Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 295 insertions, 0 deletions

diff --git a/third_party/jpeg-xl/lib/jxl/enc_cluster.cc b/third_party/jpeg-xl/lib/jxl/enc_cluster.cc
new file mode 100644
index 0000000000..c79b3ac834
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/enc_cluster.cc
@@ -0,0 +1,295 @@
+// Copyright (c) the JPEG XL 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.
+
+#include "lib/jxl/enc_cluster.h"
+
+#include <algorithm>
+#include <cmath>
+#include <limits>
+#include <map>
+#include <memory>
+#include <numeric>
+#include <queue>
+#include <tuple>
+
+#undef HWY_TARGET_INCLUDE
+#define HWY_TARGET_INCLUDE "lib/jxl/enc_cluster.cc"
+#include <hwy/foreach_target.h>
+#include <hwy/highway.h>
+
+#include "lib/jxl/ac_context.h"
+#include "lib/jxl/base/profiler.h"
+#include "lib/jxl/fast_math-inl.h"
+HWY_BEFORE_NAMESPACE();
+namespace jxl {
+namespace HWY_NAMESPACE {
+
+// These templates are not found via ADL.
+using hwy::HWY_NAMESPACE::Eq;
+using hwy::HWY_NAMESPACE::IfThenZeroElse;
+
+template <class V>
+V Entropy(V count, V inv_total, V total) {
+  const HWY_CAPPED(float, Histogram::kRounding) d;
+  const auto zero = Set(d, 0.0f);
+  // TODO(eustas): why (0 - x) instead of Neg(x)?
+  return IfThenZeroElse(
+      Eq(count, total),
+      Sub(zero, Mul(count, FastLog2f(d, Mul(inv_total, count)))));
+}
+
+void HistogramEntropy(const Histogram& a) {
+  a.entropy_ = 0.0f;
+  if (a.total_count_ == 0) return;
+
+  const HWY_CAPPED(float, Histogram::kRounding) df;
+  const HWY_CAPPED(int32_t, Histogram::kRounding) di;
+
+  const auto inv_tot = Set(df, 1.0f / a.total_count_);
+  auto entropy_lanes = Zero(df);
+  auto total = Set(df, a.total_count_);
+
+  for (size_t i = 0; i < a.data_.size(); i += Lanes(di)) {
+    const auto counts = LoadU(di, &a.data_[i]);
+    entropy_lanes =
+        Add(entropy_lanes, Entropy(ConvertTo(df, counts), inv_tot, total));
+  }
+  a.entropy_ += GetLane(SumOfLanes(df, entropy_lanes));
+}
+
+float HistogramDistance(const Histogram& a, const Histogram& b) {
+  if (a.total_count_ == 0 || b.total_count_ == 0) return 0;
+
+  const HWY_CAPPED(float, Histogram::kRounding) df;
+  const HWY_CAPPED(int32_t, Histogram::kRounding) di;
+
+  const auto inv_tot = Set(df, 1.0f / (a.total_count_ + b.total_count_));
+  auto distance_lanes = Zero(df);
+  auto total = Set(df, a.total_count_ + b.total_count_);
+
+  for (size_t i = 0; i < std::max(a.data_.size(), b.data_.size());
+       i += Lanes(di)) {
+    const auto a_counts =
+        a.data_.size() > i ? LoadU(di, &a.data_[i]) : Zero(di);
+    const auto b_counts =
+        b.data_.size() > i ? LoadU(di, &b.data_[i]) : Zero(di);
+    const auto counts = ConvertTo(df, Add(a_counts, b_counts));
+    distance_lanes = Add(distance_lanes, Entropy(counts, inv_tot, total));
+  }
+  const float total_distance = GetLane(SumOfLanes(df, distance_lanes));
+  return total_distance - a.entropy_ - b.entropy_;
+}
+
+// First step of a k-means clustering with a fancy distance metric.
+void FastClusterHistograms(const std::vector<Histogram>& in,
+                           size_t max_histograms, std::vector<Histogram>* out,
+                           std::vector<uint32_t>* histogram_symbols) {
+  PROFILER_FUNC;
+  out->clear();
+  out->reserve(max_histograms);
+  histogram_symbols->clear();
+  histogram_symbols->resize(in.size(), max_histograms);
+
+  std::vector<float> dists(in.size(), std::numeric_limits<float>::max());
+  size_t largest_idx = 0;
+  for (size_t i = 0; i < in.size(); i++) {
+    if (in[i].total_count_ == 0) {
+      (*histogram_symbols)[i] = 0;
+      dists[i] = 0.0f;
+      continue;
+    }
+    HistogramEntropy(in[i]);
+    if (in[i].total_count_ > in[largest_idx].total_count_) {
+      largest_idx = i;
+    }
+  }
+
+  constexpr float kMinDistanceForDistinct = 48.0f;
+  while (out->size() < max_histograms) {
+    (*histogram_symbols)[largest_idx] = out->size();
+    out->push_back(in[largest_idx]);
+    dists[largest_idx] = 0.0f;
+    largest_idx = 0;
+    for (size_t i = 0; i < in.size(); i++) {
+      if (dists[i] == 0.0f) continue;
+      dists[i] = std::min(HistogramDistance(in[i], out->back()), dists[i]);
+      if (dists[i] > dists[largest_idx]) largest_idx = i;
+    }
+    if (dists[largest_idx] < kMinDistanceForDistinct) break;
+  }
+
+  for (size_t i = 0; i < in.size(); i++) {
+    if ((*histogram_symbols)[i] != max_histograms) continue;
+    size_t best = 0;
+    float best_dist = HistogramDistance(in[i], (*out)[best]);
+    for (size_t j = 1; j < out->size(); j++) {
+      float dist = HistogramDistance(in[i], (*out)[j]);
+      if (dist < best_dist) {
+        best = j;
+        best_dist = dist;
+      }
+    }
+    (*out)[best].AddHistogram(in[i]);
+    HistogramEntropy((*out)[best]);
+    (*histogram_symbols)[i] = best;
+  }
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace jxl
+HWY_AFTER_NAMESPACE();
+
+#if HWY_ONCE
+namespace jxl {
+HWY_EXPORT(FastClusterHistograms);  // Local function
+HWY_EXPORT(HistogramEntropy);       // Local function
+
+float Histogram::ShannonEntropy() const {
+  HWY_DYNAMIC_DISPATCH(HistogramEntropy)(*this);
+  return entropy_;
+}
+
+namespace {
+// -----------------------------------------------------------------------------
+// Histogram refinement
+
+// Reorder histograms in *out so that the new symbols in *symbols come in
+// increasing order.
+void HistogramReindex(std::vector<Histogram>* out,
+                      std::vector<uint32_t>* symbols) {
+  std::vector<Histogram> tmp(*out);
+  std::map<int, int> new_index;
+  int next_index = 0;
+  for (uint32_t symbol : *symbols) {
+    if (new_index.find(symbol) == new_index.end()) {
+      new_index[symbol] = next_index;
+      (*out)[next_index] = tmp[symbol];
+      ++next_index;
+    }
+  }
+  out->resize(next_index);
+  for (uint32_t& symbol : *symbols) {
+    symbol = new_index[symbol];
+  }
+}
+
+}  // namespace
+
+// Clusters similar histograms in 'in' together, the selected histograms are
+// placed in 'out', and for each index in 'in', *histogram_symbols will
+// indicate which of the 'out' histograms is the best approximation.
+void ClusterHistograms(const HistogramParams params,
+                       const std::vector<Histogram>& in, size_t max_histograms,
+                       std::vector<Histogram>* out,
+                       std::vector<uint32_t>* histogram_symbols) {
+  max_histograms = std::min(max_histograms, params.max_histograms);
+  max_histograms = std::min(max_histograms, in.size());
+  if (params.clustering == HistogramParams::ClusteringType::kFastest) {
+    max_histograms = std::min(max_histograms, static_cast<size_t>(4));
+  }
+
+  HWY_DYNAMIC_DISPATCH(FastClusterHistograms)
+  (in, max_histograms, out, histogram_symbols);
+
+  if (params.clustering == HistogramParams::ClusteringType::kBest) {
+    for (size_t i = 0; i < out->size(); i++) {
+      (*out)[i].entropy_ =
+          ANSPopulationCost((*out)[i].data_.data(), (*out)[i].data_.size());
+    }
+    uint32_t next_version = 2;
+    std::vector<uint32_t> version(out->size(), 1);
+    std::vector<uint32_t> renumbering(out->size());
+    std::iota(renumbering.begin(), renumbering.end(), 0);
+
+    // Try to pair up clusters if doing so reduces the total cost.
+
+    struct HistogramPair {
+      // validity of a pair: p.version == max(version[i], version[j])
+      float cost;
+      uint32_t first;
+      uint32_t second;
+      uint32_t version;
+      // We use > because priority queues sort in *decreasing* order, but we
+      // want lower cost elements to appear first.
+      bool operator<(const HistogramPair& other) const {
+        return std::make_tuple(cost, first, second, version) >
+               std::make_tuple(other.cost, other.first, other.second,
+                               other.version);
+      }
+    };
+
+    // Create list of all pairs by increasing merging cost.
+    std::priority_queue<HistogramPair> pairs_to_merge;
+    for (uint32_t i = 0; i < out->size(); i++) {
+      for (uint32_t j = i + 1; j < out->size(); j++) {
+        Histogram histo;
+        histo.AddHistogram((*out)[i]);
+        histo.AddHistogram((*out)[j]);
+        float cost = ANSPopulationCost(histo.data_.data(), histo.data_.size()) -
+                     (*out)[i].entropy_ - (*out)[j].entropy_;
+        // Avoid enqueueing pairs that are not advantageous to merge.
+        if (cost >= 0) continue;
+        pairs_to_merge.push(
+            HistogramPair{cost, i, j, std::max(version[i], version[j])});
+      }
+    }
+
+    // Merge the best pair to merge, add new pairs that get formed as a
+    // consequence.
+    while (!pairs_to_merge.empty()) {
+      uint32_t first = pairs_to_merge.top().first;
+      uint32_t second = pairs_to_merge.top().second;
+      uint32_t ver = pairs_to_merge.top().version;
+      pairs_to_merge.pop();
+      if (ver != std::max(version[first], version[second]) ||
+          version[first] == 0 || version[second] == 0) {
+        continue;
+      }
+      (*out)[first].AddHistogram((*out)[second]);
+      (*out)[first].entropy_ = ANSPopulationCost((*out)[first].data_.data(),
+                                                 (*out)[first].data_.size());
+      for (size_t i = 0; i < renumbering.size(); i++) {
+        if (renumbering[i] == second) {
+          renumbering[i] = first;
+        }
+      }
+      version[second] = 0;
+      version[first] = next_version++;
+      for (uint32_t j = 0; j < out->size(); j++) {
+        if (j == first) continue;
+        if (version[j] == 0) continue;
+        Histogram histo;
+        histo.AddHistogram((*out)[first]);
+        histo.AddHistogram((*out)[j]);
+        float cost = ANSPopulationCost(histo.data_.data(), histo.data_.size()) -
+                     (*out)[first].entropy_ - (*out)[j].entropy_;
+        // Avoid enqueueing pairs that are not advantageous to merge.
+        if (cost >= 0) continue;
+        pairs_to_merge.push(
+            HistogramPair{cost, std::min(first, j), std::max(first, j),
+                          std::max(version[first], version[j])});
+      }
+    }
+    std::vector<uint32_t> reverse_renumbering(out->size(), -1);
+    size_t num_alive = 0;
+    for (size_t i = 0; i < out->size(); i++) {
+      if (version[i] == 0) continue;
+      (*out)[num_alive++] = (*out)[i];
+      reverse_renumbering[i] = num_alive - 1;
+    }
+    out->resize(num_alive);
+    for (size_t i = 0; i < histogram_symbols->size(); i++) {
+      (*histogram_symbols)[i] =
+          reverse_renumbering[renumbering[(*histogram_symbols)[i]]];
+    }
+  }
+
+  // Convert the context map to a canonical form.
+  HistogramReindex(out, histogram_symbols);
+}
+
+}  // namespace jxl
+#endif  // HWY_ONCE