Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 328 insertions, 0 deletions

diff --git a/third_party/jpeg-xl/lib/jxl/enc_huffman_tree.cc b/third_party/jpeg-xl/lib/jxl/enc_huffman_tree.cc
new file mode 100644
index 0000000000..5c40dea770
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/enc_huffman_tree.cc
@@ -0,0 +1,328 @@
+// 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_huffman_tree.h"
+
+#include <algorithm>
+#include <limits>
+#include <vector>
+
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+void SetDepth(const HuffmanTree& p, HuffmanTree* pool, uint8_t* depth,
+              uint8_t level) {
+  if (p.index_left >= 0) {
+    ++level;
+    SetDepth(pool[p.index_left], pool, depth, level);
+    SetDepth(pool[p.index_right_or_value], pool, depth, level);
+  } else {
+    depth[p.index_right_or_value] = level;
+  }
+}
+
+// Sort the root nodes, least popular first.
+static JXL_INLINE bool Compare(const HuffmanTree& v0, const HuffmanTree& v1) {
+  return v0.total_count < v1.total_count;
+}
+
+// This function will create a Huffman tree.
+//
+// The catch here is that the tree cannot be arbitrarily deep.
+// Brotli specifies a maximum depth of 15 bits for "code trees"
+// and 7 bits for "code length code trees."
+//
+// count_limit is the value that is to be faked as the minimum value
+// and this minimum value is raised until the tree matches the
+// maximum length requirement.
+//
+// This algorithm is not of excellent performance for very long data blocks,
+// especially when population counts are longer than 2**tree_limit, but
+// we are not planning to use this with extremely long blocks.
+//
+// See http://en.wikipedia.org/wiki/Huffman_coding
+void CreateHuffmanTree(const uint32_t* data, const size_t length,
+                       const int tree_limit, uint8_t* depth) {
+  // For block sizes below 64 kB, we never need to do a second iteration
+  // of this loop. Probably all of our block sizes will be smaller than
+  // that, so this loop is mostly of academic interest. If we actually
+  // would need this, we would be better off with the Katajainen algorithm.
+  for (uint32_t count_limit = 1;; count_limit *= 2) {
+    std::vector<HuffmanTree> tree;
+    tree.reserve(2 * length + 1);
+
+    for (size_t i = length; i != 0;) {
+      --i;
+      if (data[i]) {
+        const uint32_t count = std::max(data[i], count_limit - 1);
+        tree.emplace_back(count, -1, static_cast<int16_t>(i));
+      }
+    }
+
+    const size_t n = tree.size();
+    if (n == 1) {
+      // Fake value; will be fixed on upper level.
+      depth[tree[0].index_right_or_value] = 1;
+      break;
+    }
+
+    std::stable_sort(tree.begin(), tree.end(), Compare);
+
+    // The nodes are:
+    // [0, n): the sorted leaf nodes that we start with.
+    // [n]: we add a sentinel here.
+    // [n + 1, 2n): new parent nodes are added here, starting from
+    //              (n+1). These are naturally in ascending order.
+    // [2n]: we add a sentinel at the end as well.
+    // There will be (2n+1) elements at the end.
+    const HuffmanTree sentinel(std::numeric_limits<uint32_t>::max(), -1, -1);
+    tree.push_back(sentinel);
+    tree.push_back(sentinel);
+
+    size_t i = 0;      // Points to the next leaf node.
+    size_t j = n + 1;  // Points to the next non-leaf node.
+    for (size_t k = n - 1; k != 0; --k) {
+      size_t left, right;
+      if (tree[i].total_count <= tree[j].total_count) {
+        left = i;
+        ++i;
+      } else {
+        left = j;
+        ++j;
+      }
+      if (tree[i].total_count <= tree[j].total_count) {
+        right = i;
+        ++i;
+      } else {
+        right = j;
+        ++j;
+      }
+
+      // The sentinel node becomes the parent node.
+      size_t j_end = tree.size() - 1;
+      tree[j_end].total_count =
+          tree[left].total_count + tree[right].total_count;
+      tree[j_end].index_left = static_cast<int16_t>(left);
+      tree[j_end].index_right_or_value = static_cast<int16_t>(right);
+
+      // Add back the last sentinel node.
+      tree.push_back(sentinel);
+    }
+    JXL_DASSERT(tree.size() == 2 * n + 1);
+    SetDepth(tree[2 * n - 1], &tree[0], depth, 0);
+
+    // We need to pack the Huffman tree in tree_limit bits.
+    // If this was not successful, add fake entities to the lowest values
+    // and retry.
+    if (*std::max_element(&depth[0], &depth[length]) <= tree_limit) {
+      break;
+    }
+  }
+}
+
+void Reverse(uint8_t* v, size_t start, size_t end) {
+  --end;
+  while (start < end) {
+    uint8_t tmp = v[start];
+    v[start] = v[end];
+    v[end] = tmp;
+    ++start;
+    --end;
+  }
+}
+
+void WriteHuffmanTreeRepetitions(const uint8_t previous_value,
+                                 const uint8_t value, size_t repetitions,
+                                 size_t* tree_size, uint8_t* tree,
+                                 uint8_t* extra_bits_data) {
+  JXL_DASSERT(repetitions > 0);
+  if (previous_value != value) {
+    tree[*tree_size] = value;
+    extra_bits_data[*tree_size] = 0;
+    ++(*tree_size);
+    --repetitions;
+  }
+  if (repetitions == 7) {
+    tree[*tree_size] = value;
+    extra_bits_data[*tree_size] = 0;
+    ++(*tree_size);
+    --repetitions;
+  }
+  if (repetitions < 3) {
+    for (size_t i = 0; i < repetitions; ++i) {
+      tree[*tree_size] = value;
+      extra_bits_data[*tree_size] = 0;
+      ++(*tree_size);
+    }
+  } else {
+    repetitions -= 3;
+    size_t start = *tree_size;
+    while (true) {
+      tree[*tree_size] = 16;
+      extra_bits_data[*tree_size] = repetitions & 0x3;
+      ++(*tree_size);
+      repetitions >>= 2;
+      if (repetitions == 0) {
+        break;
+      }
+      --repetitions;
+    }
+    Reverse(tree, start, *tree_size);
+    Reverse(extra_bits_data, start, *tree_size);
+  }
+}
+
+void WriteHuffmanTreeRepetitionsZeros(size_t repetitions, size_t* tree_size,
+                                      uint8_t* tree, uint8_t* extra_bits_data) {
+  if (repetitions == 11) {
+    tree[*tree_size] = 0;
+    extra_bits_data[*tree_size] = 0;
+    ++(*tree_size);
+    --repetitions;
+  }
+  if (repetitions < 3) {
+    for (size_t i = 0; i < repetitions; ++i) {
+      tree[*tree_size] = 0;
+      extra_bits_data[*tree_size] = 0;
+      ++(*tree_size);
+    }
+  } else {
+    repetitions -= 3;
+    size_t start = *tree_size;
+    while (true) {
+      tree[*tree_size] = 17;
+      extra_bits_data[*tree_size] = repetitions & 0x7;
+      ++(*tree_size);
+      repetitions >>= 3;
+      if (repetitions == 0) {
+        break;
+      }
+      --repetitions;
+    }
+    Reverse(tree, start, *tree_size);
+    Reverse(extra_bits_data, start, *tree_size);
+  }
+}
+
+static void DecideOverRleUse(const uint8_t* depth, const size_t length,
+                             bool* use_rle_for_non_zero,
+                             bool* use_rle_for_zero) {
+  size_t total_reps_zero = 0;
+  size_t total_reps_non_zero = 0;
+  size_t count_reps_zero = 1;
+  size_t count_reps_non_zero = 1;
+  for (size_t i = 0; i < length;) {
+    const uint8_t value = depth[i];
+    size_t reps = 1;
+    for (size_t k = i + 1; k < length && depth[k] == value; ++k) {
+      ++reps;
+    }
+    if (reps >= 3 && value == 0) {
+      total_reps_zero += reps;
+      ++count_reps_zero;
+    }
+    if (reps >= 4 && value != 0) {
+      total_reps_non_zero += reps;
+      ++count_reps_non_zero;
+    }
+    i += reps;
+  }
+  *use_rle_for_non_zero = total_reps_non_zero > count_reps_non_zero * 2;
+  *use_rle_for_zero = total_reps_zero > count_reps_zero * 2;
+}
+
+void WriteHuffmanTree(const uint8_t* depth, size_t length, size_t* tree_size,
+                      uint8_t* tree, uint8_t* extra_bits_data) {
+  uint8_t previous_value = 8;
+
+  // Throw away trailing zeros.
+  size_t new_length = length;
+  for (size_t i = 0; i < length; ++i) {
+    if (depth[length - i - 1] == 0) {
+      --new_length;
+    } else {
+      break;
+    }
+  }
+
+  // First gather statistics on if it is a good idea to do rle.
+  bool use_rle_for_non_zero = false;
+  bool use_rle_for_zero = false;
+  if (length > 50) {
+    // Find rle coding for longer codes.
+    // Shorter codes seem not to benefit from rle.
+    DecideOverRleUse(depth, new_length, &use_rle_for_non_zero,
+                     &use_rle_for_zero);
+  }
+
+  // Actual rle coding.
+  for (size_t i = 0; i < new_length;) {
+    const uint8_t value = depth[i];
+    size_t reps = 1;
+    if ((value != 0 && use_rle_for_non_zero) ||
+        (value == 0 && use_rle_for_zero)) {
+      for (size_t k = i + 1; k < new_length && depth[k] == value; ++k) {
+        ++reps;
+      }
+    }
+    if (value == 0) {
+      WriteHuffmanTreeRepetitionsZeros(reps, tree_size, tree, extra_bits_data);
+    } else {
+      WriteHuffmanTreeRepetitions(previous_value, value, reps, tree_size, tree,
+                                  extra_bits_data);
+      previous_value = value;
+    }
+    i += reps;
+  }
+}
+
+namespace {
+
+uint16_t ReverseBits(int num_bits, uint16_t bits) {
+  static const size_t kLut[16] = {// Pre-reversed 4-bit values.
+                                  0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe,
+                                  0x1, 0x9, 0x5, 0xd, 0x3, 0xb, 0x7, 0xf};
+  size_t retval = kLut[bits & 0xf];
+  for (int i = 4; i < num_bits; i += 4) {
+    retval <<= 4;
+    bits = static_cast<uint16_t>(bits >> 4);
+    retval |= kLut[bits & 0xf];
+  }
+  retval >>= (-num_bits & 0x3);
+  return static_cast<uint16_t>(retval);
+}
+
+}  // namespace
+
+void ConvertBitDepthsToSymbols(const uint8_t* depth, size_t len,
+                               uint16_t* bits) {
+  // In Brotli, all bit depths are [1..15]
+  // 0 bit depth means that the symbol does not exist.
+  const int kMaxBits = 16;  // 0..15 are values for bits
+  uint16_t bl_count[kMaxBits] = {0};
+  {
+    for (size_t i = 0; i < len; ++i) {
+      ++bl_count[depth[i]];
+    }
+    bl_count[0] = 0;
+  }
+  uint16_t next_code[kMaxBits];
+  next_code[0] = 0;
+  {
+    int code = 0;
+    for (size_t i = 1; i < kMaxBits; ++i) {
+      code = (code + bl_count[i - 1]) << 1;
+      next_code[i] = static_cast<uint16_t>(code);
+    }
+  }
+  for (size_t i = 0; i < len; ++i) {
+    if (depth[i]) {
+      bits[i] = ReverseBits(depth[i], next_code[depth[i]]++);
+    }
+  }
+}
+
+}  // namespace jxl