vp9/common/vp9_blockd.h - platform/external/libaom - Git at Google

 /*
  *  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_ports/mem.h"
 #include "vpx_scale/yv12config.h"

 #include "vp9/common/vp9_common.h"
 #include "vp9/common/vp9_common_data.h"
 #include "vp9/common/vp9_enums.h"
 #include "vp9/common/vp9_mv.h"
 #include "vp9/common/vp9_scale.h"
 #include "vp9/common/vp9_seg_common.h"
 #include "vp9/common/vp9_treecoder.h"

 #define BLOCK_SIZE_GROUPS   4
 #define MBSKIP_CONTEXTS 3

 /* Segment Feature Masks */
 #define MAX_MV_REF_CANDIDATES 2

 #define INTRA_INTER_CONTEXTS 4
 #define COMP_INTER_CONTEXTS 5
 #define REF_CONTEXTS 5

 typedef enum {
   PLANE_TYPE_Y_WITH_DC,
   PLANE_TYPE_UV,
 } PLANE_TYPE;

 typedef char ENTROPY_CONTEXT;

 typedef char PARTITION_CONTEXT;

 static INLINE int combine_entropy_contexts(ENTROPY_CONTEXT a,
                                            ENTROPY_CONTEXT b) {
   return (a != 0) + (b != 0);
 }

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

 typedef enum {
   EIGHTTAP = 0,
   EIGHTTAP_SMOOTH = 1,
   EIGHTTAP_SHARP = 2,
   BILINEAR = 3,
   SWITCHABLE = 4  /* should be the last one */
 } INTERPOLATIONFILTERTYPE;

 typedef enum {
   DC_PRED,         // Average of above and left pixels
   V_PRED,          // Vertical
   H_PRED,          // Horizontal
   D45_PRED,        // Directional 45  deg = round(arctan(1/1) * 180/pi)
   D135_PRED,       // Directional 135 deg = 180 - 45
   D117_PRED,       // Directional 117 deg = 180 - 63
   D153_PRED,       // Directional 153 deg = 180 - 27
   D27_PRED,        // Directional 27  deg = round(arctan(1/2) * 180/pi)
   D63_PRED,        // Directional 63  deg = round(arctan(2/1) * 180/pi)
   TM_PRED,         // True-motion
   NEARESTMV,
   NEARMV,
   ZEROMV,
   NEWMV,
   MB_MODE_COUNT
 } MB_PREDICTION_MODE;

 static INLINE int is_intra_mode(MB_PREDICTION_MODE mode) {
   return mode <= TM_PRED;
 }

 static INLINE int is_inter_mode(MB_PREDICTION_MODE mode) {
   return mode >= NEARESTMV && mode <= NEWMV;
 }

 #define VP9_INTRA_MODES (TM_PRED + 1)

 #define VP9_INTER_MODES (1 + NEWMV - NEARESTMV)

 static INLINE int inter_mode_offset(MB_PREDICTION_MODE mode) {
   return (mode - NEARESTMV);
 }

 /* 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 {
   MB_PREDICTION_MODE 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 b_width_log2(BLOCK_SIZE_TYPE sb_type) {
   return b_width_log2_lookup[sb_type];
 }
 static INLINE int b_height_log2(BLOCK_SIZE_TYPE sb_type) {
   return b_height_log2_lookup[sb_type];
 }

 static INLINE int mi_width_log2(BLOCK_SIZE_TYPE sb_type) {
   return mi_width_log2_lookup[sb_type];
 }

 static INLINE int mi_height_log2(BLOCK_SIZE_TYPE sb_type) {
   return mi_height_log2_lookup[sb_type];
 }

 // This structure now relates to 8x8 block regions.
 typedef struct {
   MB_PREDICTION_MODE mode, uv_mode;
   MV_REFERENCE_FRAME ref_frame[2];
   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;

   uint8_t mode_context[MAX_REF_FRAMES];

   unsigned char skip_coeff;    // 0=need to decode coeffs, 1=no coefficients
   unsigned char segment_id;    // Segment id for this block.

   // Flags used for prediction status of various bit-stream signals
   unsigned char seg_id_predicted;

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

   INTERPOLATIONFILTERTYPE interp_filter;

   BLOCK_SIZE_TYPE sb_type;
 } MB_MODE_INFO;

 typedef struct {
   MB_MODE_INFO mbmi;
   union b_mode_info bmi[4];
 } MODE_INFO;

 static INLINE int is_inter_block(const MB_MODE_INFO *mbmi) {
   return mbmi->ref_frame[0] > INTRA_FRAME;
 }

 static INLINE int has_second_ref(const MB_MODE_INFO *mbmi) {
   return mbmi->ref_frame[1] > INTRA_FRAME;
 }

 enum mv_precision {
   MV_PRECISION_Q3,
   MV_PRECISION_Q4
 };

 #if CONFIG_ALPHA
 enum { MAX_MB_PLANE = 4 };
 #else
 enum { MAX_MB_PLANE = 3 };
 #endif

 struct buf_2d {
   uint8_t *buf;
   int stride;
 };

 struct macroblockd_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;
   struct buf_2d dst;
   struct buf_2d pre[2];
   int16_t *dequant;
   ENTROPY_CONTEXT *above_context;
   ENTROPY_CONTEXT *left_context;
 };

 #define BLOCK_OFFSET(x, i) ((x) + (i) * 16)

 typedef struct macroblockd {
   struct macroblockd_plane plane[MAX_MB_PLANE];

   struct scale_factors scale_factor[2];

   MODE_INFO *prev_mode_info_context;
   MODE_INFO *mode_info_context;
   int mode_info_stride;

   int up_available;
   int left_available;
   int right_available;

   // partition contexts
   PARTITION_CONTEXT *above_seg_context;
   PARTITION_CONTEXT *left_seg_context;

   /* 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;

   int lossless;
   /* Inverse transform function pointers. */
   void (*inv_txm4x4_1_add)(int16_t *input, uint8_t *dest, int stride);
   void (*inv_txm4x4_add)(int16_t *input, uint8_t *dest, int stride);
   void (*itxm_add)(int16_t *input, uint8_t *dest, int stride, int eob);

   struct subpix_fn_table  subpix;

   int allow_high_precision_mv;

   int corrupted;

   unsigned char sb_index;   // index of 32x32 block inside the 64x64 block
   unsigned char mb_index;   // index of 16x16 block inside the 32x32 block
   unsigned char b_index;    // index of 8x8 block inside the 16x16 block
   unsigned char ab_index;   // index of 4x4 block inside the 8x8 block

   int q_index;

 } MACROBLOCKD;

 static INLINE unsigned char *get_sb_index(MACROBLOCKD *xd, BLOCK_SIZE_TYPE subsize) {
   switch (subsize) {
     case BLOCK_64X64:
     case BLOCK_64X32:
     case BLOCK_32X64:
     case BLOCK_32X32:
       return &xd->sb_index;
     case BLOCK_32X16:
     case BLOCK_16X32:
     case BLOCK_16X16:
       return &xd->mb_index;
     case BLOCK_16X8:
     case BLOCK_8X16:
     case BLOCK_8X8:
       return &xd->b_index;
     case BLOCK_8X4:
     case BLOCK_4X8:
     case BLOCK_4X4:
       return &xd->ab_index;
     default:
       assert(0);
       return NULL;
   }
 }

 static INLINE void update_partition_context(MACROBLOCKD *xd,
                                             BLOCK_SIZE_TYPE sb_type,
                                             BLOCK_SIZE_TYPE sb_size) {
   const int bsl = b_width_log2(sb_size), bs = (1 << bsl) / 2;
   const int bwl = b_width_log2(sb_type);
   const int bhl = b_height_log2(sb_type);
   const int boffset = b_width_log2(BLOCK_64X64) - bsl;
   const char pcval0 = ~(0xe << boffset);
   const char pcval1 = ~(0xf << boffset);
   const char pcvalue[2] = {pcval0, pcval1};

   assert(MAX(bwl, bhl) <= bsl);

   // update the partition context at the end notes. set partition bits
   // of block sizes larger than the current one to be one, and partition
   // bits of smaller block sizes to be zero.
   vpx_memset(xd->above_seg_context, pcvalue[bwl == bsl], bs);
   vpx_memset(xd->left_seg_context, pcvalue[bhl == bsl], bs);
 }

 static INLINE int partition_plane_context(MACROBLOCKD *xd,
                                           BLOCK_SIZE_TYPE sb_type) {
   int bsl = mi_width_log2(sb_type), bs = 1 << bsl;
   int above = 0, left = 0, i;
   int boffset = mi_width_log2(BLOCK_64X64) - bsl;

   assert(mi_width_log2(sb_type) == mi_height_log2(sb_type));
   assert(bsl >= 0);
   assert(boffset >= 0);

   for (i = 0; i < bs; i++)
     above |= (xd->above_seg_context[i] & (1 << boffset));
   for (i = 0; i < bs; i++)
     left |= (xd->left_seg_context[i] & (1 << boffset));

   above = (above > 0);
   left  = (left > 0);

   return (left * 2 + above) + bsl * PARTITION_PLOFFSET;
 }

 static BLOCK_SIZE_TYPE get_subsize(BLOCK_SIZE_TYPE bsize,
                                    PARTITION_TYPE partition) {
   const BLOCK_SIZE_TYPE subsize = subsize_lookup[partition][bsize];
   assert(subsize < BLOCK_SIZES);
   return subsize;
 }

 extern const TX_TYPE mode2txfm_map[MB_MODE_COUNT];

 static INLINE TX_TYPE get_tx_type_4x4(PLANE_TYPE plane_type,
                                       const MACROBLOCKD *xd, int ib) {
   const MODE_INFO *const mi = xd->mode_info_context;
   const MB_MODE_INFO *const mbmi = &mi->mbmi;

   if (plane_type != PLANE_TYPE_Y_WITH_DC ||
       xd->lossless ||
       is_inter_block(mbmi))
     return DCT_DCT;

   return mode2txfm_map[mbmi->sb_type < BLOCK_8X8 ?
                        mi->bmi[ib].as_mode : mbmi->mode];
 }

 static INLINE TX_TYPE get_tx_type_8x8(PLANE_TYPE plane_type,
                                       const MACROBLOCKD *xd) {
   return plane_type == PLANE_TYPE_Y_WITH_DC ?
              mode2txfm_map[xd->mode_info_context->mbmi.mode] : DCT_DCT;
 }

 static INLINE TX_TYPE get_tx_type_16x16(PLANE_TYPE plane_type,
                                         const MACROBLOCKD *xd) {
   return plane_type == PLANE_TYPE_Y_WITH_DC ?
              mode2txfm_map[xd->mode_info_context->mbmi.mode] : DCT_DCT;
 }

 static void setup_block_dptrs(MACROBLOCKD *xd, int ss_x, int ss_y) {
   int i;

   for (i = 0; i < MAX_MB_PLANE; i++) {
     xd->plane[i].plane_type = i ? PLANE_TYPE_UV : PLANE_TYPE_Y_WITH_DC;
     xd->plane[i].subsampling_x = i ? ss_x : 0;
     xd->plane[i].subsampling_y = i ? ss_y : 0;
   }
 #if CONFIG_ALPHA
   // TODO(jkoleszar): Using the Y w/h for now
   xd->plane[3].subsampling_x = 0;
   xd->plane[3].subsampling_y = 0;
 #endif
 }


 static INLINE TX_SIZE get_uv_tx_size(const MB_MODE_INFO *mbmi) {
   return MIN(mbmi->txfm_size, max_uv_txsize_lookup[mbmi->sb_type]);
 }

 static BLOCK_SIZE_TYPE get_plane_block_size(BLOCK_SIZE_TYPE bsize,
                            const struct macroblockd_plane *pd) {
   BLOCK_SIZE_TYPE bs = ss_size_lookup[bsize]
                                      [pd->subsampling_x][pd->subsampling_y];
   assert(bs < BLOCK_SIZES);
   return bs;
 }

 static INLINE int plane_block_width(BLOCK_SIZE_TYPE bsize,
                                     const struct macroblockd_plane* plane) {
   return 4 << (b_width_log2(bsize) - plane->subsampling_x);
 }

 static INLINE int plane_block_height(BLOCK_SIZE_TYPE bsize,
                                      const struct macroblockd_plane* plane) {
   return 4 << (b_height_log2(bsize) - plane->subsampling_y);
 }

 typedef void (*foreach_transformed_block_visitor)(int plane, int block,
                                                   BLOCK_SIZE_TYPE plane_bsize,
                                                   TX_SIZE tx_size,
                                                   void *arg);

 static INLINE void foreach_transformed_block_in_plane(
     const MACROBLOCKD *const xd, BLOCK_SIZE_TYPE bsize, int plane,
     foreach_transformed_block_visitor visit, void *arg) {
   const struct macroblockd_plane *const pd = &xd->plane[plane];
   const MB_MODE_INFO* mbmi = &xd->mode_info_context->mbmi;
   // block and transform sizes, in number of 4x4 blocks log 2 ("*_b")
   // 4x4=0, 8x8=2, 16x16=4, 32x32=6, 64x64=8
   // transform size varies per plane, look it up in a common way.
   const TX_SIZE tx_size = plane ? get_uv_tx_size(mbmi)
                                 : mbmi->txfm_size;
   const BLOCK_SIZE_TYPE plane_bsize = get_plane_block_size(bsize, pd);
   const int num_4x4_w = num_4x4_blocks_wide_lookup[plane_bsize];
   const int num_4x4_h = num_4x4_blocks_high_lookup[plane_bsize];
   const int step = 1 << (tx_size << 1);
   int i;

   // If mb_to_right_edge is < 0 we are in a situation in which
   // the current block size extends into the UMV and we won't
   // visit the sub blocks that are wholly within the UMV.
   if (xd->mb_to_right_edge < 0 || xd->mb_to_bottom_edge < 0) {
     int r, c;

     int max_blocks_wide = num_4x4_w;
     int max_blocks_high = num_4x4_h;

     // xd->mb_to_right_edge is in units of pixels * 8.  This converts
     // it to 4x4 block sizes.
     if (xd->mb_to_right_edge < 0)
       max_blocks_wide += (xd->mb_to_right_edge >> (5 + pd->subsampling_x));

     if (xd->mb_to_bottom_edge < 0)
       max_blocks_high += (xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));

     i = 0;
     // Unlike the normal case - in here we have to keep track of the
     // row and column of the blocks we use so that we know if we are in
     // the unrestricted motion border.
     for (r = 0; r < num_4x4_h; r += (1 << tx_size)) {
       for (c = 0; c < num_4x4_w; c += (1 << tx_size)) {
         if (r < max_blocks_high && c < max_blocks_wide)
           visit(plane, i, plane_bsize, tx_size, arg);
         i += step;
       }
     }
   } else {
     for (i = 0; i < num_4x4_w * num_4x4_h; i += step)
       visit(plane, i, plane_bsize, tx_size, arg);
   }
 }

 static INLINE void foreach_transformed_block(
     const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
     foreach_transformed_block_visitor visit, void *arg) {
   int plane;

   for (plane = 0; plane < MAX_MB_PLANE; plane++)
     foreach_transformed_block_in_plane(xd, bsize, plane, visit, arg);
 }

 static INLINE void foreach_transformed_block_uv(
     const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
     foreach_transformed_block_visitor visit, void *arg) {
   int plane;

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

 // TODO(jkoleszar): In principle, pred_w, pred_h are unnecessary, as we could
 // calculate the subsampled BLOCK_SIZE_TYPE, but that type isn't defined for
 // sizes smaller than 16x16 yet.
 typedef void (*foreach_predicted_block_visitor)(int plane, int block,
                                                 BLOCK_SIZE_TYPE bsize,
                                                 int pred_w, int pred_h,
                                                 void *arg);
 static INLINE void foreach_predicted_block_in_plane(
     const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize, int plane,
     foreach_predicted_block_visitor visit, void *arg) {
   int i, x, y;

   // block sizes in number of 4x4 blocks log 2 ("*_b")
   // 4x4=0, 8x8=2, 16x16=4, 32x32=6, 64x64=8
   // subsampled size of the block
   const int bwl = b_width_log2(bsize) - xd->plane[plane].subsampling_x;
   const int bhl = b_height_log2(bsize) - xd->plane[plane].subsampling_y;

   // size of the predictor to use.
   int pred_w, pred_h;

   if (xd->mode_info_context->mbmi.sb_type < BLOCK_8X8) {
     assert(bsize == BLOCK_8X8);
     pred_w = 0;
     pred_h = 0;
   } else {
     pred_w = bwl;
     pred_h = bhl;
   }
   assert(pred_w <= bwl);
   assert(pred_h <= bhl);

   // visit each subblock in raster order
   i = 0;
   for (y = 0; y < 1 << bhl; y += 1 << pred_h) {
     for (x = 0; x < 1 << bwl; x += 1 << pred_w) {
       visit(plane, i, bsize, pred_w, pred_h, arg);
       i += 1 << pred_w;
     }
     i += (1 << (bwl + pred_h)) - (1 << bwl);
   }
 }
 static INLINE void foreach_predicted_block(
     const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
     foreach_predicted_block_visitor visit, void *arg) {
   int plane;

   for (plane = 0; plane < MAX_MB_PLANE; plane++)
     foreach_predicted_block_in_plane(xd, bsize, plane, visit, arg);
 }

 static int raster_block_offset(BLOCK_SIZE_TYPE plane_bsize,
                                int raster_block, int stride) {
   const int bw = b_width_log2(plane_bsize);
   const int y = 4 * (raster_block >> bw);
   const int x = 4 * (raster_block & ((1 << bw) - 1));
   return y * stride + x;
 }
 static int16_t* raster_block_offset_int16(BLOCK_SIZE_TYPE plane_bsize,
                                           int raster_block, int16_t *base) {
   const int stride = 4 << b_width_log2(plane_bsize);
   return base + raster_block_offset(plane_bsize, raster_block, stride);
 }
 static uint8_t* raster_block_offset_uint8(BLOCK_SIZE_TYPE plane_bsize,
                                           int raster_block, uint8_t *base,
                                           int stride) {
   return base + raster_block_offset(plane_bsize, raster_block, stride);
 }

 static int txfrm_block_to_raster_block(BLOCK_SIZE_TYPE plane_bsize,
                                        TX_SIZE tx_size, int block) {
   const int bwl = b_width_log2(plane_bsize);
   const int tx_cols_log2 = bwl - tx_size;
   const int tx_cols = 1 << tx_cols_log2;
   const int raster_mb = block >> (tx_size << 1);
   const int x = (raster_mb & (tx_cols - 1)) << tx_size;
   const int y = (raster_mb >> tx_cols_log2) << tx_size;
   return x + (y << bwl);
 }

 static void txfrm_block_to_raster_xy(BLOCK_SIZE_TYPE plane_bsize,
                                      TX_SIZE tx_size, int block,
                                      int *x, int *y) {
   const int bwl = b_width_log2(plane_bsize);
   const int tx_cols_log2 = bwl - tx_size;
   const int tx_cols = 1 << tx_cols_log2;
   const int raster_mb = block >> (tx_size << 1);
   *x = (raster_mb & (tx_cols - 1)) << tx_size;
   *y = (raster_mb >> tx_cols_log2) << tx_size;
 }

 static void extend_for_intra(MACROBLOCKD* const xd, BLOCK_SIZE_TYPE plane_bsize,
                              int plane, int block, TX_SIZE tx_size) {
   struct macroblockd_plane *const pd = &xd->plane[plane];
   uint8_t *const buf = pd->dst.buf;
   const int stride = pd->dst.stride;

   int x, y;
   txfrm_block_to_raster_xy(plane_bsize, tx_size, block, &x, &y);
   x = x * 4 - 1;
   y = y * 4 - 1;
   // Copy a pixel into the umv if we are in a situation where the block size
   // extends into the UMV.
   // TODO(JBB): Should be able to do the full extend in place so we don't have
   // to do this multiple times.
   if (xd->mb_to_right_edge < 0) {
     const int bw = 4 << b_width_log2(plane_bsize);
     const int umv_border_start = bw + (xd->mb_to_right_edge >>
                                        (3 + pd->subsampling_x));

     if (x + bw > umv_border_start)
       vpx_memset(&buf[y * stride + umv_border_start],
                  buf[y * stride + umv_border_start - 1], bw);
   }

   if (xd->mb_to_bottom_edge < 0) {
     const int bh = 4 << b_height_log2(plane_bsize);
     const int umv_border_start = bh + (xd->mb_to_bottom_edge >>
                                        (3 + pd->subsampling_y));
     int i;
     const uint8_t c = buf[(umv_border_start - 1) * stride + x];
     uint8_t *d = &buf[umv_border_start * stride + x];

     if (y + bh > umv_border_start)
       for (i = 0; i < bh; ++i, d += stride)
         *d = c;
   }
 }
 static void set_contexts_on_border(MACROBLOCKD *xd,
                                    struct macroblockd_plane *pd,
                                    BLOCK_SIZE_TYPE plane_bsize,
                                    int tx_size_in_blocks, int has_eob,
                                    int aoff, int loff,
                                    ENTROPY_CONTEXT *A, ENTROPY_CONTEXT *L) {
   int mi_blocks_wide = num_4x4_blocks_wide_lookup[plane_bsize];
   int mi_blocks_high = num_4x4_blocks_high_lookup[plane_bsize];
   int above_contexts = tx_size_in_blocks;
   int left_contexts = tx_size_in_blocks;
   int pt;

   // xd->mb_to_right_edge is in units of pixels * 8.  This converts
   // it to 4x4 block sizes.
   if (xd->mb_to_right_edge < 0)
     mi_blocks_wide += (xd->mb_to_right_edge >> (5 + pd->subsampling_x));

   if (xd->mb_to_bottom_edge < 0)
     mi_blocks_high += (xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));

   // this code attempts to avoid copying into contexts that are outside
   // our border.  Any blocks that do are set to 0...
   if (above_contexts + aoff > mi_blocks_wide)
     above_contexts = mi_blocks_wide - aoff;

   if (left_contexts + loff > mi_blocks_high)
     left_contexts = mi_blocks_high - loff;

   for (pt = 0; pt < above_contexts; pt++)
     A[pt] = has_eob;
   for (pt = above_contexts; pt < tx_size_in_blocks; pt++)
     A[pt] = 0;
   for (pt = 0; pt < left_contexts; pt++)
     L[pt] = has_eob;
   for (pt = left_contexts; pt < tx_size_in_blocks; pt++)
     L[pt] = 0;
 }

 static void set_contexts(MACROBLOCKD *xd, struct macroblockd_plane *pd,
                          BLOCK_SIZE_TYPE plane_bsize, TX_SIZE tx_size,
                          int has_eob, int aoff, int loff) {
   ENTROPY_CONTEXT *const A = pd->above_context + aoff;
   ENTROPY_CONTEXT *const L = pd->left_context + loff;
   const int tx_size_in_blocks = 1 << tx_size;

   if (xd->mb_to_right_edge < 0 || xd->mb_to_bottom_edge < 0) {
     set_contexts_on_border(xd, pd, plane_bsize, tx_size_in_blocks, has_eob,
                            aoff, loff, A, L);
   } else {
     vpx_memset(A, has_eob, sizeof(ENTROPY_CONTEXT) * tx_size_in_blocks);
     vpx_memset(L, has_eob, sizeof(ENTROPY_CONTEXT) * tx_size_in_blocks);
   }
 }

 #endif  // VP9_COMMON_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_ports/mem.h"
	#include "vpx_scale/yv12config.h"

	#include "vp9/common/vp9_common.h"
	#include "vp9/common/vp9_common_data.h"
	#include "vp9/common/vp9_enums.h"
	#include "vp9/common/vp9_mv.h"
	#include "vp9/common/vp9_scale.h"
	#include "vp9/common/vp9_seg_common.h"
	#include "vp9/common/vp9_treecoder.h"

	#define BLOCK_SIZE_GROUPS 4
	#define MBSKIP_CONTEXTS 3

	/* Segment Feature Masks */
	#define MAX_MV_REF_CANDIDATES 2

	#define INTRA_INTER_CONTEXTS 4
	#define COMP_INTER_CONTEXTS 5
	#define REF_CONTEXTS 5

	typedef enum {
	PLANE_TYPE_Y_WITH_DC,
	PLANE_TYPE_UV,
	} PLANE_TYPE;

	typedef char ENTROPY_CONTEXT;

	typedef char PARTITION_CONTEXT;

	static INLINE int combine_entropy_contexts(ENTROPY_CONTEXT a,
	ENTROPY_CONTEXT b) {
	return (a != 0) + (b != 0);
	}

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

	typedef enum {
	EIGHTTAP = 0,
	EIGHTTAP_SMOOTH = 1,
	EIGHTTAP_SHARP = 2,
	BILINEAR = 3,
	SWITCHABLE = 4 /* should be the last one */
	} INTERPOLATIONFILTERTYPE;

	typedef enum {
	DC_PRED, // Average of above and left pixels
	V_PRED, // Vertical
	H_PRED, // Horizontal
	D45_PRED, // Directional 45 deg = round(arctan(1/1) * 180/pi)
	D135_PRED, // Directional 135 deg = 180 - 45
	D117_PRED, // Directional 117 deg = 180 - 63
	D153_PRED, // Directional 153 deg = 180 - 27
	D27_PRED, // Directional 27 deg = round(arctan(1/2) * 180/pi)
	D63_PRED, // Directional 63 deg = round(arctan(2/1) * 180/pi)
	TM_PRED, // True-motion
	NEARESTMV,
	NEARMV,
	ZEROMV,
	NEWMV,
	MB_MODE_COUNT
	} MB_PREDICTION_MODE;

	static INLINE int is_intra_mode(MB_PREDICTION_MODE mode) {
	return mode <= TM_PRED;
	}

	static INLINE int is_inter_mode(MB_PREDICTION_MODE mode) {
	return mode >= NEARESTMV && mode <= NEWMV;
	}

	#define VP9_INTRA_MODES (TM_PRED + 1)

	#define VP9_INTER_MODES (1 + NEWMV - NEARESTMV)

	static INLINE int inter_mode_offset(MB_PREDICTION_MODE mode) {
	return (mode - NEARESTMV);
	}

	/* 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 {
	MB_PREDICTION_MODE 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 b_width_log2(BLOCK_SIZE_TYPE sb_type) {
	return b_width_log2_lookup[sb_type];
	}
	static INLINE int b_height_log2(BLOCK_SIZE_TYPE sb_type) {
	return b_height_log2_lookup[sb_type];
	}

	static INLINE int mi_width_log2(BLOCK_SIZE_TYPE sb_type) {
	return mi_width_log2_lookup[sb_type];
	}

	static INLINE int mi_height_log2(BLOCK_SIZE_TYPE sb_type) {
	return mi_height_log2_lookup[sb_type];
	}

	// This structure now relates to 8x8 block regions.
	typedef struct {
	MB_PREDICTION_MODE mode, uv_mode;
	MV_REFERENCE_FRAME ref_frame[2];
	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;

	uint8_t mode_context[MAX_REF_FRAMES];

	unsigned char skip_coeff; // 0=need to decode coeffs, 1=no coefficients
	unsigned char segment_id; // Segment id for this block.

	// Flags used for prediction status of various bit-stream signals
	unsigned char seg_id_predicted;

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

	INTERPOLATIONFILTERTYPE interp_filter;

	BLOCK_SIZE_TYPE sb_type;
	} MB_MODE_INFO;

	typedef struct {
	MB_MODE_INFO mbmi;
	union b_mode_info bmi[4];
	} MODE_INFO;

	static INLINE int is_inter_block(const MB_MODE_INFO *mbmi) {
	return mbmi->ref_frame[0] > INTRA_FRAME;
	}

	static INLINE int has_second_ref(const MB_MODE_INFO *mbmi) {
	return mbmi->ref_frame[1] > INTRA_FRAME;
	}

	enum mv_precision {
	MV_PRECISION_Q3,
	MV_PRECISION_Q4
	};

	#if CONFIG_ALPHA
	enum { MAX_MB_PLANE = 4 };
	#else
	enum { MAX_MB_PLANE = 3 };
	#endif

	struct buf_2d {
	uint8_t *buf;
	int stride;
	};

	struct macroblockd_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;
	struct buf_2d dst;
	struct buf_2d pre[2];
	int16_t *dequant;
	ENTROPY_CONTEXT *above_context;
	ENTROPY_CONTEXT *left_context;
	};

	#define BLOCK_OFFSET(x, i) ((x) + (i) * 16)

	typedef struct macroblockd {
	struct macroblockd_plane plane[MAX_MB_PLANE];

	struct scale_factors scale_factor[2];

	MODE_INFO *prev_mode_info_context;
	MODE_INFO *mode_info_context;
	int mode_info_stride;

	int up_available;
	int left_available;
	int right_available;

	// partition contexts
	PARTITION_CONTEXT *above_seg_context;
	PARTITION_CONTEXT *left_seg_context;

	/* 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;

	int lossless;
	/* Inverse transform function pointers. */
	void (inv_txm4x4_1_add)(int16_t input, uint8_t *dest, int stride);
	void (inv_txm4x4_add)(int16_t input, uint8_t *dest, int stride);
	void (itxm_add)(int16_t input, uint8_t *dest, int stride, int eob);

	struct subpix_fn_table subpix;

	int allow_high_precision_mv;

	int corrupted;

	unsigned char sb_index; // index of 32x32 block inside the 64x64 block
	unsigned char mb_index; // index of 16x16 block inside the 32x32 block
	unsigned char b_index; // index of 8x8 block inside the 16x16 block
	unsigned char ab_index; // index of 4x4 block inside the 8x8 block

	int q_index;

	} MACROBLOCKD;

	static INLINE unsigned char get_sb_index(MACROBLOCKD xd, BLOCK_SIZE_TYPE subsize) {
	switch (subsize) {
	case BLOCK_64X64:
	case BLOCK_64X32:
	case BLOCK_32X64:
	case BLOCK_32X32:
	return &xd->sb_index;
	case BLOCK_32X16:
	case BLOCK_16X32:
	case BLOCK_16X16:
	return &xd->mb_index;
	case BLOCK_16X8:
	case BLOCK_8X16:
	case BLOCK_8X8:
	return &xd->b_index;
	case BLOCK_8X4:
	case BLOCK_4X8:
	case BLOCK_4X4:
	return &xd->ab_index;
	default:
	assert(0);
	return NULL;
	}
	}

	static INLINE void update_partition_context(MACROBLOCKD *xd,
	BLOCK_SIZE_TYPE sb_type,
	BLOCK_SIZE_TYPE sb_size) {
	const int bsl = b_width_log2(sb_size), bs = (1 << bsl) / 2;
	const int bwl = b_width_log2(sb_type);
	const int bhl = b_height_log2(sb_type);
	const int boffset = b_width_log2(BLOCK_64X64) - bsl;
	const char pcval0 = ~(0xe << boffset);
	const char pcval1 = ~(0xf << boffset);
	const char pcvalue[2] = {pcval0, pcval1};

	assert(MAX(bwl, bhl) <= bsl);

	// update the partition context at the end notes. set partition bits
	// of block sizes larger than the current one to be one, and partition
	// bits of smaller block sizes to be zero.
	vpx_memset(xd->above_seg_context, pcvalue[bwl == bsl], bs);
	vpx_memset(xd->left_seg_context, pcvalue[bhl == bsl], bs);
	}

	static INLINE int partition_plane_context(MACROBLOCKD *xd,
	BLOCK_SIZE_TYPE sb_type) {
	int bsl = mi_width_log2(sb_type), bs = 1 << bsl;
	int above = 0, left = 0, i;
	int boffset = mi_width_log2(BLOCK_64X64) - bsl;

	assert(mi_width_log2(sb_type) == mi_height_log2(sb_type));
	assert(bsl >= 0);
	assert(boffset >= 0);

	for (i = 0; i < bs; i++)
	above \|= (xd->above_seg_context[i] & (1 << boffset));
	for (i = 0; i < bs; i++)
	left \|= (xd->left_seg_context[i] & (1 << boffset));

	above = (above > 0);
	left = (left > 0);

	return (left * 2 + above) + bsl * PARTITION_PLOFFSET;
	}

	static BLOCK_SIZE_TYPE get_subsize(BLOCK_SIZE_TYPE bsize,
	PARTITION_TYPE partition) {
	const BLOCK_SIZE_TYPE subsize = subsize_lookup[partition][bsize];
	assert(subsize < BLOCK_SIZES);
	return subsize;
	}

	extern const TX_TYPE mode2txfm_map[MB_MODE_COUNT];

	static INLINE TX_TYPE get_tx_type_4x4(PLANE_TYPE plane_type,
	const MACROBLOCKD *xd, int ib) {
	const MODE_INFO *const mi = xd->mode_info_context;
	const MB_MODE_INFO *const mbmi = &mi->mbmi;

	if (plane_type != PLANE_TYPE_Y_WITH_DC \|\|
	xd->lossless \|\|
	is_inter_block(mbmi))
	return DCT_DCT;

	return mode2txfm_map[mbmi->sb_type < BLOCK_8X8 ?
	mi->bmi[ib].as_mode : mbmi->mode];
	}

	static INLINE TX_TYPE get_tx_type_8x8(PLANE_TYPE plane_type,
	const MACROBLOCKD *xd) {
	return plane_type == PLANE_TYPE_Y_WITH_DC ?
	mode2txfm_map[xd->mode_info_context->mbmi.mode] : DCT_DCT;
	}

	static INLINE TX_TYPE get_tx_type_16x16(PLANE_TYPE plane_type,
	const MACROBLOCKD *xd) {
	return plane_type == PLANE_TYPE_Y_WITH_DC ?
	mode2txfm_map[xd->mode_info_context->mbmi.mode] : DCT_DCT;
	}

	static void setup_block_dptrs(MACROBLOCKD *xd, int ss_x, int ss_y) {
	int i;

	for (i = 0; i < MAX_MB_PLANE; i++) {
	xd->plane[i].plane_type = i ? PLANE_TYPE_UV : PLANE_TYPE_Y_WITH_DC;
	xd->plane[i].subsampling_x = i ? ss_x : 0;
	xd->plane[i].subsampling_y = i ? ss_y : 0;
	}
	#if CONFIG_ALPHA
	// TODO(jkoleszar): Using the Y w/h for now
	xd->plane[3].subsampling_x = 0;
	xd->plane[3].subsampling_y = 0;
	#endif
	}


	static INLINE TX_SIZE get_uv_tx_size(const MB_MODE_INFO *mbmi) {
	return MIN(mbmi->txfm_size, max_uv_txsize_lookup[mbmi->sb_type]);
	}

	static BLOCK_SIZE_TYPE get_plane_block_size(BLOCK_SIZE_TYPE bsize,
	const struct macroblockd_plane *pd) {
	BLOCK_SIZE_TYPE bs = ss_size_lookup[bsize]
	[pd->subsampling_x][pd->subsampling_y];
	assert(bs < BLOCK_SIZES);
	return bs;
	}

	static INLINE int plane_block_width(BLOCK_SIZE_TYPE bsize,
	const struct macroblockd_plane* plane) {
	return 4 << (b_width_log2(bsize) - plane->subsampling_x);
	}

	static INLINE int plane_block_height(BLOCK_SIZE_TYPE bsize,
	const struct macroblockd_plane* plane) {
	return 4 << (b_height_log2(bsize) - plane->subsampling_y);
	}

	typedef void (*foreach_transformed_block_visitor)(int plane, int block,
	BLOCK_SIZE_TYPE plane_bsize,
	TX_SIZE tx_size,
	void *arg);

	static INLINE void foreach_transformed_block_in_plane(
	const MACROBLOCKD *const xd, BLOCK_SIZE_TYPE bsize, int plane,
	foreach_transformed_block_visitor visit, void *arg) {
	const struct macroblockd_plane *const pd = &xd->plane[plane];
	const MB_MODE_INFO* mbmi = &xd->mode_info_context->mbmi;
	// block and transform sizes, in number of 4x4 blocks log 2 ("*_b")
	// 4x4=0, 8x8=2, 16x16=4, 32x32=6, 64x64=8
	// transform size varies per plane, look it up in a common way.
	const TX_SIZE tx_size = plane ? get_uv_tx_size(mbmi)
	: mbmi->txfm_size;
	const BLOCK_SIZE_TYPE plane_bsize = get_plane_block_size(bsize, pd);
	const int num_4x4_w = num_4x4_blocks_wide_lookup[plane_bsize];
	const int num_4x4_h = num_4x4_blocks_high_lookup[plane_bsize];
	const int step = 1 << (tx_size << 1);
	int i;

	// If mb_to_right_edge is < 0 we are in a situation in which
	// the current block size extends into the UMV and we won't
	// visit the sub blocks that are wholly within the UMV.
	if (xd->mb_to_right_edge < 0 \|\| xd->mb_to_bottom_edge < 0) {
	int r, c;

	int max_blocks_wide = num_4x4_w;
	int max_blocks_high = num_4x4_h;

	// xd->mb_to_right_edge is in units of pixels * 8. This converts
	// it to 4x4 block sizes.
	if (xd->mb_to_right_edge < 0)
	max_blocks_wide += (xd->mb_to_right_edge >> (5 + pd->subsampling_x));

	if (xd->mb_to_bottom_edge < 0)
	max_blocks_high += (xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));

	i = 0;
	// Unlike the normal case - in here we have to keep track of the
	// row and column of the blocks we use so that we know if we are in
	// the unrestricted motion border.
	for (r = 0; r < num_4x4_h; r += (1 << tx_size)) {
	for (c = 0; c < num_4x4_w; c += (1 << tx_size)) {
	if (r < max_blocks_high && c < max_blocks_wide)
	visit(plane, i, plane_bsize, tx_size, arg);
	i += step;
	}
	}
	} else {
	for (i = 0; i < num_4x4_w * num_4x4_h; i += step)
	visit(plane, i, plane_bsize, tx_size, arg);
	}
	}

	static INLINE void foreach_transformed_block(
	const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
	foreach_transformed_block_visitor visit, void *arg) {
	int plane;

	for (plane = 0; plane < MAX_MB_PLANE; plane++)
	foreach_transformed_block_in_plane(xd, bsize, plane, visit, arg);
	}

	static INLINE void foreach_transformed_block_uv(
	const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
	foreach_transformed_block_visitor visit, void *arg) {
	int plane;

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

	// TODO(jkoleszar): In principle, pred_w, pred_h are unnecessary, as we could
	// calculate the subsampled BLOCK_SIZE_TYPE, but that type isn't defined for
	// sizes smaller than 16x16 yet.
	typedef void (*foreach_predicted_block_visitor)(int plane, int block,
	BLOCK_SIZE_TYPE bsize,
	int pred_w, int pred_h,
	void *arg);
	static INLINE void foreach_predicted_block_in_plane(
	const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize, int plane,
	foreach_predicted_block_visitor visit, void *arg) {
	int i, x, y;

	// block sizes in number of 4x4 blocks log 2 ("*_b")
	// 4x4=0, 8x8=2, 16x16=4, 32x32=6, 64x64=8
	// subsampled size of the block
	const int bwl = b_width_log2(bsize) - xd->plane[plane].subsampling_x;
	const int bhl = b_height_log2(bsize) - xd->plane[plane].subsampling_y;

	// size of the predictor to use.
	int pred_w, pred_h;

	if (xd->mode_info_context->mbmi.sb_type < BLOCK_8X8) {
	assert(bsize == BLOCK_8X8);
	pred_w = 0;
	pred_h = 0;
	} else {
	pred_w = bwl;
	pred_h = bhl;
	}
	assert(pred_w <= bwl);
	assert(pred_h <= bhl);

	// visit each subblock in raster order
	i = 0;
	for (y = 0; y < 1 << bhl; y += 1 << pred_h) {
	for (x = 0; x < 1 << bwl; x += 1 << pred_w) {
	visit(plane, i, bsize, pred_w, pred_h, arg);
	i += 1 << pred_w;
	}
	i += (1 << (bwl + pred_h)) - (1 << bwl);
	}
	}
	static INLINE void foreach_predicted_block(
	const MACROBLOCKD* const xd, BLOCK_SIZE_TYPE bsize,
	foreach_predicted_block_visitor visit, void *arg) {
	int plane;

	for (plane = 0; plane < MAX_MB_PLANE; plane++)
	foreach_predicted_block_in_plane(xd, bsize, plane, visit, arg);
	}

	static int raster_block_offset(BLOCK_SIZE_TYPE plane_bsize,
	int raster_block, int stride) {
	const int bw = b_width_log2(plane_bsize);
	const int y = 4 * (raster_block >> bw);
	const int x = 4 * (raster_block & ((1 << bw) - 1));
	return y * stride + x;
	}
	static int16_t* raster_block_offset_int16(BLOCK_SIZE_TYPE plane_bsize,
	int raster_block, int16_t *base) {
	const int stride = 4 << b_width_log2(plane_bsize);
	return base + raster_block_offset(plane_bsize, raster_block, stride);
	}
	static uint8_t* raster_block_offset_uint8(BLOCK_SIZE_TYPE plane_bsize,
	int raster_block, uint8_t *base,
	int stride) {
	return base + raster_block_offset(plane_bsize, raster_block, stride);
	}

	static int txfrm_block_to_raster_block(BLOCK_SIZE_TYPE plane_bsize,
	TX_SIZE tx_size, int block) {
	const int bwl = b_width_log2(plane_bsize);
	const int tx_cols_log2 = bwl - tx_size;
	const int tx_cols = 1 << tx_cols_log2;
	const int raster_mb = block >> (tx_size << 1);
	const int x = (raster_mb & (tx_cols - 1)) << tx_size;
	const int y = (raster_mb >> tx_cols_log2) << tx_size;
	return x + (y << bwl);
	}

	static void txfrm_block_to_raster_xy(BLOCK_SIZE_TYPE plane_bsize,
	TX_SIZE tx_size, int block,
	int x, int y) {
	const int bwl = b_width_log2(plane_bsize);
	const int tx_cols_log2 = bwl - tx_size;
	const int tx_cols = 1 << tx_cols_log2;
	const int raster_mb = block >> (tx_size << 1);
	*x = (raster_mb & (tx_cols - 1)) << tx_size;
	*y = (raster_mb >> tx_cols_log2) << tx_size;
	}

	static void extend_for_intra(MACROBLOCKD* const xd, BLOCK_SIZE_TYPE plane_bsize,
	int plane, int block, TX_SIZE tx_size) {
	struct macroblockd_plane *const pd = &xd->plane[plane];
	uint8_t *const buf = pd->dst.buf;
	const int stride = pd->dst.stride;

	int x, y;
	txfrm_block_to_raster_xy(plane_bsize, tx_size, block, &x, &y);
	x = x * 4 - 1;
	y = y * 4 - 1;
	// Copy a pixel into the umv if we are in a situation where the block size
	// extends into the UMV.
	// TODO(JBB): Should be able to do the full extend in place so we don't have
	// to do this multiple times.
	if (xd->mb_to_right_edge < 0) {
	const int bw = 4 << b_width_log2(plane_bsize);
	const int umv_border_start = bw + (xd->mb_to_right_edge >>
	(3 + pd->subsampling_x));

	if (x + bw > umv_border_start)
	vpx_memset(&buf[y * stride + umv_border_start],
	buf[y * stride + umv_border_start - 1], bw);
	}

	if (xd->mb_to_bottom_edge < 0) {
	const int bh = 4 << b_height_log2(plane_bsize);
	const int umv_border_start = bh + (xd->mb_to_bottom_edge >>
	(3 + pd->subsampling_y));
	int i;
	const uint8_t c = buf[(umv_border_start - 1) * stride + x];
	uint8_t d = &buf[umv_border_start stride + x];

	if (y + bh > umv_border_start)
	for (i = 0; i < bh; ++i, d += stride)
	*d = c;
	}
	}
	static void set_contexts_on_border(MACROBLOCKD *xd,
	struct macroblockd_plane *pd,
	BLOCK_SIZE_TYPE plane_bsize,
	int tx_size_in_blocks, int has_eob,
	int aoff, int loff,
	ENTROPY_CONTEXT A, ENTROPY_CONTEXT L) {
	int mi_blocks_wide = num_4x4_blocks_wide_lookup[plane_bsize];
	int mi_blocks_high = num_4x4_blocks_high_lookup[plane_bsize];
	int above_contexts = tx_size_in_blocks;
	int left_contexts = tx_size_in_blocks;
	int pt;

	// xd->mb_to_right_edge is in units of pixels * 8. This converts
	// it to 4x4 block sizes.
	if (xd->mb_to_right_edge < 0)
	mi_blocks_wide += (xd->mb_to_right_edge >> (5 + pd->subsampling_x));

	if (xd->mb_to_bottom_edge < 0)
	mi_blocks_high += (xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));

	// this code attempts to avoid copying into contexts that are outside
	// our border. Any blocks that do are set to 0...
	if (above_contexts + aoff > mi_blocks_wide)
	above_contexts = mi_blocks_wide - aoff;

	if (left_contexts + loff > mi_blocks_high)
	left_contexts = mi_blocks_high - loff;

	for (pt = 0; pt < above_contexts; pt++)
	A[pt] = has_eob;
	for (pt = above_contexts; pt < tx_size_in_blocks; pt++)
	A[pt] = 0;
	for (pt = 0; pt < left_contexts; pt++)
	L[pt] = has_eob;
	for (pt = left_contexts; pt < tx_size_in_blocks; pt++)
	L[pt] = 0;
	}

	static void set_contexts(MACROBLOCKD xd, struct macroblockd_plane pd,
	BLOCK_SIZE_TYPE plane_bsize, TX_SIZE tx_size,
	int has_eob, int aoff, int loff) {
	ENTROPY_CONTEXT *const A = pd->above_context + aoff;
	ENTROPY_CONTEXT *const L = pd->left_context + loff;
	const int tx_size_in_blocks = 1 << tx_size;

	if (xd->mb_to_right_edge < 0 \|\| xd->mb_to_bottom_edge < 0) {
	set_contexts_on_border(xd, pd, plane_bsize, tx_size_in_blocks, has_eob,
	aoff, loff, A, L);
	} else {
	vpx_memset(A, has_eob, sizeof(ENTROPY_CONTEXT) * tx_size_in_blocks);
	vpx_memset(L, has_eob, sizeof(ENTROPY_CONTEXT) * tx_size_in_blocks);
	}
	}

	#endif // VP9_COMMON_VP9_BLOCKD_H_