.cso
Encyclopedia
.CSO is a compression
method for the ISO image
format. It is used to compress dumped PlayStation Portable
UMD
games, and is an alternative to the .DAX compression method. It is also sometimes called "CISO".
It was the first compression method for ISO. It was created so that more memory space can be saved. Booster created the first code; it was later optimized for better compression. Other formats tried to replace it by fixing up certain issues such as lag in games, such as .DAX and .JSO. However at the time, the popular application homebrew
"DevHook" used CSO. .DAX needed another loader, and .JSO was basically unused.
CSO provides nine levels of compression. While the highest levels of compression can introduce slowdown and lengthy load-times in software which relies heavily on disc streaming, even the lower levels are capable of substantial compression. This is partially due to the data layout of a UMD
, though more frequently due to the use of Dummy Files as both an anti-piracy tool and a means to more optimally lay the data out physically on the disc.
In addition to being used for compressing PlayStation Portable
UMD
games, the PSP port of PicoDrive supports compressed Sega Mega-CD
disc images in the CSO format.
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
method for the ISO image
ISO image
An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...
format. It is used to compress dumped PlayStation Portable
PlayStation Portable
The is a handheld game console manufactured and marketed by Sony Corporation Development of the console was announced during E3 2003, and it was unveiled on , 2004, at a Sony press conference before E3 2004...
UMD
Universal Media Disc
The Universal Media Disc is an optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform...
games, and is an alternative to the .DAX compression method. It is also sometimes called "CISO".
It was the first compression method for ISO. It was created so that more memory space can be saved. Booster created the first code; it was later optimized for better compression. Other formats tried to replace it by fixing up certain issues such as lag in games, such as .DAX and .JSO. However at the time, the popular application homebrew
Homebrew (video games)
Homebrew is a term frequently applied to video games or other software produced by consumers to target proprietary hardware platforms not typically user-programmable or that use proprietary storage methods...
"DevHook" used CSO. .DAX needed another loader, and .JSO was basically unused.
CSO provides nine levels of compression. While the highest levels of compression can introduce slowdown and lengthy load-times in software which relies heavily on disc streaming, even the lower levels are capable of substantial compression. This is partially due to the data layout of a UMD
Universal Media Disc
The Universal Media Disc is an optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform...
, though more frequently due to the use of Dummy Files as both an anti-piracy tool and a means to more optimally lay the data out physically on the disc.
In addition to being used for compressing PlayStation Portable
PlayStation Portable
The is a handheld game console manufactured and marketed by Sony Corporation Development of the console was announced during E3 2003, and it was unveiled on , 2004, at a Sony press conference before E3 2004...
UMD
Universal Media Disc
The Universal Media Disc is an optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform...
games, the PSP port of PicoDrive supports compressed Sega Mega-CD
Sega Mega-CD
The is an add-on device for the Mega Drive video game console, designed and produced by Sega and released in Japan, Europe, Australia, New Zealand, and South Africa. The device was also released in North America under the name Sega CD, for the Sega Genesis...
disc images in the CSO format.
Related file formats
- BIN/CUE
- BWT, BWI, BWS, BWABlindWriteBlindWrite, the successor to BlindRead, is a computer program that writes to recordable CDs. The Blindread software, which reads CDs and writes CD image files, has been discontinued as a separately released product, but BlindRead's code is included in the newer BlindWrite suite of software that...
- DAADirect Access ArchiveDirect Access Archive, or DAA, is a proprietary file format developed by PowerISO Computing for disk image files. The format supports features such as compression, password protection, and splitting to multiple volumes...
(.daa) - MDF/MDS (.mdf)
- NRGNRG (file format)A .nrg file is a proprietary CD image file format used by Nero Burning ROM, a utility suite made by Nero AG, to create and burn ISO 9660 CD images.Other than Nero Burning ROM, a variety of software titles can use these image files...
(.nrg) - DMG (Apple disk image) (.dmg)
- UIF (Universal Image Format)MagicISOMagicISO is a CD/DVD image shareware utility that can extract, edit, create, and burn disc image files. It offers the possibility of converting between ISO and CUE/BIN and their proprietary Universal Image Format disc image format.In addition to being able to edit the contents of the disc images...
(.uif) - IMA (.ima)
- IMG (.img)
- DK.dk.dk is the country code top-level domain for Denmark. The supervision of the .dk top-level domain is handled exclusively by DK Hostmaster. Any new .dk domain name has to be applied for via an approved registrator. Then the domain name applicant can ask the registrator to manage his domain name or...
(.dk) - WIM (.wim)