libavcodec/png.h

   1 /*
   2  * PNG image format
   3  * Copyright (c) 2003 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef AVCODEC_PNG_H
  23 #define AVCODEC_PNG_H
  24
  25 #include <stdint.h>
  26
  27 #define PNG_COLOR_MASK_PALETTE    1
  28 #define PNG_COLOR_MASK_COLOR      2
  29 #define PNG_COLOR_MASK_ALPHA      4
  30
  31 #define PNG_COLOR_TYPE_GRAY 0
  32 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
  33 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
  34 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
  35 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
  36
  37 #define PNG_FILTER_TYPE_LOCO   64
  38 #define PNG_FILTER_VALUE_NONE  0
  39 #define PNG_FILTER_VALUE_SUB   1
  40 #define PNG_FILTER_VALUE_UP    2
  41 #define PNG_FILTER_VALUE_AVG   3
  42 #define PNG_FILTER_VALUE_PAETH 4
  43 #define PNG_FILTER_VALUE_MIXED 5
  44
  45 #define PNG_IHDR      0x0001
  46 #define PNG_IDAT      0x0002
  47 #define PNG_ALLIMAGE  0x0004
  48 #define PNG_PLTE      0x0008
  49
  50 #define NB_PASSES 7
  51
  52 extern const uint8_t ff_pngsig[8];
  53 extern const uint8_t ff_mngsig[8];
  54
  55 /* Mask to determine which y pixels are valid in a pass */
  56 extern const uint8_t ff_png_pass_ymask[NB_PASSES];
  57
  58 /* minimum x value */
  59 extern const uint8_t ff_png_pass_xmin[NB_PASSES];
  60
  61 /* x shift to get row width */
  62 extern const uint8_t ff_png_pass_xshift[NB_PASSES];
  63
  64 /* Mask to determine which pixels are valid in a pass */
  65 extern const uint8_t ff_png_pass_mask[NB_PASSES];
  66
  67 void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size);
  68
  69 void ff_png_zfree(void *opaque, void *ptr);
  70
  71 int ff_png_get_nb_channels(int color_type);
  72
  73 /* compute the row size of an interleaved pass */
  74 int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
  75
  76 #endif /* AVCODEC_PNG_H */