vp9_blockd.h

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */


#ifndef VP9_COMMON_VP9_BLOCKD_H_
#define VP9_COMMON_VP9_BLOCKD_H_

#include "./vpx_config.h"
#include "vpx_scale/yv12config.h"
#include "vp9/common/vp9_convolve.h"
#include "vp9/common/vp9_mv.h"
#include "vp9/common/vp9_treecoder.h"
#include "vpx_ports/mem.h"
#include "vp9/common/vp9_common.h"
#include "vp9/common/vp9_enums.h"

// #define MODE_STATS

#define MB_FEATURE_TREE_PROBS   3
#define PREDICTION_PROBS 3

#define MBSKIP_CONTEXTS 3

#define MAX_MB_SEGMENTS         4

#define MAX_REF_LF_DELTAS       4
#define MAX_MODE_LF_DELTAS      4

/* Segment Feature Masks */
#define SEGMENT_DELTADATA   0
#define SEGMENT_ABSDATA     1
#define MAX_MV_REFS 9
#define MAX_MV_REF_CANDIDATES 4

typedef enum {
  PLANE_TYPE_Y_WITH_DC,
  PLANE_TYPE_UV,
} PLANE_TYPE;

typedef char ENTROPY_CONTEXT;
typedef struct {
  ENTROPY_CONTEXT y1[4];
  ENTROPY_CONTEXT u[2];
  ENTROPY_CONTEXT v[2];
} ENTROPY_CONTEXT_PLANES;

#define VP9_COMBINEENTROPYCONTEXTS(Dest, A, B) \
  Dest = ((A)!=0) + ((B)!=0);

typedef enum {
  KEY_FRAME = 0,
  INTER_FRAME = 1
} FRAME_TYPE;

typedef enum {
#if CONFIG_ENABLE_6TAP
  SIXTAP,
#endif
  EIGHTTAP_SMOOTH,
  EIGHTTAP,
  EIGHTTAP_SHARP,
  BILINEAR,
  SWITCHABLE  /* should be the last one */
} INTERPOLATIONFILTERTYPE;

typedef enum {
  DC_PRED,            /* average of above and left pixels */
  V_PRED,             /* vertical prediction */
  H_PRED,             /* horizontal prediction */
  D45_PRED,           /* Directional 45 deg prediction  [anti-clockwise from 0 deg hor] */
  D135_PRED,          /* Directional 135 deg prediction [anti-clockwise from 0 deg hor] */
  D117_PRED,          /* Directional 112 deg prediction [anti-clockwise from 0 deg hor] */
  D153_PRED,          /* Directional 157 deg prediction [anti-clockwise from 0 deg hor] */
  D27_PRED,           /* Directional 22 deg prediction  [anti-clockwise from 0 deg hor] */
  D63_PRED,           /* Directional 67 deg prediction  [anti-clockwise from 0 deg hor] */
  TM_PRED,            /* Truemotion prediction */
  I8X8_PRED,          /* 8x8 based prediction, each 8x8 has its own mode */
  I4X4_PRED,          /* 4x4 based prediction, each 4x4 has its own mode */
  NEARESTMV,
  NEARMV,
  ZEROMV,
  NEWMV,
  SPLITMV,
  MB_MODE_COUNT
} MB_PREDICTION_MODE;

// Segment level features.
typedef enum {
  SEG_LVL_ALT_Q = 0,               // Use alternate Quantizer ....
  SEG_LVL_ALT_LF = 1,              // Use alternate loop filter value...
  SEG_LVL_REF_FRAME = 2,           // Optional Segment reference frame
  SEG_LVL_SKIP = 3,                // Optional Segment (0,0) + skip mode
  SEG_LVL_MAX = 4                  // Number of MB level features supported
} SEG_LVL_FEATURES;

// Segment level features.
typedef enum {
  TX_4X4 = 0,                      // 4x4 dct transform
  TX_8X8 = 1,                      // 8x8 dct transform
  TX_16X16 = 2,                    // 16x16 dct transform
  TX_SIZE_MAX_MB = 3,              // Number of different transforms available
  TX_32X32 = TX_SIZE_MAX_MB,       // 32x32 dct transform
  TX_SIZE_MAX_SB,                  // Number of transforms available to SBs
} TX_SIZE;

typedef enum {
  DCT_DCT   = 0,                      // DCT  in both horizontal and vertical
  ADST_DCT  = 1,                      // ADST in vertical, DCT in horizontal
  DCT_ADST  = 2,                      // DCT  in vertical, ADST in horizontal
  ADST_ADST = 3                       // ADST in both directions
} TX_TYPE;

#define VP9_YMODES  (I4X4_PRED + 1)
#define VP9_UV_MODES (TM_PRED + 1)
#define VP9_I8X8_MODES (TM_PRED + 1)
#define VP9_I32X32_MODES (TM_PRED + 1)

#define VP9_MVREFS (1 + SPLITMV - NEARESTMV)

#define WHT_UPSCALE_FACTOR 2

typedef enum {
  B_DC_PRED,          /* average of above and left pixels */
  B_V_PRED,          /* vertical prediction */
  B_H_PRED,          /* horizontal prediction */
  B_D45_PRED,
  B_D135_PRED,
  B_D117_PRED,
  B_D153_PRED,
  B_D27_PRED,
  B_D63_PRED,
  B_TM_PRED,
#if CONFIG_NEWBINTRAMODES
  B_CONTEXT_PRED,
#endif

  LEFT4X4,
  ABOVE4X4,
  ZERO4X4,
  NEW4X4,

  B_MODE_COUNT
} B_PREDICTION_MODE;

#define VP9_BINTRAMODES (LEFT4X4)
#define VP9_SUBMVREFS (1 + NEW4X4 - LEFT4X4)

#if CONFIG_NEWBINTRAMODES
/* The number of I4X4_PRED intra modes that are replaced by B_CONTEXT_PRED */
#define CONTEXT_PRED_REPLACEMENTS  0
#define VP9_KF_BINTRAMODES (VP9_BINTRAMODES - 1)
#define VP9_NKF_BINTRAMODES  (VP9_BINTRAMODES - CONTEXT_PRED_REPLACEMENTS)
#else
#define VP9_KF_BINTRAMODES (VP9_BINTRAMODES)   /* 10 */
#define VP9_NKF_BINTRAMODES (VP9_BINTRAMODES)  /* 10 */
#endif

typedef enum {
  PARTITIONING_16X8 = 0,
  PARTITIONING_8X16,
  PARTITIONING_8X8,
  PARTITIONING_4X4,
  NB_PARTITIONINGS,
} SPLITMV_PARTITIONING_TYPE;

/* For keyframes, intra block modes are predicted by the (already decoded)
   modes for the Y blocks to the left and above us; for interframes, there
   is a single probability table. */

union b_mode_info {
  struct {
    B_PREDICTION_MODE first;
#if CONFIG_NEWBINTRAMODES
    B_PREDICTION_MODE context;
#endif
  } as_mode;
  int_mv as_mv[2];  // first, second inter predictor motion vectors
};

typedef enum {
  NONE = -1,
  INTRA_FRAME = 0,
  LAST_FRAME = 1,
  GOLDEN_FRAME = 2,
  ALTREF_FRAME = 3,
  MAX_REF_FRAMES = 4
} MV_REFERENCE_FRAME;

static INLINE int mb_width_log2(BLOCK_SIZE_TYPE sb_type) {
  switch (sb_type) {
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB16X32:
#endif
    case BLOCK_SIZE_MB16X16: return 0;
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB32X16:
    case BLOCK_SIZE_SB32X64:
#endif
    case BLOCK_SIZE_SB32X32: return 1;
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB64X32:
#endif
    case BLOCK_SIZE_SB64X64: return 2;
    default: assert(0);
  }
}

static INLINE int mb_height_log2(BLOCK_SIZE_TYPE sb_type) {
  switch (sb_type) {
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB32X16:
#endif
    case BLOCK_SIZE_MB16X16: return 0;
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB16X32:
    case BLOCK_SIZE_SB64X32:
#endif
    case BLOCK_SIZE_SB32X32: return 1;
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB32X64:
#endif
    case BLOCK_SIZE_SB64X64: return 2;
    default: assert(0);
  }
}

// parse block dimension in the unit of 4x4 blocks
static INLINE int b_width_log2(BLOCK_SIZE_TYPE sb_type) {
  return mb_width_log2(sb_type) + 2;
}

static INLINE int b_height_log2(BLOCK_SIZE_TYPE sb_type) {
  return mb_height_log2(sb_type) + 2;
}

typedef enum {
  BLOCK_4X4_LG2 = 0,
  BLOCK_8X8_LG2 = 2,
  BLOCK_16X16_LG2 = 4,
  BLOCK_32X32_LG2 = 6,
  BLOCK_64X64_LG2 = 8
} BLOCK_SIZE_LG2;

typedef struct {
  MB_PREDICTION_MODE mode, uv_mode;
#if CONFIG_COMP_INTERINTRA_PRED
  MB_PREDICTION_MODE interintra_mode, interintra_uv_mode;
#endif
  MV_REFERENCE_FRAME ref_frame, second_ref_frame;
  TX_SIZE txfm_size;
  int_mv mv[2]; // for each reference frame used
  int_mv ref_mvs[MAX_REF_FRAMES][MAX_MV_REF_CANDIDATES];
  int_mv best_mv, best_second_mv;
#if CONFIG_NEW_MVREF
  int best_index, best_second_index;
#endif

  int mb_mode_context[MAX_REF_FRAMES];

  SPLITMV_PARTITIONING_TYPE partitioning;
  unsigned char mb_skip_coeff;                                /* does this mb has coefficients at all, 1=no coefficients, 0=need decode tokens */
  unsigned char need_to_clamp_mvs;
  unsigned char need_to_clamp_secondmv;
  unsigned char segment_id;                  /* Which set of segmentation parameters should be used for this MB */

  // Flags used for prediction status of various bistream signals
  unsigned char seg_id_predicted;
  unsigned char ref_predicted;

  // Indicates if the mb is part of the image (1) vs border (0)
  // This can be useful in determining whether the MB provides
  // a valid predictor
  unsigned char mb_in_image;

  INTERPOLATIONFILTERTYPE interp_filter;

  BLOCK_SIZE_TYPE sb_type;
#if CONFIG_CODE_NONZEROCOUNT
  uint16_t nzcs[256+64*2];
#endif
} MB_MODE_INFO;

typedef struct {
  MB_MODE_INFO mbmi;
  union b_mode_info bmi[16];
} MODE_INFO;

typedef struct blockd {
  uint8_t *predictor;
  int16_t *diff;
  int16_t *dequant;

  /* 16 Y blocks, 4 U blocks, 4 V blocks each with 16 entries */
  uint8_t **base_pre;
  uint8_t **base_second_pre;
  int pre;
  int pre_stride;

  uint8_t **base_dst;
  int dst;
  int dst_stride;

  union b_mode_info bmi;
} BLOCKD;

struct scale_factors {
  int x_num;
  int x_den;
  int x_offset_q4;
  int x_step_q4;
  int y_num;
  int y_den;
  int y_offset_q4;
  int y_step_q4;

  int (*scale_value_x)(int val, const struct scale_factors *scale);
  int (*scale_value_y)(int val, const struct scale_factors *scale);
  void (*set_scaled_offsets)(struct scale_factors *scale, int row, int col);
  int_mv32 (*scale_motion_vector_q3_to_q4)(const int_mv *src_mv,
                                           const struct scale_factors *scale);
  int32_t (*scale_motion_vector_component_q4)(int mv_q4,
                                              int num,
                                              int den,
                                              int offset_q4);

#if CONFIG_IMPLICIT_COMPOUNDINTER_WEIGHT
  convolve_fn_t predict[2][2][8];  // horiz, vert, weight (0 - 7)
#else
  convolve_fn_t predict[2][2][2];  // horiz, vert, avg
#endif
};

enum { MAX_MB_PLANE = 3 };

struct mb_plane {
  DECLARE_ALIGNED(16, int16_t,  qcoeff[64 * 64]);
  DECLARE_ALIGNED(16, int16_t,  dqcoeff[64 * 64]);
  DECLARE_ALIGNED(16, uint16_t, eobs[256]);
  PLANE_TYPE plane_type;
  int subsampling_x;
  int subsampling_y;
};

#define BLOCK_OFFSET(x, i, n) ((x) + (i) * (n))

#define MB_SUBBLOCK_FIELD(x, field, i) (\
  ((i) < 16) ? BLOCK_OFFSET((x)->plane[0].field, (i), 16) : \
  ((i) < 20) ? BLOCK_OFFSET((x)->plane[1].field, ((i) - 16), 16) : \
  BLOCK_OFFSET((x)->plane[2].field, ((i) - 20), 16))

typedef struct macroblockd {
  DECLARE_ALIGNED(16, int16_t,  diff[64*64+32*32*2]);      /* from idct diff */
  DECLARE_ALIGNED(16, uint8_t,  predictor[384]);  // unused for superblocks
#if CONFIG_CODE_NONZEROCOUNT
  DECLARE_ALIGNED(16, uint16_t, nzcs[256+64*2]);
#endif
  struct mb_plane plane[MAX_MB_PLANE];

  /* 16 Y blocks, 4 U, 4 V, each with 16 entries. */
  BLOCKD block[24];

  YV12_BUFFER_CONFIG pre; /* Filtered copy of previous frame reconstruction */
  YV12_BUFFER_CONFIG second_pre;
  YV12_BUFFER_CONFIG dst;
  struct scale_factors scale_factor[2];
  struct scale_factors scale_factor_uv[2];

  MODE_INFO *prev_mode_info_context;
  MODE_INFO *mode_info_context;
  int mode_info_stride;

  FRAME_TYPE frame_type;

  int up_available;
  int left_available;
  int right_available;

  /* Y,U,V */
  ENTROPY_CONTEXT_PLANES *above_context;
  ENTROPY_CONTEXT_PLANES *left_context;

  /* 0 indicates segmentation at MB level is not enabled. Otherwise the individual bits indicate which features are active. */
  unsigned char segmentation_enabled;

  /* 0 (do not update) 1 (update) the macroblock segmentation map. */
  unsigned char update_mb_segmentation_map;

  /* 0 (do not update) 1 (update) the macroblock segmentation feature data. */
  unsigned char update_mb_segmentation_data;

  /* 0 (do not update) 1 (update) the macroblock segmentation feature data. */
  unsigned char mb_segment_abs_delta;

  /* Per frame flags that define which MB level features (such as quantizer or loop filter level) */
  /* are enabled and when enabled the proabilities used to decode the per MB flags in MB_MODE_INFO */

  // Probability Tree used to code Segment number
  vp9_prob mb_segment_tree_probs[MB_FEATURE_TREE_PROBS];
  vp9_prob mb_segment_mispred_tree_probs[MAX_MB_SEGMENTS];

#if CONFIG_NEW_MVREF
  vp9_prob mb_mv_ref_probs[MAX_REF_FRAMES][MAX_MV_REF_CANDIDATES-1];
#endif

  // Segment features
  signed char segment_feature_data[MAX_MB_SEGMENTS][SEG_LVL_MAX];
  unsigned int segment_feature_mask[MAX_MB_SEGMENTS];

  /* mode_based Loop filter adjustment */
  unsigned char mode_ref_lf_delta_enabled;
  unsigned char mode_ref_lf_delta_update;

  /* Delta values have the range +/- MAX_LOOP_FILTER */
  /* 0 = Intra, Last, GF, ARF */
  signed char last_ref_lf_deltas[MAX_REF_LF_DELTAS];
  /* 0 = Intra, Last, GF, ARF */
  signed char ref_lf_deltas[MAX_REF_LF_DELTAS];
  /* 0 = I4X4_PRED, ZERO_MV, MV, SPLIT */
  signed char last_mode_lf_deltas[MAX_MODE_LF_DELTAS];
  /* 0 = I4X4_PRED, ZERO_MV, MV, SPLIT */
  signed char mode_lf_deltas[MAX_MODE_LF_DELTAS];

  /* Distance of MB away from frame edges */
  int mb_to_left_edge;
  int mb_to_right_edge;
  int mb_to_top_edge;
  int mb_to_bottom_edge;

  unsigned int frames_since_golden;
  unsigned int frames_till_alt_ref_frame;

  int lossless;
  /* Inverse transform function pointers. */
  void (*inv_txm4x4_1)(int16_t *input, int16_t *output, int pitch);
  void (*inv_txm4x4)(int16_t *input, int16_t *output, int pitch);
  void (*itxm_add)(int16_t *input, const int16_t *dq, uint8_t *dest,
    int stride, int eob);
  void (*itxm_add_y_block)(int16_t *q, const int16_t *dq,
    uint8_t *dst, int stride, struct macroblockd *xd);
  void (*itxm_add_uv_block)(int16_t *q, const int16_t *dq,
    uint8_t *dst, int stride, uint16_t *eobs);

  struct subpix_fn_table  subpix;

  int allow_high_precision_mv;

  int corrupted;

  int sb_index;
  int mb_index;   // Index of the MB in the SB (0..3)
  int q_index;

} MACROBLOCKD;

#define ACTIVE_HT   110                // quantization stepsize threshold

#define ACTIVE_HT8  300

#define ACTIVE_HT16 300

// convert MB_PREDICTION_MODE to B_PREDICTION_MODE
static B_PREDICTION_MODE pred_mode_conv(MB_PREDICTION_MODE mode) {
  switch (mode) {
    case DC_PRED: return B_DC_PRED;
    case V_PRED: return B_V_PRED;
    case H_PRED: return B_H_PRED;
    case TM_PRED: return B_TM_PRED;
    case D45_PRED: return B_D45_PRED;
    case D135_PRED: return B_D135_PRED;
    case D117_PRED: return B_D117_PRED;
    case D153_PRED: return B_D153_PRED;
    case D27_PRED: return B_D27_PRED;
    case D63_PRED: return B_D63_PRED;
    default:
       assert(0);
       return B_MODE_COUNT;  // Dummy value
  }
}

// transform mapping
static TX_TYPE txfm_map(B_PREDICTION_MODE bmode) {
  switch (bmode) {
    case B_TM_PRED :
    case B_D135_PRED :
      return ADST_ADST;

    case B_V_PRED :
    case B_D117_PRED :
      return ADST_DCT;

    case B_H_PRED :
    case B_D153_PRED :
    case B_D27_PRED :
      return DCT_ADST;

#if CONFIG_NEWBINTRAMODES
    case B_CONTEXT_PRED:
      assert(0);
      break;
#endif

    default:
      return DCT_DCT;
  }
}

extern const uint8_t vp9_block2left[TX_SIZE_MAX_MB][24];
extern const uint8_t vp9_block2above[TX_SIZE_MAX_MB][24];
extern const uint8_t vp9_block2left_sb[TX_SIZE_MAX_SB][96];
extern const uint8_t vp9_block2above_sb[TX_SIZE_MAX_SB][96];
extern const uint8_t vp9_block2left_sb64[TX_SIZE_MAX_SB][384];
extern const uint8_t vp9_block2above_sb64[TX_SIZE_MAX_SB][384];

#define USE_ADST_FOR_I16X16_8X8   1
#define USE_ADST_FOR_I16X16_4X4   1
#define USE_ADST_FOR_I8X8_4X4     1
#define USE_ADST_PERIPHERY_ONLY   1
#define USE_ADST_FOR_SB           1
#define USE_ADST_FOR_REMOTE_EDGE  0

static TX_TYPE get_tx_type_4x4(const MACROBLOCKD *xd, int ib) {
  // TODO(debargha): explore different patterns for ADST usage when blocksize
  // is smaller than the prediction size
  TX_TYPE tx_type = DCT_DCT;
  const BLOCK_SIZE_TYPE sb_type = xd->mode_info_context->mbmi.sb_type;
  const int wb = mb_width_log2(sb_type), hb = mb_height_log2(sb_type);
#if !USE_ADST_FOR_SB
  if (sb_type > BLOCK_SIZE_MB16X16)
    return tx_type;
#endif
  if (ib >= (16 << (wb + hb)))  // no chroma adst
    return tx_type;
  if (xd->lossless)
    return DCT_DCT;
  if (xd->mode_info_context->mbmi.mode == I4X4_PRED &&
      xd->q_index < ACTIVE_HT) {
    const BLOCKD *b = &xd->block[ib];
    tx_type = txfm_map(
#if CONFIG_NEWBINTRAMODES
        b->bmi.as_mode.first == B_CONTEXT_PRED ? b->bmi.as_mode.context :
#endif
        b->bmi.as_mode.first);
  } else if (xd->mode_info_context->mbmi.mode == I8X8_PRED &&
             xd->q_index < ACTIVE_HT) {
    const BLOCKD *b = &xd->block[ib];
    const int ic = (ib & 10);
#if USE_ADST_FOR_I8X8_4X4
#if USE_ADST_PERIPHERY_ONLY
    // Use ADST for periphery blocks only
    const int inner = ib & 5;
    b += ic - ib;
    tx_type = txfm_map(pred_mode_conv(
        (MB_PREDICTION_MODE)b->bmi.as_mode.first));
#if USE_ADST_FOR_REMOTE_EDGE
    if (inner == 5)
      tx_type = DCT_DCT;
#else
    if (inner == 1) {
      if (tx_type == ADST_ADST) tx_type = ADST_DCT;
      else if (tx_type == DCT_ADST) tx_type = DCT_DCT;
    } else if (inner == 4) {
      if (tx_type == ADST_ADST) tx_type = DCT_ADST;
      else if (tx_type == ADST_DCT) tx_type = DCT_DCT;
    } else if (inner == 5) {
      tx_type = DCT_DCT;
    }
#endif
#else
    // Use ADST
    b += ic - ib;
    tx_type = txfm_map(pred_mode_conv(
        (MB_PREDICTION_MODE)b->bmi.as_mode.first));
#endif
#else
    // Use 2D DCT
    tx_type = DCT_DCT;
#endif
  } else if (xd->mode_info_context->mbmi.mode < I8X8_PRED &&
             xd->q_index < ACTIVE_HT) {
#if USE_ADST_FOR_I16X16_4X4
#if USE_ADST_PERIPHERY_ONLY
    const int hmax = 4 << wb;
    tx_type = txfm_map(pred_mode_conv(xd->mode_info_context->mbmi.mode));
#if USE_ADST_FOR_REMOTE_EDGE
    if ((ib & (hmax - 1)) != 0 && ib >= hmax)
      tx_type = DCT_DCT;
#else
    if (ib >= 1 && ib < hmax) {
      if (tx_type == ADST_ADST) tx_type = ADST_DCT;
      else if (tx_type == DCT_ADST) tx_type = DCT_DCT;
    } else if (ib >= 1 && (ib & (hmax - 1)) == 0) {
      if (tx_type == ADST_ADST) tx_type = DCT_ADST;
      else if (tx_type == ADST_DCT) tx_type = DCT_DCT;
    } else if (ib != 0) {
      tx_type = DCT_DCT;
    }
#endif
#else
    // Use ADST
    tx_type = txfm_map(pred_mode_conv(xd->mode_info_context->mbmi.mode));
#endif
#else
    // Use 2D DCT
    tx_type = DCT_DCT;
#endif
  }
  return tx_type;
}

static TX_TYPE get_tx_type_8x8(const MACROBLOCKD *xd, int ib) {
  // TODO(debargha): explore different patterns for ADST usage when blocksize
  // is smaller than the prediction size
  TX_TYPE tx_type = DCT_DCT;
  const BLOCK_SIZE_TYPE sb_type = xd->mode_info_context->mbmi.sb_type;
  const int wb = mb_width_log2(sb_type), hb = mb_height_log2(sb_type);
#if !USE_ADST_FOR_SB
  if (sb_type > BLOCK_SIZE_MB16X16)
    return tx_type;
#endif
  if (ib >= (16 << (wb + hb)))  // no chroma adst
    return tx_type;
  if (xd->mode_info_context->mbmi.mode == I8X8_PRED &&
      xd->q_index < ACTIVE_HT8) {
    const BLOCKD *b = &xd->block[ib];
    // TODO(rbultje): MB_PREDICTION_MODE / B_PREDICTION_MODE should be merged
    // or the relationship otherwise modified to address this type conversion.
    tx_type = txfm_map(pred_mode_conv(
           (MB_PREDICTION_MODE)b->bmi.as_mode.first));
  } else if (xd->mode_info_context->mbmi.mode < I8X8_PRED &&
             xd->q_index < ACTIVE_HT8) {
#if USE_ADST_FOR_I16X16_8X8
#if USE_ADST_PERIPHERY_ONLY
    const int hmax = 4 << wb;
    tx_type = txfm_map(pred_mode_conv(xd->mode_info_context->mbmi.mode));
#if USE_ADST_FOR_REMOTE_EDGE
    if ((ib & (hmax - 1)) != 0 && ib >= hmax)
      tx_type = DCT_DCT;
#else
    if (ib >= 1 && ib < hmax) {
      if (tx_type == ADST_ADST) tx_type = ADST_DCT;
      else if (tx_type == DCT_ADST) tx_type = DCT_DCT;
    } else if (ib >= 1 && (ib & (hmax - 1)) == 0) {
      if (tx_type == ADST_ADST) tx_type = DCT_ADST;
      else if (tx_type == ADST_DCT) tx_type = DCT_DCT;
    } else if (ib != 0) {
      tx_type = DCT_DCT;
    }
#endif
#else
    // Use ADST
    tx_type = txfm_map(pred_mode_conv(xd->mode_info_context->mbmi.mode));
#endif
#else
    // Use 2D DCT
    tx_type = DCT_DCT;
#endif
  }
  return tx_type;
}

static TX_TYPE get_tx_type_16x16(const MACROBLOCKD *xd, int ib) {
  TX_TYPE tx_type = DCT_DCT;
  const BLOCK_SIZE_TYPE sb_type = xd->mode_info_context->mbmi.sb_type;
  const int wb = mb_width_log2(sb_type), hb = mb_height_log2(sb_type);
#if !USE_ADST_FOR_SB
  if (sb_type > BLOCK_SIZE_MB16X16)
    return tx_type;
#endif
  if (ib >= (16 << (wb + hb)))
    return tx_type;
  if (xd->mode_info_context->mbmi.mode < I8X8_PRED &&
      xd->q_index < ACTIVE_HT16) {
    tx_type = txfm_map(pred_mode_conv(xd->mode_info_context->mbmi.mode));
#if USE_ADST_PERIPHERY_ONLY
    if (sb_type > BLOCK_SIZE_MB16X16) {
      const int hmax = 4 << wb;
#if USE_ADST_FOR_REMOTE_EDGE
      if ((ib & (hmax - 1)) != 0 && ib >= hmax)
        tx_type = DCT_DCT;
#else
      if (ib >= 1 && ib < hmax) {
        if (tx_type == ADST_ADST) tx_type = ADST_DCT;
        else if (tx_type == DCT_ADST) tx_type = DCT_DCT;
      } else if (ib >= 1 && (ib & (hmax - 1)) == 0) {
        if (tx_type == ADST_ADST) tx_type = DCT_ADST;
        else if (tx_type == ADST_DCT) tx_type = DCT_DCT;
      } else if (ib != 0) {
        tx_type = DCT_DCT;
      }
#endif
    }
#endif
  }
  return tx_type;
}

void vp9_build_block_doffsets(MACROBLOCKD *xd);
void vp9_setup_block_dptrs(MACROBLOCKD *xd);

static void update_blockd_bmi(MACROBLOCKD *xd) {
  const MB_PREDICTION_MODE mode = xd->mode_info_context->mbmi.mode;

  if (mode == SPLITMV || mode == I8X8_PRED || mode == I4X4_PRED) {
    int i;
    for (i = 0; i < 16; i++)
      xd->block[i].bmi = xd->mode_info_context->bmi[i];
  }
}

static TX_SIZE get_uv_tx_size(const MACROBLOCKD *xd) {
  MB_MODE_INFO *mbmi = &xd->mode_info_context->mbmi;
  const TX_SIZE size = mbmi->txfm_size;
  const MB_PREDICTION_MODE mode = mbmi->mode;

  switch (mbmi->sb_type) {
    case BLOCK_SIZE_SB64X64:
      return size;
#if CONFIG_SBSEGMENT
    case BLOCK_SIZE_SB64X32:
    case BLOCK_SIZE_SB32X64:
#endif
    case BLOCK_SIZE_SB32X32:
      if (size == TX_32X32)
        return TX_16X16;
      else
        return size;
    default:
      if (size == TX_16X16)
        return TX_8X8;
      else if (size == TX_8X8 && (mode == I8X8_PRED || mode == SPLITMV))
        return TX_4X4;
      else
        return size;
  }

  return size;
}

#if CONFIG_CODE_NONZEROCOUNT
static int get_nzc_used(TX_SIZE tx_size) {
  return (tx_size >= TX_16X16);
}
#endif

struct plane_block_idx {
  int plane;
  int block;
};

// TODO(jkoleszar): returning a struct so it can be used in a const context,
// expect to refactor this further later.
static INLINE struct plane_block_idx plane_block_idx(int y_blocks,
                                                      int b_idx) {
  const int v_offset = y_blocks * 5 / 4;
  struct plane_block_idx res;

  if (b_idx < y_blocks) {
    res.plane = 0;
    res.block = b_idx;
  } else if (b_idx < v_offset) {
    res.plane = 1;
    res.block = b_idx - y_blocks;
  } else {
    assert(b_idx < y_blocks * 3 / 2);
    res.plane = 2;
    res.block = b_idx - v_offset;
  }
  return res;
}

/* TODO(jkoleszar): Probably best to remove instances that require this,
 * as the data likely becomes per-plane and stored in the per-plane structures.
 * This is a stub to work with the existing code.
 */
static INLINE int old_block_idx_4x4(MACROBLOCKD* const xd, int block_size_b,
                                    int plane, int i) {
  const int luma_blocks = 1 << block_size_b;
  assert(xd->plane[0].subsampling_x == 0);
  assert(xd->plane[0].subsampling_y == 0);
  assert(xd->plane[1].subsampling_x == 1);
  assert(xd->plane[1].subsampling_y == 1);
  assert(xd->plane[2].subsampling_x == 1);
  assert(xd->plane[2].subsampling_y == 1);
  return plane == 0 ? i :
         plane == 1 ? luma_blocks + i :
                      luma_blocks * 5 / 4 + i;
}

typedef void (*foreach_transformed_block_visitor)(int plane, int block,
                                                  int block_size_b,
                                                  int ss_txfrm_size,
                                                  void *arg);
static INLINE void foreach_transformed_block_in_plane(
    const MACROBLOCKD* const xd, int block_size, int plane,
    int is_split, foreach_transformed_block_visitor visit, void *arg) {
  // block and transform sizes, in number of 4x4 blocks log 2 ("*_b")
  // 4x4=0, 8x8=2, 16x16=4, 32x32=6, 64x64=8
  const TX_SIZE tx_size = xd->mode_info_context->mbmi.txfm_size;
  const int block_size_b = block_size;
  const int txfrm_size_b = tx_size * 2;

  // subsampled size of the block
  const int ss_sum = xd->plane[plane].subsampling_x +
                     xd->plane[plane].subsampling_y;
  const int ss_block_size = block_size_b - ss_sum;

  // size of the transform to use. scale the transform down if it's larger
  // than the size of the subsampled data, or forced externally by the mb mode.
  const int ss_max = MAX(xd->plane[plane].subsampling_x,
                         xd->plane[plane].subsampling_y);
  const int ss_txfrm_size = txfrm_size_b > ss_block_size || is_split
                                ? txfrm_size_b - ss_max * 2
                                : txfrm_size_b;

  // TODO(jkoleszar): 1 may not be correct here with larger chroma planes.
  const int inc = is_split ? 1 : (1 << ss_txfrm_size);
  int i;

  assert(txfrm_size_b <= block_size_b);
  assert(ss_txfrm_size <= ss_block_size);
  for (i = 0; i < (1 << ss_block_size); i += inc) {
    visit(plane, i, block_size_b, ss_txfrm_size, arg);
  }
}

static INLINE void foreach_transformed_block(
    const MACROBLOCKD* const xd, int block_size,
    foreach_transformed_block_visitor visit, void *arg) {
  const MB_PREDICTION_MODE mode = xd->mode_info_context->mbmi.mode;
  const int is_split =
      xd->mode_info_context->mbmi.txfm_size == TX_8X8 &&
      (mode == I8X8_PRED || mode == SPLITMV);
  int plane;

  for (plane = 0; plane < MAX_MB_PLANE; plane++) {
    const int is_split_chroma = is_split &&
         xd->plane[plane].plane_type == PLANE_TYPE_UV;

    foreach_transformed_block_in_plane(xd, block_size, plane, is_split_chroma,
                                       visit, arg);
  }
}

static INLINE void foreach_transformed_block_uv(
    const MACROBLOCKD* const xd, int block_size,
    foreach_transformed_block_visitor visit, void *arg) {
  const MB_PREDICTION_MODE mode = xd->mode_info_context->mbmi.mode;
  const int is_split =
      xd->mode_info_context->mbmi.txfm_size == TX_8X8 &&
      (mode == I8X8_PRED || mode == SPLITMV);
  int plane;

  for (plane = 1; plane < MAX_MB_PLANE; plane++) {
    foreach_transformed_block_in_plane(xd, block_size, plane, is_split,
                                       visit, arg);
  }
}

#endif  // VP9_COMMON_VP9_BLOCKD_H_