FFmpeg/libavutil/color_utils.h
Kevin Wheatley bac9048265 avutil/color_utils: Add basic transfer functions for each AVColorTransferCharacteristic
Most functions are valid over a domain and range of [0.0-1.0] but
some are defined over greater. This patch does not deal with
AVColorRange and assumes AVCOL_RANGE_JPEG for the returned values.

Signed-off-by: Kevin Wheatley <kevin.j.wheatley@gmail.com>
2015-09-10 23:53:05 +02:00

57 lines
2.0 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
*/
#ifndef AVUTIL_COLOR_UTILS_H
#define AVUTIL_COLOR_UTILS_H
#include "libavutil/pixfmt.h"
/**
* 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)
*
* @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 avpriv_get_gamma_from_trc(enum AVColorTransferCharacteristic trc);
typedef double (*avpriv_trc_function)(double);
/**
* 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:
*/
avpriv_trc_function avpriv_get_trc_function_from_trc(enum AVColorTransferCharacteristic trc);
#endif