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 #include "pngdsp.h"
  28
  29 #define PNG_COLOR_MASK_PALETTE    1
  30 #define PNG_COLOR_MASK_COLOR      2
  31 #define PNG_COLOR_MASK_ALPHA      4
  32
  33 #define PNG_COLOR_TYPE_GRAY 0
  34 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
  35 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
  36 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
  37 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
  38
  39 #define PNG_FILTER_TYPE_LOCO   64
  40 #define PNG_FILTER_VALUE_NONE  0
  41 #define PNG_FILTER_VALUE_SUB   1
  42 #define PNG_FILTER_VALUE_UP    2
  43 #define PNG_FILTER_VALUE_AVG   3
  44 #define PNG_FILTER_VALUE_PAETH 4
  45 #define PNG_FILTER_VALUE_MIXED 5
  46
  47 #define NB_PASSES 7
  48
  49 #define PNGSIG 0x89504e470d0a1a0a
  50 #define MNGSIG 0x8a4d4e470d0a1a0a
  51
  52 /* Mask to determine which y pixels are valid in a pass */
  53 extern const uint8_t ff_png_pass_ymask[NB_PASSES];
  54
  55 int ff_png_get_nb_channels(int color_type);
  56
  57 /* compute the row size of an interleaved pass */
  58 int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
  59
  60 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
  61
  62 void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
  63                        uint8_t *src, uint8_t *last, int size, int bpp);
  64
  65 #endif /* AVCODEC_PNG_H */