{{Short description|DVD copy protection system by Sony}} {{about|Sony's copy-protection system|the inverse trigonometric function of the cosine|arccos (trigonometry)}} {{update|date=November 2010}}
'''ARccOS''' (Advanced Regional Copy Control Operating Solution) is a [[Copy protection|copy-protection]] system made by [[Sony]] that is used on some [[DVD]]s. Designed as an additional layer to be used in conjunction with [[Content Scramble System]] (CSS), the system deliberately creates corrupted [[Cylinder-head-sector|sectors]] on the DVD, which cause copying software to produce errors (see [[bad sector]]). The corrupted sectors are in areas of the disc that most DVD players do not access, but most copying software does.
Despite being promoted as "fully compatible with available DVD players and drives,"<ref>{{cite web |title=ARccOS |url=http://www.sonydadc.com/americas/prod.newtech.arccos1.go |accessdate=2007-04-18 |archiveurl=https://web.archive.org/web/20070510052739/http://www.sonydadc.com/americas/prod.newtech.arccos1.go |archivedate=2007-05-10 |url-status=dead }}</ref> some DVDs with ARccOS cannot be played on some DVD players: Sony DVPCX995, [[Toshiba]] SD4700, Harman Kardon DVD101, Microsoft [[Xbox]] and others.<ref>{{cite web | title = Sony copy protection taking heat again: now DVDs won't play | author = Erik Hanson | work = engadget | date = 2007-04-16 | url = https://www.engadget.com/2007/04/16/sony-copy-protection-taking-heat-again-now-dvds-wont-play/ | accessdate = 2007-04-17 | archiveurl= https://web.archive.org/web/20070420113300/http://www.engadget.com/2007/04/16/sony-copy-protection-taking-heat-again-now-dvds-wont-play/#comments| archivedate= 20 April 2007 | url-status= live}}</ref> Sony has announced a future [[firmware]] update for their players to fix this incompatibility issue.<ref>{{cite web | title = Sony Pictures DVDs have a new a copy protection that makes the movies unplayable on some Sony (and other makes) DVD players! | date = 2007-04-19 | url = http://sonystrikesagain.wordpress.com/2007/03/19/hello-world/ | accessdate = 2007-04-21 | archiveurl= https://web.archive.org/web/20070518084437/http://sonystrikesagain.wordpress.com/2007/03/19/hello-world/| archivedate= 18 May 2007 | url-status= live}}</ref><ref>{{cite web | title = Sony admits, fixes problem with DVD DRM | author = Jacqui Cheng | date = 2007-04-18 | url = https://arstechnica.com/news.ars/post/20070418-sony-to-replace-incompatible-dvds.html | accessdate = 2007-04-19 | archiveurl= https://web.archive.org/web/20070427001721/http://arstechnica.com/news.ars/post/20070418-sony-to-replace-incompatible-dvds.html| archivedate= 27 April 2007 | url-status= live}}</ref> One revision of the ARccOS scheme used by Sony was incompatible with a higher number of players than average. Sony has offered to replace those discs for owners having problems; the replacement discs will have a newer version of ARccOS coding on them, which Sony claims is more compatible.<ref>{{cite web | title = Sony fixes problem with ARccOS-protected DVDs | author = Adrian Kingsley-Hughes | date = 2007-04-18 | url = http://blogs.zdnet.com/hardware/?p=360 | access-date = 2007-04-21 | archive-url= https://web.archive.org/web/20070427055945/http://blogs.zdnet.com/hardware/?p=360| archive-date= 27 April 2007 | url-status= dead}}</ref><ref>{{cite web | title = Sony Replaces ARccOS-Protected DVDs | date = 2007-04-19 | url = http://www.cdrinfo.com/Sections/News/Details.aspx?NewsId=20244 | accessdate = 2007-04-21 }}</ref> Some DVD rental companies have warned users that the Sony DVDs in question may not play on their machines.<ref>{{cite web | title = Netflix ARccOS Warning | website=[[Netflix]] | url = http://www.netflix.com/FAQ?p_faqid=2462 | accessdate = 2008-09-09 }}</ref> Many [[DVD ripper]]s have been designed to overcome ARccOS protection; it is also naturally overcome by using [[ddrescue]], a Linux utility designed to copy images with errors.
==See also== * [[Compact Disc and DVD copy protection]]
==References== {{reflist|2}}
{{DEFAULTSORT:Arccos Protection}} [[Category:CD and DVD copy protection]] [[Category:Sony products]]