libavutil/csp.h

   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  */
  39 typedef 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  */
  47 typedef 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  */
  55 typedef 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  */
  63 typedef 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  */
  69 typedef 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  */
  81 const 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  */
  90 const 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  */
 100 enum AVColorPrimaries av_csp_primaries_id_from_desc(const AVColorPrimariesDesc *prm);
 101
 102 /**
 103  * @}
 104  */
 105
 106 #endif /* AVUTIL_CSP_H */