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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
commit6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch)
treea68f146d7fa01f0134297619fbe7e33db084e0aa /third_party/jpeg-xl/lib/jpegli/huffman.cc
parentInitial commit. (diff)
downloadthunderbird-upstream.tar.xz
thunderbird-upstream.zip
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--third_party/jpeg-xl/lib/jpegli/huffman.cc321
1 files changed, 321 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jpegli/huffman.cc b/third_party/jpeg-xl/lib/jpegli/huffman.cc
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+// 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/jpegli/huffman.h"
+
+#include <limits>
+#include <vector>
+
+#include "lib/jpegli/common.h"
+#include "lib/jpegli/error.h"
+
+namespace jpegli {
+
+// Returns the table width of the next 2nd level table, count is the histogram
+// of bit lengths for the remaining symbols, len is the code length of the next
+// processed symbol.
+static inline int NextTableBitSize(const int* count, int len) {
+ int left = 1 << (len - kJpegHuffmanRootTableBits);
+ while (len < static_cast<int>(kJpegHuffmanMaxBitLength)) {
+ left -= count[len];
+ if (left <= 0) break;
+ ++len;
+ left <<= 1;
+ }
+ return len - kJpegHuffmanRootTableBits;
+}
+
+void BuildJpegHuffmanTable(const uint32_t* count, const uint32_t* symbols,
+ HuffmanTableEntry* lut) {
+ HuffmanTableEntry code; // current table entry
+ HuffmanTableEntry* table; // next available space in table
+ int len; // current code length
+ int idx; // symbol index
+ int key; // prefix code
+ int reps; // number of replicate key values in current table
+ int low; // low bits for current root entry
+ int table_bits; // key length of current table
+ int table_size; // size of current table
+
+ // Make a local copy of the input bit length histogram.
+ int tmp_count[kJpegHuffmanMaxBitLength + 1] = {0};
+ int total_count = 0;
+ for (len = 1; len <= static_cast<int>(kJpegHuffmanMaxBitLength); ++len) {
+ tmp_count[len] = count[len];
+ total_count += tmp_count[len];
+ }
+
+ table = lut;
+ table_bits = kJpegHuffmanRootTableBits;
+ table_size = 1 << table_bits;
+
+ // Special case code with only one value.
+ if (total_count == 1) {
+ code.bits = 0;
+ code.value = symbols[0];
+ for (key = 0; key < table_size; ++key) {
+ table[key] = code;
+ }
+ return;
+ }
+
+ // Fill in root table.
+ key = 0;
+ idx = 0;
+ for (len = 1; len <= kJpegHuffmanRootTableBits; ++len) {
+ for (; tmp_count[len] > 0; --tmp_count[len]) {
+ code.bits = len;
+ code.value = symbols[idx++];
+ reps = 1 << (kJpegHuffmanRootTableBits - len);
+ while (reps--) {
+ table[key++] = code;
+ }
+ }
+ }
+
+ // Fill in 2nd level tables and add pointers to root table.
+ table += table_size;
+ table_size = 0;
+ low = 0;
+ for (len = kJpegHuffmanRootTableBits + 1;
+ len <= static_cast<int>(kJpegHuffmanMaxBitLength); ++len) {
+ for (; tmp_count[len] > 0; --tmp_count[len]) {
+ // Start a new sub-table if the previous one is full.
+ if (low >= table_size) {
+ table += table_size;
+ table_bits = NextTableBitSize(tmp_count, len);
+ table_size = 1 << table_bits;
+ low = 0;
+ lut[key].bits = table_bits + kJpegHuffmanRootTableBits;
+ lut[key].value = (table - lut) - key;
+ ++key;
+ }
+ code.bits = len - kJpegHuffmanRootTableBits;
+ code.value = symbols[idx++];
+ reps = 1 << (table_bits - code.bits);
+ while (reps--) {
+ table[low++] = code;
+ }
+ }
+ }
+}
+
+// A node of a Huffman tree.
+struct HuffmanTree {
+ HuffmanTree(uint32_t count, int16_t left, int16_t right)
+ : total_count(count), index_left(left), index_right_or_value(right) {}
+ uint32_t total_count;
+ int16_t index_left;
+ int16_t index_right_or_value;
+};
+
+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 ValidateHuffmanTable(j_common_ptr cinfo, const JHUFF_TBL* table,
+ bool is_dc) {
+ size_t total_symbols = 0;
+ size_t total_p = 0;
+ size_t max_depth = 0;
+ for (size_t d = 1; d <= kJpegHuffmanMaxBitLength; ++d) {
+ uint8_t count = table->bits[d];
+ if (count) {
+ total_symbols += count;
+ total_p += (1u << (kJpegHuffmanMaxBitLength - d)) * count;
+ max_depth = d;
+ }
+ }
+ total_p += 1u << (kJpegHuffmanMaxBitLength - max_depth); // sentinel symbol
+ if (total_symbols == 0) {
+ JPEGLI_ERROR("Empty Huffman table");
+ }
+ if (total_symbols > kJpegHuffmanAlphabetSize) {
+ JPEGLI_ERROR("Too many symbols in Huffman table");
+ }
+ if (total_p != (1u << kJpegHuffmanMaxBitLength)) {
+ JPEGLI_ERROR("Invalid bit length distribution");
+ }
+ uint8_t symbol_seen[kJpegHuffmanAlphabetSize] = {};
+ for (size_t i = 0; i < total_symbols; ++i) {
+ uint8_t symbol = table->huffval[i];
+ if (symbol_seen[symbol]) {
+ JPEGLI_ERROR("Duplicate symbol %d in Huffman table", symbol);
+ }
+ symbol_seen[symbol] = 1;
+ }
+}
+
+void AddStandardHuffmanTables(j_common_ptr cinfo, bool is_dc) {
+ // Huffman tables from the JPEG standard.
+ static constexpr JHUFF_TBL kStandardDCTables[2] = {
+ // DC luma
+ {{0, 0, 1, 5, 1, 1, 1, 1, 1, 1},
+ {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
+ FALSE},
+ // DC chroma
+ {{0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
+ FALSE}};
+ static constexpr JHUFF_TBL kStandardACTables[2] = {
+ // AC luma
+ {{0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125},
+ {0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06,
+ 0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
+ 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, 0x24, 0x33, 0x62, 0x72,
+ 0x82, 0x09, 0x0a, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
+ 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45,
+ 0x46, 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+ 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74, 0x75,
+ 0x76, 0x77, 0x78, 0x79, 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
+ 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3,
+ 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
+ 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9,
+ 0xca, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
+ 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf1, 0xf2, 0xf3, 0xf4,
+ 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa},
+ FALSE},
+ // AC chroma
+ {{0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 119},
+ {0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31, 0x06, 0x12, 0x41,
+ 0x51, 0x07, 0x61, 0x71, 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
+ 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 0x15, 0x62, 0x72, 0xd1,
+ 0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
+ 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44,
+ 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+ 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74,
+ 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a,
+ 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
+ 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+ 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
+ 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf2, 0xf3, 0xf4,
+ 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa},
+ FALSE}};
+ const JHUFF_TBL* std_tables = is_dc ? kStandardDCTables : kStandardACTables;
+ JHUFF_TBL** tables;
+ if (cinfo->is_decompressor) {
+ j_decompress_ptr cinfo_d = reinterpret_cast<j_decompress_ptr>(cinfo);
+ tables = is_dc ? cinfo_d->dc_huff_tbl_ptrs : cinfo_d->ac_huff_tbl_ptrs;
+ } else {
+ j_compress_ptr cinfo_c = reinterpret_cast<j_compress_ptr>(cinfo);
+ tables = is_dc ? cinfo_c->dc_huff_tbl_ptrs : cinfo_c->ac_huff_tbl_ptrs;
+ }
+ for (int i = 0; i < 2; ++i) {
+ if (tables[i] == nullptr) {
+ tables[i] = jpegli_alloc_huff_table(cinfo);
+ memcpy(tables[i], &std_tables[i], sizeof(JHUFF_TBL));
+ ValidateHuffmanTable(cinfo, tables[i], is_dc);
+ }
+ }
+}
+
+} // namespace jpegli