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easy7zip/C/zstdmt/README.md
2017-08-14 23:38:52 +02:00

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# Multithreading Library for [Brotli], [Lizard], [LZ4], [LZ5] and [Zstandard]
## Description
- works with skippables frame id 0x184D2A50 (12 bytes per compressed frame)
- brotli is supported the same way, it will encapsulate the real brotli stream
within an 16 byte frame header
## Generic skippable frame definition
- the frame header for [Lizard], [LZ4], [LZ5] and [Zstandard] is like this:
size | value | description
--------|-------------------|------------
4 bytes | 0x184D2A50U | magic for skippable frame
4 bytes | 4 | size of skippable frame
4 bytes | compressed size | size of the following frame (compressed data)
## [Brotli] frame definition
- the frame header for brotli is defined a bit different:
size | value | description
--------|-------------------|------------
4 bytes | 0x184D2A50U | magic for skippable frame (like zstd)
4 bytes | 8 | size of skippable frame
4 bytes | compressed size | size of the following frame (compressed data)
2 bytes | 0x5242U | magic for brotli "BR"
2 bytes | uncompressed size | allocation hint for decompressor (64KB * this size)
## Usage of the Testutils
- see [programs](https://github.com/mcmilk/zstdmt/tree/master/programs)
## Usage of the Library
- see [lib](https://github.com/mcmilk/zstdmt/tree/master/lib)
[Brotli]:https://github.com/google/brotli/
[LZ4]:https://github.com/lz4/lz4/
[LZ5]:https://github.com/inikep/lz5/
[Zstandard]:https://github.com/facebook/zstd/
[Lizard]:https://github.com/inikep/lizard/
/TR 2017-05-24