Glossary R-T
R | |
RAID | Redundant Array of Independent Disks. A standardization/categorization method for fault-tolerant disk systems. |
RAMbo Drive | A DVD-RAM drive capable of reading and writing both CD-Rs and CD-RWs. |
Random Erase | Erasing single files from a CD-RW, creating more free space which can be used (just like on a floppy disk). |
Raw | An uncompressed video bitstream. |
RCE | Regional Coding Enhancement. An addition to standard DVD regional coding which will stop Region 1 discs from being playable on code-free players. See Regional Coding. |
Recordable Disc | A CD or DVD that can have data written to it with a laser. |
Red Book | The specifications for standard audio CDs. |
Reed-Solomon (or RS-PC) | An error-correction encoding system that cycles data through mathematical transformations to increase its effectiveness. |
Regional Coding | Coding hard-wired into DVD players to ensure that a DVD can only be played in one of six different world regions:
A multi-region DVD player may allow you to play movies from different regions, but the difference in frame rates (NTSC 29.97 fps, PAL/SECAM 25 fps) means an adapter might be needed to make the DVD viewable. |
Registry | A database that contains information about a computer’s configuration, which can include:
Although a computer’s registry can be updated with a simple text editor, it is a VERY good idea to back up the original version before making any changes. Registry errors can cause serious operating system problems. |
Resampling | Converting from one resolution to another, whether spatial or temporal resolutions. |
Reserved Bytes | Bytes in the header of a DVD sector reserved for future use. |
Resolution | A measure of an image’s detail and overall quality, usually a numerical value based on the units making up the image. For instance, the effective resolution of an analog TV screen is 512 × 400 pixels, while HDTV can reach 1920 × 1080 pixels. The higher the resolution number is, the clearer the picture becomes. |
RF | Radio Frequency. Part of the electromagnetic spectrum is used for radio transmissions; frequencies of 535 kHz–1605 kHz are used for AM radio, while FM radio is broadcast at frequencies between 88 MHz–108 MHz. |
RGB | Red, Green and Blue; the three primary colors of light. Different levels and combinations of these three colors create the entire range of visible light. |
Rip | To copy files off a CD or DVD, often converting them into another format (Audio CD tracks to MP3 files, DVD video to VOB files). |
RLC | Run-Length Coding. A lossless method of compression method that makes use of contiguous samples with identical values. |
Rock Ridge | An ISO 9660 extension that supports the UNIX file system. |
Romeo | A temporary (and now outdated) solution to the “8-dot-3” Windows filename restriction before the creation of Joliet. See Joliet. |
RSDL | Reverse Spiral Dual Layer (disc). A disc format that permits splitting a movie across two layers of a disc and then joining the layers for seamless continuous playback. |
Run-In/Run-Out Blocks | Blocks of data written before and after a packet or a track on a disc that allow a recorder to synchronize with the data and to finish up interleaved data. Each packet gets four run-in blocks and two run-out blocks. |
S | |
S/PDIF | Sony/Philips Digital Interface. The standard for transmitting digital signals (like Dolby Digital) on consumer-grade systems. |
SACD | Super Audio CD. A newer disc format that can play uncompressed digital multi-channel surround sound. SACD discs can be played in current CD players, but the output will only have normal CD quality sound. A “format war” is in progress between SACD and DVD-Audio to see which will become the new audio standard. |
Sample Rate | The number of times a digital sample is taken (samples per second, or Hertz). A higher rate means better reproduction of the original signal; a sampling rate must be double the original signal frequency in order to avoid aliasing. |
Sampling | Converting analog signals into a digital format by measuring the analog signal’s value at regular intervals and encoding the numerical values in digital form. |
SATA | Serial ATA. A descendant of Parallel ATA with a higher transfer rate. Parallel ATA maxes out at 133MBps; Serial ATA’s base speed is 150MBps, and can max out at 600MBps. |
Saturation | The amount of gray in a color; effectively, the intensity of a hue. |
Scalability | Scalability offers a set of tools by which video can be coded at different resolutions in a single bitstream. When played, the bitstream is decoded at a suitable resolution (scale). |
Scanning Velocity | Rate at which a laser travels along the spiral track of a disc. |
SCART | Syndicat des Constructeurs d’Appareils Radiorécepteurs et Téléviseurs. The standard 21-pin European AV connector/socket for TVs, VCRs and DVD players. |
Scene Access | The ability to skip to a certain scene on a DVD by using menus or pressing chapter numbers on a remote control. |
Screener | A pre-release of a video which is sent to censors and film critics. Sometimes a copyright message is visible on the screen throughout the program to prevent illegal duplication. |
SCSI | Small Computer System Interface. A standard electronic interface between a computer and its peripherals, such as hard drives or CD/DVD drives. |
SDDS | Sony Dynamic Digital Sound. Sony’s multi-channel (six or eight channels) surround sound format, available only in movie theaters. |
SDTV | Standard Definition Television. Digital signals transmitted at 480-line resolution. The picture and sound are better than a standard analog NTSC, but not as good as HDTV. |
Seamless Branching | A DVD that can switch instantaneously between separate video, audio and subtitle tracks. |
SECAM | Séquential Couleur Avec Mémoire. A composite color standard similar to PAL but currently used only in France and a few other countries. PAL video can be transcoded to SECAM by either the player or the transmitter. |
Sector | A collection of bytes at the data layer; the smallest recordable unit on a disc. One sector can hold 2048 bytes of data or 2324 bytes of audio/video information. |
Sector Information | A sector’s header that provides the sector number. |
Sector Number | A number identifying the physical sector on a disc. |
Sequence | An MPEG definition for a set of dependently coded pictures that follow a sequence header until a sequence_end_code appears. All pictures in a sequence have the same common bit rate, buffer size, picture size, aspect ratio and frame rate. See GOP, B Frame, I Frame, P Frame. |
Sequence Header | Encoding and displaying parameters placed before one or more GOPs in an MPEG file. |
Sequential Erase | Erasing an entire disc so that it can be re-used. |
Session | A recorded segment of a disc which may contain one or more tracks of any type (data, audio or video). Data recordings usually have one track per session, but there can be multiple sessions on a disc. All video and audio tracks should be in a single session. A lead-in and a lead-out are recorded for each session on a disc. |
Session-at-Once | A subset of Disc-at-Once. In Session-at-Once recording, a first session containing multiple audio tracks is recorded in a single pass, and then the laser is turned off, but the disc is not closed. Then a second session (data) is written and closed. See Disc-at-Once. |
SIF | Source Interchange Format. A compressed video format standard: 352 × 240, 29.97 fps for NTSC and 352 × 288, 25 fps for PAL and SECAM. Image quality is roughly equivalent to VHS tape. |
Slice | An independently coded portion of an image. Video decoding and error correction can take place at the slice layer of a disc. |
Spindown | A power-saving feature on some drives that stop a disc from spinning when the drive is not in use. This can cause buffer underruns during the recording process. |
Square Pixels | The pixels that make up an image can have different height-to-width ratios. A square pixel has a ratio of 1.0. |
SSDL | Single-Sided Dual-Layer DVD. |
SSSL | Single-Sided Single-Layer DVD. |
Still Gallery | A collection of stationary images on a DVD; a viewer can use the skip button on their remote control to move from one image to the next. A single DVD can hold thousands of images. |
Subchannels (or Subcodes) | Eight subchannels of non-audio data on a CD (lettered P–W). Channels P and Q contain instructions for an audio player, telling it how to play the disc. On a CD+G disc, one of the subchannels would be used for storing song lyrics. |
Sub-Picture | A picture superimposed over a video. |
Substrate | The clear polycarbonate that surrounds and protects the information on a DVD. It also helps to ensure greater accuracy in the laser pick-up. |
Subtitles | Text appearing on the screen for viewers to read, either due to a hearing problem (closed-captioning) or because the film is in a foreign language. DVDs can hold up to 32 subtitle tracks. |
Subwoofer | A speaker designed to reproduce extremely low frequencies (bass). Since bass is not very directional, most home theater systems only need one mono bass speaker. |
Surround Speakers | Speakers in a surround sound system that individually handle the different audio channels. For instance, a ProLogic sound system uses five surround speakers: center, front left, front right, rear left and rear right. |
SVCD | Super VideoCD. An SVCD disc can hold 35–60 minutes of MPEG-2 video along with two stereo audio tracks and four selectable subtitles. |
S-Video Output | Video signals that are split into two parts: chrominance (color) and luminance (light and dark). This provides a better picture than composite video, but not as good as component video. |
T | |
Table of Contents | Shows the number of tracks, their starting locations, and the total length of the data area on a disc (either whole or for any session on it). |
TBC | Time Base Corrector. A device that removes or masks variations in video synchronizing signals by automatically delaying the video signals, ensuring that each line starts at the correct time. |
Teaser (Theatrical) Trailer | A very short movie trailer that does not give away any significant plot elements. |
Telecine | Adding frames to a film so the 24 fps film rate more closely matches the 29.97 fps NTSC video speed. See Pulldown. |
Telesync | A bootlegged video recorded with sophisticated camera equipment (instead of a hand-held camcorder). The audio track is either recorded directly from the theater’s audio system or the bootleg is made in an empty theater so there is no audience noise. |
Thermal Calibration | Recalibrating the read/write heads in a CD/DVD recorder to take into account thermal expansion; CDs and DVDs, like many materials, expand when heated, and the reading/writing process does generate a fair amount of heat. Most modern recorders handle the calibration themselves. |
THX | A high-performance playback specification developed by Lucasfilm Ltd. |
Timbre Matching | Matching tonal characteristics between speakers in a surround-sound audio system. |
Time Code (or SMPTE time code) | Information that indicates a position in time on an audio or video recording, usually with values for hours, minutes, seconds and frames. |
Title | A logically distinct section of a DVD, such as the main feature, a documentary or cast interviews. One DVD can have up to 99 titles. |
Titles and Chapters | The directory structure on a DVD that allows navigation to a specific part of a movie. |
TMPGenc | An MPEG-1/MPEG-2 encoder used to encode VCD, SVCD and DVD. |
Track |
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Track Buffer | A unit that keeps bitstream rates constant when disc access rates fluctuate. |
Track Pitch | Distance along radial vector between adjacent tracks. |
Track-at-Once | A data recording method where the recording laser is stopped after each track is completed. |
Trailer | A short preview for a feature film, television program or other multimedia content (like a videogame). |
Transcoding | Reformatting content to another type of content without changing the source. |
Transport Stream | Once a movie file has been multiplexed (or muxed), a transport stream is used to send it across a network. Viewers receive and decode the signal, allowing them to watch the movie. The transport stream used for HDTV is MPEG2; each MPEG2 file contains audio, video and other data in packetized elementary stream (PES) packets. |
TSCV | A VCD/SVCD authoring program for use with VCDimager (a VideoCD image mastering and ripping tool). |