LZ4
From Just Solve the File Format Problem
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(Updated FormatInfo, updated links, added examples where lz4 is used under Linux and citations, added Wikipedia page.) |
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|subcat=Compression | |subcat=Compression | ||
|extensions={{ext|lz4}} | |extensions={{ext|lz4}} | ||
| + | |wikidata={{wikidata|Q15624241}} (Compression algorithm)<br />{{wikidata|Q28770292}} (file format) | ||
| + | |compression=lossless, mandatory | ||
| + | |magic=02 21 4c 18 (legacy)<br />04 22 4d 18 | ||
|released=2011 | |released=2011 | ||
}} | }} | ||
'''LZ4''' is a lossless data compression algorithm and compressed data format. It is designed to support very fast compression. | '''LZ4''' is a lossless data compression algorithm and compressed data format. It is designed to support very fast compression. | ||
| + | |||
| + | In [[Linux]], LZ4 appears as one of the many compression format for: | ||
| + | * [[vmlinuz]]<ref>[https://github.com/torvalds/linux/blob/master/scripts/extract-vmlinux#L56 extract-vmlinux shell script (line 56) - Linus Torvalds' kernel - GitHub]</ref> | ||
| + | * [[initramfs]]<ref>[https://github.com/dracut-ng/dracut-ng/blob/main/man/dracut.conf.5.adoc?plain=1#L119-L123 dracut.conf.5.adoc - dracut-ng manual pages - GitHub]</ref><ref>[https://gitlab.archlinux.org/archlinux/mkinitcpio/mkinitcpio/-/blob/master/mkinitcpio.conf?ref_type=heads#L61-67 mkinitcpio.conf (lines 61-67) - mkinitcpio - Arch Linux GitLab]</ref><ref>[https://github.com/anatol/booster/blob/master/docs/manpage.md?plain=1#L57 manpage.md (line 57) - booster - GitHub]</ref> | ||
| + | * [[SquashFS|<code>squashfs-tools</code>]]<ref>[https://github.com/plougher/squashfs-tools/blob/master/squashfs-tools/compressor.c#L31-L77 compressor.c (lines 31-77) - squashfs-tools - GitHub]</ref> | ||
| + | * zram<ref>[https://docs.kernel.org/admin-guide/blockdev/zram.html#select-compression-algorithm 2) Select compression algorithm - zram: Compressed RAM-based block devices -- The Linux Kernel documentation]</ref> - Compressed RAM-based block devices. | ||
== Identification == | == Identification == | ||
| − | When used as a file format, LZ4 files begin with signature bytes | + | When used as a file format, LZ4 files begin with signature bytes {{magic|04 22 4d 18}}. |
| − | There is also a legacy format, whose signature is | + | There is also a legacy format, whose signature is {{magic|02 21 4c 18}}. |
== Resources == | == Resources == | ||
| + | * [[wikipedia:LZ4 (compression algorithm)| LZ4 compression algorithm on Wikipedia]] | ||
* [https://github.com/Cyan4973/lz4 LZ4 website] | * [https://github.com/Cyan4973/lz4 LZ4 website] | ||
| − | * [ | + | * [https://fastcompression.blogspot.com/2011/05/lz4-explained.html LZ4 explained] |
* [https://ticki.github.io/blog/how-lz4-works/ How LZ4 works] | * [https://ticki.github.io/blog/how-lz4-works/ How LZ4 works] | ||
* [http://blog.securitymouse.com/2014/06/raising-lazarus-20-year-old-bug-that.html Raising Lazarus - The 20 Year Old Bug that Went to Mars] vs. [http://fastcompression.blogspot.com/2014/06/debunking-lz4-20-years-old-bug-myth.html Debunking the LZ4 "20 years old bug" myth] | * [http://blog.securitymouse.com/2014/06/raising-lazarus-20-year-old-bug-that.html Raising Lazarus - The 20 Year Old Bug that Went to Mars] vs. [http://fastcompression.blogspot.com/2014/06/debunking-lz4-20-years-old-bug-myth.html Debunking the LZ4 "20 years old bug" myth] | ||
| + | |||
| + | == References == | ||
| + | <references/> | ||
Revision as of 08:36, 16 August 2025
LZ4 is a lossless data compression algorithm and compressed data format. It is designed to support very fast compression.
In Linux, LZ4 appears as one of the many compression format for:
Identification
When used as a file format, LZ4 files begin with signature bytes 04 22 4d 18.
There is also a legacy format, whose signature is 02 21 4c 18.
Resources
- LZ4 compression algorithm on Wikipedia
- LZ4 website
- LZ4 explained
- How LZ4 works
- Raising Lazarus - The 20 Year Old Bug that Went to Mars vs. Debunking the LZ4 "20 years old bug" myth
References
- ↑ extract-vmlinux shell script (line 56) - Linus Torvalds' kernel - GitHub
- ↑ dracut.conf.5.adoc - dracut-ng manual pages - GitHub
- ↑ mkinitcpio.conf (lines 61-67) - mkinitcpio - Arch Linux GitLab
- ↑ manpage.md (line 57) - booster - GitHub
- ↑ compressor.c (lines 31-77) - squashfs-tools - GitHub
- ↑ 2) Select compression algorithm - zram: Compressed RAM-based block devices -- The Linux Kernel documentation
