An optical disc is a flat, usually disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid of a beam of light. Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side.
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, but recent drives can both read and record, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives.
Ripping is the extraction of digital content from a container, such as a CD, onto a new digital location. Originally, the term meant to rip music from Commodore 64 games. Later, the term was applied to ripping WAV or MP3 files from digital audio CDs, and after that to the extraction of contents from any storage media, including DVD and Blu-ray discs, as well as the extraction of video game sprites.
A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems.
MPEG transport stream or simply transport stream (TS) is a standard digital container format for transmission and storage of audio, video, and Program and System Information Protocol (PSIP) data. It is used in broadcast systems such as DVB, ATSC and IPTV.
MultiLevel Recording was a technology originally developed by Optex Corporation and promoted by Calimetrics to increase the storage capacity of optical discs. It failed to establish itself on the market. Through a combination of proprietary media, recorder, reader and player modifications, Calimetrics proposed that ML could increase the capacity of a CD-ROM, CD-R or CD-RW to 2 GB, a single-layer DVD, DVD-R, DVD+R, DVD-RW, DVD+RW or DVD-RAM to 7.1 to 10 GB and a single-layer Blu-ray Disc (BD) to as much as 60 GB. An optionally integrated digital rights management (DRM) system entitled MovieGuard was also suggested. An industry group called the ML Alliance was formed in 2000 to help commercialize ML technology. Members eventually included Calimetrics, TDK, Sanyo Semiconductor, Plextor, Matsushita Kotobuki Electronics, Mitsubishi Chemical Corporation, Verbatim, Teac and Yamaha.
On an optical disc, a track (CD) or title (DVD) is a subdivision of its content. Specifically, it is a consecutive set of sectors on the disc containing a block of data. One session may contain one or more tracks of the same or different types. There are several kinds of tracks, and there is also a sub-track index for finding points within a track.
A hybrid disc is a disc, such as CD-ROM or Blu-ray, which contains multiple types of data which can be used differently on different devices. These include CD-ROM music albums containing video files viewable on a personal computer, or feature film Blu-rays containing interactive content when used with a PlayStation 3 game console.
BD-J, or Blu-ray Disc Java, is a specification supporting Java ME Xlets for advanced content on Blu-ray Disc and the Packaged Media profile of Globally Executable MHP (GEM).
Blu-ray Disc Recordable (BD-R) and Blu-ray Disc Recordable Erasable (BD-RE) refer to two direct to disc optical disc recording technologies that can be recorded on to a Blu-ray-based optical disc with an optical disc recorder. BD-R discs can only be written to once, whereas BD-RE discs can be erased and re-recorded multiple times, similar to CD-R and CD-RW for a compact disc (CD). Disc capacities are 25 GB for single-layer discs, 50 GB for double-layer discs, 100 GB ("XL") for triple-layer, and 128 GB for quadruple-layer.
This article compares the technical specifications of multiple high-definition formats, including HD DVD and Blu-ray Disc; two mutually incompatible, high-definition optical disc formats that, beginning in 2006, attempted to improve upon and eventually replace the DVD standard. The two formats remained in a format war until February 19, 2008, when Toshiba, HD DVD's creator, announced plans to cease development, manufacturing and marketing of HD DVD players and recorders.
The Advanced Access Content System (AACS) is a standard for content distribution and digital rights management, intended to restrict access to and copying of the post-DVD generation of optical discs. The specification was publicly released in April 2005. The standard has been adopted as the access restriction scheme for HD DVD and Blu-ray Disc (BD). It is developed by AACS Licensing Administrator, LLC, a consortium that includes Disney, Intel, Microsoft, Panasonic, Warner Bros., IBM, Toshiba and Sony. AACS has been operating under an "interim agreement" since the final specification has not yet been finalized.
Blu-ray is a digital optical disc data storage format designed to supersede the DVD format. It was invented and developed in 2005 and released worldwide on June 20, 2006, capable of storing several hours of high-definition video. The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, PlayStation 5, Xbox One, and Xbox Series X. The name refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.
HD DVD is an obsolete high-density optical disc format for storing data and playback of high-definition video. Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format, but lost to Blu-ray, supported by Sony and others.
BD+ is a component of the Blu-ray Disc digital rights management system. It was developed by Cryptography Research Inc. and is based on their Self-Protecting Digital Content concept. Its intent was to prevent unauthorized copies of Blu-ray discs and the playback of Blu-ray media using unauthorized devices.
As of 2021, multiple consumer-oriented, optical-disk media formats are or were available:
.m2ts is a filename extension used for the Blu-ray disc Audio-Video (BDAV) MPEG-2 Transport Stream (M2TS) container file format. It is used for multiplexing audio, video and other streams, such as subtitles. It is based on the MPEG-2 transport stream container. This container format is commonly used for high-definition video on Blu-ray Disc and AVCHD.
In computing, the burst cutting area (BCA) or narrow burst cutting area (NBCA) is the circular area near the center of a DVD, HD DVD or Blu-ray Disc, where a barcode can be written for additional information such as ID codes, manufacturing information, and serial numbers. The BCA can be written during mastering and will be common for all discs from that master or, more usually, will be written using a YAG laser to “cut” the barcode into the aluminum reflective layer of the finished disc, potentially adding a unique barcode to each manufactured disc.
Cinavia, originally called Verance Copy Management System for Audiovisual Content (VCMS/AV), is an analog watermarking and steganography system under development by Verance since 1999, and released in 2010. In conjunction with the existing Advanced Access Content System (AACS) digital rights management (DRM) inclusion of Cinavia watermarking detection support became mandatory for all consumer Blu-ray Disc players from 2012.
