53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
|
/*
|
||
|
|
* 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;
|
||
|
|
}
|