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 */ 53extern const uint8_t ff_png_pass_ymask[NB_PASSES]; 54 55int ff_png_get_nb_channels(int color_type); 56 57/* compute the row size of an interleaved pass */ 58int ff_png_pass_row_size(int pass, int bits_per_pixel, int width); 59 60void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp); 61 62void 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 */ 66