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 52extern const uint8_t ff_pngsig[8]; 53extern const uint8_t ff_mngsig[8]; 54 55/* Mask to determine which y pixels are valid in a pass */ 56extern const uint8_t ff_png_pass_ymask[NB_PASSES]; 57 58/* minimum x value */ 59extern const uint8_t ff_png_pass_xmin[NB_PASSES]; 60 61/* x shift to get row width */ 62extern const uint8_t ff_png_pass_xshift[NB_PASSES]; 63 64/* Mask to determine which pixels are valid in a pass */ 65extern const uint8_t ff_png_pass_mask[NB_PASSES]; 66 67void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size); 68 69void ff_png_zfree(void *opaque, void *ptr); 70 71int ff_png_get_nb_channels(int color_type); 72 73/* compute the row size of an interleaved pass */ 74int ff_png_pass_row_size(int pass, int bits_per_pixel, int width); 75 76void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp); 77 78#endif /* AVCODEC_PNG_H */ 79