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LZFSE
LZFSE (Lempel–Ziv Finite State Entropy) is an open source lossless data compression algorithm created by Apple Inc. It was released with a simpler algorithm called LZVN. Overview The name is an acronym for Lempel–Ziv and finite-state entropy (implementation of asymmetric numeral systems). LZFSE was introduced by Apple at its Worldwide Developer Conference 2015. It shipped with that year's iOS 9 and OS X 10.11 releases. Apple claims that LZFSE compresses with a ratio comparable to that of zlib ( DEFLATE) and decompresses two to three times faster while using fewer resources, therefore offering higher energy efficiency than zlib. It was aimed for scenarios where decompression speed and rate should be prioritised equally. Part of this energy efficiency was achieved by optimising the algorithm for modern micro-architectures, specifically focusing on arm64. Third-party benchmarking confirms that LZFSE decompresses faster than zlib, but also suggests that many other modern c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asymmetric Numeral Systems
Asymmetric numeral systems (ANS)J. Duda, K. Tahboub, N. J. Gadil, E. J. Delp''The use of asymmetric numeral systems as an accurate replacement for Huffman coding'' Picture Coding Symposium, 2015.J. Duda''Asymmetric numeral systems: entropy coding combining speed of Huffman coding with compression rate of arithmetic coding'' arXiv:1311.2540, 2013. is a family of entropy encoding methods introduced by Jarosław (Jarek) Duda from Jagiellonian University, used in data compression since 2014 due to improved performance compared to previous methods. ANS combines the compression ratio of arithmetic coding (which uses a nearly accurate probability distribution), with a processing cost similar to that of Huffman coding. In the tabled ANS (tANS) variant, this is achieved by constructing a finite-state machine to operate on a large alphabet without using multiplication. Among others, ANS is used in the Facebook Zstandard compressor [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Disk Image
Apple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Finder. An Apple Disk Image can be structured according to one of several proprietary disk image formats, including the Universal Disk Image Format (UDIF) from Mac OS X and the New Disk Image Format (NDIF) from Mac OS 9. An Apple disk image file's name usually has ".dmg" as its extension. A disk image is a compressed copy of the contents of a disk or folder. To see the contents of a disk image, one must first open the disk image so it appears on the desktop or in a Finder window. Features Apple Disk Image files are published with a MIME type of ''application/x-apple-diskimage''. Different file systems can be contained inside these disk images, and there is also support for creating hybrid optical media images that contain multiple file systems. Some of the file systems supported include Hierarchical File System (HFS), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zstd
Zstandard is a lossless data compression algorithm developed by Yann Collet at Facebook. Zstd is the corresponding reference implementation in C, released as open-source software on 31 August 2016. The algorithm was published in 2018 as , which also defines an associated media type "application/zstd", filename extension "zst", and HTTP content encoding "zstd". Features Zstandard was designed to give a compression ratio comparable to that of the DEFLATE algorithm (developed in 1991 and used in the original ZIP and gzip programs), but faster, especially for decompression. It is tunable with compression levels ranging from negative 7 (fastest) to 22 (slowest in compression speed, but best compression ratio). Starting from version 1.3.2 (October 2017), zstd optionally implements very-long-range search and deduplication (, 128 MiB window) similar to rzip or lrzip. Compression speed can vary by a factor of 20 or more between the fastest and slowest levels, while decom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HFS Plus
HFS Plus or HFS+ (also known as Mac OS Extended or HFS Extended) is a journaling file system developed by Apple Inc. It replaced the Hierarchical File System (HFS) as the primary file system of Apple computers with the 1998 release of Mac OS 8.1. HFS+ continued as the primary Mac OS X file system until it was itself replaced with the Apple File System (APFS), released with macOS High Sierra in 2017. HFS+ is also one of the formats supported by the iPod digital music player. Compared to its predecessor HFS, also called ''Mac OS Standard'' or ''HFS Standard,'' HFS Plus supports much larger files (block addresses are 32-bit length instead of 16-bit) and using Unicode (instead of Mac OS Roman or any of several other character sets) for naming items. Like HFS, HFS Plus uses B-trees to store most volume metadata, but unlike most file systems that support hard links, HFS Plus supports hard links to directories. HFS Plus permits filenames up to 255 characters in length, and n-forke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple File System
Apple File System (APFS) is a Proprietary software, proprietary file system developed and deployed by Apple Inc. for macOS macOS Sierra, Sierra (10.12.4) and later, iOS iOS 10 , 10.3, tvOS 10.2, watchOS 3.2, and all versions of iPadOS. It aims to fix HFS Plus#Criticisms, core problems of HFS Plus, HFS+ (also called Mac OS Extended), APFS's predecessor which had been in use since 1998. APFS is optimized for solid-state drive storage and supports encryption, Snapshot_(computer_storage) , snapshots, and improved handling of file system#metadata, metadata integrity. History Apple File System was announced at Apple Inc., Apple's Apple Worldwide Developers Conference, developers’ conference (WWDC) in June 2016 as a replacement for HFS Plus, HFS+, which had been in use since 1998. APFS was released for 64-bit computing, 64-bit iOS devices on March 27, 2017, with the release of iOS 10.3, and for macOS devices on September 25, 2017, with the release of MacOS High Sierra, macOS 10.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossless Data Compression
Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits Redundancy (information theory), statistical redundancy. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved Bit rate#Bitrates in multimedia, compression rates (and therefore reduced media sizes). By operation of the pigeonhole principle, no lossless compression algorithm can shrink the size of all possible data: Some data will get longer by at least one symbol or bit. Compression algorithms are usually effective for human- and machine-readable documents and cannot shrink the size of random data that contain no Redundancy (information theory), redundancy. Different algorithms exist that are designed either with a specific type of input data in mind or with speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS X El Capitan
OS X El Capitan ( ) () is the twelfth major release of macOS (named OS X at the time of El Capitan's release), Apple Inc.'s desktop and server operating system for Macintosh. It focuses mainly on performance, stability, and security. Following the California location-based naming scheme introduced with OS X Mavericks, El Capitan was named after the famous eponymous rock formation in Yosemite National Park. El Capitan is the final version to be released under the name OS X. OS X El Capitan received far better reviews than Yosemite. The first beta of OS X El Capitan was released to developers shortly following the WWDC keynote on June 8, 2015. The first public beta was made available on July 9, 2015. There were multiple betas released after the keynote. OS X El Capitan was released to end users on September 30, 2015, as a free upgrade through the Mac App Store. OS X El Capitan is the final version of OS X to support aluminum Macs and Xserve, as its successor macOS Sierra i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARM64
AArch64, also known as ARM64, is a 64-bit version of the ARM architecture family, a widely used set of computer processor designs. It was introduced in 2011 with the ARMv8 architecture and later became part of the ARMv9 series. AArch64 allows processors to handle more memory and perform faster calculations than earlier 32-bit versions. It is designed to work alongside the older 32-bit mode, known as AArch32, allowing compatibility with a wide range of software. Devices that use AArch64 include smartphones, tablets, personal computers, and servers. The AArch64 architecture has continued to evolve through updates that improve performance, security, and support for advanced computing tasks. AArch64 Execution state In ARMv8-A, ARMv8-R, and ARMv9-A, an "Execution state" defines key characteristics of the processor’s environment. This includes the number of bits used in the primary processor registers, the supported instruction sets, and other aspects of the processor's execut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacOS High Sierra
macOS High Sierra (version 10.13) is the fourteenth major release of macOS, Apple Inc.'s desktop operating system for Macintosh computers. macOS High Sierra was announced at the WWDC 2017 on June 5, 2017 and was released on September 25, 2017. The name "High Sierra" refers to the High Sierra region in California. Its name signified its goal to be a refinement of the previous macOS version, macOS Sierra, focused on performance improvements and technical updates rather than features. This makes it similar to previous macOS releases Snow Leopard, Mountain Lion and El Capitan. Among the apps with notable changes are Photos and Safari. macOS High Sierra is the final version of macOS to support the Unibody iMac and the Polycarbonate Unibody MacBook, as its successor, macOS Mojave, drops support for the late 2009 and final models. System requirements All Macs that supported macOS Sierra support macOS High Sierra. *iMac (Late 2009 or later) * MacBook (Late 2009 or later) *MacBo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacOS Big Sur
macOS Big Sur (version 11) is the seventeenth software versioning, major release of macOS, Apple Inc., Apple's operating system for Macintosh computers. It was announced at Apple's Worldwide Developers Conference (WWDC) on June 22, 2020, and was released to the public on November 12, 2020. Big Sur is the successor to macOS Catalina (macOS 10.15). The release of Big Sur was the first time the major version number of the operating system had been incremented since the Mac OS X Public Beta in 2000. After sixteen distinct versions of macOS 10 ("Mac OS X"), macOS Big Sur was presented as version 11 in 2020, and every subsequent version has also incremented the major version number, similarly to Classic Mac OS and to iOS and Apple's other current OSes. For the first time since OS X Yosemite six years earlier, macOS Big Sur features a user interface redesign. It features new blurs to establish a visual hierarchy, along with making icons more square and UI elements more consistent. Ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacOS Monterey
macOS Monterey (version 12) is the eighteenth major release of macOS, Apple's desktop operating system for Macintosh computers. The successor to macOS Big Sur, it was announced at WWDC 2021 on June 7, 2021, and released on October 25, 2021. macOS Monterey was succeeded by macOS Ventura, which was released on October 24, 2022. The operating system is named after Monterey Bay, continuing the trend of releases named after California locations since 2013's 10.9 Mavericks. macOS Monterey is the final version of macOS that supports the 2015–2017 MacBook Air, Retina MacBook Pro, 2014 Mac Mini, 2015 iMac and cylindrical Mac Pro, as its successor, macOS Ventura, drops support for those models. It is the last version of macOS that can run on Macs with 4GB of RAM. Changes Monterey introduced several new features and changes, including the following: * Shortcuts for the Mac * TestFlight for the Mac *Provisions to allow the planned introduction of Universal Control, which allows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
