mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
719a93f4e4
libavutil/color_utils contains some avpriv_ symbols that map
enum AVTransferCharacteristic values to gamma-curve approximations and
to the actual transfer functions to invert them (i.e. -> linear).
There's two issues with this:
(1) avpriv is evil and should be avoided whenever possible
(2) libavutil/csp.h exposes a public API for handling color that
already handles primaries and matricies
I don't see any reason this API has to be private, so this commit takes
the functionality from avutil/color_utils and merges it into avutil/csp
with an exposed av_ API rather than the previous avpriv_ API.
Every reference to the previous API has been updated to point to the
new one. color_utils.h has been deleted as well. This should not break
any applications as it only contained avpriv_ symbols in the first
place, so nothing in that header could be referenced by other
applications.
Signed-off-by: Leo Izen <leo.izen@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
151 lines
4.8 KiB
C
151 lines
4.8 KiB
C
/*
|
|
* Copyright (c) 2015 Kevin Wheatley <kevin.j.wheatley@gmail.com>
|
|
* Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com>
|
|
* Copyright (c) 2023 Leo Izen <leo.izen@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
|
|
*/
|
|
|
|
#ifndef AVUTIL_CSP_H
|
|
#define AVUTIL_CSP_H
|
|
|
|
#include "pixfmt.h"
|
|
#include "rational.h"
|
|
|
|
/**
|
|
* @file
|
|
* Colorspace value utility functions for libavutil.
|
|
* @ingroup lavu_math_csp
|
|
* @author Ronald S. Bultje <rsbultje@gmail.com>
|
|
* @author Leo Izen <leo.izen@gmail.com>
|
|
* @author Kevin Wheatley <kevin.j.wheatley@gmail.com>
|
|
*/
|
|
|
|
/**
|
|
* @defgroup lavu_math_csp Colorspace Utility
|
|
* @ingroup lavu_math
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* Struct containing luma coefficients to be used for RGB to YUV/YCoCg, or similar
|
|
* calculations.
|
|
*/
|
|
typedef struct AVLumaCoefficients {
|
|
AVRational cr, cg, cb;
|
|
} AVLumaCoefficients;
|
|
|
|
/**
|
|
* Struct containing chromaticity x and y values for the standard CIE 1931
|
|
* chromaticity definition.
|
|
*/
|
|
typedef struct AVCIExy {
|
|
AVRational x, y;
|
|
} AVCIExy;
|
|
|
|
/**
|
|
* Struct defining the red, green, and blue primary locations in terms of CIE
|
|
* 1931 chromaticity x and y.
|
|
*/
|
|
typedef struct AVPrimaryCoefficients {
|
|
AVCIExy r, g, b;
|
|
} AVPrimaryCoefficients;
|
|
|
|
/**
|
|
* Struct defining white point location in terms of CIE 1931 chromaticity x
|
|
* and y.
|
|
*/
|
|
typedef AVCIExy AVWhitepointCoefficients;
|
|
|
|
/**
|
|
* Struct that contains both white point location and primaries location, providing
|
|
* the complete description of a color gamut.
|
|
*/
|
|
typedef struct AVColorPrimariesDesc {
|
|
AVWhitepointCoefficients wp;
|
|
AVPrimaryCoefficients prim;
|
|
} AVColorPrimariesDesc;
|
|
|
|
/**
|
|
* Function pointer representing a double -> double transfer function that performs
|
|
* an EOTF transfer inversion. This function outputs linear light.
|
|
*/
|
|
typedef double (*av_csp_trc_function)(double);
|
|
|
|
/**
|
|
* Retrieves the Luma coefficients necessary to construct a conversion matrix
|
|
* from an enum constant describing the colorspace.
|
|
* @param csp An enum constant indicating YUV or similar colorspace.
|
|
* @return The Luma coefficients associated with that colorspace, or NULL
|
|
* if the constant is unknown to libavutil.
|
|
*/
|
|
const AVLumaCoefficients *av_csp_luma_coeffs_from_avcsp(enum AVColorSpace csp);
|
|
|
|
/**
|
|
* Retrieves a complete gamut description from an enum constant describing the
|
|
* color primaries.
|
|
* @param prm An enum constant indicating primaries
|
|
* @return A description of the colorspace gamut associated with that enum
|
|
* constant, or NULL if the constant is unknown to libavutil.
|
|
*/
|
|
const AVColorPrimariesDesc *av_csp_primaries_desc_from_id(enum AVColorPrimaries prm);
|
|
|
|
/**
|
|
* Detects which enum AVColorPrimaries constant corresponds to the given complete
|
|
* gamut description.
|
|
* @see enum AVColorPrimaries
|
|
* @param prm A description of the colorspace gamut
|
|
* @return The enum constant associated with this gamut, or
|
|
* AVCOL_PRI_UNSPECIFIED if no clear match can be idenitified.
|
|
*/
|
|
enum AVColorPrimaries av_csp_primaries_id_from_desc(const AVColorPrimariesDesc *prm);
|
|
|
|
/**
|
|
* Determine a suitable 'gamma' value to match the supplied
|
|
* AVColorTransferCharacteristic.
|
|
*
|
|
* See Apple Technical Note TN2257 (https://developer.apple.com/library/mac/technotes/tn2257/_index.html)
|
|
*
|
|
* This function returns the gamma exponent for the OETF. For example, sRGB is approximated
|
|
* by gamma 2.2, not by gamma 0.45455.
|
|
*
|
|
* @return Will return an approximation to the simple gamma function matching
|
|
* the supplied Transfer Characteristic, Will return 0.0 for any
|
|
* we cannot reasonably match against.
|
|
*/
|
|
double av_csp_approximate_trc_gamma(enum AVColorTransferCharacteristic trc);
|
|
|
|
/**
|
|
* Determine the function needed to apply the given
|
|
* AVColorTransferCharacteristic to linear input.
|
|
*
|
|
* The function returned should expect a nominal domain and range of [0.0-1.0]
|
|
* values outside of this range maybe valid depending on the chosen
|
|
* characteristic function.
|
|
*
|
|
* @return Will return pointer to the function matching the
|
|
* supplied Transfer Characteristic. If unspecified will
|
|
* return NULL:
|
|
*/
|
|
av_csp_trc_function av_csp_trc_func_from_id(enum AVColorTransferCharacteristic trc);
|
|
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
#endif /* AVUTIL_CSP_H */
|