Updates to Brotli compression format, decoder and encoder

This commit contains a batch of changes that were made to the Brotli
compression algorithm in the last month. Most important changes:

   * Fixes to the spec.
   * Change of code length code order.
   * Use a 2-level Huffman lookup table in the decoder.
   * Faster uncompressed meta-block decoding.
   * Optimized encoding of the Huffman code.
   * Detection of UTF-8 input encoding.
   * UTF-8 based literal cost modeling for improved
     backward reference selection.
This commit is contained in:
Zoltan Szabadka
2014-02-14 15:04:23 +01:00
parent dfc5a9f215
commit cbd5cb55f4
16 changed files with 912 additions and 635 deletions
+3 -3
View File
@@ -31,16 +31,16 @@
namespace brotli {
static const int kMaxLiteralHistograms = 48;
static const int kMaxLiteralHistograms = 100;
static const int kMaxCommandHistograms = 50;
static const double kLiteralBlockSwitchCost = 26;
static const double kCommandBlockSwitchCost = 13.5;
static const double kDistanceBlockSwitchCost = 14.6;
static const int kLiteralStrideLength = 70;
static const int kCommandStrideLength = 40;
static const int kSymbolsPerLiteralHistogram = 550;
static const int kSymbolsPerLiteralHistogram = 544;
static const int kSymbolsPerCommandHistogram = 530;
static const int kSymbolsPerDistanceHistogram = 550;
static const int kSymbolsPerDistanceHistogram = 544;
static const int kMinLengthForBlockSplitting = 128;
static const int kIterMulForRefining = 2;
static const int kMinItersForRefining = 100;