vpx/vp9/common/vp9_entropymv.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 "vp9/common/vp9_onyxc_int.h"
#include "vp9/common/vp9_entropymv.h"

//#define MV_COUNT_TESTING

#define MV_COUNT_SAT 20
#define MV_MAX_UPDATE_FACTOR 128

/* Integer pel reference mv threshold for use of high-precision 1/8 mv */
#define COMPANDED_MVREF_THRESH    8

/* Smooth or bias the mv-counts before prob computation */
/* #define SMOOTH_MV_COUNTS */

const vp9_tree_index vp9_mv_joint_tree[2 * MV_JOINTS - 2] = {
  -MV_JOINT_ZERO, 2,
  -MV_JOINT_HNZVZ, 4,
  -MV_JOINT_HZVNZ, -MV_JOINT_HNZVNZ
};
struct vp9_token vp9_mv_joint_encodings[MV_JOINTS];

const vp9_tree_index vp9_mv_class_tree[2 * MV_CLASSES - 2] = {
  -MV_CLASS_0, 2,
  -MV_CLASS_1, 4,
  6, 8,
  -MV_CLASS_2, -MV_CLASS_3,
  10, 12,
  -MV_CLASS_4, -MV_CLASS_5,
  -MV_CLASS_6, 14,
  16, 18,
  -MV_CLASS_7, -MV_CLASS_8,
  -MV_CLASS_9, -MV_CLASS_10,
};
struct vp9_token vp9_mv_class_encodings[MV_CLASSES];

const vp9_tree_index vp9_mv_class0_tree [2 * CLASS0_SIZE - 2] = {
  -0, -1,
};
struct vp9_token vp9_mv_class0_encodings[CLASS0_SIZE];

const vp9_tree_index vp9_mv_fp_tree [2 * 4 - 2] = {
  -0, 2,
  -1, 4,
  -2, -3
};
struct vp9_token vp9_mv_fp_encodings[4];

const nmv_context vp9_default_nmv_context = {
  {32, 64, 96},
  {
    { /* vert component */
      128,                                                  /* sign */
      {224, 144, 192, 168, 192, 176, 192, 198, 198, 245},   /* class */
      {216},                                                /* class0 */
      {136, 140, 148, 160, 176, 192, 224, 234, 234, 240},   /* bits */
      {{128, 128, 64}, {96, 112, 64}},                      /* class0_fp */
      {64, 96, 64},                                         /* fp */
      160,                                                  /* class0_hp bit */
      128,                                                  /* hp */
    },
    { /* hor component */
      128,                                                  /* sign */
      {216, 128, 176, 160, 176, 176, 192, 198, 198, 208},   /* class */
      {208},                                                /* class0 */
      {136, 140, 148, 160, 176, 192, 224, 234, 234, 240},   /* bits */
      {{128, 128, 64}, {96, 112, 64}},                      /* class0_fp */
      {64, 96, 64},                                         /* fp */
      160,                                                  /* class0_hp bit */
      128,                                                  /* hp */
    }
  },
};

#define mv_class_base(c) ((c) ? (CLASS0_SIZE << (c + 2)) : 0)

MV_CLASS_TYPE vp9_get_mv_class(int z, int *offset) {
  MV_CLASS_TYPE c = MV_CLASS_0;
  if      (z < CLASS0_SIZE * 8)    c = MV_CLASS_0;
  else if (z < CLASS0_SIZE * 16)   c = MV_CLASS_1;
  else if (z < CLASS0_SIZE * 32)   c = MV_CLASS_2;
  else if (z < CLASS0_SIZE * 64)   c = MV_CLASS_3;
  else if (z < CLASS0_SIZE * 128)  c = MV_CLASS_4;
  else if (z < CLASS0_SIZE * 256)  c = MV_CLASS_5;
  else if (z < CLASS0_SIZE * 512)  c = MV_CLASS_6;
  else if (z < CLASS0_SIZE * 1024) c = MV_CLASS_7;
  else if (z < CLASS0_SIZE * 2048) c = MV_CLASS_8;
  else if (z < CLASS0_SIZE * 4096) c = MV_CLASS_9;
  else if (z < CLASS0_SIZE * 8192) c = MV_CLASS_10;
  else assert(0);
  if (offset)
    *offset = z - mv_class_base(c);
  return c;
}

int vp9_use_mv_hp(const MV *ref) {
  return (abs(ref->row) >> 3) < COMPANDED_MVREF_THRESH &&
         (abs(ref->col) >> 3) < COMPANDED_MVREF_THRESH;
}

int vp9_get_mv_mag(MV_CLASS_TYPE c, int offset) {
  return mv_class_base(c) + offset;
}

static void inc_mv_component_count(int v, nmv_component_counts *comp_counts,
                                   int incr) {
  assert (v != 0);
  comp_counts->mvcount[MV_MAX + v] += incr;
}

static void inc_mv_component(int v, nmv_component_counts *comp_counts,
                             int incr, int usehp) {
  int s, z, c, o, d, e, f;
  if (!incr)
    return;
  assert (v != 0);            /* should not be zero */
  s = v < 0;
  comp_counts->sign[s] += incr;
  z = (s ? -v : v) - 1;       /* magnitude - 1 */

  c = vp9_get_mv_class(z, &o);
  comp_counts->classes[c] += incr;

  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) {
    comp_counts->class0[d] += incr;
  } else {
    int i;
    int b = c + CLASS0_BITS - 1;  // number of bits
    for (i = 0; i < b; ++i)
      comp_counts->bits[i][((d >> i) & 1)] += incr;
  }

  /* Code the fractional pel bits */
  if (c == MV_CLASS_0) {
    comp_counts->class0_fp[d][f] += incr;
  } else {
    comp_counts->fp[f] += incr;
  }

  /* Code the high precision bit */
  if (usehp) {
    if (c == MV_CLASS_0) {
      comp_counts->class0_hp[e] += incr;
    } else {
      comp_counts->hp[e] += incr;
    }
  }
}

#ifdef SMOOTH_MV_COUNTS
static void smooth_counts(nmv_component_counts *mvcomp) {
  static const int flen = 3;  // (filter_length + 1) / 2
  static const int fval[] = {8, 3, 1};
  static const int fvalbits = 4;
  int i;
  unsigned int smvcount[MV_VALS];
  vpx_memcpy(smvcount, mvcomp->mvcount, sizeof(smvcount));
  smvcount[MV_MAX] = (smvcount[MV_MAX - 1] + smvcount[MV_MAX + 1]) >> 1;
  for (i = flen - 1; i <= MV_VALS - flen; ++i) {
    int j, s = smvcount[i] * fval[0];
    for (j = 1; j < flen; ++j)
      s += (smvcount[i - j] + smvcount[i + j]) * fval[j];
    mvcomp->mvcount[i] = (s + (1 << (fvalbits - 1))) >> fvalbits;
  }
}
#endif

static void counts_to_context(nmv_component_counts *mvcomp, int usehp) {
  int v;
  vpx_memset(mvcomp->sign, 0, sizeof(nmv_component_counts) - sizeof(mvcomp->mvcount));
  for (v = 1; v <= MV_MAX; v++) {
    inc_mv_component(-v, mvcomp, mvcomp->mvcount[MV_MAX - v], usehp);
    inc_mv_component( v, mvcomp, mvcomp->mvcount[MV_MAX + v], usehp);
  }
}

void vp9_inc_mv(const MV *mv, const MV *ref, nmv_context_counts *mvctx,
                       int usehp) {
  const MV_JOINT_TYPE j = vp9_get_mv_joint(mv);
  mvctx->joints[j]++;
  usehp = usehp && vp9_use_mv_hp(ref);
  if (mv_joint_vertical(j))
    inc_mv_component_count(mv->row, &mvctx->comps[0], 1);

  if (mv_joint_horizontal(j))
    inc_mv_component_count(mv->col, &mvctx->comps[1], 1);
}

static void adapt_prob(vp9_prob *dest, vp9_prob prep, unsigned int ct[2]) {
  const int count = MIN(ct[0] + ct[1], MV_COUNT_SAT);
  if (count) {
    const vp9_prob newp = get_binary_prob(ct[0], ct[1]);
    const int factor = MV_MAX_UPDATE_FACTOR * count / MV_COUNT_SAT;
    *dest = weighted_prob(prep, newp, factor);
  } else {
    *dest = prep;
  }
}

void vp9_counts_process(nmv_context_counts *nmv_count, int usehp) {
  counts_to_context(&nmv_count->comps[0], usehp);
  counts_to_context(&nmv_count->comps[1], usehp);
}

static unsigned int adapt_probs(unsigned int i,
                                vp9_tree tree,
                                vp9_prob this_probs[],
                                const vp9_prob last_probs[],
                                const unsigned int num_events[]) {
  vp9_prob this_prob;

  const uint32_t left = tree[i] <= 0
          ? num_events[-tree[i]]
          : adapt_probs(tree[i], tree, this_probs, last_probs, num_events);

  const uint32_t right = tree[i + 1] <= 0
          ? num_events[-tree[i + 1]]
          : adapt_probs(tree[i + 1], tree, this_probs, last_probs, num_events);

  uint32_t weight = left + right;
  if (weight) {
    this_prob = get_binary_prob(left, right);
    weight = weight > MV_COUNT_SAT ? MV_COUNT_SAT : weight;
    this_prob = weighted_prob(last_probs[i >> 1], this_prob,
                              MV_MAX_UPDATE_FACTOR * weight / MV_COUNT_SAT);
  } else {
    this_prob = last_probs[i >> 1];
  }
  this_probs[i >> 1] = this_prob;
  return left + right;
}


void vp9_adapt_mv_probs(VP9_COMMON *cm, int usehp) {
  int i, j;
#ifdef MV_COUNT_TESTING
  printf("joints count: ");
  for (j = 0; j < MV_JOINTS; ++j) printf("%d ", cm->fc.NMVcount.joints[j]);
  printf("\n"); fflush(stdout);
  printf("signs count:\n");
  for (i = 0; i < 2; ++i)
    printf("%d/%d ", cm->fc.NMVcount.comps[i].sign[0], cm->fc.NMVcount.comps[i].sign[1]);
  printf("\n"); fflush(stdout);
  printf("classes count:\n");
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < MV_CLASSES; ++j)
      printf("%d ", cm->fc.NMVcount.comps[i].classes[j]);
    printf("\n"); fflush(stdout);
  }
  printf("class0 count:\n");
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j)
      printf("%d ", cm->fc.NMVcount.comps[i].class0[j]);
    printf("\n"); fflush(stdout);
  }
  printf("bits count:\n");
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < MV_OFFSET_BITS; ++j)
      printf("%d/%d ", cm->fc.NMVcount.comps[i].bits[j][0],
                       cm->fc.NMVcount.comps[i].bits[j][1]);
    printf("\n"); fflush(stdout);
  }
  printf("class0_fp count:\n");
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j) {
      printf("{");
      for (k = 0; k < 4; ++k)
        printf("%d ", cm->fc.NMVcount.comps[i].class0_fp[j][k]);
      printf("}, ");
    }
    printf("\n"); fflush(stdout);
  }
  printf("fp count:\n");
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < 4; ++j)
      printf("%d ", cm->fc.NMVcount.comps[i].fp[j]);
    printf("\n"); fflush(stdout);
  }
  if (usehp) {
    printf("class0_hp count:\n");
    for (i = 0; i < 2; ++i)
      printf("%d/%d ", cm->fc.NMVcount.comps[i].class0_hp[0],
                       cm->fc.NMVcount.comps[i].class0_hp[1]);
    printf("\n"); fflush(stdout);
    printf("hp count:\n");
    for (i = 0; i < 2; ++i)
      printf("%d/%d ", cm->fc.NMVcount.comps[i].hp[0],
                       cm->fc.NMVcount.comps[i].hp[1]);
    printf("\n"); fflush(stdout);
  }
#endif
#ifdef SMOOTH_MV_COUNTS
  smooth_counts(&cm->fc.NMVcount.comps[0]);
  smooth_counts(&cm->fc.NMVcount.comps[1]);
#endif
  vp9_counts_process(&cm->fc.NMVcount, usehp);

  adapt_probs(0, vp9_mv_joint_tree,
              cm->fc.nmvc.joints, cm->fc.pre_nmvc.joints,
              cm->fc.NMVcount.joints);

  for (i = 0; i < 2; ++i) {
    adapt_prob(&cm->fc.nmvc.comps[i].sign,
               cm->fc.pre_nmvc.comps[i].sign,
               cm->fc.NMVcount.comps[i].sign);
    adapt_probs(0, vp9_mv_class_tree,
                cm->fc.nmvc.comps[i].classes, cm->fc.pre_nmvc.comps[i].classes,
                cm->fc.NMVcount.comps[i].classes);
    adapt_probs(0, vp9_mv_class0_tree,
                cm->fc.nmvc.comps[i].class0, cm->fc.pre_nmvc.comps[i].class0,
                cm->fc.NMVcount.comps[i].class0);
    for (j = 0; j < MV_OFFSET_BITS; ++j) {
      adapt_prob(&cm->fc.nmvc.comps[i].bits[j],
                 cm->fc.pre_nmvc.comps[i].bits[j],
                 cm->fc.NMVcount.comps[i].bits[j]);
    }
  }
  for (i = 0; i < 2; ++i) {
    for (j = 0; j < CLASS0_SIZE; ++j) {
      adapt_probs(0, vp9_mv_fp_tree,
                  cm->fc.nmvc.comps[i].class0_fp[j],
                  cm->fc.pre_nmvc.comps[i].class0_fp[j],
                  cm->fc.NMVcount.comps[i].class0_fp[j]);
    }
    adapt_probs(0, vp9_mv_fp_tree,
                cm->fc.nmvc.comps[i].fp,
                cm->fc.pre_nmvc.comps[i].fp,
                cm->fc.NMVcount.comps[i].fp);
  }
  if (usehp) {
    for (i = 0; i < 2; ++i) {
      adapt_prob(&cm->fc.nmvc.comps[i].class0_hp,
                 cm->fc.pre_nmvc.comps[i].class0_hp,
                 cm->fc.NMVcount.comps[i].class0_hp);
      adapt_prob(&cm->fc.nmvc.comps[i].hp,
                 cm->fc.pre_nmvc.comps[i].hp,
                 cm->fc.NMVcount.comps[i].hp);
    }
  }
}

void vp9_entropy_mv_init() {
  vp9_tokens_from_tree(vp9_mv_joint_encodings, vp9_mv_joint_tree);
  vp9_tokens_from_tree(vp9_mv_class_encodings, vp9_mv_class_tree);
  vp9_tokens_from_tree(vp9_mv_class0_encodings, vp9_mv_class0_tree);
  vp9_tokens_from_tree(vp9_mv_fp_encodings, vp9_mv_fp_tree);
}

void vp9_init_mv_probs(VP9_COMMON *cm) {
  vpx_memcpy(&cm->fc.nmvc, &vp9_default_nmv_context, sizeof(nmv_context));
}