Commit Graph

137 Commits

Author SHA1 Message Date
Zoltan Szabadka
d6d69ec4ac Add quality and lgwin to the BrotliParams.
Remove the hard-coded constants for window size
and meta-block size.

Initialize internal storage for each metablock
separately and reserve only as much as needed
for the actual input.
2015-04-01 16:10:15 +02:00
Zoltan Szabadka
ca3a7a98f2 Use FastLog2() instead of log() in BitsEntropy(). 2015-03-30 13:41:52 +02:00
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
497814eebd Remove the redundant EncodeMetaBlockHeader() function.
Use Store{Compressed,Uncompressed}MetaBlockHeader() instead.
2015-03-24 10:18:06 +01:00
Zoltan Szabadka
28135ea9e8 Fix another use of log2() in literal_cost.cc 2015-02-27 16:53:00 +01:00
Zoltan Szabadka
fab601e81f Fix encoder compilation error on MSVS 2010.
As reported by @anthrotype, log2() is missing from MSVS 2010.
This patch uses log() and a multiplication in FastLog2()
for _MSV_VER <= 1600 and uses FastLog2() in literal_cost.cc
instead of log2().
2015-02-27 16:04:43 +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
5bc56a17ee Fully qualify std::max_element, std::push_heap and std::pop_heap names. 2015-02-25 10:29:24 +01:00
Zoltan Szabadka
e643328a7a Speed up FindMatchLength for non-x86 64-bit targets.
This CL enables 64-bit optimization for non-x86 target.
2015-02-25 10:24:13 +01:00
Zoltan Szabadka
e1739826c0 Add command-line tool and tests. 2014-10-30 13:59:37 +01:00
Zoltan Szabadka
96d04e53d7 Disable transforms in the encoder by default.
This change reduces the startup-time of the encoder considerably.
2014-10-29 15:39:35 +01:00
Zoltan Szabadka
485ad82e94 Fix potential output buffer overflow in encoder. 2014-10-28 14:05:53 +01:00
Zoltan Szabadka
0428f2d1bd Move the context map encoding function to the brotli_bit_stream library. 2014-10-28 13:47:21 +01:00
Zoltan Szabadka
f321ba1964 Make the histogram clustering function more generic.
Change the template parameter to be the histogram class
instead of the alphabet size of the histogram.
2014-10-28 13:36:21 +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
ca8c2890aa Fix storing of the meta-block header for last empty meta-block. 2014-10-28 12:09:18 +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
39cde017e6 Fix TODO markups. 2014-10-15 14:14:34 +02:00
Zoltan Szabadka
d6d9fc60e1 Factor out serialization functions into their own file.
Create a brotli_bit_stream library that is responsible for writing
various structures (headers, Huffman codes, etc.) directly into the
bit-stream.
2014-10-15 14:01:36 +02:00
Zoltan Szabadka
12c6d1fbe4 Apply const qualifier to call operator of comparator class. 2014-10-15 13:33:56 +02:00
Zoltan Szabadka
fe6e9b0148 Remove broken Makefiles.
Makefiles will be added together with a command-line interface in a
later commit.
2014-10-14 13:39:48 +02:00
Zoltan Szabadka
e8d668f873 Add top-level README file.
Remove brotlispec.txt and add a link to the latest internet-draft instead.
2014-10-14 13:08:35 +02:00
Zoltan Szabadka
3f655b63de Fix buffer overflow bug in the brotli encoder. 2014-03-27 16:38:07 +01:00
Zoltan Szabadka
347781947a Update the dictionary and the transforms. 2014-03-25 16:48:25 +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
2f268ad158 Add the initial version of the static dictionary and transforms to Brotli. 2014-02-17 14:25:36 +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
2bcd58bb5a Brotli format change: small improvement to the encoding of Huffman codes
Combine the HSKIP and the simple/complex Huffman code type bits.
2014-01-08 12:28:28 +01:00
Zoltan Szabadka
d762bc6845 Bug fixes for the brotli encoder and decoder. 2014-01-06 16:01:57 +01:00
Zoltan Szabadka
1447345cbb Brotli format change: improved encoding of Huffman codes
This change removes the redundant HCLEN, HLENINC and HLEN
fields from the encoding of the complex Huffman codes and
derives these from an invariant of the code length sequence.
Based on a patch by Robert Obryk.
2013-12-17 17:17:57 +01:00
Roderick Sheeter
c23cb1e83d Support for OSX build; tested using OSX 10.9/clang-500.2.79 2013-12-12 10:43:05 -08:00
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
8d7081f2d0 Add draft specification of the brotli format 2013-11-28 17:37:13 +01:00
Roderick Sheeter
1cdcbd851f Added Brotli compress/decompress utilities and makefiles 2013-11-19 14:32:56 -08:00
Zoltan Szabadka
c6b9c7c5c8 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 three weeks. Most important changes:

  * Added UTF8 context model for good text compression.
  * Simplified context modeling by having only 4 context modes.
  * Per-block context mode selection.
  * Faster backward copying and bit reading functions.
  * More efficient histogram coding.
  * Streaming support for the decoder and encoder.
2013-11-15 19:02:17 +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