Ejemplo n.º 1
0
static int FinalizeTokenProbas(VP8Proba* const proba) {
  int has_changed = 0;
  int size = 0;
  int t, b, c, p;
  for (t = 0; t < NUM_TYPES; ++t) {
    for (b = 0; b < NUM_BANDS; ++b) {
      for (c = 0; c < NUM_CTX; ++c) {
        for (p = 0; p < NUM_PROBAS; ++p) {
          const proba_t stats = proba->stats_[t][b][c][p];
          const int nb = (stats >> 0) & 0xffff;
          const int total = (stats >> 16) & 0xffff;
          const int update_proba = VP8CoeffsUpdateProba[t][b][c][p];
          const int old_p = VP8CoeffsProba0[t][b][c][p];
          const int new_p = CalcTokenProba(nb, total);
          const int old_cost = BranchCost(nb, total, old_p)
                             + VP8BitCost(0, update_proba);
          const int new_cost = BranchCost(nb, total, new_p)
                             + VP8BitCost(1, update_proba)
                             + 8 * 256;
          const int use_new_p = (old_cost > new_cost);
          size += VP8BitCost(use_new_p, update_proba);
          if (use_new_p) {  // only use proba that seem meaningful enough.
            proba->coeffs_[t][b][c][p] = new_p;
            has_changed |= (new_p != old_p);
            size += 8 * 256;
          } else {
            proba->coeffs_[t][b][c][p] = old_p;
          }
        }
      }
    }
  }
  proba->dirty_ = has_changed;
  return size;
}
Ejemplo n.º 2
0
void VP8CalculateLevelCosts(VP8EncProba* const proba) {
    int ctype, band, ctx;

    if (!proba->dirty_) return;  // nothing to do.

    for (ctype = 0; ctype < NUM_TYPES; ++ctype) {
        int n;
        for (band = 0; band < NUM_BANDS; ++band) {
            for (ctx = 0; ctx < NUM_CTX; ++ctx) {
                const uint8_t* const p = proba->coeffs_[ctype][band][ctx];
                uint16_t* const table = proba->level_cost_[ctype][band][ctx];
                const int cost0 = (ctx > 0) ? VP8BitCost(1, p[0]) : 0;
                const int cost_base = VP8BitCost(1, p[1]) + cost0;
                int v;
                table[0] = VP8BitCost(0, p[1]) + cost0;
                for (v = 1; v <= MAX_VARIABLE_LEVEL; ++v) {
                    table[v] = cost_base + VariableLevelCost(v, p);
                }
                // Starting at level 67 and up, the variable part of the cost is
                // actually constant.
            }
        }
        for (n = 0; n < 16; ++n) {    // replicate bands. We don't need to sentinel.
            for (ctx = 0; ctx < NUM_CTX; ++ctx) {
                proba->remapped_costs_[ctype][n][ctx] =
                    proba->level_cost_[ctype][VP8EncBands[n]][ctx];
            }
        }
    }
    proba->dirty_ = 0;
}
Ejemplo n.º 3
0
static int GetResidualCost(int ctx0, const VP8Residual* const res) {
  int n = res->first;
  // should be prob[VP8EncBands[n]], but it's equivalent for n=0 or 1
  const int p0 = res->prob[n][ctx0][0];
  const uint16_t* t = res->cost[n][ctx0];
  // bit_cost(1, p0) is already incorporated in t[] tables, but only if ctx != 0
  // (as required by the syntax). For ctx0 == 0, we need to add it here or it'll
  // be missing during the loop.
  int cost = (ctx0 == 0) ? VP8BitCost(1, p0) : 0;

  if (res->last < 0) {
    return VP8BitCost(0, p0);
  }
  for (; n < res->last; ++n) {
    const int v = abs(res->coeffs[n]);
    const int b = VP8EncBands[n + 1];
    const int ctx = (v >= 2) ? 2 : v;
    cost += VP8LevelCost(t, v);
    t = res->cost[b][ctx];
  }
  // Last coefficient is always non-zero
  {
    const int v = abs(res->coeffs[n]);
    assert(v != 0);
    cost += VP8LevelCost(t, v);
    if (n < 15) {
      const int b = VP8EncBands[n + 1];
      const int ctx = (v == 1) ? 1 : 2;
      const int last_p0 = res->prob[b][ctx][0];
      cost += VP8BitCost(0, last_p0);
    }
  }
  return cost;
}
Ejemplo n.º 4
0
static int GetResidualCostSSE2(int ctx0, const VP8Residual* const res) {
  uint8_t levels[16], ctxs[16];
  uint16_t abs_levels[16];
  int n = res->first;
  // should be prob[VP8EncBands[n]], but it's equivalent for n=0 or 1
  const int p0 = res->prob[n][ctx0][0];
  CostArrayPtr const costs = res->costs;
  const uint16_t* t = costs[n][ctx0];
  // bit_cost(1, p0) is already incorporated in t[] tables, but only if ctx != 0
  // (as required by the syntax). For ctx0 == 0, we need to add it here or it'll
  // be missing during the loop.
  int cost = (ctx0 == 0) ? VP8BitCost(1, p0) : 0;

  if (res->last < 0) {
    return VP8BitCost(0, p0);
  }

  {   // precompute clamped levels and contexts, packed to 8b.
    const __m128i zero = _mm_setzero_si128();
    const __m128i kCst2 = _mm_set1_epi8(2);
    const __m128i kCst67 = _mm_set1_epi8(MAX_VARIABLE_LEVEL);
    const __m128i c0 = _mm_loadu_si128((const __m128i*)&res->coeffs[0]);
    const __m128i c1 = _mm_loadu_si128((const __m128i*)&res->coeffs[8]);
    const __m128i D0 = _mm_sub_epi16(zero, c0);
    const __m128i D1 = _mm_sub_epi16(zero, c1);
    const __m128i E0 = _mm_max_epi16(c0, D0);   // abs(v), 16b
    const __m128i E1 = _mm_max_epi16(c1, D1);
    const __m128i F = _mm_packs_epi16(E0, E1);
    const __m128i G = _mm_min_epu8(F, kCst2);    // context = 0,1,2
    const __m128i H = _mm_min_epu8(F, kCst67);   // clamp_level in [0..67]

    _mm_storeu_si128((__m128i*)&ctxs[0], G);
    _mm_storeu_si128((__m128i*)&levels[0], H);

    _mm_storeu_si128((__m128i*)&abs_levels[0], E0);
    _mm_storeu_si128((__m128i*)&abs_levels[8], E1);
  }
  for (; n < res->last; ++n) {
    const int ctx = ctxs[n];
    const int level = levels[n];
    const int flevel = abs_levels[n];   // full level
    cost += VP8LevelFixedCosts[flevel] + t[level];  // simplified VP8LevelCost()
    t = costs[n + 1][ctx];
  }
  // Last coefficient is always non-zero
  {
    const int level = levels[n];
    const int flevel = abs_levels[n];
    assert(flevel != 0);
    cost += VP8LevelFixedCosts[flevel] + t[level];
    if (n < 15) {
      const int b = VP8EncBands[n + 1];
      const int ctx = ctxs[n];
      const int last_p0 = res->prob[b][ctx][0];
      cost += VP8BitCost(0, last_p0);
    }
  }
  return cost;
}
Ejemplo n.º 5
0
static void SetSegmentProbas(VP8Encoder* const enc) {
  int p[NUM_MB_SEGMENTS] = { 0 };
  int n;

  for (n = 0; n < enc->mb_w_ * enc->mb_h_; ++n) {
    const VP8MBInfo* const mb = &enc->mb_info_[n];
    p[mb->segment_]++;
  }
  if (enc->pic_->stats != NULL) {
    for (n = 0; n < NUM_MB_SEGMENTS; ++n) {
      enc->pic_->stats->segment_size[n] = p[n];
    }
  }
  if (enc->segment_hdr_.num_segments_ > 1) {
    uint8_t* const probas = enc->proba_.segments_;
    probas[0] = GetProba(p[0] + p[1], p[2] + p[3]);
    probas[1] = GetProba(p[0], p[1]);
    probas[2] = GetProba(p[2], p[3]);

    enc->segment_hdr_.update_map_ =
        (probas[0] != 255) || (probas[1] != 255) || (probas[2] != 255);
    enc->segment_hdr_.size_ =
        p[0] * (VP8BitCost(0, probas[0]) + VP8BitCost(0, probas[1])) +
        p[1] * (VP8BitCost(0, probas[0]) + VP8BitCost(1, probas[1])) +
        p[2] * (VP8BitCost(1, probas[0]) + VP8BitCost(0, probas[2])) +
        p[3] * (VP8BitCost(1, probas[0]) + VP8BitCost(1, probas[2]));
  } else {
    enc->segment_hdr_.update_map_ = 0;
    enc->segment_hdr_.size_ = 0;
  }
}
Ejemplo n.º 6
0
// Returns the bit-cost for coding the skip probability.
static int FinalizeSkipProba(VP8Encoder* const enc) {
  VP8Proba* const proba = &enc->proba_;
  const int nb_mbs = enc->mb_w_ * enc->mb_h_;
  const int nb_events = proba->nb_skip_;
  int size;
  proba->skip_proba_ = CalcSkipProba(nb_events, nb_mbs);
  proba->use_skip_proba_ = (proba->skip_proba_ < SKIP_PROBA_THRESHOLD);
  size = 256;   // 'use_skip_proba' bit
  if (proba->use_skip_proba_) {
    size +=  nb_events * VP8BitCost(1, proba->skip_proba_)
         + (nb_mbs - nb_events) * VP8BitCost(0, proba->skip_proba_);
    size += 8 * 256;   // cost of signaling the skip_proba_ itself.
  }
  return size;
}
Ejemplo n.º 7
0
void VP8CalculateLevelCosts(VP8Proba* const proba) {
  int ctype, band, ctx;
  for (ctype = 0; ctype < NUM_TYPES; ++ctype) {
    for (band = 0; band < NUM_BANDS; ++band) {
      for(ctx = 0; ctx < NUM_CTX; ++ctx) {
        const uint8_t* const p = proba->coeffs_[ctype][band][ctx];
        uint16_t* const table = proba->level_cost_[ctype][band][ctx];
        const int cost_base = VP8BitCost(1, p[1]);
        int v;
        table[0] = VP8BitCost(0, p[1]);
        for (v = 1; v <= MAX_VARIABLE_LEVEL; ++v) {
          table[v] = cost_base + VariableLevelCost(v, p);
        }
        // Starting at level 67 and up, the variable part of the cost is
        // actually constant.
      }
    }
  }
}
Ejemplo n.º 8
0
static int VariableLevelCost(int level, const uint8_t probas[NUM_PROBAS]) {
  int pattern = VP8LevelCodes[level - 1][0];
  int bits = VP8LevelCodes[level - 1][1];
  int cost = 0;
  int i;
  for (i = 2; pattern; ++i) {
    if (pattern & 1) {
      cost += VP8BitCost(bits & 1, probas[i]);
    }
    bits >>= 1;
    pattern >>= 1;
  }
  return cost;
}
Ejemplo n.º 9
0
// Cost of coding 'nb' 1's and 'total-nb' 0's using 'proba' probability.
static int BranchCost(int nb, int total, int proba) {
  return nb * VP8BitCost(1, proba) + (total - nb) * VP8BitCost(0, proba);
}
Ejemplo n.º 10
0
static int TrellisQuantizeBlock(const VP8EncIterator* const it,
                                int16_t in[16], int16_t out[16],
                                int ctx0, int coeff_type,
                                const VP8Matrix* const mtx,
                                int lambda) {
  ProbaArray* const last_costs = it->enc_->proba_.coeffs_[coeff_type];
  CostArray* const costs = it->enc_->proba_.level_cost_[coeff_type];
  const int first = (coeff_type == 0) ? 1 : 0;
  Node nodes[17][NUM_NODES];
  int best_path[3] = {-1, -1, -1};   // store best-last/best-level/best-previous
  score_t best_score;
  int best_node;
  int last = first - 1;
  int n, m, p, nz;

  {
    score_t cost;
    score_t max_error;
    const int thresh = mtx->q_[1] * mtx->q_[1] / 4;
    const int last_proba = last_costs[VP8EncBands[first]][ctx0][0];

    // compute maximal distortion.
    max_error = 0;
    for (n = first; n < 16; ++n) {
      const int j  = kZigzag[n];
      const int err = in[j] * in[j];
      max_error += kWeightTrellis[j] * err;
      if (err > thresh) last = n;
    }
    // we don't need to go inspect up to n = 16 coeffs. We can just go up
    // to last + 1 (inclusive) without losing much.
    if (last < 15) ++last;

    // compute 'skip' score. This is the max score one can do.
    cost = VP8BitCost(0, last_proba);
    best_score = RDScoreTrellis(lambda, cost, max_error);

    // initialize source node.
    n = first - 1;
    for (m = -MIN_DELTA; m <= MAX_DELTA; ++m) {
      NODE(n, m).cost = 0;
      NODE(n, m).error = max_error;
      NODE(n, m).ctx = ctx0;
    }
  }

  // traverse trellis.
  for (n = first; n <= last; ++n) {
    const int j  = kZigzag[n];
    const int Q  = mtx->q_[j];
    const int iQ = mtx->iq_[j];
    const int B = BIAS(0x00);     // neutral bias
    // note: it's important to take sign of the _original_ coeff,
    // so we don't have to consider level < 0 afterward.
    const int sign = (in[j] < 0);
    int coeff0 = (sign ? -in[j] : in[j]) + mtx->sharpen_[j];
    int level0;
    if (coeff0 > 2047) coeff0 = 2047;

    level0 = QUANTDIV(coeff0, iQ, B);
    // test all alternate level values around level0.
    for (m = -MIN_DELTA; m <= MAX_DELTA; ++m) {
      Node* const cur = &NODE(n, m);
      int delta_error, new_error;
      score_t cur_score = MAX_COST;
      int level = level0 + m;
      int last_proba;

      cur->sign = sign;
      cur->level = level;
      cur->ctx = (level == 0) ? 0 : (level == 1) ? 1 : 2;
      if (level >= 2048 || level < 0) {   // node is dead?
        cur->cost = MAX_COST;
        continue;
      }
      last_proba = last_costs[VP8EncBands[n + 1]][cur->ctx][0];

      // Compute delta_error = how much coding this level will
      // subtract as distortion to max_error
      new_error = coeff0 - level * Q;
      delta_error =
        kWeightTrellis[j] * (coeff0 * coeff0 - new_error * new_error);

      // Inspect all possible non-dead predecessors. Retain only the best one.
      for (p = -MIN_DELTA; p <= MAX_DELTA; ++p) {
        const Node* const prev = &NODE(n - 1, p);
        const int prev_ctx = prev->ctx;
        const uint16_t* const tcost = costs[VP8EncBands[n]][prev_ctx];
        const score_t total_error = prev->error - delta_error;
        score_t cost, base_cost, score;

        if (prev->cost >= MAX_COST) {   // dead node?
          continue;
        }

        // Base cost of both terminal/non-terminal
        base_cost = prev->cost + VP8LevelCost(tcost, level);

        // Examine node assuming it's a non-terminal one.
        cost = base_cost;
        if (level && n < 15) {
          cost += VP8BitCost(1, last_proba);
        }
        score = RDScoreTrellis(lambda, cost, total_error);
        if (score < cur_score) {
          cur_score = score;
          cur->cost  = cost;
          cur->error = total_error;
          cur->prev  = p;
        }

        // Now, record best terminal node (and thus best entry in the graph).
        if (level) {
          cost = base_cost;
          if (n < 15) cost += VP8BitCost(0, last_proba);
          score = RDScoreTrellis(lambda, cost, total_error);
          if (score < best_score) {
            best_score = score;
            best_path[0] = n;   // best eob position
            best_path[1] = m;   // best level
            best_path[2] = p;   // best predecessor
          }
        }
      }
    }
  }

  // Fresh start
  memset(in + first, 0, (16 - first) * sizeof(*in));
  memset(out + first, 0, (16 - first) * sizeof(*out));
  if (best_path[0] == -1) {
    return 0;   // skip!
  }

  // Unwind the best path.
  // Note: best-prev on terminal node is not necessarily equal to the
  // best_prev for non-terminal. So we patch best_path[2] in.
  n = best_path[0];
  best_node = best_path[1];
  NODE(n, best_node).prev = best_path[2];   // force best-prev for terminal
  nz = 0;

  for (; n >= first; --n) {
    const Node* const node = &NODE(n, best_node);
    const int j = kZigzag[n];
    out[n] = node->sign ? -node->level : node->level;
    nz |= (node->level != 0);
    in[j] = out[n] * mtx->q_[j];
    best_node = node->prev;
  }
  return nz;
}