Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 255 insertions, 0 deletions

diff --git a/third_party/jpeg-xl/lib/jxl/dec_huffman.cc b/third_party/jpeg-xl/lib/jxl/dec_huffman.cc
new file mode 100644
index 0000000000..05b275773a
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/dec_huffman.cc
@@ -0,0 +1,255 @@
+// 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/dec_huffman.h"
+
+#include <string.h> /* for memset */
+
+#include <vector>
+
+#include "lib/jxl/ans_params.h"
+#include "lib/jxl/base/bits.h"
+#include "lib/jxl/huffman_table.h"
+
+namespace jxl {
+
+static const int kCodeLengthCodes = 18;
+static const uint8_t kCodeLengthCodeOrder[kCodeLengthCodes] = {
+    1, 2, 3, 4, 0, 5, 17, 6, 16, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+};
+static const uint8_t kDefaultCodeLength = 8;
+static const uint8_t kCodeLengthRepeatCode = 16;
+
+int ReadHuffmanCodeLengths(const uint8_t* code_length_code_lengths,
+                           int num_symbols, uint8_t* code_lengths,
+                           BitReader* br) {
+  int symbol = 0;
+  uint8_t prev_code_len = kDefaultCodeLength;
+  int repeat = 0;
+  uint8_t repeat_code_len = 0;
+  int space = 32768;
+  HuffmanCode table[32];
+
+  uint16_t counts[16] = {0};
+  for (int i = 0; i < kCodeLengthCodes; ++i) {
+    ++counts[code_length_code_lengths[i]];
+  }
+  if (!BuildHuffmanTable(table, 5, code_length_code_lengths, kCodeLengthCodes,
+                         &counts[0])) {
+    return 0;
+  }
+
+  while (symbol < num_symbols && space > 0) {
+    const HuffmanCode* p = table;
+    uint8_t code_len;
+    br->Refill();
+    p += br->PeekFixedBits<5>();
+    br->Consume(p->bits);
+    code_len = (uint8_t)p->value;
+    if (code_len < kCodeLengthRepeatCode) {
+      repeat = 0;
+      code_lengths[symbol++] = code_len;
+      if (code_len != 0) {
+        prev_code_len = code_len;
+        space -= 32768u >> code_len;
+      }
+    } else {
+      const int extra_bits = code_len - 14;
+      int old_repeat;
+      int repeat_delta;
+      uint8_t new_len = 0;
+      if (code_len == kCodeLengthRepeatCode) {
+        new_len = prev_code_len;
+      }
+      if (repeat_code_len != new_len) {
+        repeat = 0;
+        repeat_code_len = new_len;
+      }
+      old_repeat = repeat;
+      if (repeat > 0) {
+        repeat -= 2;
+        repeat <<= extra_bits;
+      }
+      repeat += (int)br->ReadBits(extra_bits) + 3;
+      repeat_delta = repeat - old_repeat;
+      if (symbol + repeat_delta > num_symbols) {
+        return 0;
+      }
+      memset(&code_lengths[symbol], repeat_code_len, (size_t)repeat_delta);
+      symbol += repeat_delta;
+      if (repeat_code_len != 0) {
+        space -= repeat_delta << (15 - repeat_code_len);
+      }
+    }
+  }
+  if (space != 0) {
+    return 0;
+  }
+  memset(&code_lengths[symbol], 0, (size_t)(num_symbols - symbol));
+  return true;
+}
+
+static JXL_INLINE bool ReadSimpleCode(size_t alphabet_size, BitReader* br,
+                                      HuffmanCode* table) {
+  size_t max_bits =
+      (alphabet_size > 1u) ? FloorLog2Nonzero(alphabet_size - 1u) + 1 : 0;
+
+  size_t num_symbols = br->ReadFixedBits<2>() + 1;
+
+  uint16_t symbols[4] = {0};
+  for (size_t i = 0; i < num_symbols; ++i) {
+    uint16_t symbol = br->ReadBits(max_bits);
+    if (symbol >= alphabet_size) {
+      return false;
+    }
+    symbols[i] = symbol;
+  }
+
+  for (size_t i = 0; i < num_symbols - 1; ++i) {
+    for (size_t j = i + 1; j < num_symbols; ++j) {
+      if (symbols[i] == symbols[j]) return false;
+    }
+  }
+
+  // 4 symbols have to option to encode.
+  if (num_symbols == 4) num_symbols += br->ReadFixedBits<1>();
+
+  const auto swap_symbols = [&symbols](size_t i, size_t j) {
+    uint16_t t = symbols[j];
+    symbols[j] = symbols[i];
+    symbols[i] = t;
+  };
+
+  size_t table_size = 1;
+  switch (num_symbols) {
+    case 1:
+      table[0] = {0, symbols[0]};
+      break;
+    case 2:
+      if (symbols[0] > symbols[1]) swap_symbols(0, 1);
+      table[0] = {1, symbols[0]};
+      table[1] = {1, symbols[1]};
+      table_size = 2;
+      break;
+    case 3:
+      if (symbols[1] > symbols[2]) swap_symbols(1, 2);
+      table[0] = {1, symbols[0]};
+      table[2] = {1, symbols[0]};
+      table[1] = {2, symbols[1]};
+      table[3] = {2, symbols[2]};
+      table_size = 4;
+      break;
+    case 4: {
+      for (size_t i = 0; i < 3; ++i) {
+        for (size_t j = i + 1; j < 4; ++j) {
+          if (symbols[i] > symbols[j]) swap_symbols(i, j);
+        }
+      }
+      table[0] = {2, symbols[0]};
+      table[2] = {2, symbols[1]};
+      table[1] = {2, symbols[2]};
+      table[3] = {2, symbols[3]};
+      table_size = 4;
+      break;
+    }
+    case 5: {
+      if (symbols[2] > symbols[3]) swap_symbols(2, 3);
+      table[0] = {1, symbols[0]};
+      table[1] = {2, symbols[1]};
+      table[2] = {1, symbols[0]};
+      table[3] = {3, symbols[2]};
+      table[4] = {1, symbols[0]};
+      table[5] = {2, symbols[1]};
+      table[6] = {1, symbols[0]};
+      table[7] = {3, symbols[3]};
+      table_size = 8;
+      break;
+    }
+    default: {
+      // Unreachable.
+      return false;
+    }
+  }
+
+  const uint32_t goal_size = 1u << kHuffmanTableBits;
+  while (table_size != goal_size) {
+    memcpy(&table[table_size], &table[0],
+           (size_t)table_size * sizeof(table[0]));
+    table_size <<= 1;
+  }
+
+  return true;
+}
+
+bool HuffmanDecodingData::ReadFromBitStream(size_t alphabet_size,
+                                            BitReader* br) {
+  if (alphabet_size > (1 << PREFIX_MAX_BITS)) return false;
+
+  /* simple_code_or_skip is used as follows:
+     1 for simple code;
+     0 for no skipping, 2 skips 2 code lengths, 3 skips 3 code lengths */
+  uint32_t simple_code_or_skip = br->ReadFixedBits<2>();
+  if (simple_code_or_skip == 1u) {
+    table_.resize(1u << kHuffmanTableBits);
+    return ReadSimpleCode(alphabet_size, br, table_.data());
+  }
+
+  std::vector<uint8_t> code_lengths(alphabet_size, 0);
+  uint8_t code_length_code_lengths[kCodeLengthCodes] = {0};
+  int space = 32;
+  int num_codes = 0;
+  /* Static Huffman code for the code length code lengths */
+  static const HuffmanCode huff[16] = {
+      {2, 0}, {2, 4}, {2, 3}, {3, 2}, {2, 0}, {2, 4}, {2, 3}, {4, 1},
+      {2, 0}, {2, 4}, {2, 3}, {3, 2}, {2, 0}, {2, 4}, {2, 3}, {4, 5},
+  };
+  for (size_t i = simple_code_or_skip; i < kCodeLengthCodes && space > 0; ++i) {
+    const int code_len_idx = kCodeLengthCodeOrder[i];
+    const HuffmanCode* p = huff;
+    uint8_t v;
+    br->Refill();
+    p += br->PeekFixedBits<4>();
+    br->Consume(p->bits);
+    v = (uint8_t)p->value;
+    code_length_code_lengths[code_len_idx] = v;
+    if (v != 0) {
+      space -= (32u >> v);
+      ++num_codes;
+    }
+  }
+  bool ok = (num_codes == 1 || space == 0) &&
+            ReadHuffmanCodeLengths(code_length_code_lengths, alphabet_size,
+                                   &code_lengths[0], br);
+
+  if (!ok) return false;
+  uint16_t counts[16] = {0};
+  for (size_t i = 0; i < alphabet_size; ++i) {
+    ++counts[code_lengths[i]];
+  }
+  table_.resize(alphabet_size + 376);
+  uint32_t table_size =
+      BuildHuffmanTable(table_.data(), kHuffmanTableBits, &code_lengths[0],
+                        alphabet_size, &counts[0]);
+  table_.resize(table_size);
+  return (table_size > 0);
+}
+
+// Decodes the next Huffman coded symbol from the bit-stream.
+uint16_t HuffmanDecodingData::ReadSymbol(BitReader* br) const {
+  size_t n_bits;
+  const HuffmanCode* table = table_.data();
+  table += br->PeekBits(kHuffmanTableBits);
+  n_bits = table->bits;
+  if (n_bits > kHuffmanTableBits) {
+    br->Consume(kHuffmanTableBits);
+    n_bits -= kHuffmanTableBits;
+    table += table->value;
+    table += br->PeekBits(n_bits);
+  }
+  br->Consume(table->bits);
+  return table->value;
+}
+
+}  // namespace jxl