FFmpeg4/libavcodec/hevcdec.h

/*
 * HEVC video decoder
 *
 * Copyright (C) 2012 - 2013 Guillaume Martres
 *
 * 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 AVCODEC_HEVCDEC_H
#define AVCODEC_HEVCDEC_H

#include <stdatomic.h>

#include "libavutil/buffer.h"
#include "libavutil/md5.h"

#include "avcodec.h"
#include "bswapdsp.h"
#include "cabac.h"
#include "get_bits.h"
#include "hevcpred.h"
#include "h2645_parse.h"
#include "hevc.h"
#include "hevc_ps.h"
#include "hevc_sei.h"
#include "hevcdsp.h"
#include "internal.h"
#include "thread.h"
#include "videodsp.h"

#define MAX_NB_THREADS 16
#define SHIFT_CTB_WPP 2

//TODO: check if this is really the maximum
#define MAX_TRANSFORM_DEPTH 5

#define MAX_TB_SIZE 32
#define MAX_QP 51
#define DEFAULT_INTRA_TC_OFFSET 2

#define HEVC_CONTEXTS 199

#define MRG_MAX_NUM_CANDS     5

#define L0 0
#define L1 1

#define EPEL_EXTRA_BEFORE 1
#define EPEL_EXTRA_AFTER  2
#define EPEL_EXTRA        3
#define QPEL_EXTRA_BEFORE 3
#define QPEL_EXTRA_AFTER  4
#define QPEL_EXTRA        7

#define EDGE_EMU_BUFFER_STRIDE 80

/**
 * Value of the luma sample at position (x, y) in the 2D array tab.
 */
#define SAMPLE(tab, x, y) ((tab)[(y) * s->sps->width + (x)])
#define SAMPLE_CTB(tab, x, y) ((tab)[(y) * min_cb_width + (x)])

#define IS_IDR(s) ((s)->nal_unit_type == HEVC_NAL_IDR_W_RADL || (s)->nal_unit_type == HEVC_NAL_IDR_N_LP)
#define IS_BLA(s) ((s)->nal_unit_type == HEVC_NAL_BLA_W_RADL || (s)->nal_unit_type == HEVC_NAL_BLA_W_LP || \
                   (s)->nal_unit_type == HEVC_NAL_BLA_N_LP)
#define IS_IRAP(s) ((s)->nal_unit_type >= 16 && (s)->nal_unit_type <= 23)

enum RPSType {
    ST_CURR_BEF = 0,
    ST_CURR_AFT,
    ST_FOLL,
    LT_CURR,
    LT_FOLL,
    NB_RPS_TYPE,
};

enum SyntaxElement {
    SAO_MERGE_FLAG = 0,
    SAO_TYPE_IDX,
    SAO_EO_CLASS,
    SAO_BAND_POSITION,
    SAO_OFFSET_ABS,
    SAO_OFFSET_SIGN,
    END_OF_SLICE_FLAG,
    SPLIT_CODING_UNIT_FLAG,
    CU_TRANSQUANT_BYPASS_FLAG,
    SKIP_FLAG,
    CU_QP_DELTA,
    PRED_MODE_FLAG,
    PART_MODE,
    PCM_FLAG,
    PREV_INTRA_LUMA_PRED_FLAG,
    MPM_IDX,
    REM_INTRA_LUMA_PRED_MODE,
    INTRA_CHROMA_PRED_MODE,
    MERGE_FLAG,
    MERGE_IDX,
    INTER_PRED_IDC,
    REF_IDX_L0,
    REF_IDX_L1,
    ABS_MVD_GREATER0_FLAG,
    ABS_MVD_GREATER1_FLAG,
    ABS_MVD_MINUS2,
    MVD_SIGN_FLAG,
    MVP_LX_FLAG,
    NO_RESIDUAL_DATA_FLAG,
    SPLIT_TRANSFORM_FLAG,
    CBF_LUMA,
    CBF_CB_CR,
    TRANSFORM_SKIP_FLAG,
    EXPLICIT_RDPCM_FLAG,
    EXPLICIT_RDPCM_DIR_FLAG,
    LAST_SIGNIFICANT_COEFF_X_PREFIX,
    LAST_SIGNIFICANT_COEFF_Y_PREFIX,
    LAST_SIGNIFICANT_COEFF_X_SUFFIX,
    LAST_SIGNIFICANT_COEFF_Y_SUFFIX,
    SIGNIFICANT_COEFF_GROUP_FLAG,
    SIGNIFICANT_COEFF_FLAG,
    COEFF_ABS_LEVEL_GREATER1_FLAG,
    COEFF_ABS_LEVEL_GREATER2_FLAG,
    COEFF_ABS_LEVEL_REMAINING,
    COEFF_SIGN_FLAG,
    LOG2_RES_SCALE_ABS,
    RES_SCALE_SIGN_FLAG,
    CU_CHROMA_QP_OFFSET_FLAG,
    CU_CHROMA_QP_OFFSET_IDX,
};

enum PartMode {
    PART_2Nx2N = 0,
    PART_2NxN  = 1,
    PART_Nx2N  = 2,
    PART_NxN   = 3,
    PART_2NxnU = 4,
    PART_2NxnD = 5,
    PART_nLx2N = 6,
    PART_nRx2N = 7,
};

enum PredMode {
    MODE_INTER = 0,
    MODE_INTRA,
    MODE_SKIP,
};

enum InterPredIdc {
    PRED_L0 = 0,
    PRED_L1,
    PRED_BI,
};

enum PredFlag {
    PF_INTRA = 0,
    PF_L0,
    PF_L1,
    PF_BI,
};

enum IntraPredMode {
    INTRA_PLANAR = 0,
    INTRA_DC,
    INTRA_ANGULAR_2,
    INTRA_ANGULAR_3,
    INTRA_ANGULAR_4,
    INTRA_ANGULAR_5,
    INTRA_ANGULAR_6,
    INTRA_ANGULAR_7,
    INTRA_ANGULAR_8,
    INTRA_ANGULAR_9,
    INTRA_ANGULAR_10,
    INTRA_ANGULAR_11,
    INTRA_ANGULAR_12,
    INTRA_ANGULAR_13,
    INTRA_ANGULAR_14,
    INTRA_ANGULAR_15,
    INTRA_ANGULAR_16,
    INTRA_ANGULAR_17,
    INTRA_ANGULAR_18,
    INTRA_ANGULAR_19,
    INTRA_ANGULAR_20,
    INTRA_ANGULAR_21,
    INTRA_ANGULAR_22,
    INTRA_ANGULAR_23,
    INTRA_ANGULAR_24,
    INTRA_ANGULAR_25,
    INTRA_ANGULAR_26,
    INTRA_ANGULAR_27,
    INTRA_ANGULAR_28,
    INTRA_ANGULAR_29,
    INTRA_ANGULAR_30,
    INTRA_ANGULAR_31,
    INTRA_ANGULAR_32,
    INTRA_ANGULAR_33,
    INTRA_ANGULAR_34,
};

enum SAOType {
    SAO_NOT_APPLIED = 0,
    SAO_BAND,
    SAO_EDGE,
    SAO_APPLIED
};

enum SAOEOClass {
    SAO_EO_HORIZ = 0,
    SAO_EO_VERT,
    SAO_EO_135D,
    SAO_EO_45D,
};

enum ScanType {
    SCAN_DIAG = 0,
    SCAN_HORIZ,
    SCAN_VERT,
};

typedef struct LongTermRPS {
    int     poc[32];
    uint8_t poc_msb_present[32];
    uint8_t used[32];
    uint8_t nb_refs;
} LongTermRPS;

typedef struct RefPicList {
    struct HEVCFrame *ref[HEVC_MAX_REFS];
    int list[HEVC_MAX_REFS];
    int isLongTerm[HEVC_MAX_REFS];
    int nb_refs;
} RefPicList;

typedef struct RefPicListTab {
    RefPicList refPicList[2];
} RefPicListTab;

typedef struct SliceHeader {
    unsigned int pps_id;

    ///< address (in raster order) of the first block in the current slice segment
    unsigned int   slice_segment_addr;
    ///< address (in raster order) of the first block in the current slice
    unsigned int   slice_addr;

    enum HEVCSliceType slice_type;

    int pic_order_cnt_lsb;

    uint8_t first_slice_in_pic_flag;
    uint8_t dependent_slice_segment_flag;
    uint8_t pic_output_flag;
    uint8_t colour_plane_id;

    ///< RPS coded in the slice header itself is stored here
    int short_term_ref_pic_set_sps_flag;
    int short_term_ref_pic_set_size;
    ShortTermRPS slice_rps;
    const ShortTermRPS *short_term_rps;
    int long_term_ref_pic_set_size;
    LongTermRPS long_term_rps;
    unsigned int list_entry_lx[2][32];

    uint8_t rpl_modification_flag[2];
    uint8_t no_output_of_prior_pics_flag;
    uint8_t slice_temporal_mvp_enabled_flag;

    unsigned int nb_refs[2];

    uint8_t slice_sample_adaptive_offset_flag[3];
    uint8_t mvd_l1_zero_flag;

    uint8_t cabac_init_flag;
    uint8_t disable_deblocking_filter_flag; ///< slice_header_disable_deblocking_filter_flag
    uint8_t slice_loop_filter_across_slices_enabled_flag;
    uint8_t collocated_list;

    unsigned int collocated_ref_idx;

    int slice_qp_delta;
    int slice_cb_qp_offset;
    int slice_cr_qp_offset;

    uint8_t cu_chroma_qp_offset_enabled_flag;

    int beta_offset;    ///< beta_offset_div2 * 2
    int tc_offset;      ///< tc_offset_div2 * 2

    unsigned int max_num_merge_cand; ///< 5 - 5_minus_max_num_merge_cand

    unsigned *entry_point_offset;
    int * offset;
    int * size;
    int num_entry_point_offsets;

    int8_t slice_qp;

    uint8_t luma_log2_weight_denom;
    int16_t chroma_log2_weight_denom;

    int16_t luma_weight_l0[16];
    int16_t chroma_weight_l0[16][2];
    int16_t chroma_weight_l1[16][2];
    int16_t luma_weight_l1[16];

    int16_t luma_offset_l0[16];
    int16_t chroma_offset_l0[16][2];

    int16_t luma_offset_l1[16];
    int16_t chroma_offset_l1[16][2];

    int slice_ctb_addr_rs;
} SliceHeader;

typedef struct CodingUnit {
    int x;
    int y;

    enum PredMode pred_mode;    ///< PredMode
    enum PartMode part_mode;    ///< PartMode

    // Inferred parameters
    uint8_t intra_split_flag;   ///< IntraSplitFlag
    uint8_t max_trafo_depth;    ///< MaxTrafoDepth
    uint8_t cu_transquant_bypass_flag;
} CodingUnit;

typedef struct Mv {
    int16_t x;  ///< horizontal component of motion vector
    int16_t y;  ///< vertical component of motion vector
} Mv;

typedef struct MvField {
    DECLARE_ALIGNED(4, Mv, mv)[2];
    int8_t ref_idx[2];
    int8_t pred_flag;
} MvField;

typedef struct NeighbourAvailable {
    int cand_bottom_left;
    int cand_left;
    int cand_up;
    int cand_up_left;
    int cand_up_right;
    int cand_up_right_sap;
} NeighbourAvailable;

typedef struct PredictionUnit {
    int mpm_idx;
    int rem_intra_luma_pred_mode;
    uint8_t intra_pred_mode[4];
    Mv mvd;
    uint8_t merge_flag;
    uint8_t intra_pred_mode_c[4];
    uint8_t chroma_mode_c[4];
} PredictionUnit;

typedef struct TransformUnit {
    int cu_qp_delta;

    int res_scale_val;

    // Inferred parameters;
    int intra_pred_mode;
    int intra_pred_mode_c;
    int chroma_mode_c;
    uint8_t is_cu_qp_delta_coded;
    uint8_t is_cu_chroma_qp_offset_coded;
    int8_t  cu_qp_offset_cb;
    int8_t  cu_qp_offset_cr;
    uint8_t cross_pf;
} TransformUnit;

typedef struct DBParams {
    int beta_offset;
    int tc_offset;
} DBParams;

#define HEVC_FRAME_FLAG_OUTPUT    (1 << 0)
#define HEVC_FRAME_FLAG_SHORT_REF (1 << 1)
#define HEVC_FRAME_FLAG_LONG_REF  (1 << 2)
#define HEVC_FRAME_FLAG_BUMPING   (1 << 3)

typedef struct HEVCFrame {
    AVFrame *frame;
    ThreadFrame tf;
    MvField *tab_mvf;
    RefPicList *refPicList;
    RefPicListTab **rpl_tab;
    int ctb_count;
    int poc;
    struct HEVCFrame *collocated_ref;

    AVBufferRef *tab_mvf_buf;
    AVBufferRef *rpl_tab_buf;
    AVBufferRef *rpl_buf;

    AVBufferRef *hwaccel_priv_buf;
    void *hwaccel_picture_private;

    /**
     * A sequence counter, so that old frames are output first
     * after a POC reset
     */
    uint16_t sequence;

    /**
     * A combination of HEVC_FRAME_FLAG_*
     */
    uint8_t flags;
} HEVCFrame;

typedef struct HEVCLocalContext {
    uint8_t cabac_state[HEVC_CONTEXTS];

    uint8_t stat_coeff[4];

    uint8_t first_qp_group;

    GetBitContext gb;
    CABACContext cc;

    int8_t qp_y;
    int8_t curr_qp_y;

    int qPy_pred;

    TransformUnit tu;

    uint8_t ctb_left_flag;
    uint8_t ctb_up_flag;
    uint8_t ctb_up_right_flag;
    uint8_t ctb_up_left_flag;
    int     end_of_tiles_x;
    int     end_of_tiles_y;
    /* +7 is for subpixel interpolation, *2 for high bit depths */
    DECLARE_ALIGNED(32, uint8_t, edge_emu_buffer)[(MAX_PB_SIZE + 7) * EDGE_EMU_BUFFER_STRIDE * 2];
    /* The extended size between the new edge emu buffer is abused by SAO */
    DECLARE_ALIGNED(32, uint8_t, edge_emu_buffer2)[(MAX_PB_SIZE + 7) * EDGE_EMU_BUFFER_STRIDE * 2];
    DECLARE_ALIGNED(32, int16_t, tmp)[MAX_PB_SIZE * MAX_PB_SIZE];

    int ct_depth;
    CodingUnit cu;
    PredictionUnit pu;
    NeighbourAvailable na;

#define BOUNDARY_LEFT_SLICE     (1 << 0)
#define BOUNDARY_LEFT_TILE      (1 << 1)
#define BOUNDARY_UPPER_SLICE    (1 << 2)
#define BOUNDARY_UPPER_TILE     (1 << 3)
    /* properties of the boundary of the current CTB for the purposes
     * of the deblocking filter */
    int boundary_flags;
} HEVCLocalContext;

typedef struct HEVCContext {
    const AVClass *c;  // needed by private avoptions
    AVCodecContext *avctx;

    struct HEVCContext  *sList[MAX_NB_THREADS];

    HEVCLocalContext    *HEVClcList[MAX_NB_THREADS];
    HEVCLocalContext    *HEVClc;

    uint8_t             threads_type;
    uint8_t             threads_number;

    int                 width;
    int                 height;

    uint8_t *cabac_state;

    /** 1 if the independent slice segment header was successfully parsed */
    uint8_t slice_initialized;

    AVFrame *frame;
    AVFrame *output_frame;
    uint8_t *sao_pixel_buffer_h[3];
    uint8_t *sao_pixel_buffer_v[3];

    HEVCParamSets ps;
    HEVCSEI sei;
    struct AVMD5 *md5_ctx;

    AVBufferPool *tab_mvf_pool;
    AVBufferPool *rpl_tab_pool;

    ///< candidate references for the current frame
    RefPicList rps[5];

    SliceHeader sh;
    SAOParams *sao;
    DBParams *deblock;
    enum HEVCNALUnitType nal_unit_type;
    int temporal_id;  ///< temporal_id_plus1 - 1
    HEVCFrame *ref;
    HEVCFrame DPB[32];
    int poc;
    int pocTid0;
    int slice_idx; ///< number of the slice being currently decoded
    int eos;       ///< current packet contains an EOS/EOB NAL
    int last_eos;  ///< last packet contains an EOS/EOB NAL
    int max_ra;
    int bs_width;
    int bs_height;
    int overlap;

    int is_decoded;
    int no_rasl_output_flag;

    HEVCPredContext hpc;
    HEVCDSPContext hevcdsp;
    VideoDSPContext vdsp;
    BswapDSPContext bdsp;
    int8_t *qp_y_tab;
    uint8_t *horizontal_bs;
    uint8_t *vertical_bs;

    int32_t *tab_slice_address;

    //  CU
    uint8_t *skip_flag;
    uint8_t *tab_ct_depth;
    // PU
    uint8_t *tab_ipm;

    uint8_t *cbf_luma; // cbf_luma of colocated TU
    uint8_t *is_pcm;

    // CTB-level flags affecting loop filter operation
    uint8_t *filter_slice_edges;

    /** used on BE to byteswap the lines for checksumming */
    uint8_t *checksum_buf;
    int      checksum_buf_size;

    /**
     * Sequence counters for decoded and output frames, so that old
     * frames are output first after a POC reset
     */
    uint16_t seq_decode;
    uint16_t seq_output;

    int enable_parallel_tiles;
    atomic_int wpp_err;

    const uint8_t *data;

    H2645Packet pkt;
    // type of the first VCL NAL of the current frame
    enum HEVCNALUnitType first_nal_type;

    uint8_t context_initialized;
    int is_nalff;           ///< this flag is != 0 if bitstream is encapsulated
                            ///< as a format defined in 14496-15
    int apply_defdispwin;

    int nal_length_size;    ///< Number of bytes used for nal length (1, 2 or 4)
    int nuh_layer_id;
} HEVCContext;

/**
 * Mark all frames in DPB as unused for reference.
 */
void ff_hevc_clear_refs(HEVCContext *s);

/**
 * Drop all frames currently in DPB.
 */
void ff_hevc_flush_dpb(HEVCContext *s);

RefPicList *ff_hevc_get_ref_list(HEVCContext *s, HEVCFrame *frame,
                                 int x0, int y0);

/**
 * Construct the reference picture sets for the current frame.
 */
int ff_hevc_frame_rps(HEVCContext *s);

/**
 * Construct the reference picture list(s) for the current slice.
 */
int ff_hevc_slice_rpl(HEVCContext *s);

void ff_hevc_save_states(HEVCContext *s, int ctb_addr_ts);
int ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts);
int ff_hevc_sao_merge_flag_decode(HEVCContext *s);
int ff_hevc_sao_type_idx_decode(HEVCContext *s);
int ff_hevc_sao_band_position_decode(HEVCContext *s);
int ff_hevc_sao_offset_abs_decode(HEVCContext *s);
int ff_hevc_sao_offset_sign_decode(HEVCContext *s);
int ff_hevc_sao_eo_class_decode(HEVCContext *s);
int ff_hevc_end_of_slice_flag_decode(HEVCContext *s);
int ff_hevc_cu_transquant_bypass_flag_decode(HEVCContext *s);
int ff_hevc_skip_flag_decode(HEVCContext *s, int x0, int y0,
                             int x_cb, int y_cb);
int ff_hevc_pred_mode_decode(HEVCContext *s);
int ff_hevc_split_coding_unit_flag_decode(HEVCContext *s, int ct_depth,
                                          int x0, int y0);
int ff_hevc_part_mode_decode(HEVCContext *s, int log2_cb_size);
int ff_hevc_pcm_flag_decode(HEVCContext *s);
int ff_hevc_prev_intra_luma_pred_flag_decode(HEVCContext *s);
int ff_hevc_mpm_idx_decode(HEVCContext *s);
int ff_hevc_rem_intra_luma_pred_mode_decode(HEVCContext *s);
int ff_hevc_intra_chroma_pred_mode_decode(HEVCContext *s);
int ff_hevc_merge_idx_decode(HEVCContext *s);
int ff_hevc_merge_flag_decode(HEVCContext *s);
int ff_hevc_inter_pred_idc_decode(HEVCContext *s, int nPbW, int nPbH);
int ff_hevc_ref_idx_lx_decode(HEVCContext *s, int num_ref_idx_lx);
int ff_hevc_mvp_lx_flag_decode(HEVCContext *s);
int ff_hevc_no_residual_syntax_flag_decode(HEVCContext *s);
int ff_hevc_split_transform_flag_decode(HEVCContext *s, int log2_trafo_size);
int ff_hevc_cbf_cb_cr_decode(HEVCContext *s, int trafo_depth);
int ff_hevc_cbf_luma_decode(HEVCContext *s, int trafo_depth);
int ff_hevc_log2_res_scale_abs(HEVCContext *s, int idx);
int ff_hevc_res_scale_sign_flag(HEVCContext *s, int idx);

/**
 * Get the number of candidate references for the current frame.
 */
int ff_hevc_frame_nb_refs(const HEVCContext *s);

int ff_hevc_set_new_ref(HEVCContext *s, AVFrame **frame, int poc);

static av_always_inline int ff_hevc_nal_is_nonref(enum HEVCNALUnitType type)
{
    switch (type) {
    case HEVC_NAL_TRAIL_N:
    case HEVC_NAL_TSA_N:
    case HEVC_NAL_STSA_N:
    case HEVC_NAL_RADL_N:
    case HEVC_NAL_RASL_N:
    case HEVC_NAL_VCL_N10:
    case HEVC_NAL_VCL_N12:
    case HEVC_NAL_VCL_N14:
        return 1;
    default: break;
    }
    return 0;
}

/**
 * Find next frame in output order and put a reference to it in frame.
 * @return 1 if a frame was output, 0 otherwise
 */
int ff_hevc_output_frame(HEVCContext *s, AVFrame *frame, int flush);

void ff_hevc_bump_frame(HEVCContext *s);

void ff_hevc_unref_frame(HEVCContext *s, HEVCFrame *frame, int flags);

void ff_hevc_set_neighbour_available(HEVCContext *s, int x0, int y0,
                                     int nPbW, int nPbH);
void ff_hevc_luma_mv_merge_mode(HEVCContext *s, int x0, int y0,
                                int nPbW, int nPbH, int log2_cb_size,
                                int part_idx, int merge_idx, MvField *mv);
void ff_hevc_luma_mv_mvp_mode(HEVCContext *s, int x0, int y0,
                              int nPbW, int nPbH, int log2_cb_size,
                              int part_idx, int merge_idx,
                              MvField *mv, int mvp_lx_flag, int LX);
void ff_hevc_set_qPy(HEVCContext *s, int xBase, int yBase,
                     int log2_cb_size);
void ff_hevc_deblocking_boundary_strengths(HEVCContext *s, int x0, int y0,
                                           int log2_trafo_size);
int ff_hevc_cu_qp_delta_sign_flag(HEVCContext *s);
int ff_hevc_cu_qp_delta_abs(HEVCContext *s);
int ff_hevc_cu_chroma_qp_offset_flag(HEVCContext *s);
int ff_hevc_cu_chroma_qp_offset_idx(HEVCContext *s);
void ff_hevc_hls_filter(HEVCContext *s, int x, int y, int ctb_size);
void ff_hevc_hls_filters(HEVCContext *s, int x_ctb, int y_ctb, int ctb_size);
void ff_hevc_hls_residual_coding(HEVCContext *s, int x0, int y0,
                                 int log2_trafo_size, enum ScanType scan_idx,
                                 int c_idx);

void ff_hevc_hls_mvd_coding(HEVCContext *s, int x0, int y0, int log2_cb_size);

extern const uint8_t ff_hevc_qpel_extra_before[4];
extern const uint8_t ff_hevc_qpel_extra_after[4];
extern const uint8_t ff_hevc_qpel_extra[4];

#endif /* AVCODEC_HEVCDEC_H */