DVD glossary

RAW

Real time Read-After-Write feature of certain mastering techniques. Or, a transparent, unmetallized disc.

Raw Bit Error Rate

Probability of a bit being erroneous without use of any error correction techniques.

Record

A sequence of bytes treated as a unit of information.

Recordable

Storage medium that can only be read, not modified, after information is initially written (also see WORM.)

Red Book

Proprietary Philips/Sony specification (red cover) for CD-Audio, subsequently published as IEC 908.

Reed-Solomon Code

Byte-structured parity format that cycles data multiple times through a mathematical transformation in order to increase its effectiveness, often used with optical and magnetic computer media for error detection and/or correction. The algebraic code belongs to the class of BCH (Bose-Chaudry-Hocquehen) multiple burst correcting cyclic codes. Method published in 1960 by Irving S. Reed and Gustave Solomon, staff members of MIT's Lincoln Laboratory.

Reference Plane

Plane normal to the axis of rotation of a disc defined by the perfectly flat annular surface of an ideal spindle onto which the CD or DVD clamping area is physically connected.

Reflectance (Reflectivity)

Proportion of incident light that is returned from a reflective surface.

Relative Time (PTime)

Elapsed time from the start of a logical track.

Replication

Production of a copy using simultaneous, parallel transfer of all information elements from an original image to a replica. High mastering and equipment costs and long preparation times are offset by high throughput, making the technique attractive for high volumes. Examples would be CD-ROM replication from a stamper using molding, stamping, or coining, or making copies of text by lithographic means (also see Injection Molding.)

Rewritable

Storage medium that can be overwritten multiple times, normally without pre-erasure.

Rock Ridge

IEEE standard for UNIX file structure, named for the mythical town in the movie Blazing Saddles.

RS-PC

Reed-Solomon Product Code is a method of error correction employing several (usually two) groups of Reed-Solomon parity bytes computed from rows, columns, or diagonals of a rectangular data array. DVD discs correct small read errors using inner parity, or PI, that operates on rows, and corrects large read errors using outer parity, or PO, that operates on columns of the data array.

Runout

Radial variation of a non-data physical dimension (also see Eccentricity.)

Raw
A bitstream format in which the video data is uncompressed.

Reed-Solomon
Cyclical method of error correction.

Reed-Soloman Product Code
Two pass (row x col) application of Reed-Soloman code designed to exploit interleaving of data sectors.

Regional Coding
A provision in the DVD Specification that requires DVD players to be hard-coded to accept DVDs that is only meant to be played within one of six designated world regions. A Code 1 disc cannot be played in a Code 3 region for example. This technique was developed to enable Hollywood companies to release movies at different times in different regions.
The DVD regions are defined as:
Region 1 - United States of America, Canada
Region 2 - Europe, Greece, Turkey, Egypt, Arabia, Japan and South Africa
Region 3 - Korea, Thailand, Vietnam, Borneo and Indonesia
Region 4 - Australia and New Zealand, Mexico, the Caribbean, and South America
Region 5 - India, Africa, Russia and former USSR countries
Region 6 - Peoples Republic of China
Movies are released on DVD at different times around the world, typically America and Canada first, Australia and Japan 6 months later, and Europe 12 months after US release. In some instances, DVD movies are available for purchase in America and Canada before they are released in European cinemas.

Regional Coding Enhancement
Recently, the Motion Picture Association of American (MPAA) has developed a new system called Regional Coding Enhancement (RCE) which will be included on almost all new region 1 DVD releases. This new technology was created to prevent consumers with codefree DVD players from watching DVD discs purchased in North America. From now on, most region 1 DVD discs will be including this technology. As such, you may find in the future that some DVD discs bought in the United States will not work on your codefree DVD player.

Reserved bytes
6 bytes in the header of each DVD sector reserved for future use.

Resolution
The width and height of the video window, in pixels. DVD resolution is 720X480.

RF
Radio Frequency.

RGB
Red, Green & Blue. The three primary colors of light. A color model used in computer/monitor displays, in which different colors are specified according to the combination of their red, green and blue components.

RSDL
Reverse Spiral Dual Layer - a technique by which a movie is split across two layers of a single disc and is joined together for continuous playback. Allows longer movies (or movies with extra content) to be shown uninterrupted on a single side of a disc and twice (8.5 GB) the ordinary amount of DVD data per side. Usually, about 133 minutes of video can fit on a single layer. However, an RSDL disc can contain about 4 hours or more of interrupted video and audio. A dual-layer disc is easy to spot because it is gold in color, versus the silver shimmer of its single-layered brother.

Run-length coding
Lossless compression method that exploits continuous samples with same value.