ffmpeg/libavutil/film_grain_params.h

169 lines
5.1 KiB
C

/*
* 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_FILM_GRAIN_PARAMS_H
#define AVUTIL_FILM_GRAIN_PARAMS_H
#include "frame.h"
enum AVFilmGrainParamsType {
AV_FILM_GRAIN_PARAMS_NONE = 0,
/**
* The union is valid when interpreted as AVFilmGrainAOMParams (codec.aom)
*/
AV_FILM_GRAIN_PARAMS_AV1,
};
/**
* This structure describes how to handle film grain synthesis for AOM codecs.
*
* @note The struct must be allocated as part of AVFilmGrainParams using
* av_film_grain_params_alloc(). Its size is not a part of the public ABI.
*/
typedef struct AVFilmGrainAOMParams {
/**
* Number of points, and the scale and value for each point of the
* piecewise linear scaling function for the uma plane.
*/
int num_y_points;
uint8_t y_points[14][2 /* value, scaling */];
/**
* Signals whether to derive the chroma scaling function from the luma.
* Not equivalent to copying the luma values and scales.
*/
int chroma_scaling_from_luma;
/**
* If chroma_scaling_from_luma is set to 0, signals the chroma scaling
* function parameters.
*/
int num_uv_points[2 /* cb, cr */];
uint8_t uv_points[2 /* cb, cr */][10][2 /* value, scaling */];
/**
* Specifies the shift applied to the chroma components. For AV1, its within
* [8; 11] and determines the range and quantization of the film grain.
*/
int scaling_shift;
/**
* Specifies the auto-regression lag.
*/
int ar_coeff_lag;
/**
* Luma auto-regression coefficients. The number of coefficients is given by
* 2 * ar_coeff_lag * (ar_coeff_lag + 1).
*/
int8_t ar_coeffs_y[24];
/**
* Chroma auto-regression coefficients. The number of coefficients is given by
* 2 * ar_coeff_lag * (ar_coeff_lag + 1) + !!num_y_points.
*/
int8_t ar_coeffs_uv[2 /* cb, cr */][25];
/**
* Specifies the range of the auto-regressive coefficients. Values of 6,
* 7, 8 and so on represent a range of [-2, 2), [-1, 1), [-0.5, 0.5) and
* so on. For AV1 must be between 6 and 9.
*/
int ar_coeff_shift;
/**
* Signals the down shift applied to the generated gaussian numbers during
* synthesis.
*/
int grain_scale_shift;
/**
* Specifies the luma/chroma multipliers for the index to the component
* scaling function.
*/
int uv_mult[2 /* cb, cr */];
int uv_mult_luma[2 /* cb, cr */];
/**
* Offset used for component scaling function. For AV1 its a 9-bit value
* with a range [-256, 255]
*/
int uv_offset[2 /* cb, cr */];
/**
* Signals whether to overlap film grain blocks.
*/
int overlap_flag;
/**
* Signals to clip to limited color levels after film grain application.
*/
int limit_output_range;
} AVFilmGrainAOMParams;
/**
* This structure describes how to handle film grain synthesis in video
* for specific codecs. Must be present on every frame where film grain is
* meant to be synthesised for correct presentation.
*
* @note The struct must be allocated with av_film_grain_params_alloc() and
* its size is not a part of the public ABI.
*/
typedef struct AVFilmGrainParams {
/**
* Specifies the codec for which this structure is valid.
*/
enum AVFilmGrainParamsType type;
/**
* Seed to use for the synthesis process, if the codec allows for it.
*/
uint64_t seed;
/**
* Additional fields may be added both here and in any structure included.
* If a codec's film grain structure differs slightly over another
* codec's, fields within may change meaning depending on the type.
*/
union {
AVFilmGrainAOMParams aom;
} codec;
} AVFilmGrainParams;
/**
* Allocate an AVFilmGrainParams structure and set its fields to
* default values. The resulting struct can be freed using av_freep().
* If size is not NULL it will be set to the number of bytes allocated.
*
* @return An AVFilmGrainParams filled with default values or NULL
* on failure.
*/
AVFilmGrainParams *av_film_grain_params_alloc(size_t *size);
/**
* Allocate a complete AVFilmGrainParams and add it to the frame.
*
* @param frame The frame which side data is added to.
*
* @return The AVFilmGrainParams structure to be filled by caller.
*/
AVFilmGrainParams *av_film_grain_params_create_side_data(AVFrame *frame);
#endif /* AVUTIL_FILM_GRAIN_PARAMS_H */