Refers to the vertical axis of the VIDI/O Analyst vectorscope viewport. R-Y is one of the color difference signals used in NTSC and is obtained by electrically subtracting the luminance (Y) signal from the red (R) component signal.
A special type of cabinet in which equipment is installed. Most common are racks that will accept equipment that is 19 inches across with places for it to be screwed into the front. Many rack will have ground busses, power strips and back doors. Some will provide air conditioning vents.
Rack Unit - RU
One rack unit or RU is 1.75 inches in height. Most equipment in broadcasting is specified to be mounted in increments of RUs in heighth. For example, 2 RUs would be 3.5 inches high.
of independent disks. A grouping of standard disk drives together
with a RAID controller to create storage that acts as one disk to
provide performance beyond that available from individual drives.
Primarily designed for operation with computers RAIDs can offer very
high capacities, fast data transfer rates and much-increased security
of data. The latter is achieved through disk redundancy so that disk
errors or failures can be detected and corrected.
No redundancy-benefits only of speed and capacity-generated by combining a number of disks. Also known as "striping."
Complete mirror system-two sets of disks both reading and writing the same data. This has the benefits of level 0 plus the security of full redundancy-but at twice the cost. Some performance advantage can be gained in read because only one copy need be read, so two reads can occur simultaneously.
An array of nine disks. Each byte is recorded with one bit on each of eight disks and a parity bit recorded to the ninth. This level is rarely, if ever, used.
An array of n+1
disks recording 512 byte sectors on each of the n disks to create
n x 512 "super sectors" + 1 x 512 parity sector on the additional
disk which is used to check the data.
The same as Level 3 but individual blocks can be transferred. When data is written it is necessary to read the old data and parity blocks before writing the new data as well as the updated parity block, which reduces performance.
The same as Level 4, but the role of parity the disk is rotated for each block. In level 4 the parity disk receives excessive load for writes and no load for reads. In Level 5 the load is balanced across the disks.
A RAID system implemented by low level software in the host system instead of a dedicated RAID controller. While saving on hardware, operation consumes some of the host's power.
RAM (Random-Access Memory)
A temporary, volatile memory into which data can be written or from which data can be read by specifying an address.
Also referred to as instant access, a term used to define the capability of a videodisc to access specific frames regardless of location on the disc.
The process of beginning to read and decode the coded bit stream at an arbitrary point.
The pattern of the moving electron scanning beam in a CRT—usually moving left to right and repeating over the image from top to bottom as a series of horizontal scan lines. In an NTSC system, the raster scan of one TV frame consists of 525 individual scanned lines made up of two interlaced fields of 262.5 lines each. The scanning pattern creates a new frame every 30th of a second.
A video display device where the image is the representation of a scanning process. The raster is the scanned representation of the image.
1. The process of converting from one digital sample rate to another. The digital sample rate for the component digital video format is 13.5 MHz. For the composite digital video format, it is either 14.3 MHz for NTSC or 17.7 MHz for PAL. 2. Often used incorrectly to indicate both re-sampling of digital rates and encoding/decoding.
A Rayleigh channel is a time-varying frequency selective fading model for an RF channel.
RDBMS (Relational Database Management System)
A database management system in which data that is stored in two-dimensional tables of columns and rows can be related if the tables have a common column or field.
Read Before Write
A feature of some videotape recorders that plays back the video or audio signal off of tape before it reaches the record heads, sends the signal to an external device for modification, and then applies the modified signal to the record heads so that it can be re-recorded onto the tape in its original position.
The space available on a videodisc or tape.
Computation or processing
done in the present to control physical events occurring in the present.
For example, when a digital effects system operator moves a joystick
and the video images on the monitor appear to move simultaneously,
the computations required to make the images move are said to have
occurred in realtime.
A translucent screen of glass or acrylic with a specially formulated coating on which the image is transmitted through the screen for individual or group viewing. The screen is placed between the projector and the viewer.
Rear Screen Projection
Projection of an image onto a translucent screen material for viewing from the opposite side.
Receive Only Picture Processor
A picture processor which operates as a decoder only, and therefore, is only capable of receiving video images. Acts as the complement to a send-only picture processor or coder.
1. In SunUp applications, where the signal from a satellite is detected. The receiver then delivers the signal to a router. If the signal is analog, the signal may need stabilization, brought into synchronization with the plant and then converted to digital before going to the router (assuming it is a digital facility). 2. An electronic device, such as a radio or TV, for collecting broadcast transmissions and decoding them for output on either an audio or video player/amplifier in their original form.
The process of clocking digital data with a regenerated clock.
The TCS Record application has two major functions: (1) Review Caching results and Record events created by the Caching process; and (2) File materials manually using drag and drop in the TCS Record to create record events.
Electromagnetic device on a tape recorder that writes new material on a tape. A coil of wire that is wrapped around a circular soft-iron magnet incorporating a very small gap.
The size of a computer record, usually specified in bytes.
An NTSC color test signal.
Making a copy of smaller size than the original by optical printing.
A mathematical polynomial code developed by Irving Reed and Gustav Solomon, used extensively in digital error correction circuits.
Reference Black Level (Pedestal)
Part of the video signal that provides a reference level for total picture brightness.
The process of precisely aligning the output of three imagers within a tube camera. Registration is accomplished in the manufacturing process within CCD cameras so that no registration is required of the operator.
The variation in position of a signal’s transition relative to those of a clock extracted from the signal. The extracted clock will contain some of the signal’s jitter frequency domain components, depending on he bandwidth of the phase-locked-loop controlling the regenerated clock VCO.
The length of time it takes for a processing device to return to normal after acting upon an input signal.
To draw an image as it actually appears in schematic or blueprint form.
The process of non-realtime drawing of a picture relying on computer processing speed for graphics and compositing.
The mass reproduction of prerecorded videodiscs or compact discs.
This term, when used in clauses defining the coded bit stream, indicates that the value may be used in the future for Digital Television Standard extensions. Unless other specified within the Digital Television Standard, all reserved bits shall be set to “1”.
This is a basic measurement of how much information is on the screen. It is usually described as "some number" by "some number". The first "some number" is the horizontal (across the screen) resolution and the second "some number" is the vertical resolution (down the screen). The higher the number, the better, since that means there is more detail. Some examples:
NTSC VHS: 240 x 485
NTSC broadcast: 330 x 485
NTSC laserdisc: 425 x 485
ITU-R BT.601 (525/60): 720 x 485
Computer screen: 1280 x 1024
The maximum definition a particular system is capable of reproducing. Resolution is measured in the number of discrete observable lines that can be reproduced on a system. The higher the resolution a system is capable of producing, the sharper the picture will appear. In TV, resolution is measured in vertical and horizontal lines or the total number of observable black to white line transitions observable in the picture. Horizontal resolution is limited by the bandwidth of the television circuit, while vertical resolution is limited by the total number of TV scan lines. A high-resolution video camera or monitor can display 700 horizontal lines of resolution and 480 vertical lines or 700 x 480 resolution. While influenced by the number of pixels in an image (for high definition approximately 2,000 x 1,000, broadcast NTSC TV 720 x 487, broadcast PAL TV 720 x 576), note that the pixel numbers do not define ultimate resolution but merely the resolution of that part of the equipment. The quality of lenses, display tubes, film process and film scanners, etc., used to produce the image on the screen must all be taken into account. This is why a live broadcast of the Super Bowl looks better than a broadcast recorded and played off of VHS, while all are NTSC or PAL.
Amount of detail in the video image is measured along both the horizontal and vertical axes. In digital systems, resolution is the number of pixels on a display surface. Computer CRT resolutions are usually given as the number of pixels per scan line and the number of scan lines, e.g. 640 x 480. Video resolution is measured in terms of lines of detail per horizontal scan line (horizontal resolution) and total number of scan lines (vertical resolution).
The clarity or graininess of a video or computer image as measured by lines or pixels; the smallest resolvable detail in the image. The perceivable detail, or the ability of an image reproducing system to reproduce fine detail.
Term used to describe the notion of equipment that can operate at more than one resolution. Dedicated TV equipment is designed to operate at a single resolution although some modern equipment, especially that using the ITU-R 601 standard, can switch between the specific formats and aspect ratios of 525/60 and 625/50.
By their nature, computers can handle files of any size, so when applied to imaging, they are termed resolution independent. As the images get bigger so the amount of processing, storage and data transfer demanded increases-in proportion to the resulting file size. So, for a given platform, the speed of operation slows. Other considerations when changing image resolution may be reformatting disks, checking if the RAM is sufficient to handle the required size of file, allowing extra time for RAM/disk caching and how to show the picture on an appropriate display.
The formation of a coarse,
crackled surface on the emulsion coating of a film during improper
processing. If some process solution is too hot or too alkaline, it
may cause excessive swelling of the emulsion and this swollen gelatin
may fail to dry down as a smooth homogeneous layer.
A type of film stock which,
after processing, produces a positive image. Once popular for news
gathering, it is now often used because of the distinctive high
contrast look which it creates.
(Request for Comments). The name of the result and the process for creating a standard on the Internet. A new standard is proposed and published as a "Request For Comments." If the standard is established, the reference number/name for the standard retains the acronym "RFC." For example, the official standard for FTP is RFC 959.
RGB (Red, Green, Blue)
The abbreviation for the red, green and blue signals, the primary colors of light (and television). Cameras and telecines have red, blue and green receptors, the TV screen has red, green and blue phosphors illuminated by red, green and blue guns. Much of the picture monitoring in a production center is in RGB. RGB is digitized with 4:4:4 sampling which occupies 50 percent more data than 4:2:2.
Device for converting composite video to RGB video.
A low-impedance type of microphone that operates on electromagnetic principals.
An oscillatory transient on a signal occurring as a result of band-width restrictions and/or phase distortions. A type of ringing causes ghosting in the video picture.
To make the same change to a
number of events. Ripple Value = to make the same grading adjustments
to a block of events.
A method of moving a block of
scenes in the Telecine Decision List (TDL) by the same number of
A grading adjustment, made in one scene, and applied to adjacent scenes. Also referred to as a “Trim” Another definition is to make the same grading adjustments to a block of events. 888 systems provide for Absolute, Relative and Static Ripple Value operations.
RLC (Run Length Coding)
Coding of data with different number of bits. A system for compressing data. Frequently recurring data has the smallest number of bits, data seldom recurring having the highest number of sites. The principle is to store a pixel value along with a message detailing the number of adjacent pixels with that same value. This gives a very efficient way of storing large areas of flat color and text but is not so efficient with pictures from a camera, where the random nature of the information, including noise, may actually mean that more data is produced than was needed for the original picture.
RLE (Run Length Encoding)
A compression scheme. A run of pixels or bytes of the same color or value are coded as a single value recording the color or byte value and the number duplications in the run.
ROM (Read-Only Memory)
A memory device that is programmed only once with a permanent program or data that cannot be erased.
The first working edit of a program, often performed on low-end equipment, to be refined eventually into the master edit.
Signal routing device. See DVS. Takes any number of inputs and sends them to any number of selectable outputs. The signals being routed are usually in digital format. Example: Taking a signal from a playback device and sending it to an uplink transmitter via any designated encoding/encryption equipment. Receiving a turnaround or satellite downlink feed and sending it via a GPRC to a recording/storage device. Routers are normally controlled by the Automation System
Directing a signal through various audio and/or video components.
Hard-wired, automated patch bays that allow system connections to be made simply by pushing a button.
A SMPTE parallel component digital video standard. See: SMPTE 125M.
The technical standard adopted by the EIA for color television systems. RS-170 refers to monochrome (black and white) video, while RS-170A is color.
The proposed standard of the Society of Motion Picture and Television Engineers (SMPTE) for Composite Analog Video Signal - NTSC for Studio Applications, dated January 1993. A revised version of the RS-170A industry standard.
ANSI standard defining the single-ended (unbalanced) interconnection scheme for serial data communications.
A medium range (typically up to 300 m/1000 ft or more) balanced serial data transmission standard. Data is sent using an ECL signal on two twisted pairs for bi-directional operation. Full specification includes 9-way D-type connectors and optional additional signal lines. RS-422 is widely used for control links around production and post areas for a range of equipment.
RS Protection Code (RS-204, 188, 8)
16-byte long error control code added to every 187 (scrambled) +1 syncbyte-long transport packet with the following result: The packet has a length of 204 bytes and the decoder can correct up to T = 8 errored bytes This code ensures a residual error bit rate of approximately 1x10-11 at an input error rate of 2x10-4.
RST (Running Status Table)
Gives the status of an event (running/not running) allowing timely automatic switching to events.
The look of images and sound which have been synchronized, but
where the synch drifts in and out, often as a result of post synching
Dailies. The first positive prints made by the laboratory from the negative photographed on the previous day. The term is today also used to refer to the uncut processed negative, and the video transfer of such material.