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 /*

  *  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.

  */

 #include "findnearmv.h"

 const unsigned char vp8_mbsplit_offset[4][16] = {

     { 0,  8,  0,  0,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},

     { 0,  2,  0,  0,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},

     { 0,  2,  8, 10,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},

     { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15}

 };

 /* Predict motion vectors using those from already-decoded nearby blocks.

    Note that we only consider one 4x4 subblock from each candidate 16x16

    macroblock.   */

 void vp8_find_near_mvs

 (

     MACROBLOCKD *xd,

     const MODE_INFO *here,

     int_mv *nearest,

     int_mv *nearby,

     int_mv *best_mv,

     int cnt[4],

     int refframe,

     int *ref_frame_sign_bias

 )

 {

     const MODE_INFO *above = here - xd->mode_info_stride;

     const MODE_INFO *left = here - 1;

     const MODE_INFO *aboveleft = above - 1;

     int_mv            near_mvs[4];

     int_mv           *mv = near_mvs;

     int             *cntx = cnt;

     enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV};

     /* Zero accumulators */

     mv[0].as_int = mv[1].as_int = mv[2].as_int = 0;

     cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;

     /* Process above */

     if (above->mbmi.ref_frame != INTRA_FRAME)

     {

         if (above->mbmi.mv.as_int)

         {

             (++mv)->as_int = above->mbmi.mv.as_int;

             mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame], refframe, mv, ref_frame_sign_bias);

             ++cntx;

         }

         *cntx += 2;

     }

     /* Process left */

     if (left->mbmi.ref_frame != INTRA_FRAME)

     {

         if (left->mbmi.mv.as_int)

         {

             int_mv this_mv;

             this_mv.as_int = left->mbmi.mv.as_int;

             mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame], refframe, &this_mv, ref_frame_sign_bias);

             if (this_mv.as_int != mv->as_int)

             {

                 (++mv)->as_int = this_mv.as_int;

                 ++cntx;

             }

             *cntx += 2;

         }

         else

             cnt[CNT_INTRA] += 2;

     }

     /* Process above left */

     if (aboveleft->mbmi.ref_frame != INTRA_FRAME)

     {

         if (aboveleft->mbmi.mv.as_int)

         {

             int_mv this_mv;

             this_mv.as_int = aboveleft->mbmi.mv.as_int;

             mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame], refframe, &this_mv, ref_frame_sign_bias);

             if (this_mv.as_int != mv->as_int)

             {

                 (++mv)->as_int = this_mv.as_int;

                 ++cntx;

             }

             *cntx += 1;

         }

         else

             cnt[CNT_INTRA] += 1;

     }

     /* If we have three distinct MV's ... */

     if (cnt[CNT_SPLITMV])

     {

         /* See if above-left MV can be merged with NEAREST */

         if (mv->as_int == near_mvs[CNT_NEAREST].as_int)

             cnt[CNT_NEAREST] += 1;

     }

     cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV)

                         + (left->mbmi.mode == SPLITMV)) * 2

                        + (aboveleft->mbmi.mode == SPLITMV);

     /* Swap near and nearest if necessary */

     if (cnt[CNT_NEAR] > cnt[CNT_NEAREST])

     {

         int tmp;

         tmp = cnt[CNT_NEAREST];

         cnt[CNT_NEAREST] = cnt[CNT_NEAR];

         cnt[CNT_NEAR] = tmp;

         tmp = near_mvs[CNT_NEAREST].as_int;

         near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;

         near_mvs[CNT_NEAR].as_int = tmp;

     }

     /* Use near_mvs[0] to store the "best" MV */

     if (cnt[CNT_NEAREST] >= cnt[CNT_INTRA])

         near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST];

     /* Set up return values */

     best_mv->as_int = near_mvs[0].as_int;

     nearest->as_int = near_mvs[CNT_NEAREST].as_int;

     nearby->as_int = near_mvs[CNT_NEAR].as_int;

 }

 static void invert_and_clamp_mvs(int_mv *inv, int_mv *src, MACROBLOCKD *xd)

 {

     inv->as_mv.row = src->as_mv.row * -1;

     inv->as_mv.col = src->as_mv.col * -1;

     vp8_clamp_mv2(inv, xd);

     vp8_clamp_mv2(src, xd);

 }

 int vp8_find_near_mvs_bias

 (

     MACROBLOCKD *xd,

     const MODE_INFO *here,

     int_mv mode_mv_sb[2][MB_MODE_COUNT],

     int_mv best_mv_sb[2],

     int cnt[4],

     int refframe,

     int *ref_frame_sign_bias

 )

 {

     int sign_bias = ref_frame_sign_bias[refframe];

     vp8_find_near_mvs(xd,

                       here,

                       &mode_mv_sb[sign_bias][NEARESTMV],

                       &mode_mv_sb[sign_bias][NEARMV],

                       &best_mv_sb[sign_bias],

                       cnt,

                       refframe,

                       ref_frame_sign_bias);

     invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARESTMV],

                          &mode_mv_sb[sign_bias][NEARESTMV], xd);

     invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARMV],

                          &mode_mv_sb[sign_bias][NEARMV], xd);

     invert_and_clamp_mvs(&best_mv_sb[!sign_bias],

                          &best_mv_sb[sign_bias], xd);

     return sign_bias;

 }

 vp8_prob *vp8_mv_ref_probs(

     vp8_prob p[VP8_MVREFS-1], const int near_mv_ref_ct[4]

 )

 {

     p[0] = vp8_mode_contexts [near_mv_ref_ct[0]] [0];

     p[1] = vp8_mode_contexts [near_mv_ref_ct[1]] [1];

     p[2] = vp8_mode_contexts [near_mv_ref_ct[2]] [2];

     p[3] = vp8_mode_contexts [near_mv_ref_ct[3]] [3];

     /*p[3] = vp8_mode_contexts [near_mv_ref_ct[1] + near_mv_ref_ct[2] + near_mv_ref_ct[3]] [3];*/

     return p;

 }