mirror of https://github.com/google/brotli
5b80ef0fd1
In the following three cases we allow more choices
for the compressor, which can potentially lead to
less compressed bits.
(1) Allow brotli streams where the block counts
do not count down to exactly zero at the end
of the meta-block. This makes it possible
for compressors to sometimes choose a block
count which can be represented with less bits
than the exact block count.
(2) Remove the restriction that prefix code
descriptions with exactly one non-zero
length symbol in the code length alphabet
must have 1 bit depth. This is because
bit depth 1 requires the most bits to encode.
(3) Allow any copy length value in the last
command where the copy part is ignored.
This makes it possible for a compressor
to choose a copy length which can be
represented with the least amount of bits.
In addition to the changes above, this commit also
has a wording clarification in the overview section
where the use of the 'context ID' expression is
changed to be consistent with the rest of the
specification, i.e. that it is a function of the
last two literals or the copy length.
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| docs | ||
| enc | ||
| python | ||
| tests | ||
| tools | ||
| .gitignore | ||
| LICENSE | ||
| README.md | ||
| setup.py | ||
| shared.mk | ||
README.md
brotli
Brotli is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression.
The specification of the Brotli Compressed Data Format is defined in the following internet draft: http://www.ietf.org/id/draft-alakuijala-brotli
Brotli is open-sourced under the Apache License, Version 2.0, see the LICENSE file.