LZO1

LZO1 is a designation used within the LZO data compression library to identify a baseline compression preset in the LZO family. LZO, short for Lempel-Ziv-Oberhumer, is a lossless data compression algorithm released in the 1990s that emphasizes high-speed operation and small memory footprints. LZO1-based formats are designed to provide fast compression and, especially, rapid decompression, making them suitable for performance-sensitive environments such as embedded systems, network software, and real-time data processing. The exact encoding details of LZO1 are defined by the library version, but broadly the approach relies on literals and back-references to represent data efficiently.

Within the LZO ecosystem, LZO1 is one of several presets that balance speed and compression ratio, with other variants such as LZO1X, LZO1Y, or LZO2 profiles offering different trade-offs. In practice, software that uses LZO1 may also expose corresponding formats or flags to choose between presets, depending on the application and platform.

Implementation and usage: The LZO library provides APIs to compress data using LZO1, as well as to decompress data created by any compatible preset. The lzop tool, a common command-line utility for LZO, can produce and read data compressed with LZO presets that include LZO1-based configurations. Because LZO1 is a preset rather than a single fixed algorithm, implementation details and performance can vary between library versions and platforms.

See also: LZO, LZOP, data compression, LZ77.