FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
color_utils.c
Go to the documentation of this file.
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 #include "libavutil/color_utils.h"
22 #include "libavutil/pixfmt.h"
23 
25 {
26  double gamma;
27  switch (trc) {
28  case AVCOL_TRC_BT709:
34  /* these share a segmented TRC, but gamma 1.961 is a close
35  approximation, and also more correct for decoding content */
36  gamma = 1.961;
37  break;
38  case AVCOL_TRC_GAMMA22:
40  gamma = 2.2;
41  break;
42  case AVCOL_TRC_GAMMA28:
43  gamma = 2.8;
44  break;
45  case AVCOL_TRC_LINEAR:
46  gamma = 1.0;
47  break;
48  default:
49  gamma = 0.0; // Unknown value representation
50  }
51  return gamma;
52 }