/* * Copyright (c) 2015 Kevin Wheatley <kevin.j.wheatley@gmail.com> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/color_utils.h" #include "libavutil/pixfmt.h" double avpriv_get_gamma_from_trc(enum AVColorTransferCharacteristic trc) { double gamma; switch (trc) { case AVCOL_TRC_BT709: case AVCOL_TRC_SMPTE170M: case AVCOL_TRC_SMPTE240M: case AVCOL_TRC_BT1361_ECG: case AVCOL_TRC_BT2020_10: case AVCOL_TRC_BT2020_12: /* these share a segmented TRC, but gamma 1.961 is a close approximation, and also more correct for decoding content */ gamma = 1.961; break; case AVCOL_TRC_GAMMA22: case AVCOL_TRC_IEC61966_2_1: gamma = 2.2; break; case AVCOL_TRC_GAMMA28: gamma = 2.8; break; case AVCOL_TRC_LINEAR: gamma = 1.0; break; default: gamma = 0.0; // Unknown value representation } return gamma; }