xref: /third_party/ffmpeg/libavutil/csp.h (revision cabdff1a) 
1/*
2 * Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com>
3 * This file is part of FFmpeg.
4 *
5 * FFmpeg is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * FFmpeg is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with FFmpeg; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20#ifndef AVUTIL_CSP_H
21#define AVUTIL_CSP_H
22
23#include "pixfmt.h"
24#include "rational.h"
25
26/**
27 * @file Colorspace value utility functions for libavutil.
28 * @author Ronald S. Bultje <rsbultje@gmail.com>
29 * @author Leo Izen <leo.izen@gmail.com>
30 * @defgroup lavu_math_csp Colorspace Utility
31 * @ingroup lavu_math
32 * @{
33 */
34
35/**
36 * Struct containing luma coefficients to be used for RGB to YUV/YCoCg, or similar
37 * calculations.
38 */
39typedef struct AVLumaCoefficients {
40    AVRational cr, cg, cb;
41} AVLumaCoefficients;
42
43/**
44 * Struct containing chromaticity x and y values for the standard CIE 1931
45 * chromaticity definition.
46 */
47typedef struct AVCIExy {
48    AVRational x, y;
49} AVCIExy;
50
51/**
52 * Struct defining the red, green, and blue primary locations in terms of CIE
53 * 1931 chromaticity x and y.
54 */
55typedef struct AVPrimaryCoefficients {
56    AVCIExy r, g, b;
57} AVPrimaryCoefficients;
58
59/**
60 * Struct defining white point location in terms of CIE 1931 chromaticity x
61 * and y.
62 */
63typedef AVCIExy AVWhitepointCoefficients;
64
65/**
66 * Struct that contains both white point location and primaries location, providing
67 * the complete description of a color gamut.
68 */
69typedef struct AVColorPrimariesDesc {
70    AVWhitepointCoefficients wp;
71    AVPrimaryCoefficients prim;
72} AVColorPrimariesDesc;
73
74/**
75 * Retrieves the Luma coefficients necessary to construct a conversion matrix
76 * from an enum constant describing the colorspace.
77 * @param csp An enum constant indicating YUV or similar colorspace.
78 * @return The Luma coefficients associated with that colorspace, or NULL
79 *     if the constant is unknown to libavutil.
80 */
81const AVLumaCoefficients *av_csp_luma_coeffs_from_avcsp(enum AVColorSpace csp);
82
83/**
84 * Retrieves a complete gamut description from an enum constant describing the
85 * color primaries.
86 * @param prm An enum constant indicating primaries
87 * @return A description of the colorspace gamut associated with that enum
88 *     constant, or NULL if the constant is unknown to libavutil.
89 */
90const AVColorPrimariesDesc *av_csp_primaries_desc_from_id(enum AVColorPrimaries prm);
91
92/**
93 * Detects which enum AVColorPrimaries constant corresponds to the given complete
94 * gamut description.
95 * @see enum AVColorPrimaries
96 * @param prm A description of the colorspace gamut
97 * @return The enum constant associated with this gamut, or
98 *     AVCOL_PRI_UNSPECIFIED if no clear match can be idenitified.
99 */
100enum AVColorPrimaries av_csp_primaries_id_from_desc(const AVColorPrimariesDesc *prm);
101
102/**
103 * @}
104 */
105
106#endif /* AVUTIL_CSP_H */
107