Commit Graph

10 Commits

Author SHA1 Message Date
Zoltan Szabadka
534654def1 Add a faster but less dense compression mode.
The new mode can be used by setting the greedy_block_split
field of BrotliParams to true.

This commit moves all the meta-block processing code
into its own library and moves the meta-block encoding
code to brotli_bit_stream.cc from encode.cc
2015-03-27 14:20:35 +01:00
Zoltan Szabadka
f0b88cbcdb Fixes to the encoder to support visual studio.
Changes suggested by @r-lyeh and @anthrotype.

 - Use a portable simple PRNG instead of rand_r()
 - add missing <assert.h> include
 - disambiguate log2() argument type
 - remove endian.h include from write_bits.h
2015-02-25 18:19:51 +01:00
Zoltan Szabadka
b4f39bf540 New version of the backward reference search code.
The new	interface of the backward reference search
function makes it possible to use it in	a streaming
manner.

Using the advanced cost model and static dictionary
can be turned on/off by	template parameters.

The distance short codes are now computed as part of
the backward reference search.

Added a	faster version of the Hasher.
2014-10-28 13:25:22 +01:00
Zoltan Szabadka
03b20347e1 Minor tuning of encoder heuristics. 2014-10-28 12:50:33 +01:00
Zoltan Szabadka
467e6eef80 Move the block switch stroing functions to the brotli_bit_stream library. 2014-10-28 11:53:52 +01:00
Zoltan Szabadka
e7650080a8 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:

   * Format change: don't push distances representing static dictionary words to the distance cache.
   * Fix decoder invalid memory access bug caused by building a non-complete Huffman tree.
   * Add a mode parameter to the encoder interface.
   * Use different hashers for text and font mode.
   * Add a heuristics to the hasher for skipping non-compressible data.
   * Exhaustive search of static dictionary during backward reference search.
2014-03-20 14:32:35 +01:00
Zoltan Szabadka
0454ab4ec0 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.
2014-02-14 15:04:23 +01:00
Zoltan Szabadka
d762bc6845 Bug fixes for the brotli encoder and decoder. 2014-01-06 16:01:57 +01:00
Zoltan Szabadka
60c24c0c2d 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:

   * Updated spec
   * Changed Huffman code length alphabet to use run length codes more
     efficiently, based on a suggestion by Robert Obryk
   * Changed encoding of the number of Huffman code lengths (HLEN)
   * Changed encoding of the number of Huffman trees (NTREES)
   * Added support for uncompressed meta-blocks
2013-12-12 13:18:04 +01:00
Zoltan Szabadka
c66e4e3e4f Add brotli compressor
This commit is for the encoder for brotli compression format.
Brotli is a generic byte-level compression algorithm.
2013-10-23 13:06:13 +02:00