/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

/*! \file
 * Declares various structs used to encode the current partition block.
 */
#ifndef AOM_AV1_ENCODER_BLOCK_H_
#define AOM_AV1_ENCODER_BLOCK_H_

#include "av1/common/blockd.h"
#include "av1/common/entropymv.h"
#include "av1/common/entropy.h"
#include "av1/common/enums.h"
#include "av1/common/mvref_common.h"

#include "av1/encoder/enc_enums.h"
#include "av1/encoder/mcomp_structs.h"
#if !CONFIG_REALTIME_ONLY
#include "av1/encoder/partition_cnn_weights.h"
#endif

#include "av1/encoder/hash_motion.h"

#ifdef __cplusplus
extern "C" {
#endif

//! Minimum linear dimension of a tpl block
#define MIN_TPL_BSIZE_1D 16
//! Maximum number of tpl block in a super block
#define MAX_TPL_BLK_IN_SB (MAX_SB_SIZE / MIN_TPL_BSIZE_1D)
//! Number of txfm hash records kept for the partition block.
#define RD_RECORD_BUFFER_LEN 8

/*! Maximum value taken by transform type probabilities */
#define MAX_TX_TYPE_PROB 1024
/*! \brief Superblock level encoder info
 *
 * SuperblockEnc stores superblock level information used by the encoder for
 * more efficient encoding. Currently this is mostly used to store TPL data
 * for the current superblock.
 */
typedef struct {
  //! Maximum partition size for the sb.
  BLOCK_SIZE min_partition_size;
  //! Minimum partition size for the sb.
  BLOCK_SIZE max_partition_size;

  /*****************************************************************************
   * \name TPL Info
   *
   * Information gathered from tpl_model at tpl block precision for the
   * superblock to speed up the encoding process..
   ****************************************************************************/
  /**@{*/
  //! Number of TPL blocks in this superblock.
  int tpl_data_count;
  //! TPL's estimate of inter cost for each tpl block.
  int64_t tpl_inter_cost[MAX_TPL_BLK_IN_SB * MAX_TPL_BLK_IN_SB];
  //! TPL's estimate of tpl cost for each tpl block.
  int64_t tpl_intra_cost[MAX_TPL_BLK_IN_SB * MAX_TPL_BLK_IN_SB];
  //! Motion vectors found by TPL model for each tpl block.
  int_mv tpl_mv[MAX_TPL_BLK_IN_SB * MAX_TPL_BLK_IN_SB][INTER_REFS_PER_FRAME];
  //! TPL's stride for the arrays in this struct.
  int tpl_stride;
  /**@}*/
} SuperBlockEnc;

/*! \brief Stores the best performing modes.
 */
typedef struct {
  //! The mbmi used to reconstruct the winner mode.
  MB_MODE_INFO mbmi;
  //! Rdstats of the winner mode.
  RD_STATS rd_cost;
  //! Rdcost of the winner mode
  int64_t rd;
  //! Luma rate of the winner mode.
  int rate_y;
  //! Chroma rate of the winner mode.
  int rate_uv;
  //! The color map needed to reconstruct palette mode.
  uint8_t color_index_map[MAX_SB_SQUARE];
  //! The current winner mode.
  THR_MODES mode_index;
} WinnerModeStats;

/*! \brief Each source plane of the current macroblock
 *
 * This struct also stores the txfm buffers and quantizer settings.
 */
typedef struct macroblock_plane {
  //! Stores source - pred so the txfm can be computed later
  int16_t *src_diff;
  //! Dequantized coefficients
  tran_low_t *dqcoeff;
  //! Quantized coefficients
  tran_low_t *qcoeff;
  //! Transformed coefficients
  tran_low_t *coeff;
  //! Location of the end of qcoeff (end of block).
  uint16_t *eobs;
  //! Contexts used to code the transform coefficients.
  uint8_t *txb_entropy_ctx;
  //! A buffer containing the source frame.
  struct buf_2d src;

  /*! \name Quantizer Settings
   *
   * \attention These are used/accessed only in the quantization process.
   * RDO does not and *must not* depend on any of these values.
   * All values below share the coefficient scale/shift used in TX.
   */
  /**@{*/
  //! Quantization step size used by AV1_XFORM_QUANT_FP.
  const int16_t *quant_fp_QTX;
  //! Offset used for rounding in the quantizer process by AV1_XFORM_QUANT_FP.
  const int16_t *round_fp_QTX;
  //! Quantization step size used by AV1_XFORM_QUANT_B.
  const int16_t *quant_QTX;
  //! Offset used for rounding in the quantizer process by AV1_XFORM_QUANT_B.
  const int16_t *round_QTX;
  //! Scale factor to shift coefficients toward zero. Only used by QUANT_B.
  const int16_t *quant_shift_QTX;
  //! Size of the quantization bin around 0. Only Used by QUANT_B
  const int16_t *zbin_QTX;
  //! Dequantizer
  const int16_t *dequant_QTX;
  /**@}*/
} MACROBLOCK_PLANE;

/*! \brief Costs for encoding the coefficients within a level.
 *
 * Covers everything including txb_skip, eob, dc_sign,
 */
typedef struct {
  //! Cost to skip txfm for the current txfm block.
  int txb_skip_cost[TXB_SKIP_CONTEXTS][2];
  /*! \brief Cost for encoding the base_eob of a level.
   *
   * Decoder uses base_eob to derive the base_level as base_eob := base_eob+1.
   */
  int base_eob_cost[SIG_COEF_CONTEXTS_EOB][3];
  /*! \brief Cost for encoding the base level of a coefficient.
   *
   * Decoder derives coeff_base as coeff_base := base_eob + 1.
   */
  int base_cost[SIG_COEF_CONTEXTS][8];
  /*! \brief Cost for encoding the last non-zero coefficient.
   *
   * Eob is derived from eob_extra at the decoder as eob := eob_extra + 1
   */
  int eob_extra_cost[EOB_COEF_CONTEXTS][2];
  //! Cost for encoding the dc_sign
  int dc_sign_cost[DC_SIGN_CONTEXTS][2];
  //! Cost for encoding an increment to the coefficient
  int lps_cost[LEVEL_CONTEXTS][COEFF_BASE_RANGE + 1 + COEFF_BASE_RANGE + 1];
} LV_MAP_COEFF_COST;

/*! \brief Costs for encoding the eob.
 */
typedef struct {
  //! eob_cost.
  int eob_cost[2][11];
} LV_MAP_EOB_COST;

/*! \brief Stores the transforms coefficients for the whole superblock.
 */
typedef struct {
  //! The transformed coefficients.
  tran_low_t *tcoeff[MAX_MB_PLANE];
  //! Where the transformed coefficients end.
  uint16_t *eobs[MAX_MB_PLANE];
  /*! \brief Transform block entropy contexts.
   *
   * Each element is used as a bit field.
   * - Bits 0~3: txb_skip_ctx
   * - Bits 4~5: dc_sign_ctx.
   */
  uint8_t *entropy_ctx[MAX_MB_PLANE];
} CB_COEFF_BUFFER;

/*! \brief Extended mode info derived from mbmi.
 */
typedef struct {
  // TODO(angiebird): Reduce the buffer size according to sb_type
  //! The reference mv list for the current block.
  CANDIDATE_MV ref_mv_stack[MODE_CTX_REF_FRAMES][USABLE_REF_MV_STACK_SIZE];
  //! The weights used to compute the ref mvs.
  uint16_t weight[MODE_CTX_REF_FRAMES][USABLE_REF_MV_STACK_SIZE];
  //! Number of ref mvs in the drl.
  uint8_t ref_mv_count[MODE_CTX_REF_FRAMES];
  //! Global mvs
  int_mv global_mvs[REF_FRAMES];
  //! Context used to encode the current mode.
  int16_t mode_context[MODE_CTX_REF_FRAMES];
} MB_MODE_INFO_EXT;

/*! \brief Stores best extended mode information at frame level.
 *
 * The frame level in here is used in bitstream preparation stage. The
 * information in \ref MB_MODE_INFO_EXT are copied to this struct to save
 * memory.
 */
typedef struct {
  //! \copydoc MB_MODE_INFO_EXT::ref_mv_stack
  CANDIDATE_MV ref_mv_stack[USABLE_REF_MV_STACK_SIZE];
  //! \copydoc MB_MODE_INFO_EXT::weight
  uint16_t weight[USABLE_REF_MV_STACK_SIZE];
  //! \copydoc MB_MODE_INFO_EXT::ref_mv_count
  uint8_t ref_mv_count;
  // TODO(Ravi/Remya): Reduce the buffer size of global_mvs
  //! \copydoc MB_MODE_INFO_EXT::global_mvs
  int_mv global_mvs[REF_FRAMES];
  //! \copydoc MB_MODE_INFO_EXT::mode_context
  int16_t mode_context;
  //! Offset of current coding block's coeff buffer relative to the sb.
  uint16_t cb_offset[PLANE_TYPES];
} MB_MODE_INFO_EXT_FRAME;

/*! \brief Inter-mode txfm results for a partition block.
 */
typedef struct {
  //! Txfm size used if the current mode is intra mode.
  TX_SIZE tx_size;
  //! Txfm sizes used if the current mode is inter mode.
  TX_SIZE inter_tx_size[INTER_TX_SIZE_BUF_LEN];
  //! Map showing which txfm block skips the txfm process.
  uint8_t blk_skip[MAX_MIB_SIZE * MAX_MIB_SIZE];
  //! Map showing the txfm types for each block.
  uint8_t tx_type_map[MAX_MIB_SIZE * MAX_MIB_SIZE];
  //! Rd_stats for the whole partition block.
  RD_STATS rd_stats;
  //! Hash value of the current record.
  uint32_t hash_value;
} MB_RD_INFO;

/*! \brief Hash records of the inter-mode transform results
 *
 * Hash records of the inter-mode transform results for a whole partition block
 * based on the residue. Since this operates on the partition block level, this
 * can give us a whole txfm partition tree.
 */
typedef struct {
  /*! Circular buffer that stores the inter-mode txfm results of a partition
   *  block.
   */
  MB_RD_INFO mb_rd_info[RD_RECORD_BUFFER_LEN];
  //! Index to insert the newest rd record.
  int index_start;
  //! Number of info stored in this record.
  int num;
  //! Hash function
  CRC32C crc_calculator;
} MB_RD_RECORD;

//! Number of compound rd stats
#define MAX_COMP_RD_STATS 64
/*! \brief Rdcost stats in compound mode.
 */
typedef struct {
  //! Rate of the compound modes.
  int32_t rate[COMPOUND_TYPES];
  //! Distortion of the compound modes.
  int64_t dist[COMPOUND_TYPES];
  //! Estimated rate of the compound modes.
  int32_t model_rate[COMPOUND_TYPES];
  //! Estimated distortion of the compound modes.
  int64_t model_dist[COMPOUND_TYPES];
  //! Rate need to send the mask type.
  int comp_rs2[COMPOUND_TYPES];
  //! Motion vector for each predictor.
  int_mv mv[2];
  //! Ref frame for each predictor.
  MV_REFERENCE_FRAME ref_frames[2];
  //! Current prediction mode.
  PREDICTION_MODE mode;
  //! Current interpolation filter.
  int_interpfilters filter;
  //! Refmv index in the drl.
  int ref_mv_idx;
  //! Whether the predictors are GLOBALMV.
  int is_global[2];
  //! Current parameters for interinter mode.
  INTERINTER_COMPOUND_DATA interinter_comp;
} COMP_RD_STATS;

/*! \brief Contains buffers used to speed up rdopt for obmc.
 *
 * See the comments for calc_target_weighted_pred for details.
 */
typedef struct {
  /*! \brief A new source weighted with the above and left predictors.
   *
   * Used to efficiently construct multiple obmc predictors during rdopt.
   */
  int32_t *wsrc;
  /*! \brief A new mask constructed from the original horz/vert mask.
   *
   * \copydetails wsrc
   */
  int32_t *mask;
  /*! \brief Prediction from the up predictor.
   *
   * Used to build the obmc predictor.
   */
  uint8_t *above_pred;
  /*! \brief Prediction from the up predictor.
   *
   * \copydetails above_pred
   */
  uint8_t *left_pred;
} OBMCBuffer;

/*! \brief Contains color maps used in palette mode.
 */
typedef struct {
  //! The best color map found.
  uint8_t best_palette_color_map[MAX_PALETTE_SQUARE];
  //! A temporary buffer used for k-means clustering.
  int kmeans_data_buf[2 * MAX_PALETTE_SQUARE];
} PALETTE_BUFFER;

/*! \brief Contains buffers used by av1_compound_type_rd()
 *
 * For sizes and alignment of these arrays, refer to
 * alloc_compound_type_rd_buffers() function.
 */
typedef struct {
  //! First prediction.
  uint8_t *pred0;
  //! Second prediction.
  uint8_t *pred1;
  //! Source - first prediction.
  int16_t *residual1;
  //! Second prediction - first prediction.
  int16_t *diff10;
  //! Backup of the best segmentation mask.
  uint8_t *tmp_best_mask_buf;
} CompoundTypeRdBuffers;

/*! \brief Holds some parameters related to partitioning schemes in AV1.
 */
// TODO(chiyotsai@google.com): Consolidate this with SIMPLE_MOTION_DATA_TREE
typedef struct {
#if !CONFIG_REALTIME_ONLY
  // The following 4 parameters are used for cnn-based partitioning on intra
  // frame.
  /*! \brief Current index on the partition block quad tree.
   *
   * Used to index into the cnn buffer for partition decision.
   */
  int quad_tree_idx;
  //! Whether the CNN buffer contains valid output.
  int cnn_output_valid;
  //! A buffer used by our segmentation CNN for intra-frame partitioning.
  float cnn_buffer[CNN_OUT_BUF_SIZE];
  //! log of the quantization parameter of the ancestor BLOCK_64X64.
  float log_q;
#endif

  /*! \brief Variance of the subblocks in the superblock.
   *
   * This is used by rt mode for variance based partitioning.
   * The indices corresponds to the following block sizes:
   * -   0    - 128x128
   * -  1-2   - 128x64
   * -  3-4   -  64x128
   * -  5-8   -  64x64
   * -  9-16  -  64x32
   * - 17-24  -  32x64
   * - 25-40  -  32x32
   * - 41-104 -  16x16
   */
  uint8_t variance_low[105];
} PartitionSearchInfo;

/*!\cond */
enum {
  /**
   * Do not prune transform depths.
   */
  TX_PRUNE_NONE = 0,
  /**
   * Prune largest transform (depth 0) based on NN model.
   */
  TX_PRUNE_LARGEST = 1,
  /**
   * Prune split transforms (depth>=1) based on NN model.
   */
  TX_PRUNE_SPLIT = 2,
} UENUM1BYTE(TX_PRUNE_TYPE);
/*!\endcond */

/*! \brief Defines the parameters used to perform txfm search.
 *
 * For the most part, this determines how various speed features are used.
 */
typedef struct {
  /*! \brief Whether to limit the intra txfm search type to the default txfm.
   *
   * This could either be a result of either sequence parameter or speed
   * features.
   */
  int use_default_intra_tx_type;

  /*! Probability threshold used for conditionally forcing tx type*/
  int default_inter_tx_type_prob_thresh;

  //! Whether to prune 2d transforms based on 1d transform results.
  int prune_2d_txfm_mode;

  /*! \brief Variable from \ref WinnerModeParams based on current eval mode.
   *
   * See the documentation for \ref WinnerModeParams for more detail.
   */
  unsigned int coeff_opt_thresholds[2];
  /*! \copydoc coeff_opt_thresholds */
  unsigned int tx_domain_dist_threshold;
  /*! \copydoc coeff_opt_thresholds */
  TX_SIZE_SEARCH_METHOD tx_size_search_method;
  /*! \copydoc coeff_opt_thresholds */
  unsigned int use_transform_domain_distortion;
  /*! \copydoc coeff_opt_thresholds */
  unsigned int skip_txfm_level;

  /*! \brief How to search for the optimal tx_size
   *
   * If ONLY_4X4, use TX_4X4; if TX_MODE_LARGEST, use the largest tx_size for
   * the current partition block; if TX_MODE_SELECT, search through the whole
   * tree.
   *
   * \attention
   * Although this looks suspicious similar to a bitstream element, this
   * tx_mode_search_type is only used internally by the encoder, and is *not*
   * written to the bitstream. It determines what kind of tx_mode would be
   * searched. For example, we might set it to TX_MODE_LARGEST to find a good
   * candidate, then code it as TX_MODE_SELECT.
   */
  TX_MODE tx_mode_search_type;

  /*!
   * Flag to enable/disable DC block prediction.
   */
  unsigned int predict_dc_level;

  /*!
   * Whether or not we should use the quantization matrix as weights for PSNR
   * during RD search.
   */
  int use_qm_dist_metric;

  /*!
   * Keep track of previous mode evaluation stage type. This will be used to
   * reset mb rd hash record when mode evaluation type changes.
   */
  int mode_eval_type;

#if !CONFIG_REALTIME_ONLY
  //! Indicates the transform depths for which RD evaluation is skipped.
  TX_PRUNE_TYPE nn_prune_depths_for_intra_tx;

  /*! \brief Indicates if NN model should be invoked to prune transform depths.
   *
   * Used to signal whether NN model should be evaluated to prune the R-D
   * evaluation of specific transform depths.
   */
  bool enable_nn_prune_intra_tx_depths;
#endif
} TxfmSearchParams;

/*!\cond */
#define MAX_NUM_8X8_TXBS ((MAX_MIB_SIZE >> 1) * (MAX_MIB_SIZE >> 1))
#define MAX_NUM_16X16_TXBS ((MAX_MIB_SIZE >> 2) * (MAX_MIB_SIZE >> 2))
#define MAX_NUM_32X32_TXBS ((MAX_MIB_SIZE >> 3) * (MAX_MIB_SIZE >> 3))
#define MAX_NUM_64X64_TXBS ((MAX_MIB_SIZE >> 4) * (MAX_MIB_SIZE >> 4))
/*!\endcond */

/*! \brief Stores various encoding/search decisions related to txfm search.
 *
 * This struct contains a cache of previous txfm results, and some buffers for
 * the current txfm decision.
 */
typedef struct {
  //! Whether to skip transform and quantization on a partition block level.
  int skip_txfm;

  /*! \brief Whether to skip transform and quantization on a txfm block level.
   *
   * Skips transform and quantization on a transform block level inside the
   * current partition block. Each element of this array is used as a bit-field.
   * So for example, the we are skipping on the luma plane, then the last bit
   * would be set to 1.
   */
  uint8_t blk_skip[MAX_MIB_SIZE * MAX_MIB_SIZE];

  /*! \brief Transform types inside the partition block
   *
   * Keeps a record of what kind of transform to use for each of the transform
   * block inside the partition block.
   * \attention The buffer here is *never* directly used. Instead, this just
   * allocates the memory for MACROBLOCKD::tx_type_map during rdopt on the
   * partition block. So if we need to save memory, we could move the allocation
   * to pick_sb_mode instead.
   */
  uint8_t tx_type_map_[MAX_MIB_SIZE * MAX_MIB_SIZE];

  //! Txfm hash records of inter-modes.
  MB_RD_RECORD *mb_rd_record;

  /*! \brief Number of txb splits.
   *
   * Keep track of how many times we've used split tx partition for transform
   * blocks. Somewhat misleadingly, this parameter doesn't actually keep track
   * of the count of the current block. Instead, it's a cumulative count across
   * of the whole frame. The main usage is that if txb_split_count is zero, then
   * we can signal TX_MODE_LARGEST at frame level.
   */
  // TODO(chiyotsai@google.com): Move this to a more appropriate location such
  // as ThreadData.
  unsigned int txb_split_count;
#if CONFIG_SPEED_STATS
  //! For debugging. Used to check how many txfm searches we are doing.
  unsigned int tx_search_count;
#endif  // CONFIG_SPEED_STATS
} TxfmSearchInfo;
#undef MAX_NUM_8X8_TXBS
#undef MAX_NUM_16X16_TXBS
#undef MAX_NUM_32X32_TXBS
#undef MAX_NUM_64X64_TXBS

/*! \brief Holds the entropy costs for various modes sent to the bitstream.
 *
 * \attention This does not include the costs for mv and transformed
 * coefficients.
 */
typedef struct {
  /*****************************************************************************
   * \name Partition Costs
   ****************************************************************************/
  /**@{*/
  //! Cost for coding the partition.
  int partition_cost[PARTITION_CONTEXTS][EXT_PARTITION_TYPES];
  /**@}*/

  /*****************************************************************************
   * \name Intra Costs: General
   ****************************************************************************/
  /**@{*/
  //! Luma mode cost for inter frame.
  int mbmode_cost[BLOCK_SIZE_GROUPS][INTRA_MODES];
  //! Luma mode cost for intra frame.
  int y_mode_costs[INTRA_MODES][INTRA_MODES][INTRA_MODES];
  //! Chroma mode cost
  int intra_uv_mode_cost[CFL_ALLOWED_TYPES][INTRA_MODES][UV_INTRA_MODES];
  //! filter_intra_cost
  int filter_intra_cost[BLOCK_SIZES_ALL][2];
  //! filter_intra_mode_cost
  int filter_intra_mode_cost[FILTER_INTRA_MODES];
  //! angle_delta_cost
  int angle_delta_cost[DIRECTIONAL_MODES][2 * MAX_ANGLE_DELTA + 1];

  //! Rate rate associated with each alpha codeword
  int cfl_cost[CFL_JOINT_SIGNS][CFL_PRED_PLANES][CFL_ALPHABET_SIZE];
  /**@}*/

  /*****************************************************************************
   * \name Intra Costs: Screen Contents
   ****************************************************************************/
  /**@{*/
  //! intrabc_cost
  int intrabc_cost[2];

  //! palette_y_size_cost
  int palette_y_size_cost[PALATTE_BSIZE_CTXS][PALETTE_SIZES];
  //! palette_uv_size_cost
  int palette_uv_size_cost[PALATTE_BSIZE_CTXS][PALETTE_SIZES];
  //! palette_y_color_cost
  int palette_y_color_cost[PALETTE_SIZES][PALETTE_COLOR_INDEX_CONTEXTS]
                          [PALETTE_COLORS];
  //! palette_uv_color_cost
  int palette_uv_color_cost[PALETTE_SIZES][PALETTE_COLOR_INDEX_CONTEXTS]
                           [PALETTE_COLORS];
  //! palette_y_mode_cost
  int palette_y_mode_cost[PALATTE_BSIZE_CTXS][PALETTE_Y_MODE_CONTEXTS][2];
  //! palette_uv_mode_cost
  int palette_uv_mode_cost[PALETTE_UV_MODE_CONTEXTS][2];
  /**@}*/

  /*****************************************************************************
   * \name Inter Costs: MV Modes
   ****************************************************************************/
  /**@{*/
  //! skip_mode_cost
  int skip_mode_cost[SKIP_MODE_CONTEXTS][2];
  //! newmv_mode_cost
  int newmv_mode_cost[NEWMV_MODE_CONTEXTS][2];
  //! zeromv_mode_cost
  int zeromv_mode_cost[GLOBALMV_MODE_CONTEXTS][2];
  //! refmv_mode_cost
  int refmv_mode_cost[REFMV_MODE_CONTEXTS][2];
  //! drl_mode_cost0
  int drl_mode_cost0[DRL_MODE_CONTEXTS][2];
  /**@}*/

  /*****************************************************************************
   * \name Inter Costs: Ref Frame Types
   ****************************************************************************/
  /**@{*/
  //! single_ref_cost
  int single_ref_cost[REF_CONTEXTS][SINGLE_REFS - 1][2];
  //! comp_inter_cost
  int comp_inter_cost[COMP_INTER_CONTEXTS][2];
  //! comp_ref_type_cost
  int comp_ref_type_cost[COMP_REF_TYPE_CONTEXTS]
                        [CDF_SIZE(COMP_REFERENCE_TYPES)];
  //! uni_comp_ref_cost
  int uni_comp_ref_cost[UNI_COMP_REF_CONTEXTS][UNIDIR_COMP_REFS - 1]
                       [CDF_SIZE(2)];
  /*! \brief Cost for signaling ref_frame[0] in bidir-comp mode
   *
   * Includes LAST_FRAME, LAST2_FRAME, LAST3_FRAME, and GOLDEN_FRAME.
   */
  int comp_ref_cost[REF_CONTEXTS][FWD_REFS - 1][2];
  /*! \brief Cost for signaling ref_frame[1] in bidir-comp mode
   *
   * Includes ALTREF_FRAME, ALTREF2_FRAME, and BWDREF_FRAME.
   */
  int comp_bwdref_cost[REF_CONTEXTS][BWD_REFS - 1][2];
  /**@}*/

  /*****************************************************************************
   * \name Inter Costs: Compound Types
   ****************************************************************************/
  /**@{*/
  //! intra_inter_cost
  int intra_inter_cost[INTRA_INTER_CONTEXTS][2];
  //! inter_compound_mode_cost
  int inter_compound_mode_cost[INTER_MODE_CONTEXTS][INTER_COMPOUND_MODES];
  //! compound_type_cost
  int compound_type_cost[BLOCK_SIZES_ALL][MASKED_COMPOUND_TYPES];
  //! wedge_idx_cost
  int wedge_idx_cost[BLOCK_SIZES_ALL][16];
  //! interintra_cost
  int interintra_cost[BLOCK_SIZE_GROUPS][2];
  //! wedge_interintra_cost
  int wedge_interintra_cost[BLOCK_SIZES_ALL][2];
  //! interintra_mode_cost
  int interintra_mode_cost[BLOCK_SIZE_GROUPS][INTERINTRA_MODES];
  /**@}*/

  /*****************************************************************************
   * \name Inter Costs: Compound Masks
   ****************************************************************************/
  /**@{*/
  //! comp_idx_cost
  int comp_idx_cost[COMP_INDEX_CONTEXTS][2];
  //! comp_group_idx_cost
  int comp_group_idx_cost[COMP_GROUP_IDX_CONTEXTS][2];
  /**@}*/

  /*****************************************************************************
   * \name Inter Costs: Motion Modes/Filters
   ****************************************************************************/
  /**@{*/
  //! motion_mode_cost
  int motion_mode_cost[BLOCK_SIZES_ALL][MOTION_MODES];
  //! motion_mode_cost1
  int motion_mode_cost1[BLOCK_SIZES_ALL][2];
  //! switchable_interp_costs
  int switchable_interp_costs[SWITCHABLE_FILTER_CONTEXTS][SWITCHABLE_FILTERS];
  /**@}*/

  /*****************************************************************************
   * \name Txfm Mode Costs
   ****************************************************************************/
  /**@{*/
  //! skip_txfm_cost
  int skip_txfm_cost[SKIP_CONTEXTS][2];
  //! tx_size_cost
  int tx_size_cost[TX_SIZES - 1][TX_SIZE_CONTEXTS][TX_SIZES];
  //! txfm_partition_cost
  int txfm_partition_cost[TXFM_PARTITION_CONTEXTS][2];
  //! inter_tx_type_costs
  int inter_tx_type_costs[EXT_TX_SETS_INTER][EXT_TX_SIZES][TX_TYPES];
  //! intra_tx_type_costs
  int intra_tx_type_costs[EXT_TX_SETS_INTRA][EXT_TX_SIZES][INTRA_MODES]
                         [TX_TYPES];
  /**@}*/

  /*****************************************************************************
   * \name Restoration Mode Costs
   ****************************************************************************/
  /**@{*/
  //! switchable_restore_cost
  int switchable_restore_cost[RESTORE_SWITCHABLE_TYPES];
  //! wiener_restore_cost
  int wiener_restore_cost[2];
  //! sgrproj_restore_cost
  int sgrproj_restore_cost[2];
  /**@}*/

  /*****************************************************************************
   * \name Segmentation Mode Costs
   ****************************************************************************/
  /**@{*/
  //! tmp_pred_cost
  int tmp_pred_cost[SEG_TEMPORAL_PRED_CTXS][2];
  //! spatial_pred_cost
  int spatial_pred_cost[SPATIAL_PREDICTION_PROBS][MAX_SEGMENTS];
  /**@}*/
} ModeCosts;

/*! \brief Holds mv costs for encoding and motion search.
 */
typedef struct {
  /*****************************************************************************
   * \name Encoding Costs
   * Here are the entropy costs needed to encode a given mv.
   * \ref nmv_cost_alloc and \ref nmv_cost_hp_alloc are two arrays that holds
   * the memory for holding the mv cost. But since the motion vectors can be
   * negative, we shift them to the middle and store the resulting pointer in
   * \ref nmv_cost and \ref nmv_cost_hp for easier referencing. Finally, \ref
   * mv_cost_stack points to the \ref nmv_cost with the mv precision we are
   * currently working with. In essence, only \ref mv_cost_stack is needed for
   * motion search, the other can be considered private.
   ****************************************************************************/
  /**@{*/
  //! Costs for coding the zero components.
  int nmv_joint_cost[MV_JOINTS];

  //! Allocates memory for 1/4-pel motion vector costs.
  int nmv_cost_alloc[2][MV_VALS];
  //! Allocates memory for 1/8-pel motion vector costs.
  int nmv_cost_hp_alloc[2][MV_VALS];
  //! Points to the middle of \ref nmv_cost_alloc
  int *nmv_cost[2];
  //! Points to the middle of \ref nmv_cost_hp_alloc
  int *nmv_cost_hp[2];
  //! Points to the nmv_cost_hp in use.
  int **mv_cost_stack;
  /**@}*/
} MvCosts;

/*! \brief Holds mv costs for intrabc.
 */
typedef struct {
  /*! Costs for coding the joint mv. */
  int joint_mv[MV_JOINTS];

  /*! \brief Cost of transmitting the actual motion vector.
   *  dv_costs_alloc[0][i] is the cost of motion vector with horizontal
   * component (mv_row) equal to i - MV_MAX. dv_costs_alloc[1][i] is the cost of
   * motion vector with vertical component (mv_col) equal to i - MV_MAX.
   */
  int dv_costs_alloc[2][MV_VALS];

  /*! Points to the middle of \ref dv_costs_alloc. */
  int *dv_costs[2];
} IntraBCMVCosts;

/*! \brief Holds the costs needed to encode the coefficients
 */
typedef struct {
  //! Costs for coding the coefficients.
  LV_MAP_COEFF_COST coeff_costs[TX_SIZES][PLANE_TYPES];
  //! Costs for coding the eobs.
  LV_MAP_EOB_COST eob_costs[7][2];
} CoeffCosts;

/*!\cond */
// 4: NEAREST, NEW, NEAR, GLOBAL
#define SINGLE_REF_MODES ((REF_FRAMES - 1) * 4)
/*!\endcond */
struct inter_modes_info;

/*! \brief Holds the motion samples for warp motion model estimation
 */
typedef struct {
  //! Number of samples.
  int num;
  //! Sample locations in current frame.
  int pts[16];
  //! Sample location in the reference frame.
  int pts_inref[16];
} WARP_SAMPLE_INFO;

/*!\cond */
typedef enum {
  kZeroSad = 0,
  kLowSad = 1,
  kMedSad = 2,
  kHighSad = 3
} SOURCE_SAD;

typedef struct {
  //! SAD levels in non-rd path for var-based part and inter-mode search
  SOURCE_SAD source_sad_nonrd;
  //! SAD levels in rd-path for var-based part qindex thresholds
  SOURCE_SAD source_sad_rd;
  int lighting_change;
  int low_sumdiff;
} CONTENT_STATE_SB;

// Structure to hold pixel level gradient info.
typedef struct {
  uint16_t abs_dx_abs_dy_sum;
  int8_t hist_bin_idx;
  bool is_dx_zero;
} PixelLevelGradientInfo;

// Structure to hold the variance and log(1 + variance) for 4x4 sub-blocks.
typedef struct {
  double log_var;
  int var;
} Block4x4VarInfo;

#ifndef NDEBUG
typedef struct SetOffsetsLoc {
  int mi_row;
  int mi_col;
  BLOCK_SIZE bsize;
} SetOffsetsLoc;
#endif  // NDEBUG

/*!\endcond */

/*! \brief Encoder's parameters related to the current coding block.
 *
 * This struct contains most of the information the encoder needs to encode the
 * current coding block. This includes the src and pred buffer, a copy of the
 * decoder's view of the current block, the txfm coefficients. This struct also
 * contains various buffers and data used to speed up the encoding process.
 */
typedef struct macroblock {
  /*****************************************************************************
   * \name Source, Buffers and Decoder
   ****************************************************************************/
  /**@{*/
  /*! \brief Each of the encoding plane.
   *
   * An array holding the src buffer for each of plane of the current block. It
   * also contains the txfm and quantized txfm coefficients.
   */
  struct macroblock_plane plane[MAX_MB_PLANE];

  /*! \brief Decoder's view of current coding block.
   *
   * Contains the encoder's copy of what the decoder sees in the current block.
   * Most importantly, this struct contains pointers to mbmi that is used in
   * final bitstream packing.
   */
  MACROBLOCKD e_mbd;

  /*! \brief Derived coding information.
   *
   * Contains extra information not transmitted in the bitstream but are
   * derived. For example, this contains the stack of ref_mvs.
   */
  MB_MODE_INFO_EXT mbmi_ext;

  /*! \brief Finalized mbmi_ext for the whole frame.
   *
   * Contains the finalized info in mbmi_ext that gets used at the frame level
   * for bitstream packing.
   */
  MB_MODE_INFO_EXT_FRAME *mbmi_ext_frame;

  //! Entropy context for the current row.
  FRAME_CONTEXT *row_ctx;
  /*! \brief Entropy context for the current tile.
   *
   * This context will be used to update color_map_cdf pointer which would be
   * used during pack bitstream. For single thread and tile-multithreading case
   * this pointer will be same as xd->tile_ctx, but for the case of row-mt:
   * xd->tile_ctx will point to a temporary context while tile_pb_ctx will point
   * to the accurate tile context.
   */
  FRAME_CONTEXT *tile_pb_ctx;

  /*! \brief Buffer of transformed coefficients
   *
   * Points to cb_coef_buff in the AV1_COMP struct, which contains the finalized
   * coefficients. This is here to conveniently copy the best coefficients to
   * frame level for bitstream packing. Since CB_COEFF_BUFFER is allocated on a
   * superblock level, we need to combine it with cb_offset to get the proper
   * position for the current coding block.
   */
  CB_COEFF_BUFFER *cb_coef_buff;
  //! Offset of current coding block's coeff buffer relative to the sb.
  uint16_t cb_offset[PLANE_TYPES];

  //! Modified source and masks used for fast OBMC search.
  OBMCBuffer obmc_buffer;
  //! Buffer to store the best palette map.
  PALETTE_BUFFER *palette_buffer;
  //! Buffer used for compound_type_rd().
  CompoundTypeRdBuffers comp_rd_buffer;
  //! Buffer to store convolution during averaging process in compound mode.
  CONV_BUF_TYPE *tmp_conv_dst;

  /*! \brief Temporary buffer to hold prediction.
   *
   * Points to a buffer that is used to hold temporary prediction results. This
   * is used in two ways:
   * - This is a temporary buffer used to ping-pong the prediction in
   *   handle_inter_mode.
   * - xd->tmp_obmc_bufs also points to this buffer, and is used in ombc
   *   prediction.
   */
  uint8_t *tmp_pred_bufs[2];
  /**@}*/

  /*****************************************************************************
   * \name Rdopt Costs
   ****************************************************************************/
  /**@{*/
  /*! \brief Quantization index for the current partition block.
   *
   * This is used to as the index to find quantization parameter for luma and
   * chroma transformed coefficients.
   */
  int qindex;

  /*! \brief Difference between frame-level qindex and current qindex.
   *
   *  This is used to track whether a non-zero delta for qindex is used at least
   *  once in the current frame.
   */
  int delta_qindex;

  /*! \brief Rate-distortion multiplier.
   *
   * The rd multiplier used to determine the rate-distortion trade-off. This is
   * roughly proportional to the inverse of q-index for a given frame, but this
   * can be manipulated for better rate-control. For example, in tune_ssim
   * mode, this is scaled by a factor related to the variance of the current
   * block.
   */
  int rdmult;

  //! Intra only, per sb rd adjustment.
  int intra_sb_rdmult_modifier;

  //! Superblock level distortion propagation factor.
  double rb;

  //! Energy in the current source coding block. Used to calculate \ref rdmult
  int mb_energy;
  //! Energy in the current source superblock. Used to calculate \ref rdmult
  int sb_energy_level;

  //! The rate needed to signal a mode to the bitstream.
  ModeCosts mode_costs;

  //! The rate needed to encode a new motion vector to the bitstream and some
  //! multipliers for motion search.
  MvCosts *mv_costs;

  /*! The rate needed to encode a new motion vector to the bitstream in intrabc
   *  mode.
   */
  IntraBCMVCosts *dv_costs;

  //! The rate needed to signal the txfm coefficients to the bitstream.
  CoeffCosts coeff_costs;
  /**@}*/

  /*****************************************************************************
   * \name Rate to Distortion Multipliers
   ****************************************************************************/
  /**@{*/
  //! A multiplier that converts mv cost to l2 error.
  int errorperbit;
  //! A multiplier that converts mv cost to l1 error.
  int sadperbit;
  /**@}*/

  /******************************************************************************
   * \name Segmentation
   *****************************************************************************/
  /**@{*/
  /*! \brief Skip mode for the segment
   *
   * A syntax element of the segmentation mode. In skip_block mode, all mvs are
   * set 0 and all txfms are skipped.
   */
  int seg_skip_block;

  /*! \brief Number of segment 1 blocks
   * Actual number of (4x4) blocks that were applied delta-q,
   * for segment 1.
   */
  int actual_num_seg1_blocks;

  /*!\brief Number of segment 2 blocks
   * Actual number of (4x4) blocks that were applied delta-q,
   * for segment 2.
   */
  int actual_num_seg2_blocks;

  /*!\brief Number of zero motion vectors
   */
  int cnt_zeromv;

  /*!\brief Flag to force zeromv-skip block, for nonrd path.
   */
  int force_zeromv_skip;

  /*! \brief Previous segment id for which qmatrices were updated.
   * This is used to bypass setting of qmatrices if no change in qindex.
   */
  int prev_segment_id;
  /**@}*/

  /*****************************************************************************
   * \name Superblock
   ****************************************************************************/
  /**@{*/
  //! Information on a whole superblock level.
  // TODO(chiyotsai@google.com): Refactor this out of macroblock
  SuperBlockEnc sb_enc;

  /*! \brief Characteristics of the current superblock.
   *
   *  Characteristics like whether the block has high sad, low sad, etc. This is
   *  only used by av1 realtime mode.
   */
  CONTENT_STATE_SB content_state_sb;
  /**@}*/

  /*****************************************************************************
   * \name Reference Frame Search
   ****************************************************************************/
  /**@{*/
  /*! \brief Sum absolute distortion of the predicted mv for each ref frame.
   *
   * This is used to measure how viable a reference frame is.
   */
  int pred_mv_sad[REF_FRAMES];
  /*! \brief The minimum of \ref pred_mv_sad.
   *
   * Index 0 stores the minimum \ref pred_mv_sad across past reference frames.
   * Index 1 stores the minimum \ref pred_mv_sad across future reference frames.
   */
  int best_pred_mv_sad[2];
  //! The sad of the 1st mv ref (nearest).
  int pred_mv0_sad[REF_FRAMES];
  //! The sad of the 2nd mv ref (near).
  int pred_mv1_sad[REF_FRAMES];

  /*! \brief Disables certain ref frame pruning based on tpl.
   *
   * Determines whether a given ref frame is "good" based on data from the TPL
   * model. If so, this stops selective_ref frame from pruning the given ref
   * frame at block level.
   */
  uint8_t tpl_keep_ref_frame[REF_FRAMES];

  /*! \brief Warp motion samples buffer.
   *
   * Store the motion samples used for warp motion.
   */
  WARP_SAMPLE_INFO warp_sample_info[REF_FRAMES];

  /*! \brief Reference frames picked by the square subblocks in a superblock.
   *
   * Keeps track of ref frames that are selected by square partition blocks
   * within a superblock, in MI resolution. They can be used to prune ref frames
   * for rectangular blocks.
   */
  int picked_ref_frames_mask[MAX_MIB_SIZE * MAX_MIB_SIZE];

  /*! \brief Prune ref frames in real-time mode.
   *
   * Determines whether to prune reference frames in real-time mode. For the
   * most part, this is the same as nonrd_prune_ref_frame_search in
   * cpi->sf.rt_sf.nonrd_prune_ref_frame_search, but this can be selectively
   * turned off if the only frame available is GOLDEN_FRAME.
   */
  int nonrd_prune_ref_frame_search;
  /**@}*/

  /*****************************************************************************
   * \name Partition Search
   ****************************************************************************/
  /**@{*/
  //! Stores some partition-search related buffers.
  PartitionSearchInfo part_search_info;

  /*! \brief Whether to disable some features to force a mode in current block.
   *
   * In some cases, our speed features can be overly aggressive and remove all
   * modes search in the superblock. When this happens, we set
   * must_find_valid_partition to 1 to reduce the number of speed features, and
   * recode the superblock again.
   */
  int must_find_valid_partition;
  /**@}*/

  /*****************************************************************************
   * \name Prediction Mode Search
   ****************************************************************************/
  /**@{*/
  /*! \brief Inter skip mode.
   *
   * Skip mode tries to use the closest forward and backward references for
   * inter prediction. Skip here means to skip transmitting the reference
   * frames, not to be confused with skip_txfm.
   */
  int skip_mode;

  /*! \brief Factors used for rd-thresholding.
   *
   * Determines a rd threshold to determine whether to continue searching the
   * current mode. If the current best rd is already <= threshold, then we skip
   * the current mode.
   */
  int thresh_freq_fact[BLOCK_SIZES_ALL][MAX_MODES];

  /*! \brief Tracks the winner modes in the current coding block.
   *
   * Winner mode is a two-pass strategy to find the best prediction mode. In the
   * first pass, we search the prediction modes with a limited set of txfm
   * options, and keep the top modes. These modes are called the winner modes.
   * In the second pass, we retry the winner modes with more thorough txfm
   * options.
   */
  WinnerModeStats *winner_mode_stats;
  //! Tracks how many winner modes there are.
  int winner_mode_count;

  /*! \brief The model used for rd-estimation to avoid txfm
   *
   * These are for inter_mode_rd_model_estimation, which is another two pass
   * approach. In this speed feature, we collect data in the first couple frames
   * to build an rd model to estimate the rdcost of a prediction model based on
   * the residue error. Once enough data is collected, this speed feature uses
   * the estimated rdcost to find the most performant prediction mode. Then we
   * follow up with a second pass find the best transform for the mode.
   * Determines if one would go with reduced complexity transform block
   * search model to select prediction modes, or full complexity model
   * to select transform kernel.
   */
  TXFM_RD_MODEL rd_model;

  /*! \brief Stores the inter mode information needed to build an rd model.
   *
   * These are for inter_mode_rd_model_estimation, which is another two pass
   * approach. In this speed feature, we collect data in the first couple frames
   * to build an rd model to estimate the rdcost of a prediction model based on
   * the residue error. Once enough data is collected, this speed feature uses
   * the estimated rdcost to find the most performant prediction mode. Then we
   * follow up with a second pass find the best transform for the mode.
   */
  // TODO(any): try to consolidate this speed feature with winner mode
  // processing.
  struct inter_modes_info *inter_modes_info;

  //! How to blend the compound predictions.
  uint8_t compound_idx;

  //! A caches of results of compound type search so they can be reused later.
  COMP_RD_STATS comp_rd_stats[MAX_COMP_RD_STATS];
  //! The idx for the latest compound mode in the cache \ref comp_rd_stats.
  int comp_rd_stats_idx;

  /*! \brief Whether to recompute the luma prediction.
   *
   * In interpolation search, we can usually skip recalculating the luma
   * prediction because it is already calculated by a previous predictor. This
   * flag signifies that some modes might have been skipped, so we need to
   * rebuild the prediction.
   */
  int recalc_luma_mc_data;

  /*! \brief Data structure to speed up intrabc search.
   *
   * Contains the hash table, hash function, and buffer used for intrabc.
   */
  IntraBCHashInfo intrabc_hash_info;

  /*! \brief Whether to reuse the mode stored in mb_mode_cache. */
  int use_mb_mode_cache;
  /*! \brief The mode to reuse during \ref av1_rd_pick_intra_mode_sb and
   *  \ref av1_rd_pick_inter_mode. */
  const MB_MODE_INFO *mb_mode_cache;
  /*! \brief Pointer to the buffer which caches gradient information.
   *
   * Pointer to the array of structures to store gradient information of each
   * pixel in a superblock. The buffer constitutes of MAX_SB_SQUARE pixel level
   * structures for each of the plane types (PLANE_TYPE_Y and PLANE_TYPE_UV).
   */
  PixelLevelGradientInfo *pixel_gradient_info;
  /*! \brief Flags indicating the availability of cached gradient info. */
  bool is_sb_gradient_cached[PLANE_TYPES];
  /**@}*/

  /*****************************************************************************
   * \name MV Search
   ****************************************************************************/
  /**@{*/
  /*! \brief Context used to determine the initial step size in motion search.
   *
   * This context is defined as the \f$l_\inf\f$ norm of the best ref_mvs for
   * each frame.
   */
  unsigned int max_mv_context[REF_FRAMES];

  /*! \brief Limit for the range of motion vectors.
   *
   * These define limits to motion vector components to prevent them from
   * extending outside the UMV borders
   */
  FullMvLimits mv_limits;

  /*! \brief Buffer for storing the search site config.
   *
   * When resize mode or super resolution mode is on, the stride of the
   * reference frame does not always match what's specified in \ref
   * MotionVectorSearchParams::search_site_cfg. When his happens, we update the
   * search_sine_config buffer here and use it for motion search.
   */
  search_site_config search_site_cfg_buf[NUM_DISTINCT_SEARCH_METHODS];
  /**@}*/

  /*****************************************************************************
   * \name Txfm Search
   ****************************************************************************/
  /**@{*/
  /*! \brief Parameters that control how motion search is done.
   *
   * Stores various txfm search related parameters such as txfm_type, txfm_size,
   * trellis eob search, etc.
   */
  TxfmSearchParams txfm_search_params;

  /*! \brief Results of the txfm searches that have been done.
   *
   * Caches old txfm search results and keeps the current txfm decisions to
   * facilitate rdopt.
   */
  TxfmSearchInfo txfm_search_info;

  /*! \brief Whether there is a strong color activity.
   *
   * Used in REALTIME coding mode to enhance the visual quality at the boundary
   * of moving color objects.
   */
  uint8_t color_sensitivity_sb[2];
  //! Color sensitivity flag for the coding block.
  uint8_t color_sensitivity[2];
  /**@}*/

  /*****************************************************************************
   * \name Misc
   ****************************************************************************/
  /**@{*/
  //! Variance of the source frame.
  unsigned int source_variance;
  //! SSE of the current predictor.
  unsigned int pred_sse[REF_FRAMES];
  //! Prediction for ML based partition.
#if CONFIG_RT_ML_PARTITIONING
  DECLARE_ALIGNED(16, uint8_t, est_pred[128 * 128]);
#endif
  /**@}*/

  /*! \brief NONE partition evaluated for merge.
   *
   * In variance based partitioning scheme, NONE & SPLIT partitions are
   * evaluated to check the SPLIT can be merged as NONE. This flag signifies the
   * partition is evaluated in the scheme.
   */
  int try_merge_partition;

  /*! \brief Pointer to buffer which caches sub-block variances in a superblock.
   *
   *  Pointer to the array of structures to store source variance information of
   *  each 4x4 sub-block in a superblock. Block4x4VarInfo structure is used to
   *  store source variance and log of source variance of each 4x4 sub-block.
   */
  Block4x4VarInfo *src_var_info_of_4x4_sub_blocks;
#ifndef NDEBUG
  /*! \brief A hash to make sure av1_set_offsets is called */
  SetOffsetsLoc last_set_offsets_loc;
#endif  // NDEBUG
} MACROBLOCK;
#undef SINGLE_REF_MODES

/*!\cond */
// Zeroes out 'n_stats' elements in the array x->winner_mode_stats.
// It only zeroes out what is necessary in 'color_index_map' (just the block
// size, not the whole array).
static INLINE void zero_winner_mode_stats(BLOCK_SIZE bsize, int n_stats,
                                          WinnerModeStats *stats) {
  // When winner mode stats are not required, the memory allocation is avoided
  // for x->winner_mode_stats. The stats pointer will be NULL in such cases.
  if (stats == NULL) return;

  const int block_height = block_size_high[bsize];
  const int block_width = block_size_wide[bsize];
  for (int i = 0; i < n_stats; ++i) {
    WinnerModeStats *const stat = &stats[i];
    memset(&stat->mbmi, 0, sizeof(stat->mbmi));
    memset(&stat->rd_cost, 0, sizeof(stat->rd_cost));
    memset(&stat->rd, 0, sizeof(stat->rd));
    memset(&stat->rate_y, 0, sizeof(stat->rate_y));
    memset(&stat->rate_uv, 0, sizeof(stat->rate_uv));
    // Do not reset the whole array as it is CPU intensive.
    memset(&stat->color_index_map, 0,
           block_width * block_height * sizeof(stat->color_index_map[0]));
    memset(&stat->mode_index, 0, sizeof(stat->mode_index));
  }
}

static INLINE int is_rect_tx_allowed_bsize(BLOCK_SIZE bsize) {
  static const char LUT[BLOCK_SIZES_ALL] = {
    0,  // BLOCK_4X4
    1,  // BLOCK_4X8
    1,  // BLOCK_8X4
    0,  // BLOCK_8X8
    1,  // BLOCK_8X16
    1,  // BLOCK_16X8
    0,  // BLOCK_16X16
    1,  // BLOCK_16X32
    1,  // BLOCK_32X16
    0,  // BLOCK_32X32
    1,  // BLOCK_32X64
    1,  // BLOCK_64X32
    0,  // BLOCK_64X64
    0,  // BLOCK_64X128
    0,  // BLOCK_128X64
    0,  // BLOCK_128X128
    1,  // BLOCK_4X16
    1,  // BLOCK_16X4
    1,  // BLOCK_8X32
    1,  // BLOCK_32X8
    1,  // BLOCK_16X64
    1,  // BLOCK_64X16
  };

  return LUT[bsize];
}

static INLINE int is_rect_tx_allowed(const MACROBLOCKD *xd,
                                     const MB_MODE_INFO *mbmi) {
  return is_rect_tx_allowed_bsize(mbmi->bsize) &&
         !xd->lossless[mbmi->segment_id];
}

static INLINE int tx_size_to_depth(TX_SIZE tx_size, BLOCK_SIZE bsize) {
  TX_SIZE ctx_size = max_txsize_rect_lookup[bsize];
  int depth = 0;
  while (tx_size != ctx_size) {
    depth++;
    ctx_size = sub_tx_size_map[ctx_size];
    assert(depth <= MAX_TX_DEPTH);
  }
  return depth;
}

static INLINE void set_blk_skip(uint8_t txb_skip[], int plane, int blk_idx,
                                int skip) {
  if (skip)
    txb_skip[blk_idx] |= 1UL << plane;
  else
    txb_skip[blk_idx] &= ~(1UL << plane);
#ifndef NDEBUG
  // Set chroma planes to uninitialized states when luma is set to check if
  // it will be set later
  if (plane == 0) {
    txb_skip[blk_idx] |= 1UL << (1 + 4);
    txb_skip[blk_idx] |= 1UL << (2 + 4);
  }

  // Clear the initialization checking bit
  txb_skip[blk_idx] &= ~(1UL << (plane + 4));
#endif
}

static INLINE int is_blk_skip(uint8_t *txb_skip, int plane, int blk_idx) {
#ifndef NDEBUG
  // Check if this is initialized
  assert(!(txb_skip[blk_idx] & (1UL << (plane + 4))));

  // The magic number is 0x77, this is to test if there is garbage data
  assert((txb_skip[blk_idx] & 0x88) == 0);
#endif
  return (txb_skip[blk_idx] >> plane) & 1;
}

/*!\endcond */

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  // AOM_AV1_ENCODER_BLOCK_H_