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