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* Copyright (c) 2003 Fabrice Bellard.
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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#define PNG_COLOR_MASK_PALETTE 1
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#define PNG_COLOR_MASK_COLOR 2
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#define PNG_COLOR_MASK_ALPHA 4
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#define PNG_COLOR_TYPE_GRAY 0
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#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
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#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
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#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
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#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
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#define PNG_FILTER_VALUE_NONE 0
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#define PNG_FILTER_VALUE_SUB 1
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#define PNG_FILTER_VALUE_UP 2
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#define PNG_FILTER_VALUE_AVG 3
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#define PNG_FILTER_VALUE_PAETH 4
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#define PNG_IHDR 0x0001
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#define PNG_IDAT 0x0002
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#define PNG_ALLIMAGE 0x0004
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#define PNG_PLTE 0x0008
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extern const uint8_t ff_pngsig[8];
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/* Mask to determine which y pixels are valid in a pass */
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extern const uint8_t ff_png_pass_ymask[NB_PASSES];
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extern const uint8_t ff_png_pass_xmin[NB_PASSES];
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/* x shift to get row width */
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extern const uint8_t ff_png_pass_xshift[NB_PASSES];
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/* Mask to determine which pixels are valid in a pass */
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extern const uint8_t ff_png_pass_mask[NB_PASSES];
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extern void *ff_png_zalloc(void *opaque, unsigned int items,
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extern void ff_png_zfree(void *opaque, void *ptr);
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extern int ff_png_get_nb_channels(int color_type);
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/* compute the row size of an interleaved pass */
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extern int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);