1 /* 2 * Copyright (c) 2015 Kevin Wheatley <kevin.j.wheatley@gmail.com> 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef AVUTIL_COLOR_UTILS_H 22 #define AVUTIL_COLOR_UTILS_H 23 24 25 #include "libavutil/pixfmt.h" 26 27 /** 28 * Determine a suitable 'gamma' value to match the supplied 29 * AVColorTransferCharacteristic. 30 * 31 * See Apple Technical Note TN2257 (https://developer.apple.com/library/mac/technotes/tn2257/_index.html) 32 * 33 * @return Will return an approximation to the simple gamma function matching 34 * the supplied Transfer Characteristic, Will return 0.0 for any 35 * we cannot reasonably match against. 36 */ 37 double avpriv_get_gamma_from_trc(enum AVColorTransferCharacteristic trc); 38 39 40 typedef double (*avpriv_trc_function)(double); 41 42 /** 43 * Determine the function needed to apply the given 44 * AVColorTransferCharacteristic to linear input. 45 * 46 * The function returned should expect a nominal domain and range of [0.0-1.0] 47 * values outside of this range maybe valid depending on the chosen 48 * characteristic function. 49 * 50 * @return Will return pointer to the function matching the 51 * supplied Transfer Characteristic. If unspecified will 52 * return NULL: 53 */ 54 avpriv_trc_function avpriv_get_trc_function_from_trc(enum AVColorTransferCharacteristic trc); 55 56 #endif 57