* The string is
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* "char time_buffer[29]" in png_struct. This is no longer used
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* in libpng-1.6.x and will be removed from libpng-1.7.0.
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*
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* There are seven time-related functions:
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* png.c: png_convert_to_rfc_1123_buffer() in png.c
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* (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
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* png_convert_to_rfc_1152() in error prior to libpng-0.98)
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* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
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* png_convert_from_time_t() in pngwrite.c
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* png_get_tIME() in pngget.c
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* png_handle_tIME() in pngrutil.c, called in pngread.c
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* png_set_tIME() in pngset.c
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* png_write_tIME() in pngwutil.c, called in pngwrite.c
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*
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* All handle dates properly in a Y2K environment. The
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* png_convert_from_time_t() function calls gmtime() to convert from system
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* clock time, which returns (year - 1900), which we properly convert to
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* the full 4-digit year. There is a possibility that libpng applications
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* are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
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* function, or that they are incorrectly passing only a 2-digit year
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* instead of "year - 1900" into the png_convert_from_struct_tm() function,
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* but this is not under our control. The libpng documentation has always
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* stated that it works with 4-digit years, and the APIs have been
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* documented as such.
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*
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* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
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* integer to hold the year, and can hold years as large as 65535.
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*
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* zlib, upon which libpng depends, is also Y2K compliant. It contains
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* no date-related code.
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*
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* Glenn Randers-Pehrson
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* libpng maintainer
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* PNG Development Group
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*/
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