BZ2 - Revision history

Dexvertbot: Undo revision 47337 by Dexvertbot (talk)

2023-12-28T04:56:45Z

Undo revision 47337 by Dexvertbot (talk)

Dexvertbot: Change telparia.com samples link to template

2023-12-28T04:55:22Z

Change telparia.com samples link to template

Dan Tobias at 13:34, 5 April 2014

2014-04-05T13:34:54Z

Dan Tobias: Redirected page to Bzip2

2014-04-05T13:34:42Z

Redirected page to Bzip2

New page

#REDIRECT [[Bzip2]]

@@ Line 1: / Line 1: @@
-{{FormatInfo
+#REDIRECT [[bzip2]]
-|name=bzip2
-|formattype=electronic
-|subcat=Compression
-|extensions={{ext|bz2}}
-|mimetypes={{mimetype|application/x-bzip2}}
-|pronom={{PRONOM|x-fmt/268}}
-|wikidata={{wikidata|Q27866052}}
-|released=1997
-}}
-'''bzip2''' is a data compression algorithm and compressed file format. It was developed by Julian Seward.
-−
-== Identification ==
-A bzip2 file starts with the byte pattern {{magic|42 5a 68 ?? 31 41 59 26 53 59}}.
-−
-The first three bytes are ASCII "{{magic|BZh}}". (For signature "{{magic|BZ0}}", refer to the original [[bzip]] format.) The "<code>h</code>" has been said to stand for "Huffman coding", but confirmation is needed.
-−
-The byte at offset 3 is a code for the block size. Its possible values range from <code>0x31</code> to <code>0x39</code> (ASCII "<code>1</code>" to "<code>9</code>").
-−
-The bytes at offset 4-9 are derived from the digits of the mathematical constant π ([[Binary-coded decimal|BCD]]-encoded).
-−
-The end-of-file marker uses magic number (hex) {{magic|17 72 45 38 50 90}}, derived from the square root of π. However, it is not byte-aligned. The result is that one of the following byte sequences appears beginning 10 bytes from the end of the file:
-−
- b9 22 9c 28 48
- dc 91 4e 14 24
- ee 48 a7 0a 12
-24 53 85 09
- bb 92 29 c2 84
-d c9 14 e1 42
-e e4 8a 70 a1
-72 45 38 50
-−
-== Specifications ==
-* [https://github.com/dsnet/compress/blob/master/doc/bzip2-format.pdf Unofficial specification by Joe Tsai]
-−
-== Software ==
-* [https://sourceware.org/bzip2/ bzip2 and libbzip2]
-* [[7-Zip]]
-−
-== Sample files ==
-* {{DexvertSamples|archive/bz2}}
-−
-== See also ==
-* [[Burrows–Wheeler transform]]
-* [[bzip]] (predecessor)
-−
-== Links ==
-* [[Wikipedia:Bzip2|Wikipedia article]]
-* [https://sourceware.org/bzip2/ bzip2 and libbzip2 website]
-* [https://github.com/corkami/pics/blob/master/binary/BZ2.png Chart of format details]
-* [https://lwn.net/Articles/762264/ bzip.org changes hands] (LWN article from August 9, 2018)
-* [{{ForensicsWikiURL|bzip2}} ForensicsWiki entry] (also includes more details on the headers)
-* [http://www.bzip.org/ bzip.org]

← Older revision		Revision as of 04:55, 28 December 2023
Line 1:		Line 1:
−	~~#REDIRECT~~ [[bzip2]]	+	{{FormatInfo
		+	\|name=bzip2
		+	\|formattype=electronic
		+	\|subcat=Compression
		+	\|extensions={{ext\|bz2}}
		+	\|mimetypes={{mimetype\|application/x-bzip2}}
		+	\|pronom={{PRONOM\|x-fmt/268}}
		+	\|wikidata={{wikidata\|Q27866052}}
		+	\|released=1997
		+	}}
		+	'''bzip2''' is a data compression algorithm and compressed file format. It was developed by Julian Seward.
		+
		+	== Identification ==
		+	A bzip2 file starts with the byte pattern {{magic\|42 5a 68 ?? 31 41 59 26 53 59}}.
		+
		+	The first three bytes are ASCII "{{magic\|BZh}}". (For signature "{{magic\|BZ0}}", refer to the original [[bzip]] format.) The "<code>h</code>" has been said to stand for "Huffman coding", but confirmation is needed.
		+
		+	The byte at offset 3 is a code for the block size. Its possible values range from <code>0x31</code> to <code>0x39</code> (ASCII "<code>1</code>" to "<code>9</code>").
		+
		+	The bytes at offset 4-9 are derived from the digits of the mathematical constant π ([[Binary-coded decimal\|BCD]]-encoded).
		+
		+	The end-of-file marker uses magic number (hex) {{magic\|17 72 45 38 50 90}}, derived from the square root of π. However, it is not byte-aligned. The result is that one of the following byte sequences appears beginning 10 bytes from the end of the file:
		+
		+	b9 22 9c 28 48
		+	dc 91 4e 14 24
		+	ee 48 a7 0a 12
		+	77 24 53 85 09
		+	bb 92 29 c2 84
		+	5d c9 14 e1 42
		+	2e e4 8a 70 a1
		+	17 72 45 38 50
		+
		+	== Specifications ==
		+	* [https://github.com/dsnet/compress/blob/master/doc/bzip2-format.pdf Unofficial specification by Joe Tsai]
		+
		+	== Software ==
		+	* [https://sourceware.org/bzip2/ bzip2 and libbzip2]
		+	* [[7-Zip]]
		+
		+	== Sample files ==
		+	* {{DexvertSamples\|archive/bz2}}
		+
		+	== See also ==
		+	* [[Burrows–Wheeler transform]]
		+	* [[bzip]] (predecessor)
		+
		+	== Links ==
		+	* [[Wikipedia:Bzip2\|Wikipedia article]]
		+	* [https://sourceware.org/bzip2/ bzip2 and libbzip2 website]
		+	* [https://github.com/corkami/pics/blob/master/binary/BZ2.png Chart of format details]
		+	* [https://lwn.net/Articles/762264/ bzip.org changes hands] (LWN article from August 9, 2018)
		+	* [{{ForensicsWikiURL\|bzip2}} ForensicsWiki entry] (also includes more details on the headers)
		+	* [http://www.bzip.org/ bzip.org]

← Older revision		Revision as of 13:34, 5 April 2014
Line 1:		Line 1:
−	#REDIRECT [[~~Bzip2~~]]	+	#REDIRECT [[bzip2]]