libdvdcss is a free

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 software library for accessing and unscrambling 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....

s encrypted with the Content Scramble System (CSS)

Content Scramble System

Content Scramble System is a Digital Rights Management and encryption system employed on almost all commercially produced DVD-Video discs. CSS utilizes a proprietary 40-bit stream cipher algorithm...

. libdvdcss is part of the VideoLAN

VideoLAN

VideoLAN is a project that develops software for playing video and other media formats across a local area network . It originally developed two programs for media streaming, VideoLAN Client and VideoLAN Server , but most of the features of VLS have been incorporated into VLC, with the result...

 project and is used by VLC media player

VLC media player

VLC media player is a free and open source media player and multimedia framework written by the VideoLAN project.VLC is a portable multimedia player, encoder, and streamer supporting many audio and video codecs and file formats as well as DVDs, VCDs, and various streaming protocols. It is able to...

 and other DVD player

DVD player

A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. These devices were invented in 1997 and continue to thrive...

 software such as Ogle

Ogle DVD Player

Ogle is a DVD player for GNU/Linux, and other Unix-like operating systems. It is released as free software under the GNU GPL license. It was originally developed in 1999 by a few students at Chalmers Tekniska Högskola in Göteborg, Sweden, and maintained until late 2003...

, xine

Xine

xine is a multimedia playback engine for Unix-like operating systems released under the GNU General Public License. xine is built around a shared library that supports different frontend player applications. Another important feature of xine is the ability to manually correct the synchronization...

-based players, and MPlayer

MPlayer

MPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...

.

libdvdcss is designed to be platform independent, with versions for GNU

GNU

GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...

/Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

, Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

, BeOS

BeOS

BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...

, BSD, and Solaris.

Comparison with DeCSS

libdvdcss is not to be confused with DeCSS

DeCSS

DeCSS is a computer program capable of decrypting content on a commercially produced DVD video disc. Before the release of DeCSS, there was no way for computers running a Linux-based operating system to play video DVDs....

. While DeCSS uses a cracked DVD player key to perform authentication, libdvdcss uses a generated list of possible player keys. If none of them works (for instance, when the DVD drive enforces region coding) a brute force

Brute force attack

In cryptography, a brute-force attack, or exhaustive key search, is a strategy that can, in theory, be used against any encrypted data. Such an attack might be utilized when it is not possible to take advantage of other weaknesses in an encryption system that would make the task easier...

 algorithm is tried so the region code of a DVD is ignored. Unlike DeCSS, libdvdcss has never been legally challenged.

Distribution

Many GNU/Linux distribution

Linux distribution

A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

s do not contain libdvdcss (for example Debian

Debian

Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...

, Fedora

Fedora (operating system)

Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...

, SUSE Linux

SUSE Linux distributions

SUSE Linux is a computer operating system. It is built on top of the open source Linux kernel and is distributed with system and application software from other open source projects. SUSE Linux is of German origin and mainly developed in Europe. The first version appeared in early 1994, making...

, and Ubuntu

Ubuntu (operating system)

Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

) due to fears of running afoul of DMCA

Digital Millennium Copyright Act

The Digital Millennium Copyright Act is a United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization . It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures that control access to...

-style laws, however they may provide the tools to let the user install it themselves. For example, it is available in Ubuntu through Medibuntu

Medibuntu

Medibuntu is a community-maintained repository of Debian packages that cannot be included into the Ubuntu distribution for legal reasons....

.

Distributions which come pre-installed with libdvdcss include BackTrack

BackTrack

BackTrack is an operating system based on the Ubuntu GNU/Linux distribution aimed at digital forensics and penetration testing use. It is named after backtracking, a search algorithm...

, CrunchBang Linux

CrunchBang Linux

CrunchBang Linux is a lightweight Debian based Linux distribution, created by Philip Newborough, designed to offer a good balance of speed and functionality.- Features :...

, LinuxMCE

LinuxMCE

LinuxMCE is a free and open source software platform with a 10-foot user interface designed to allow a computer to act as a home theater PC for the living-room TV, personal video recorder, and home automation system. It allows control of everything in the home, from lighting and climate to...

, Linux Mint

Linux Mint

Linux Mint is a Linux-based computer operating system best known for its usability and ease of installation, particularly for users with no previous GNU/Linux experience...

, PCLinuxOS

PCLinuxOS

PCLinuxOS, often shortened to PCLOS, is a GNU/Linux distribution, with KDE Plasma Desktop as its default user interface. It is a primarily free software operating system for personal computers aimed at ease of use...

, Puppy Linux 4.2.1

Puppy Linux

Puppy Linux is a lightweight Linux distribution that focuses on ease of use. The entire system can be run from RAM, allowing the boot medium to be removed after the operating system has started...

, Recovery Is Possible

Recovery Is Possible

Recovery Is Possible is a small, specialized Linux distribution based on Slackware that includes system maintenance and recovery applications on a live CD or USB flash drive. The RIP disc comes in two flavors: one with the X Window System and one without...

, Slax

SLAX

Slax is a LiveCD Linux distribution based on Slackware and is currently being developed by Tomáš Matějíček. Packages can be selected in a website where users can build a custom Slax iso image. Slax slogan refers to the software as a "Pocket Operating System"...

, Super OS, Pardus

Pardus (operating system)

Pardus is a Linux distribution developed with support from the Turkish government. Pardus’ main focus is office-related work, including the use in Turkish government agencies. Despite that, Pardus ships in several languages. Its ease of use and availability free of charge spawned numerous...

, and XBMC Live.

Usage

Libdvdcss alone is only a library and cannot play DVDs. DVD player applications, such as VLC Media Player

VLC media player

VLC media player is a free and open source media player and multimedia framework written by the VideoLAN project.VLC is a portable multimedia player, encoder, and streamer supporting many audio and video codecs and file formats as well as DVDs, VCDs, and various streaming protocols. It is able to...

, link to this library to decode DVDs. Libdvdcss is optional in many open-source DVD players, but without it, only non-encrypted discs will play.