The user operation prohibition (abbreviated UOP) is a form of use restriction

Digital rights management

Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

 used on video DVD

DVD

A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

 discs and Blu-ray discs. Most DVD players and Blu-ray players prohibit the viewer from performing a large majority of actions during sections of a DVD that are protected or restricted by this feature, and will display the no symbol

No symbol

The no symbol is a circle with a diagonal line through it , surrounding a pictogram used to indicate something is not permitted...

 or a message to that effect if any of these actions are attempted. It is used mainly for copyright notices or warnings, such as an FBI warning in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, and "protected" (i.e., "unskippable") commercials.

Countermeasures

Some DVD players ignore the UOP flag, allowing the user full control over DVD playback. Virtually all players that are not ad-hoc DVD player hardware (for example, a player program running on a general purpose computer) ignore the flag. There are also modchip

Modchip

A modchip is a small electronic device used to modify or disable built-in restrictions and limitations of computers, specifically videogame consoles...

s available for some standard DVD players for the same purpose. The UOP flag can be removed in DVD ripper

DVD ripper

A DVD ripper is a software program that facilitates copying the content of a DVD to a hard disk drive. They are mainly used to transfer video on DVDs to different formats, to edit or back up DVD content, and to convert DVD video for playback on media players and mobile devices...

 software such as: DVD Decrypter

DVD Decrypter

DVD Decrypter is a software application for Microsoft Windows that can create backup disk images of the DVD-Video structure of DVDs. It can be used to image any DVD, but controversially it is especially useful for decrypting copy protected movies. The program can also record images to disc...

, DVD Shrink

DVD Shrink

DVD Shrink is a freeware DVD transcoder program for Microsoft Windows that uses a DVD ripper to back up DVD movies. The final versions are 3.2.0.15 and 3.2.0.16 ; all other versions, such as DVD Shrink 2010, are scams...

, AnyDVD

AnyDVD

AnyDVD is a Microsoft Windows driver allowing decryption of DVDs on-the-fly, as well as targeted removal of copy preventions and user operation prohibitions . With an upgrade, it will also do the same for HD DVD and Blu-ray. The AnyDVD program runs in the background, making discs unrestricted and...

, AVS Video Converter, MacTheRipper

MacTheRipper

MacTheRipper is a Mac OS X application that enables users to create a playable copy of the contents of a Video DVD by defeating the Content Scramble System. During this process it may optionally modify or disable the DVD region code or the User operation prohibition features of the copied data...

, HandBrake

HandBrake

HandBrake is a general-purpose, open-source, cross-platform, multithreaded video transcoder software application. HandBrake was originally developed by titer in 2003 as a general-purpose video transcoder to make ripping a film from a DVD to a data storage device easier...

 and K9Copy

K9copy

K9Copy is a free, open source DVD backup and DVD authoring program for Unix-like operating systems such as GNU/Linux and BSD. Licensed under the GNU General Public License, K9Copy is free software.-Features:...

. On many DVD players, pressing stop-stop-play will cause the DVD player to ignore the UOP flag.

Counter-countermeasures

Nevertheless, removing UOP does not always provide navigation function in the restricted parts of the DVD. This is because those parts are sometimes lacking the navigation commands which allow skipping to the menu or other parts of the DVD. This has become more common in recent titles, in order to circumvent the UOP disabling that many applications or DVD players offer.

Counter-counter-countermeasures

Newer DVD players (c. late 2010) have, however, been designed to override the aforementioned counter-countermeasures. The DVD reader software inside the DVD player automatically generates chapters for parts of the DVD lacking navigation commands, allowing them to be fast-forwarded or skipped; pressing the menu button, even in these previously restricted sections, will cause a jump to the main menu.

External links

• User Prohibited Operations flag documentation, Unofficial DVD Specifications