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[libpng17] Document how to use different crc_action after reading the image
data in the sequential reader.
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Glenn Randers-Pehrson
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@ -1,6 +1,6 @@
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libpng-manual.txt - A description on how to use and modify libpng
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libpng version 1.7.0beta32 - February 6, 2014
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libpng version 1.7.0beta32 - February 23, 2014
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Updated and distributed by Glenn Randers-Pehrson
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<glennrp at users.sourceforge.net>
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Copyright (c) 1998-2014 Glenn Randers-Pehrson
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@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
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Based on:
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libpng versions 0.97, January 1998, through 1.7.0beta32 - February 6, 2014
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libpng versions 0.97, January 1998, through 1.7.0beta32 - February 23, 2014
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Updated and distributed by Glenn Randers-Pehrson
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Copyright (c) 1998-2014 Glenn Randers-Pehrson
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@ -2165,10 +2165,15 @@ how pngvalid.c does it.
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Finishing a sequential read
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After you are finished reading the image through the
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low-level interface, you can finish reading the file. If you are
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interested in comments or time, which may be stored either before or
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after the image data, you should pass the separate png_info struct if
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you want to keep the comments from before and after the image
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low-level interface, you can finish reading the file.
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If you want to use a different crc action for handling CRC errors in
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chunks after the image data, you can call png_set_crc_action()
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again at this point.
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If you are interested in comments or time, which may be stored either
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before or after the image data, you should pass the separate png_info
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struct if you want to keep the comments from before and after the image
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separate.
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png_infop end_info = png_create_info_struct(png_ptr);
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@ -2184,6 +2189,9 @@ separate.
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If you are not interested, you should still call png_read_end()
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but you can pass NULL, avoiding the need to create an end_info structure.
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If you do this, libpng will not process any chunks after IDAT other than
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skipping over them and perhaps (depending on whether you have called
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png_set_crc_action) checking their CRCs while looking for the IEND chunk.
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png_read_end(png_ptr, (png_infop)NULL);
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@ -2459,7 +2467,7 @@ png_infop info_ptr;
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png_progressive_combine_row(png_ptr, old_row,
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new_row);
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/* where old_row is what was displayed for
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/* where old_row is what was displayed
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previously for the row. Note that the first
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pass (pass == 0, really) will completely cover
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the old row, so the rows do not have to be
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@ -5270,7 +5278,7 @@ Other rules can be inferred by inspecting the libpng source.
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XVII. Y2K Compliance in libpng
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February 6, 2014
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February 23, 2014
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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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32
libpng.3
32
libpng.3
@ -1,4 +1,4 @@
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.TH LIBPNG 3 "February 6, 2014"
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.TH LIBPNG 3 "February 23, 2014"
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.SH NAME
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libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta32
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.SH SYNOPSIS
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@ -494,7 +494,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
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.SH LIBPNG.TXT
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libpng-manual.txt - A description on how to use and modify libpng
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libpng version 1.7.0beta32 - February 6, 2014
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libpng version 1.7.0beta32 - February 23, 2014
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Updated and distributed by Glenn Randers-Pehrson
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<glennrp at users.sourceforge.net>
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Copyright (c) 1998-2014 Glenn Randers-Pehrson
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@ -505,7 +505,7 @@ libpng-manual.txt - A description on how to use and modify libpng
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Based on:
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libpng versions 0.97, January 1998, through 1.7.0beta32 - February 6, 2014
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libpng versions 0.97, January 1998, through 1.7.0beta32 - February 23, 2014
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Updated and distributed by Glenn Randers-Pehrson
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Copyright (c) 1998-2014 Glenn Randers-Pehrson
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@ -2659,10 +2659,15 @@ how pngvalid.c does it.
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.SS Finishing a sequential read
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After you are finished reading the image through the
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low-level interface, you can finish reading the file. If you are
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interested in comments or time, which may be stored either before or
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after the image data, you should pass the separate png_info struct if
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you want to keep the comments from before and after the image
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low-level interface, you can finish reading the file.
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If you want to use a different crc action for handling CRC errors in
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chunks after the image data, you can call png_set_crc_action()
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again at this point.
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If you are interested in comments or time, which may be stored either
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before or after the image data, you should pass the separate png_info
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struct if you want to keep the comments from before and after the image
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separate.
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png_infop end_info = png_create_info_struct(png_ptr);
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@ -2678,6 +2683,9 @@ separate.
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If you are not interested, you should still call png_read_end()
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but you can pass NULL, avoiding the need to create an end_info structure.
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If you do this, libpng will not process any chunks after IDAT other than
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skipping over them and perhaps (depending on whether you have called
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png_set_crc_action) checking their CRCs while looking for the IEND chunk.
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png_read_end(png_ptr, (png_infop)NULL);
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@ -2953,7 +2961,7 @@ png_infop info_ptr;
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png_progressive_combine_row(png_ptr, old_row,
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new_row);
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/* where old_row is what was displayed for
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/* where old_row is what was displayed
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previously for the row. Note that the first
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pass (pass == 0, really) will completely cover
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the old row, so the rows do not have to be
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@ -5765,7 +5773,7 @@ Other rules can be inferred by inspecting the libpng source.
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.SH XVII. Y2K Compliance in libpng
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February 6, 2014
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February 23, 2014
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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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@ -6035,7 +6043,7 @@ possible without all of you.
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Thanks to Frank J. T. Wojcik for helping with the documentation.
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Libpng version 1.7.0beta32 - February 6, 2014:
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Libpng version 1.7.0beta32 - February 23, 2014:
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Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
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Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
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@ -6058,7 +6066,7 @@ this sentence.
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This code is released under the libpng license.
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libpng versions 1.2.6, August 15, 2004, through 1.7.0beta32, February 6, 2014, are
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libpng versions 1.2.6, August 15, 2004, through 1.7.0beta32, February 23, 2014, are
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Copyright (c) 2004,2006-2007 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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@ -6157,7 +6165,7 @@ certification mark of the Open Source Initiative.
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Glenn Randers-Pehrson
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glennrp at users.sourceforge.net
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February 6, 2014
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February 23, 2014
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.\" end of man page
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