new Methods-Extern.txt for Igor

CPP/7zip/Guid.txt

@@ -161,6 +161,7 @@ Handler GUIDs:
   0A lzma
   0B lzma86
   0C xz
+  0D ppmd
   0E zstd
   0F lz4
   10 lz5

DOC/Methods-Extern.txt

@@ -0,0 +1,175 @@
+7-Zip external method IDs, that are not included to 7-Zip
+---------------------------------------------------------
+
+History of this document
+------------------------
+
+- 7-Zip Version 15.01, initial release
+
+
+Overview of defined ID ranges
+-----------------------------
+
+F7 0x xx - reserved
+F7 10 xx - LZHAM
+F7 11 xx - ZStandard
+F7 12 xx - LZ4
+F7 13 xx - LZ5
+
+
+
+Range F7 10 xx - LZHAM
+-----------------------
+
+Description:
+Lossless data compression codec with LZMA-like ratios but 1.5x-8x faster
+decompression speed, C/C++
+
+License:
+LZHAM library is provided as open source software using a MIT license.
+
+7-Zip Container Header:
+ Byte _ver_major;
+ Byte _ver_minor;
+ Byte _level;
+ Byte _reserved[2];
+
+Algorithm author:    Rich Geldreich
+Algorithm Homepage:  https://github.com/richgel999/lzham_codec
+Source code:         https://github.com/richgel999/lzham_codec
+
+Codec plugin author: Rich Geldreich
+Codec Homepage:      http://richg42.blogspot.de/2015/02/lzham-10-integrated-into-7zip-command.html
+Source Code:         http://www.tenacioussoftware.com/7zipsrc_release3_lzham_1_0.7z
+
+Versions:
+The 7-Zip LZHAM codec will be kept in sync with the current releases of ZStandard.
+
+Range F7 11 xx, ZStandard
+-------------------------
+
+Description:
+Zstandard is a real-time compression algorithm, providing high compression
+ratios. It offers a very wide range of compression / speed trade-off, while
+being backed by a very fast decoder (see benchmarks below). It also offers a
+special mode for small data, called dictionary compression, and can create
+dictionaries from any sample set.
+
+License:
+Zstandard library is provided as open source software using a BSD license.
+
+7-Zip Container Header:
+ Byte _ver_major;
+ Byte _ver_minor;
+ Byte _level;
+ Byte _reserved[2];
+
+Algorithm author:    Yann Collet
+Algorithm Homepage:  https://facebook.github.io/zstd/
+Source code:         https://github.com/facebook/zstd
+
+Codec plugin author: Tino Reichardt
+Codec Homepage:      https://mcmilk.de/projects/7-Zip-zstd/
+Source Code:         https://github.com/mcmilk/7-Zip-zstd
+
+Modes:
+- threading is supported through skippable frame id 0x184D2A50U
+- all levels are supported (1..22)
+- future version of zstd will support multi threading out of the box
+  -> this new format is fully compatible with the one within this codec
+- the codec is used as archiv handler also, see ZstdHandler.cpp
+  - this handler is does not use any additional headers, it supports the plain
+    zstd v1.0 format (this covers all current v1.x implemetations)
+  - when compiled with ZSTD_LEGACY_SUPPORT, then support is increased to these
+    addtional version numbers of zstd: v0.1 up v0.7
+- future formats of this algorithm will be fully compatible with release v1.0 of
+  ZStandard (ZStandard 0.8 == ZStandard 1.0)
+- one ID should be okay for this codec
+
+Versions:
+The 7-Zip codec will be kept in sync with the current releases of ZStandard.
+
+
+Range F7 12 xx, LZ4
+-------------------
+
+Description:
+LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s
+per core (0.16 Bytes/cycle). It features an extremely fast decoder, with speed
+in multiple GB/s per core (0.71 Bytes/cycle). A high compression derivative,
+called LZ4_HC, is available, trading customizable CPU time for compression
+ratio. LZ4 library is provided as open source software using a BSD license.
+
+License:
+LZ4 library is provided as open source software using a BSD license.
+
+7-Zip Container Header:
+ Byte _ver_major;  // currently 1
+ Byte _ver_minor;  // currently 7
+ Byte _level;      // 1..16
+ Byte _reserved[2];
+
+Algorithm author:    Yann Collet
+Algorithm Homepage:  https://lz4.github.io/lz4/
+Source code:         https://github.com/lz4/lz4
+
+Codec plugin author: Tino Reichardt
+Codec Homepage:      https://mcmilk.de/projects/7-Zip-zstd/
+Source Code:         https://github.com/mcmilk/7-Zip-zstd
+
+Modes:
+- threading is supported through skippable frame id 0x184D2A50U
+- all levels of LZ4 v1.7.4 are supported (1..16)
+- the codec is used as archiv handler also, see Lz4Handler.cpp
+  - this handler is does not use any additional headers, it supports the plain
+    lz4 v1.7.4 format (this covers all current lz4 implemetations)
+- future formats of this algorithm should be fully compatible with current
+  release
+- one ID should be okay for this codec
+
+Versions:
+The 7-Zip codec will be kept in sync with the current releases of LZ4.
+
+
+Range F7 13 xx, LZ5
+-------------------
+
+Description:
+LZ5 is a modification of LZ4 which gives a better ratio at cost of slower
+compression and decompression.
+
+License:
+LZ5 library is provided as open source software using a BSD license.
+
+7-Zip Container Header:
+ Byte _ver_major;  // currently 1
+ Byte _ver_minor;  // currently 5
+ Byte _level;      // 1..16
+ Byte _reserved[2];
+
+Algorithm author:    Przemyslaw Skibinski
+Algorithm Homepage:  https://github.com/inikep/lz5
+Source code:         https://github.com/inikep/lz5
+
+Codec plugin author: Tino Reichardt
+Codec Homepage:      https://mcmilk.de/projects/7-Zip-zstd/
+Source Code:         https://github.com/mcmilk/7-Zip-zstd
+
+Modes:
+- threading is supported through skippable frame id 0x184D2A50U
+- all levels of v1.5 are supported (1..16)
+- the codec is used as archiv handler also, see Lz5Handler.cpp
+  - this handler is does not use any additional headers, it supports the plain
+    lz5 v1.5 format
+- future formats of this algorithm will not be compatible with current release,
+  this codec is very experimental
+- multiple ID's are required for this codec
+
+Versions:
+The 7-Zip codec will be kept in sync with the current releases of LZ5.
+The current codec plugin supports version v1.5. Version 2.0 will follow, when it
+seems to be stable.
+
+---
+End of document
+Tino Reichardt, 2016-12-28