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 void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size); 56 57 void ff_png_zfree(void *opaque, void *ptr); 58 59 int ff_png_get_nb_channels(int color_type); 60 61 /* compute the row size of an interleaved pass */ 62 int ff_png_pass_row_size(int pass, int bits_per_pixel, int width); 63 64 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp); 65 66 void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type, 67 uint8_t *src, uint8_t *last, int size, int bpp); 68 69 #endif /* AVCODEC_PNG_H */ 70