vpx/vp8/encoder/encodemv.c

/*
 *  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 "vp8/common/common.h"
#include "encodemv.h"
#include "vp8/common/entropymode.h"
#include "vp8/common/systemdependent.h"

#include <math.h>

#ifdef ENTROPY_STATS
extern unsigned int active_section;
#endif

//extern int final_packing;

#if CONFIG_NEWMVENTROPY

#ifdef NMV_STATS
nmv_context_counts tnmvcounts;
#endif

static void encode_nmv_component(vp8_writer *w,
                                 int v,
                                 int r,
                                 const nmv_component *mvcomp) {
  int s, z, c, o, d;
  assert (v != 0);            /* should not be zero */
  s = v < 0;
  vp8_write(w, s, mvcomp->sign);
  z = (s ? -v : v) - 1;       /* magnitude - 1 */

  c = vp8_get_mv_class(z, &o);

  vp8_write_token(w, vp8_mv_class_tree, mvcomp->classes,
                  vp8_mv_class_encodings + c);

  d = (o >> 3);               /* int mv data */

  if (c == MV_CLASS_0) {
    vp8_write_token(w, vp8_mv_class0_tree, mvcomp->class0,
                    vp8_mv_class0_encodings + d);
  } else {
    int i, b;
    b = c + CLASS0_BITS - 1;  /* number of bits */
    for (i = 0; i < b; ++i)
      vp8_write(w, ((d >> i) & 1), mvcomp->bits[i]);
  }
}

static void encode_nmv_component_fp(vp8_writer *w,
                                    int v,
                                    int r,
                                    const nmv_component *mvcomp,
                                    int usehp) {
  int s, z, c, o, d, f, e;
  assert (v != 0);            /* should not be zero */
  s = v < 0;
  z = (s ? -v : v) - 1;       /* magnitude - 1 */

  c = vp8_get_mv_class(z, &o);

  d = (o >> 3);               /* int mv data */
  f = (o >> 1) & 3;           /* fractional pel mv data */
  e = (o & 1);                /* high precision mv data */

  /* Code the fractional pel bits */
  if (c == MV_CLASS_0) {
    vp8_write_token(w, vp8_mv_fp_tree, mvcomp->class0_fp[d],
                    vp8_mv_fp_encodings + f);
  } else {
    vp8_write_token(w, vp8_mv_fp_tree, mvcomp->fp,
                    vp8_mv_fp_encodings + f);
  }
  /* Code the high precision bit */
  if (usehp) {
    if (c == MV_CLASS_0) {
      vp8_write(w, e, mvcomp->class0_hp);
    } else {
      vp8_write(w, e, mvcomp->hp);
    }
  }
}

static void build_nmv_component_cost_table(int *mvcost,
                                           const nmv_component *mvcomp,
                                           int usehp) {
  int i, v;
  int sign_cost[2], class_cost[MV_CLASSES], class0_cost[CLASS0_SIZE];
  int bits_cost[MV_OFFSET_BITS][2];
  int class0_fp_cost[CLASS0_SIZE][4], fp_cost[4];
  int class0_hp_cost[2], hp_cost[2];

  sign_cost[0] = vp8_cost_zero(mvcomp->sign);
  sign_cost[1] = vp8_cost_one(mvcomp->sign);
  vp8_cost_tokens(class_cost, mvcomp->classes, vp8_mv_class_tree);
  vp8_cost_tokens(class0_cost, mvcomp->class0, vp8_mv_class0_tree);
  for (i = 0; i < MV_OFFSET_BITS; ++i) {
    bits_cost[i][0] = vp8_cost_zero(mvcomp->bits[i]);
    bits_cost[i][1] = vp8_cost_one(mvcomp->bits[i]);
  }

  for (i = 0; i < CLASS0_SIZE; ++i)
    vp8_cost_tokens(class0_fp_cost[i], mvcomp->class0_fp[i], vp8_mv_fp_tree);
  vp8_cost_tokens(fp_cost, mvcomp->fp, vp8_mv_fp_tree);

  if (usehp) {
    class0_hp_cost[0] = vp8_cost_zero(mvcomp->class0_hp);
    class0_hp_cost[1] = vp8_cost_one(mvcomp->class0_hp);
    hp_cost[0] = vp8_cost_zero(mvcomp->hp);
    hp_cost[1] = vp8_cost_one(mvcomp->hp);
  }
  mvcost[0] = 0;
  for (v = 1; v <= MV_MAX; ++v) {
    int z, c, o, d, e, f, cost = 0;
    z = v - 1;
    c = vp8_get_mv_class(z, &o);
    cost += class_cost[c];
    d = (o >> 3);               /* int mv data */
    f = (o >> 1) & 3;           /* fractional pel mv data */
    e = (o & 1);                /* high precision mv data */
    if (c == MV_CLASS_0) {
      cost += class0_cost[d];
    } else {
      int i, b;
      b = c + CLASS0_BITS - 1;  /* number of bits */
      for (i = 0; i < b; ++i)
        cost += bits_cost[i][((d >> i) & 1)];
    }
    if (c == MV_CLASS_0) {
      cost += class0_fp_cost[d][f];
    } else {
      cost += fp_cost[f];
    }
    if (usehp) {
      if (c == MV_CLASS_0) {
        cost += class0_hp_cost[e];
      } else {
        cost += hp_cost[e];
      }
    }
    mvcost[v] = cost + sign_cost[0];
    mvcost[-v] = cost + sign_cost[1];
  }
}

static int update_nmv_savings(const unsigned int ct[2],
                              const vp8_prob cur_p,
                              const vp8_prob new_p,
                              const vp8_prob upd_p) {

#ifdef LOW_PRECISION_MV_UPDATE
  vp8_prob mod_p = new_p | 1;
#else
  vp8_prob mod_p = new_p;
#endif
  const int cur_b = vp8_cost_branch256(ct, cur_p);
  const int mod_b = vp8_cost_branch256(ct, mod_p);
  const int cost = 7 * 256 +
#ifndef LOW_PRECISION_MV_UPDATE
      256 +
#endif
      (vp8_cost_one(upd_p) - vp8_cost_zero(upd_p));
  if (cur_b - mod_b - cost > 0) {
    return cur_b - mod_b - cost;
  } else {
    return -vp8_cost_zero(upd_p);
  }
}

static int update_nmv(
  vp8_writer *const w,
  const unsigned int ct[2],
  vp8_prob *const cur_p,
  const vp8_prob new_p,
  const vp8_prob upd_p) {

#ifdef LOW_PRECISION_MV_UPDATE
  vp8_prob mod_p = new_p | 1;
#else
  vp8_prob mod_p = new_p;
#endif

  const int cur_b = vp8_cost_branch256(ct, *cur_p);
  const int mod_b = vp8_cost_branch256(ct, mod_p);
  const int cost = 7 * 256 +
#ifndef LOW_PRECISION_MV_UPDATE
      256 +
#endif
      (vp8_cost_one(upd_p) - vp8_cost_zero(upd_p));

  if (cur_b - mod_b > cost) {
    *cur_p = mod_p;
    vp8_write(w, 1, upd_p);
#ifdef LOW_PRECISION_MV_UPDATE
    vp8_write_literal(w, mod_p >> 1, 7);
#else
    vp8_write_literal(w, mod_p, 8);
#endif
    return 1;
  } else {
    vp8_write(w, 0, upd_p);
    return 0;
  }
}

#ifdef NMV_STATS
void init_nmvstats() {
  vp8_zero(tnmvcounts);
}

void print_nmvstats() {
  nmv_context prob;
  unsigned int branch_ct_joint[MV_JOINTS - 1][2];
  unsigned int branch_ct_sign[2][2];
  unsigned int branch_ct_classes[2][MV_CLASSES - 1][2];
  unsigned int branch_ct_class0[2][CLASS0_SIZE - 1][2];
  unsigned int branch_ct_bits[2][MV_OFFSET_BITS][2];
  unsigned int branch_ct_class0_fp[2][CLASS0_SIZE][4 - 1][2];
  unsigned int branch_ct_fp[2][4 - 1][2];
  unsigned int branch_ct_class0_hp[2][2];
  unsigned int branch_ct_hp[2][2];
  int i, j, k;
  vp8_counts_to_nmv_context(&tnmvcounts, &prob, 1,
                            branch_ct_joint, branch_ct_sign, branch_ct_classes,
                            branch_ct_class0, branch_ct_bits,
                            branch_ct_class0_fp, branch_ct_fp,
                            branch_ct_class0_hp, branch_ct_hp);

  printf("\nCounts =\n  { ");
  for (j = 0; j < MV_JOINTS; ++j)
    printf("%d, ", tnmvcounts.joints[j]);
  printf("},\n");
  for (i=0; i< 2; ++i) {
    printf("  {\n");
    printf("    %d/%d,\n", tnmvcounts.comps[i].sign[0],
                           tnmvcounts.comps[i].sign[1]);
    printf("    { ");
    for (j = 0; j < MV_CLASSES; ++j)
      printf("%d, ", tnmvcounts.comps[i].classes[j]);
    printf("},\n");
    printf("    { ");
    for (j = 0; j < CLASS0_SIZE; ++j)
      printf("%d, ", tnmvcounts.comps[i].class0[j]);
    printf("},\n");
    printf("    { ");
    for (j = 0; j < MV_OFFSET_BITS; ++j)
      printf("%d/%d, ", tnmvcounts.comps[i].bits[j][0],
                        tnmvcounts.comps[i].bits[j][1]);
    printf("},\n");

    printf("    {");
    for (j = 0; j < CLASS0_SIZE; ++j) {
      printf("{");
      for (k = 0; k < 4; ++k)
        printf("%d, ", tnmvcounts.comps[i].class0_fp[j][k]);
      printf("}, ");
    }
    printf("},\n");

    printf("    { ");
    for (j = 0; j < 4; ++j)
      printf("%d, ", tnmvcounts.comps[i].fp[j]);
    printf("},\n");

    printf("    %d/%d,\n",
           tnmvcounts.comps[i].class0_hp[0],
           tnmvcounts.comps[i].class0_hp[1]);
    printf("    %d/%d,\n",
           tnmvcounts.comps[i].hp[0],
           tnmvcounts.comps[i].hp[1]);
    printf("  },\n");
  }

  printf("\nProbs =\n  { ");
  for (j = 0; j < MV_JOINTS - 1; ++j)
    printf("%d, ", prob.joints[j]);
  printf("},\n");
  for (i=0; i< 2; ++i) {
    printf("  {\n");
    printf("    %d,\n", prob.comps[i].sign);
    printf("    { ");
    for (j = 0; j < MV_CLASSES - 1; ++j)
      printf("%d, ", prob.comps[i].classes[j]);
    printf("},\n");
    printf("    { ");
    for (j = 0; j < CLASS0_SIZE - 1; ++j)
      printf("%d, ", prob.comps[i].class0[j]);
    printf("},\n");
    printf("    { ");
    for (j = 0; j < MV_OFFSET_BITS; ++j)
      printf("%d, ", prob.comps[i].bits[j]);
    printf("},\n");
    printf("    { ");
    for (j = 0; j < CLASS0_SIZE; ++j) {
      printf("{");
      for (k = 0; k < 3; ++k)
        printf("%d, ", prob.comps[i].class0_fp[j][k]);
      printf("}, ");
    }
    printf("},\n");
    printf("    { ");
    for (j = 0; j < 3; ++j)
      printf("%d, ", prob.comps[i].fp[j]);
    printf("},\n");

    printf("    %d,\n", prob.comps[i].class0_hp);
    printf("    %d,\n", prob.comps[i].hp);
    printf("  },\n");
  }
}

static void add_nmvcount(nmv_context_counts *dst, nmv_context_counts *src) {
  int i, j, k;
  for (j = 0; j < MV_JOINTS; ++j) {
    dst->joints[j] += src->joints[j];
  }
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < MV_VALS; ++j) {
      dst->comps[i].mvcount[j] += src->comps[i].mvcount[j];
    }
    dst->comps[i].sign[0] += src->comps[i].sign[0];
    dst->comps[i].sign[1] += src->comps[i].sign[1];
    for (j = 0; j < MV_CLASSES; ++j) {
      dst->comps[i].classes[j] += src->comps[i].classes[j];
    }
    for (j = 0; j < CLASS0_SIZE; ++j) {
      dst->comps[i].class0[j] += src->comps[i].class0[j];
    }
    for (j = 0; j < MV_OFFSET_BITS; ++j) {
      dst->comps[i].bits[j][0] += src->comps[i].bits[j][0];
      dst->comps[i].bits[j][1] += src->comps[i].bits[j][1];
    }
  }
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j) {
      for (k = 0; k < 4; ++k) {
        dst->comps[i].class0_fp[j][k] += src->comps[i].class0_fp[j][k];
      }
    }
    for (j = 0; j < 4; ++j) {
      dst->comps[i].fp[j] += src->comps[i].fp[j];
    }
    dst->comps[i].class0_hp[0] += src->comps[i].class0_hp[0];
    dst->comps[i].class0_hp[1] += src->comps[i].class0_hp[1];
    dst->comps[i].hp[0] += src->comps[i].hp[0];
    dst->comps[i].hp[1] += src->comps[i].hp[1];
  }
}
#endif

void vp8_write_nmvprobs(VP8_COMP * cpi, int usehp) {
  vp8_writer *const w  = &cpi->bc;
  int i, j;
  nmv_context prob;
  unsigned int branch_ct_joint[MV_JOINTS - 1][2];
  unsigned int branch_ct_sign[2][2];
  unsigned int branch_ct_classes[2][MV_CLASSES - 1][2];
  unsigned int branch_ct_class0[2][CLASS0_SIZE - 1][2];
  unsigned int branch_ct_bits[2][MV_OFFSET_BITS][2];
  unsigned int branch_ct_class0_fp[2][CLASS0_SIZE][4 - 1][2];
  unsigned int branch_ct_fp[2][4 - 1][2];
  unsigned int branch_ct_class0_hp[2][2];
  unsigned int branch_ct_hp[2][2];
  int savings = 0;

#ifdef NMV_STATS
  if (!cpi->dummy_packing)
    add_nmvcount(&tnmvcounts, &cpi->NMVcount);
#endif
  vp8_counts_to_nmv_context(&cpi->NMVcount, &prob, usehp,
                            branch_ct_joint, branch_ct_sign, branch_ct_classes,
                            branch_ct_class0, branch_ct_bits,
                            branch_ct_class0_fp, branch_ct_fp,
                            branch_ct_class0_hp, branch_ct_hp);
  /* write updates if they help */
#ifdef MV_GROUP_UPDATE
  for (j = 0; j < MV_JOINTS - 1; ++j) {
    savings += update_nmv_savings(branch_ct_joint[j],
                                  cpi->common.fc.nmvc.joints[j],
                                  prob.joints[j],
                                  VP8_NMV_UPDATE_PROB);
  }
  for (i = 0; i < 2; ++i) {
    savings += update_nmv_savings(branch_ct_sign[i],
                                  cpi->common.fc.nmvc.comps[i].sign,
                                  prob.comps[i].sign,
                                  VP8_NMV_UPDATE_PROB);
    for (j = 0; j < MV_CLASSES - 1; ++j) {
      savings += update_nmv_savings(branch_ct_classes[i][j],
                                    cpi->common.fc.nmvc.comps[i].classes[j],
                                    prob.comps[i].classes[j],
                                    VP8_NMV_UPDATE_PROB);
    }
    for (j = 0; j < CLASS0_SIZE - 1; ++j) {
      savings += update_nmv_savings(branch_ct_class0[i][j],
                                    cpi->common.fc.nmvc.comps[i].class0[j],
                                    prob.comps[i].class0[j],
                                    VP8_NMV_UPDATE_PROB);
    }
    for (j = 0; j < MV_OFFSET_BITS; ++j) {
      savings += update_nmv_savings(branch_ct_bits[i][j],
                                    cpi->common.fc.nmvc.comps[i].bits[j],
                                    prob.comps[i].bits[j],
                                    VP8_NMV_UPDATE_PROB);
    }
  }
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j) {
      int k;
      for (k = 0; k < 3; ++k) {
        savings += update_nmv_savings(branch_ct_class0_fp[i][j][k],
                                      cpi->common.fc.nmvc.comps[i].class0_fp[j][k],
                                      prob.comps[i].class0_fp[j][k],
                                      VP8_NMV_UPDATE_PROB);
      }
    }
    for (j = 0; j < 3; ++j) {
      savings += update_nmv_savings(branch_ct_fp[i][j],
                                    cpi->common.fc.nmvc.comps[i].fp[j],
                                    prob.comps[i].fp[j],
                                    VP8_NMV_UPDATE_PROB);
    }
  }
  if (usehp) {
    for (i = 0; i < 2; ++i) {
      savings += update_nmv_savings(branch_ct_class0_hp[i],
                                    cpi->common.fc.nmvc.comps[i].class0_hp,
                                    prob.comps[i].class0_hp,
                                    VP8_NMV_UPDATE_PROB);
      savings += update_nmv_savings(branch_ct_hp[i],
                                    cpi->common.fc.nmvc.comps[i].hp,
                                    prob.comps[i].hp,
                                    VP8_NMV_UPDATE_PROB);
    }
  }
  if (savings <= 0) {
    vp8_write_bit(w, 0);
    return;
  }
  vp8_write_bit(w, 1);
#endif

  for (j = 0; j < MV_JOINTS - 1; ++j) {
    update_nmv(w, branch_ct_joint[j],
               &cpi->common.fc.nmvc.joints[j],
               prob.joints[j],
               VP8_NMV_UPDATE_PROB);
  }
  for (i = 0; i < 2; ++i) {
    update_nmv(w, branch_ct_sign[i],
               &cpi->common.fc.nmvc.comps[i].sign,
               prob.comps[i].sign,
               VP8_NMV_UPDATE_PROB);
    for (j = 0; j < MV_CLASSES - 1; ++j) {
      update_nmv(w, branch_ct_classes[i][j],
                 &cpi->common.fc.nmvc.comps[i].classes[j],
                 prob.comps[i].classes[j],
                 VP8_NMV_UPDATE_PROB);
    }
    for (j = 0; j < CLASS0_SIZE - 1; ++j) {
      update_nmv(w, branch_ct_class0[i][j],
                 &cpi->common.fc.nmvc.comps[i].class0[j],
                 prob.comps[i].class0[j],
                 VP8_NMV_UPDATE_PROB);
    }
    for (j = 0; j < MV_OFFSET_BITS; ++j) {
      update_nmv(w, branch_ct_bits[i][j],
                 &cpi->common.fc.nmvc.comps[i].bits[j],
                 prob.comps[i].bits[j],
                 VP8_NMV_UPDATE_PROB);
    }
  }
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j) {
      int k;
      for (k = 0; k < 3; ++k) {
        update_nmv(w, branch_ct_class0_fp[i][j][k],
                   &cpi->common.fc.nmvc.comps[i].class0_fp[j][k],
                   prob.comps[i].class0_fp[j][k],
                   VP8_NMV_UPDATE_PROB);
      }
    }
    for (j = 0; j < 3; ++j) {
      update_nmv(w, branch_ct_fp[i][j],
                 &cpi->common.fc.nmvc.comps[i].fp[j],
                 prob.comps[i].fp[j],
                 VP8_NMV_UPDATE_PROB);
    }
  }
  if (usehp) {
    for (i = 0; i < 2; ++i) {
      update_nmv(w, branch_ct_class0_hp[i],
                 &cpi->common.fc.nmvc.comps[i].class0_hp,
                 prob.comps[i].class0_hp,
                 VP8_NMV_UPDATE_PROB);
      update_nmv(w, branch_ct_hp[i],
                 &cpi->common.fc.nmvc.comps[i].hp,
                 prob.comps[i].hp,
                 VP8_NMV_UPDATE_PROB);
    }
  }
}

void vp8_encode_nmv(vp8_writer *w, const MV *mv, const MV *ref,
                    const nmv_context *mvctx) {
  MV_JOINT_TYPE j = vp8_get_mv_joint(*mv);
  vp8_write_token(w, vp8_mv_joint_tree, mvctx->joints,
                  vp8_mv_joint_encodings + j);
  if (j == MV_JOINT_HZVNZ || j == MV_JOINT_HNZVNZ) {
    encode_nmv_component(w, mv->row, ref->col, &mvctx->comps[0]);
  }
  if (j == MV_JOINT_HNZVZ || j == MV_JOINT_HNZVNZ) {
    encode_nmv_component(w, mv->col, ref->col, &mvctx->comps[1]);
  }
}

void vp8_encode_nmv_fp(vp8_writer *w, const MV *mv, const MV *ref,
                       const nmv_context *mvctx, int usehp) {
  MV_JOINT_TYPE j = vp8_get_mv_joint(*mv);
  usehp = usehp && vp8_use_nmv_hp(ref);
  if (j == MV_JOINT_HZVNZ || j == MV_JOINT_HNZVNZ) {
    encode_nmv_component_fp(w, mv->row, ref->row, &mvctx->comps[0], usehp);
  }
  if (j == MV_JOINT_HNZVZ || j == MV_JOINT_HNZVNZ) {
    encode_nmv_component_fp(w, mv->col, ref->col, &mvctx->comps[1], usehp);
  }
}

void vp8_build_nmv_cost_table(int *mvjoint,
                              int *mvcost[2],
                              const nmv_context *mvctx,
                              int usehp,
                              int mvc_flag_v,
                              int mvc_flag_h) {
  vp8_clear_system_state();
  vp8_cost_tokens(mvjoint, mvctx->joints, vp8_mv_joint_tree);
  if (mvc_flag_v)
    build_nmv_component_cost_table(mvcost[0], &mvctx->comps[0], usehp);
  if (mvc_flag_h)
    build_nmv_component_cost_table(mvcost[1], &mvctx->comps[1], usehp);
}

#else  /* CONFIG_NEWMVENTROPY */

static void encode_mvcomponent(
  vp8_writer *const w,
  const int v,
  const struct mv_context *mvc
) {
  const vp8_prob *p = mvc->prob;
  const int x = v < 0 ? -v : v;

  if (x < mvnum_short) {   // Small
    vp8_write(w, 0, p [mvpis_short]);
    vp8_treed_write(w, vp8_small_mvtree, p + MVPshort, x, mvnum_short_bits);
    if (!x)
      return;         // no sign bit
  } else {                // Large
    int i = 0;

    vp8_write(w, 1, p [mvpis_short]);

    do
      vp8_write(w, (x >> i) & 1, p [MVPbits + i]);

    while (++i < mvnum_short_bits);

    i = mvlong_width - 1;  /* Skip bit 3, which is sometimes implicit */

    do
      vp8_write(w, (x >> i) & 1, p [MVPbits + i]);

    while (--i > mvnum_short_bits);

    if (x & ~((2 << mvnum_short_bits) - 1))
      vp8_write(w, (x >> mvnum_short_bits) & 1, p [MVPbits + mvnum_short_bits]);
  }

  vp8_write(w, v < 0, p [MVPsign]);
}

void vp8_encode_motion_vector(vp8_writer *w, const MV *mv, const MV_CONTEXT *mvc) {
  encode_mvcomponent(w, mv->row >> 1, &mvc[0]);
  encode_mvcomponent(w, mv->col >> 1, &mvc[1]);
}


static unsigned int cost_mvcomponent(const int v, const struct mv_context *mvc) {
  const vp8_prob *p = mvc->prob;
  const int x = v;   // v<0? -v:v;
  unsigned int cost;

  if (x < mvnum_short) {
    cost = vp8_cost_zero(p [mvpis_short])
           + vp8_treed_cost(vp8_small_mvtree, p + MVPshort, x, mvnum_short_bits);

    if (!x)
      return cost;
  } else {
    int i = 0;
    cost = vp8_cost_one(p [mvpis_short]);

    do
      cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);

    while (++i < mvnum_short_bits);

    i = mvlong_width - 1;  /* Skip bit 3, which is sometimes implicit */

    do
      cost += vp8_cost_bit(p [MVPbits + i], (x >> i) & 1);

    while (--i > mvnum_short_bits);

    if (x & ~((2 << mvnum_short_bits) - 1))
      cost += vp8_cost_bit(p [MVPbits + mvnum_short_bits], (x >> mvnum_short_bits) & 1);
  }

  return cost;   // + vp8_cost_bit( p [MVPsign], v < 0);
}

void vp8_build_component_cost_table(int *mvcost[2], const MV_CONTEXT *mvc, int mvc_flag[2]) {
  int i = 1;   // -mv_max;
  unsigned int cost0 = 0;
  unsigned int cost1 = 0;

  vp8_clear_system_state();

  i = 1;

  if (mvc_flag[0]) {
    mvcost [0] [0] = cost_mvcomponent(0, &mvc[0]);

    do {
      // mvcost [0] [i] = cost_mvcomponent( i, &mvc[0]);
      cost0 = cost_mvcomponent(i, &mvc[0]);

      mvcost [0] [i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign]);
      mvcost [0] [-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign]);
    } while (++i <= mv_max);
  }

  i = 1;

  if (mvc_flag[1]) {
    mvcost [1] [0] = cost_mvcomponent(0, &mvc[1]);

    do {
      // mvcost [1] [i] = cost_mvcomponent( i, mvc[1]);
      cost1 = cost_mvcomponent(i, &mvc[1]);

      mvcost [1] [i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign]);
      mvcost [1] [-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign]);
    } while (++i <= mv_max);
  }
}


// Motion vector probability table update depends on benefit.
// Small correction allows for the fact that an update to an MV probability
// may have benefit in subsequent frames as well as the current one.

#define MV_PROB_UPDATE_CORRECTION   -1


__inline static void calc_prob(vp8_prob *p, const unsigned int ct[2]) {
  const unsigned int tot = ct[0] + ct[1];

  if (tot) {
    const vp8_prob x = ((ct[0] * 255) / tot) & -2;
    *p = x ? x : 1;
  }
}

static void update(
  vp8_writer *const w,
  const unsigned int ct[2],
  vp8_prob *const cur_p,
  const vp8_prob new_p,
  const vp8_prob update_p,
  int *updated
) {
  const int cur_b = vp8_cost_branch(ct, *cur_p);
  const int new_b = vp8_cost_branch(ct, new_p);
  const int cost = 7 + MV_PROB_UPDATE_CORRECTION + ((vp8_cost_one(update_p) - vp8_cost_zero(update_p) + 128) >> 8);

  if (cur_b - new_b > cost) {
    *cur_p = new_p;
    vp8_write(w, 1, update_p);
    vp8_write_literal(w, new_p >> 1, 7);
    *updated = 1;

  } else
    vp8_write(w, 0, update_p);
}

static void write_component_probs(
  vp8_writer *const w,
  struct mv_context *cur_mvc,
  const struct mv_context *default_mvc_,
  const struct mv_context *update_mvc,
  const unsigned int events [MVvals],
  unsigned int rc,
  int *updated
) {
  vp8_prob *Pcur = cur_mvc->prob;
  const vp8_prob *default_mvc = default_mvc_->prob;
  const vp8_prob *Pupdate = update_mvc->prob;
  unsigned int is_short_ct[2], sign_ct[2];

  unsigned int bit_ct [mvlong_width] [2];

  unsigned int short_ct  [mvnum_short];
  unsigned int short_bct [mvnum_short - 1] [2];

  vp8_prob Pnew [MVPcount];

  (void) rc;
  vp8_copy_array(Pnew, default_mvc, MVPcount);

  vp8_zero(is_short_ct)
  vp8_zero(sign_ct)
  vp8_zero(bit_ct)
  vp8_zero(short_ct)
  vp8_zero(short_bct)


  // j=0
  {
    const int c = events [mv_max];

    is_short_ct [0] += c;    // Short vector
    short_ct [0] += c;       // Magnitude distribution
  }

  // j: 1 ~ mv_max (1023)
  {
    int j = 1;

    do {
      const int c1 = events [mv_max + j];  // positive
      const int c2 = events [mv_max - j];  // negative
      const int c  = c1 + c2;
      int a = j;

      sign_ct [0] += c1;
      sign_ct [1] += c2;

      if (a < mvnum_short) {
        is_short_ct [0] += c;     // Short vector
        short_ct [a] += c;       // Magnitude distribution
      } else {
        int k = mvlong_width - 1;
        is_short_ct [1] += c;     // Long vector

        /*  bit 3 not always encoded. */
        do
          bit_ct [k] [(a >> k) & 1] += c;

        while (--k >= 0);
      }
    } while (++j <= mv_max);
  }

  calc_prob(Pnew + mvpis_short, is_short_ct);

  calc_prob(Pnew + MVPsign, sign_ct);

  {
    vp8_prob p [mvnum_short - 1];    /* actually only need branch ct */
    int j = 0;

    vp8_tree_probs_from_distribution(
      mvnum_short, vp8_small_mvencodings, vp8_small_mvtree,
      p, short_bct, short_ct,
      256, 1
    );

    do
      calc_prob(Pnew + MVPshort + j, short_bct[j]);

    while (++j < mvnum_short - 1);
  }

  {
    int j = 0;

    do
      calc_prob(Pnew + MVPbits + j, bit_ct[j]);

    while (++j < mvlong_width);
  }

  update(w, is_short_ct, Pcur + mvpis_short, Pnew[mvpis_short], *Pupdate++, updated);

  update(w, sign_ct, Pcur + MVPsign, Pnew[MVPsign], *Pupdate++, updated);

  {
    const vp8_prob *const new_p = Pnew + MVPshort;
    vp8_prob *const cur_p = Pcur + MVPshort;

    int j = 0;

    do

      update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated);

    while (++j < mvnum_short - 1);
  }

  {
    const vp8_prob *const new_p = Pnew + MVPbits;
    vp8_prob *const cur_p = Pcur + MVPbits;

    int j = 0;

    do

      update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated);

    while (++j < mvlong_width);
  }
}

void vp8_write_mvprobs(VP8_COMP *cpi) {
  vp8_writer *const w  = &cpi->bc;
  MV_CONTEXT *mvc = cpi->common.fc.mvc;
  int flags[2] = {0, 0};
#ifdef ENTROPY_STATS
  active_section = 4;
#endif
  write_component_probs(
    w, &mvc[0], &vp8_default_mv_context[0], &vp8_mv_update_probs[0], cpi->MVcount[0], 0, &flags[0]
  );
  write_component_probs(
    w, &mvc[1], &vp8_default_mv_context[1], &vp8_mv_update_probs[1], cpi->MVcount[1], 1, &flags[1]
  );

  if (flags[0] || flags[1])
    vp8_build_component_cost_table(cpi->mb.mvcost, (const MV_CONTEXT *) cpi->common.fc.mvc, flags);

#ifdef ENTROPY_STATS
  active_section = 5;
#endif
}


static void encode_mvcomponent_hp(
  vp8_writer *const w,
  const int v,
  const struct mv_context_hp *mvc
) {
  const vp8_prob *p = mvc->prob;
  const int x = v < 0 ? -v : v;

  if (x < mvnum_short_hp) {   // Small
    vp8_write(w, 0, p [mvpis_short_hp]);
    vp8_treed_write(w, vp8_small_mvtree_hp, p + MVPshort_hp, x,
                    mvnum_short_bits_hp);
    if (!x)
      return;         // no sign bit
  } else {                // Large
    int i = 0;

    vp8_write(w, 1, p [mvpis_short_hp]);

    do
      vp8_write(w, (x >> i) & 1, p [MVPbits_hp + i]);

    while (++i < mvnum_short_bits_hp);

    i = mvlong_width_hp - 1;  /* Skip bit 3, which is sometimes implicit */

    do
      vp8_write(w, (x >> i) & 1, p [MVPbits_hp + i]);

    while (--i > mvnum_short_bits_hp);

    if (x & ~((2 << mvnum_short_bits_hp) - 1))
      vp8_write(w, (x >> mvnum_short_bits_hp) & 1,
                p [MVPbits_hp + mvnum_short_bits_hp]);
  }

  vp8_write(w, v < 0, p [MVPsign_hp]);
}

void vp8_encode_motion_vector_hp(vp8_writer *w, const MV *mv,
                                 const MV_CONTEXT_HP *mvc) {

  encode_mvcomponent_hp(w, mv->row, &mvc[0]);
  encode_mvcomponent_hp(w, mv->col, &mvc[1]);
}


static unsigned int cost_mvcomponent_hp(const int v,
                                        const struct mv_context_hp *mvc) {
  const vp8_prob *p = mvc->prob;
  const int x = v;   // v<0? -v:v;
  unsigned int cost;

  if (x < mvnum_short_hp) {
    cost = vp8_cost_zero(p [mvpis_short_hp])
           + vp8_treed_cost(vp8_small_mvtree_hp, p + MVPshort_hp, x,
                            mvnum_short_bits_hp);

    if (!x)
      return cost;
  } else {
    int i = 0;
    cost = vp8_cost_one(p [mvpis_short_hp]);

    do
      cost += vp8_cost_bit(p [MVPbits_hp + i], (x >> i) & 1);

    while (++i < mvnum_short_bits_hp);

    i = mvlong_width_hp - 1;  /* Skip bit 3, which is sometimes implicit */

    do
      cost += vp8_cost_bit(p [MVPbits_hp + i], (x >> i) & 1);

    while (--i > mvnum_short_bits_hp);

    if (x & ~((2 << mvnum_short_bits_hp) - 1))
      cost += vp8_cost_bit(p [MVPbits_hp + mvnum_short_bits_hp],
                           (x >> mvnum_short_bits_hp) & 1);
  }

  return cost;   // + vp8_cost_bit( p [MVPsign], v < 0);
}

void vp8_build_component_cost_table_hp(int *mvcost[2],
                                       const MV_CONTEXT_HP *mvc,
                                       int mvc_flag[2]) {
  int i = 1;   // -mv_max;
  unsigned int cost0 = 0;
  unsigned int cost1 = 0;

  vp8_clear_system_state();

  i = 1;

  if (mvc_flag[0]) {
    mvcost [0] [0] = cost_mvcomponent_hp(0, &mvc[0]);

    do {
      // mvcost [0] [i] = cost_mvcomponent( i, &mvc[0]);
      cost0 = cost_mvcomponent_hp(i, &mvc[0]);

      mvcost [0] [i] = cost0 + vp8_cost_zero(mvc[0].prob[MVPsign_hp]);
      mvcost [0] [-i] = cost0 + vp8_cost_one(mvc[0].prob[MVPsign_hp]);
    } while (++i <= mv_max_hp);
  }

  i = 1;

  if (mvc_flag[1]) {
    mvcost [1] [0] = cost_mvcomponent_hp(0, &mvc[1]);

    do {
      // mvcost [1] [i] = cost_mvcomponent( i, mvc[1]);
      cost1 = cost_mvcomponent_hp(i, &mvc[1]);

      mvcost [1] [i] = cost1 + vp8_cost_zero(mvc[1].prob[MVPsign_hp]);
      mvcost [1] [-i] = cost1 + vp8_cost_one(mvc[1].prob[MVPsign_hp]);
    } while (++i <= mv_max_hp);
  }
}


static void write_component_probs_hp(
  vp8_writer *const w,
  struct mv_context_hp *cur_mvc,
  const struct mv_context_hp *default_mvc_,
  const struct mv_context_hp *update_mvc,
  const unsigned int events [MVvals_hp],
  unsigned int rc,
  int *updated
) {
  vp8_prob *Pcur = cur_mvc->prob;
  const vp8_prob *default_mvc = default_mvc_->prob;
  const vp8_prob *Pupdate = update_mvc->prob;
  unsigned int is_short_ct[2], sign_ct[2];

  unsigned int bit_ct [mvlong_width_hp] [2];

  unsigned int short_ct  [mvnum_short_hp];
  unsigned int short_bct [mvnum_short_hp - 1] [2];

  vp8_prob Pnew [MVPcount_hp];

  (void) rc;
  vp8_copy_array(Pnew, default_mvc, MVPcount_hp);

  vp8_zero(is_short_ct)
  vp8_zero(sign_ct)
  vp8_zero(bit_ct)
  vp8_zero(short_ct)
  vp8_zero(short_bct)


  // j=0
  {
    const int c = events [mv_max_hp];

    is_short_ct [0] += c;    // Short vector
    short_ct [0] += c;       // Magnitude distribution
  }

  // j: 1 ~ mv_max (1023)
  {
    int j = 1;

    do {
      const int c1 = events [mv_max_hp + j];  // positive
      const int c2 = events [mv_max_hp - j];  // negative
      const int c  = c1 + c2;
      int a = j;

      sign_ct [0] += c1;
      sign_ct [1] += c2;

      if (a < mvnum_short_hp) {
        is_short_ct [0] += c;     // Short vector
        short_ct [a] += c;       // Magnitude distribution
      } else {
        int k = mvlong_width_hp - 1;
        is_short_ct [1] += c;     // Long vector

        /*  bit 3 not always encoded. */
        do
          bit_ct [k] [(a >> k) & 1] += c;

        while (--k >= 0);
      }
    } while (++j <= mv_max_hp);
  }

  calc_prob(Pnew + mvpis_short_hp, is_short_ct);

  calc_prob(Pnew + MVPsign_hp, sign_ct);

  {
    vp8_prob p [mvnum_short_hp - 1];    /* actually only need branch ct */
    int j = 0;

    vp8_tree_probs_from_distribution(
      mvnum_short_hp, vp8_small_mvencodings_hp, vp8_small_mvtree_hp,
      p, short_bct, short_ct,
      256, 1
    );

    do
      calc_prob(Pnew + MVPshort_hp + j, short_bct[j]);

    while (++j < mvnum_short_hp - 1);
  }

  {
    int j = 0;

    do
      calc_prob(Pnew + MVPbits_hp + j, bit_ct[j]);

    while (++j < mvlong_width_hp);
  }

  update(w, is_short_ct, Pcur + mvpis_short_hp, Pnew[mvpis_short_hp],
         *Pupdate++, updated);

  update(w, sign_ct, Pcur + MVPsign_hp, Pnew[MVPsign_hp], *Pupdate++,
         updated);

  {
    const vp8_prob *const new_p = Pnew + MVPshort_hp;
    vp8_prob *const cur_p = Pcur + MVPshort_hp;

    int j = 0;

    do

      update(w, short_bct[j], cur_p + j, new_p[j], *Pupdate++, updated);

    while (++j < mvnum_short_hp - 1);
  }

  {
    const vp8_prob *const new_p = Pnew + MVPbits_hp;
    vp8_prob *const cur_p = Pcur + MVPbits_hp;

    int j = 0;

    do

      update(w, bit_ct[j], cur_p + j, new_p[j], *Pupdate++, updated);

    while (++j < mvlong_width_hp);
  }
}

void vp8_write_mvprobs_hp(VP8_COMP *cpi) {
  vp8_writer *const w  = &cpi->bc;
  MV_CONTEXT_HP *mvc = cpi->common.fc.mvc_hp;
  int flags[2] = {0, 0};
#ifdef ENTROPY_STATS
  active_section = 4;
#endif
  write_component_probs_hp(
    w, &mvc[0], &vp8_default_mv_context_hp[0], &vp8_mv_update_probs_hp[0],
    cpi->MVcount_hp[0], 0, &flags[0]
  );
  write_component_probs_hp(
    w, &mvc[1], &vp8_default_mv_context_hp[1], &vp8_mv_update_probs_hp[1],
    cpi->MVcount_hp[1], 1, &flags[1]
  );

  if (flags[0] || flags[1])
    vp8_build_component_cost_table_hp(cpi->mb.mvcost_hp,
                                      (const MV_CONTEXT_HP *)
                                      cpi->common.fc.mvc_hp, flags);
#ifdef ENTROPY_STATS
  active_section = 5;
#endif
}

#endif  /* CONFIG_NEWMVENTROPY */