include/ffmpeg/libavutil/dovi_meta.h
/*
 * Copyright (c) 2020 Vacing Fang <vacingfang@tencent.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
 */

/**
 * @file
 * DOVI configuration
 */


#ifndef AVUTIL_DOVI_META_H
#define AVUTIL_DOVI_META_H

#include <stdint.h>
#include <stddef.h>
#include "rational.h"

/*
 * DOVI configuration
 * ref: dolby-vision-bitstreams-within-the-iso-base-media-file-format-v2.1.2
        dolby-vision-bitstreams-in-mpeg-2-transport-stream-multiplex-v1.2
 * @code
 * uint8_t  dv_version_major, the major version number that the stream complies with
 * uint8_t  dv_version_minor, the minor version number that the stream complies with
 * uint8_t  dv_profile, the Dolby Vision profile
 * uint8_t  dv_level, the Dolby Vision level
 * uint8_t  rpu_present_flag
 * uint8_t  el_present_flag
 * uint8_t  bl_present_flag
 * uint8_t  dv_bl_signal_compatibility_id
 * @endcode
 *
 * @note The struct must be allocated with av_dovi_alloc() and
 *       its size is not a part of the public ABI.
 */
typedef struct AVDOVIDecoderConfigurationRecord {
    uint8_t dv_version_major;
    uint8_t dv_version_minor;
    uint8_t dv_profile;
    uint8_t dv_level;
    uint8_t rpu_present_flag;
    uint8_t el_present_flag;
    uint8_t bl_present_flag;
    uint8_t dv_bl_signal_compatibility_id;
} AVDOVIDecoderConfigurationRecord;

/**
 * Allocate a AVDOVIDecoderConfigurationRecord structure and initialize its
 * fields to default values.
 *
 * @return the newly allocated struct or NULL on failure
 */
AVDOVIDecoderConfigurationRecord *av_dovi_alloc(size_t *size);

/**
 * Dolby Vision RPU data header.
 *
 * @note sizeof(AVDOVIRpuDataHeader) is not part of the public ABI.
 */
typedef struct AVDOVIRpuDataHeader {
    uint8_t rpu_type;
    uint16_t rpu_format;
    uint8_t vdr_rpu_profile;
    uint8_t vdr_rpu_level;
    uint8_t chroma_resampling_explicit_filter_flag;
    uint8_t coef_data_type; /* informative, lavc always converts to fixed */
    uint8_t coef_log2_denom;
    uint8_t vdr_rpu_normalized_idc;
    uint8_t bl_video_full_range_flag;
    uint8_t bl_bit_depth; /* [8, 16] */
    uint8_t el_bit_depth; /* [8, 16] */
    uint8_t vdr_bit_depth; /* [8, 16] */
    uint8_t spatial_resampling_filter_flag;
    uint8_t el_spatial_resampling_filter_flag;
    uint8_t disable_residual_flag;
} AVDOVIRpuDataHeader;

enum AVDOVIMappingMethod {
    AV_DOVI_MAPPING_POLYNOMIAL = 0,
    AV_DOVI_MAPPING_MMR = 1,
};

/**
 * Coefficients of a piece-wise function. The pieces of the function span the
 * value ranges between two adjacent pivot values.
 */
#define AV_DOVI_MAX_PIECES 8
typedef struct AVDOVIReshapingCurve {
    uint8_t num_pivots;                         /* [2, 9] */
    uint16_t pivots[AV_DOVI_MAX_PIECES + 1];    /* sorted ascending */
    enum AVDOVIMappingMethod mapping_idc[AV_DOVI_MAX_PIECES];
    /* AV_DOVI_MAPPING_POLYNOMIAL */
    uint8_t poly_order[AV_DOVI_MAX_PIECES];     /* [1, 2] */
    int64_t poly_coef[AV_DOVI_MAX_PIECES][3];   /* x^0, x^1, x^2 */
    /* AV_DOVI_MAPPING_MMR */
    uint8_t mmr_order[AV_DOVI_MAX_PIECES];      /* [1, 3] */
    int64_t mmr_constant[AV_DOVI_MAX_PIECES];
    int64_t mmr_coef[AV_DOVI_MAX_PIECES][3/* order - 1 */][7];
} AVDOVIReshapingCurve;

enum AVDOVINLQMethod {
    AV_DOVI_NLQ_NONE = -1,
    AV_DOVI_NLQ_LINEAR_DZ = 0,
};

/**
 * Coefficients of the non-linear inverse quantization. For the interpretation
 * of these, see ETSI GS CCM 001.
 */
typedef struct AVDOVINLQParams {
    uint16_t nlq_offset;
    uint64_t vdr_in_max;
    /* AV_DOVI_NLQ_LINEAR_DZ */
    uint64_t linear_deadzone_slope;
    uint64_t linear_deadzone_threshold;
} AVDOVINLQParams;

/**
 * Dolby Vision RPU data mapping parameters.
 *
 * @note sizeof(AVDOVIDataMapping) is not part of the public ABI.
 */
typedef struct AVDOVIDataMapping {
    uint8_t vdr_rpu_id;
    uint8_t mapping_color_space;
    uint8_t mapping_chroma_format_idc;
    AVDOVIReshapingCurve curves[3]; /* per component */

    /* Non-linear inverse quantization */
    enum AVDOVINLQMethod nlq_method_idc;
    uint32_t num_x_partitions;
    uint32_t num_y_partitions;
    AVDOVINLQParams nlq[3]; /* per component */
} AVDOVIDataMapping;

/**
 * Dolby Vision RPU colorspace metadata parameters.
 *
 * @note sizeof(AVDOVIColorMetadata) is not part of the public ABI.
 */
typedef struct AVDOVIColorMetadata {
    uint8_t dm_metadata_id;
    uint8_t scene_refresh_flag;

    /**
     * Coefficients of the custom Dolby Vision IPT-PQ matrices. These are to be
     * used instead of the matrices indicated by the frame's colorspace tags.
     * The output of rgb_to_lms_matrix is to be fed into a BT.2020 LMS->RGB
     * matrix based on a Hunt-Pointer-Estevez transform, but without any
     * crosstalk. (See the definition of the ICtCp colorspace for more
     * information.)
     */
    AVRational ycc_to_rgb_matrix[9]; /* before PQ linearization */
    AVRational ycc_to_rgb_offset[3]; /* input offset of neutral value */
    AVRational rgb_to_lms_matrix[9]; /* after PQ linearization */

    /**
     * Extra signal metadata (see Dolby patents for more info).
     */
    uint16_t signal_eotf;
    uint16_t signal_eotf_param0;
    uint16_t signal_eotf_param1;
    uint32_t signal_eotf_param2;
    uint8_t signal_bit_depth;
    uint8_t signal_color_space;
    uint8_t signal_chroma_format;
    uint8_t signal_full_range_flag; /* [0, 3] */
    uint16_t source_min_pq;
    uint16_t source_max_pq;
    uint16_t source_diagonal;
} AVDOVIColorMetadata;

/**
 * Combined struct representing a combination of header, mapping and color
 * metadata, for attaching to frames as side data.
 *
 * @note The struct must be allocated with av_dovi_metadata_alloc() and
 *       its size is not a part of the public ABI.
 */

typedef struct AVDOVIMetadata {
    /**
     * Offset in bytes from the beginning of this structure at which the
     * respective structs start.
     */
    size_t header_offset;   /* AVDOVIRpuDataHeader */
    size_t mapping_offset;  /* AVDOVIDataMapping */
    size_t color_offset;    /* AVDOVIColorMetadata */
} AVDOVIMetadata;

static av_always_inline AVDOVIRpuDataHeader *
av_dovi_get_header(const AVDOVIMetadata *data)
{
    return (AVDOVIRpuDataHeader *)((uint8_t *) data + data->header_offset);
}

static av_always_inline AVDOVIDataMapping *
av_dovi_get_mapping(const AVDOVIMetadata *data)
{
    return (AVDOVIDataMapping *)((uint8_t *) data + data->mapping_offset);
}

static av_always_inline AVDOVIColorMetadata *
av_dovi_get_color(const AVDOVIMetadata *data)
{
    return (AVDOVIColorMetadata *)((uint8_t *) data + data->color_offset);
}

/**
 * Allocate an AVDOVIMetadata structure and initialize its
 * fields to default values.
 *
 * @param size If this parameter is non-NULL, the size in bytes of the
 *             allocated struct will be written here on success
 *
 * @return the newly allocated struct or NULL on failure
 */
AVDOVIMetadata *av_dovi_metadata_alloc(size_t *size);

#endif /* AVUTIL_DOVI_META_H */
