Click on the first letter of the word you are interested in to jump to that section of the glossary:
1000/1001
When NTSC color was being introduced into broadcast television, compromises had to be made for it to be compatible with previous black and white systems. The field rate was changed by 1/1.001 – from 60 to 59.94 frames per second. Older B&W TVs could receive color broadcasts and show them in B&W and the new color information could be encoded into the broadcast signal so that the new color TVs would show the broadcasts in color. Today, digital and HD signals have to fit in; 24, 30, and 60 frames/fields per second become 23.98, 29.97, and 59.94 to be compatible with existing NTSC formats and workflows.
1080/24p
Internationally standardized High Definition production format ITU BT 709 has a digital sampling structure of 1920 (H) x 1080 (V) and operates at 24 frames per second progressively scanned. This also loosely describe the format operating at 23.976P.
1080/60i
Standard High Definition production format (SMPTE 274M and ITU 709) with digital sampling of 1920 (H) x 1080 (V), operating in interlaced scan mode at 60 fields per second. Loosely describes the 59.94i system as well.
1280 x 720
A high definition digital sampling structure of 1280 horizontal pixels and 720 vertical pixels. All 1280x720 video is progressively scanned: 720p.
16 x 9
The aspect ratio standard for HDTV and Widescreen SDTV, with a width of 16 units and a height of 9 units.
1.78
Using the 16x9 aspect ratio for HDTV and Widescreen SDTV, the ratio of the horizontal screen size to its vertical screen size is 1.78 units wide to 1.0 units high.
1.85
The most common screen ratio for motion pictures – 1.85 units wide to 1.0 units high.
1920 x 1080
A digital sampling structure of 1920 horizontal and 1080 vertical pixels, with images either interlaced (1080i) or progressive (1080P).
2:3 Pulldown
For converting 24 frame per second film or 24P video into 59.94 interlaced video. The frame rate is slowed from 24 fps to 23.976 fps (a factor of 1000/1001) and a "3:2" field cadence is created. This is done by taking one frame of the 24 frame source and filling three of the 59.94 fields, with the next frame of the 24 frame source filling only two of the 59.94 fields, the next frame three fields, the next two fields, and so on. This results in four of the 24 frame per second original material fitting into five frames of the destination 59.94i video. Pulldown now describes any combination of 1000/1001 speed change and/or 3:2 cadence creation. The term "pulldown" originates with the mechanical action of the pulldown gate in a telecine pulling each film frame into the imaging area.
2k
Resolution of 2,048 pixels wide. The vertical pixels depend on the aspect ratio.
2.35
A widescreen motion picture film format of 2.35 units wide by 1 unit high.
23.98 or 23.976
A video image rate of 23.976 (usually shortened to 23.98) frames per second. A simple 3:2 process will produce standard 59.94 fields per second interlaced video for distribution.
24P
24 full frames per second digital video progressively captured. Usually refers to the HD picture format of 1920 x 1080; also used with 1280 x 720 images. With motion picture film, the frame rate is true 24P, in video the term 24P is still used, even though the actual frame rate is 23.976P.
24PsF
A 24 (also known as 23.98) frame progressive video divided in segments of even and odd lines for transmission, storage and display. Though transmitted like an interlaced signal, if treated as a progressive signal it does not create the same harmful artifacts caused by interlace scanning.
24-bit Color
In an RGB environment or color space, the three color components are specified for each and every pixel, using three bytes of information per pixel. A byte = 8 bits; 3 bytes x 8 bits = 24 bits per pixel, This delivers 256 shades of each color, with more than 16 million colors represented in the color palette.
29.97P
29.97 full frames per second progressively captured digital video.
30P
30 full frames per second progressively captured digital video; more properly 29.97P.
3-to-1 Rule
When using more than one microphone, put one mic three times the distance of the other mic from the sound source – put mics at least three times farther from each other than from the people using them.
4:1:1
Both high definition and standard definition systems where the ratio between luminance and chrominance samples is 4:1 – one set of color difference samples (R-Y,B-Y) for every four luminance samples (Y). In standard definition video signals it represents luminance (Y) sampling at 13.5 MHz and R-Y/B-Y channel sampling at 3.75 MHz.
4:2:0
A digital video format where the two chrominance components are sampled at half the sample rate of luminance; the horizontal chrominance resolution is halved. While this reduces the bandwidth of the video signal by one-third, there is little to no visual difference. This is used by many high-end digital video formats and interfaces.
4:2:2
Standard definition video signals with luminance (Y) sampled at 13.5 MHz and color difference (R-Y,B-Y) channels each sampled at 6.75 MHz. Now in common usage describing both high definition and standard definition systems with the ratio between luminance and chrominance samples at 2:1 – two sets of color difference samples (R-Y,B-Y) for every four luminance samples (Y).
4:4:4
Standard definition video signals with all signals (usually R,G,B but also Y, R-Y,B-Y) sampled at 13.5 MHz. Now in common usage describing both high definition and standard definition systems with sampling done on the RGB video signal components.
4:4:4:4
A digital video sample format with all signals (usually R,G,B but also Y, R-Y,B-Y) sampled at 13.5 MHz., and a key channel added.
4k
Resolution of 4,096 pixels wide. The vertical pixels depend on the aspect ratio.
5.1
An audio system with five full range channels – left, center, right, rear-left, rear-right – and one low frequency effects (LFE) channel.
59.94i
An interlaced video signal with half the total lines of the picture captured and displayed every 1/59.94th of a second.
59.94p
A progressive video signal with all lines of the picture captured and displayed every 1/59.94th of a second.
60i
An interlaced video signal with half the total lines of the picture captured and displayed every 1/60th of a second.
60p
A progressive video signal with all lines of the picture captured and displayed every 1/60th of a second.
720/60p
A High Definition production format (SMPTE 296M) with a digital sampling structure of 1280 x 720, at 60 frames per second progressively scanned. Also used to describe a 59.94P capture system.
8:8:8
A standard definition video signal, with all signals sampled at 27 MHz – usually R,G,B but also Y, R-Y, B-Y.
8-bit color
Each pixel in an image is represented by a single byte (8-bits of data), with 256 colors the maximum number of colors that can be displayed at any time.
8mm
A video tape format. Eight millimeters (roughly 1/4-inch) wide, used in consumer camcorders. (Also the width of home movie film, also called 8mm.)
A/B Switch
Device to select between two signals (cable A or cable B, for example), feeding the signal to a TV, VCR, etc.
A/D, ADC
Short for 'Analog to Digital Conversion'.
Aliasing
Commonly seen as "jaggies" or jagged edges on diagonal lines in a video image, this defect or distortion results from sampling limitations. Also seen as twinkling or brightening (beating) in picture detail.
Alpha Channel
A layer in a graphic image file used to store matte information for compositing.
Analog
Equipment or methods not using electronic digitization of a signal into data, rather a continuously variable signal of some sort.
Anamorphic
An image created by using special lenses that optically squeeze a wide aspect ratio into a smaller ratio. The projection system uses specialized lenses to restore the aspect ratio to normal.
ANSI
Short for "American National Standards Institute". This organization, among many other standards, sets the standards for measuring projector brightness, for example.
Anti-Aliasing
The smoothing and removing of under-sampling (aliasing) effects in a video, using filtering and other techniques.
Artifacts
Any unwanted element or defect in an image: for example, noise, compression blocking, moire patterns around patterns.
ASC
Short for "American Society of Cinematographers".
ASCAP
Short for "American Society of Composers and Performers". This agency licenses the use of copyrighted music.
Aspect Ratio
The relationship of an image's width to its height. HD's aspect ratio is 16:9 (16x9) at 1920x1080 or 1280x720 lines. Standard definition is 4:3 (4x3) at 640x480 lines. Typical 35mm film aspect ratios are 1.85:1 and 2.40:1.
Aspect Ratio (Pixel)
The relationship of width to height of an individual pixel. Digital video has rectangular pixels – NTSC standard (ITU-R 601). HDTV and computers have square pixels.
ATSC
Short for "Advanced Television System Committee", which established such advanced systems as HDTV, or high definition television.
Attenuator
For audio signals, an electronic device that reduces their strength.
Audio
Sound converted into an electrical signal. Also, the sound component of a TV broadcast or video.
Audio Level
The relative volume or loudness of a sound signal. For example, raising or lowering a recorder's audio level sets a recording's loudness.
Audio Limiter
An automatic control which reduces recording volume if the sound level goes too high. It has no effect on lower or middle sound ranges of the recording.
Audio Meter
A display device showing the relative volume or loudness of an audio signal.
Audio Mixer
A device for combining audio/sound signals – for example, from several microphones – into one audio signal.
Audio Monitor
A device allowing a sound signal to be listened to and its quality checked. Also: a VCR switch for selecting which channel is fed to headphones or perhaps the VCR's audio output.
Automatic Gain Control (AGC)
A circuit designed to keep a desired output signal constant when the input signal strength varies, by changing the amplification (otherwise known as gain)
AVCHD
Short for "Advanced Video Codec High Definition", this is a specific version of a compressed MPEG-4 format (AVC/H.264)
AVI
Short for "Audio Video Interleave", it is a digital format containing both audio and video in a compressed form.
B-roll
Originally film from a second camera (camera B) shooting a different perspective from the main camera (camera A) in a documentary or interview situation, with footage from the B camera (B-roll, B roll, Broll) edited into the main footage.
Baby boom
A small, microphone boom stand.
Back focus
The distance between the image sensor and the rear element of the lens, with lens mounted on the camera and focused at infinity. This distance must remain constant with zoom lenses to ensure constant subject focus during zooming.
Backlight
Light, either ambient or added, coming from behind the subject towards the camera. Also: a camera control which adjusts exposure for backlit subjects to prevent subject silhouetting.
Balanced line
Audio cable with three wires, two of which are shielded. The corresponding connector has three prongs (terminals).
Ballast (Electrical Ballast)
A device limiting the amount of current in a light's electrical circuit. May control LEDs, HMIs, fluorescent tubes, etc.
Band
A radio frequency range in wireless communication, e.g. TV broadcasting.
Banding
Sometimes inaccurately called posterization, banding is when an image shows different bands of color or luminance instead of a smooth gradation. An example of this may be found in an image of blue sky -- instead of seeing a smooth blue, there will be bands visible across the sky as the color changes.
Bandwidth
The quantity of data transmitted during a given time period. With video, the higher the quality, the greater the required bandwidth; digital video, in particular, requires large amounts. Audio and video compression lowers bandwidth requirements. The term also applies to the allotted spectrum for a broadcast station, the difference in hertz between the lowest and highest frequency it uses.
Barn doors
A set of barn doors is an attachment fitted to the front of lighting fixtures used in films, television, and theatres. The attachment has the appearance of a large set of barn doors, but in fact there are four leaves, two larger and widening on the outside, two smaller and getting narrower towards the outside. They facilitate shaping of the beam of light from the fixture, and prevent light from spilling into areas where it is not wanted, such as the camera's lens or the eyes of audience members.
Barrel connector
An electrical adapter for connecting two cables. It has a socket at each end.
Bass
Low frequency in the audio spectrum.
Bayonet mount
A bayonet mount is a fastening mechanism consisting of a male side with one or more pins or claws, and a female receptor with matching slots and springs to keep the two parts locked together. Bayonet mounts are commonly used to attach interchangeable lenses to cameras, and lens hoods to lenses.
Betacam
A half-inch videotape family of professional products developed by Sony. Often used to refer to a camcorder or recorder using the tape format, the tape, or the format itself.
Bit
The smallest element of binary digital data, either a 1 or a 0. Often used to describe the attributes of a pixel used in digital video, representing signal quality – an 8 bit signal can have 256 levels from black to white, a 10 bit signal can have 1024 levels.
Bit depth
Tells how much color information is available to describe each pixel in an image. For example, 8 bits per pixel X 3 colors (RGB) delivers 24 bits. Also describes the number of bits of information recorded for a digital audio sample.
Bitmap
Pixels, spatially mapped, displaying or storing a digital image.
Bit rate
Data transfer rate, expressed in bits per second (bps), with higher numbers delivering higher quality. Some Canon Vixia camcorders, for example, captures video at a rate of up to 24 Mbps.
Black balance
Similar in concept to white balance, but referenced to black. This function is found on some professional video cameras and is used to eliminate color tints.
Blanking
Information contained in the video data stream outside the visible content data. Includes synchronization information, time code, automatic color tuning and captioning information. This margin area is called the blanking interval or region.
Blocking
The planning of subject position and movement in a video production scene.
Blue gun
A calibration switch on a TV monitor activating only the blue phosphors' electron guns; for adjusting color hue and saturation with color bar test signals.
Blue pedestal
For balancing black levels. Color camera control adjusts the blue signal the camera generates when it "sees" no blue. The camera may have similar controls for red and green.
BMI
Short for "Broadcast Music, Inc.", an agency licensing the use of copyrighted music.
BNC
Short for "Bayonet Neill-Concelman". A common RF connector often used with video or sync cables. The advantage of this connector is the locking system, so the cable cannot be pulled out without first pushing it in and turning it.
Boom, boom stand
An arm or pole to which a microphone or light is attached, itself attached to a vertical stand usually counterweighted for stability.
Bps
Short for "Bytes Per Second", the measurement of the speed of digital data traveling through a device.
bps
Short for "Bits Per Second", the measurement of the speed of digital data traveling through a device.
Buffer memory
A temporary storage area/device holding data from the image sensor before it is handled by the image processor.
Burn in
On a CRT screen, this spot, streak, or blemish doesn't go away regardless of the image being displayed. Usually caused by extended display of a contrasty image.
Burst (photo)
A rapid sequence of still images, up to about 10 frames per second (fps). Often used for photographing moving objects.
Burst (video)
A portion of the video sync signal controlling hue and color accuracy.
Burst mode
An informally-used name for the camera setting which allows the capture of a rapid sequence of still images.
Burst phase
A color camera control which adjusts the timing of the burst signal, varying the picture's color hues. May be found on other video gear.
Burst rate
The number of digital still images captured in rapid sequence.
Bus
A subsystem transferring data between components inside a computer or between computers and peripherals, e.g. USB, FireWire.
Butterfly or Overhead
Diffusion material, in a large sheet, erected like a tent over the subject to soften light.
Byte
8 bits or 10 bits.
C
Short for "Chrominance" or color portion of a video signal.
Cable Drive
Remote control of a camera's focus and zoom using a system of cranks or knobs and cables mounted on or near a tripod's handles.
Cable guard
Metal shields to move cables aside so the camera dolly doesn't hit or roll over them.
Cam link head
Camera support which keeps the camera from abruptly nose-diving when tripod head movement controls are released, holding the camera in a safe, horizontal position.
Camcorder
Single piece camera and video recording mechanism.
Captioning Encoder
Device to translate text into data for captioned video.
Capture Rate
Used to describe the number of times per second that a picture is taken or captured in an imaging system. In a progressive system the capture rate is equal to the frame rate. In an interlaced system, the capture rate is double the frame rate because at each capture interval, only one field (a half resolution image) is acquired. It takes two fields to make a complete frame. It is standard practice to refer to the capture rate of an image as well as how it is captured when describing it instead of the frame rate (i.e. 60i (60 captures, 30 frames per second), 30P (30 captures, 30 frames per second) and 60P (60 captures, 60 frames per second) Also see Frame Rate, Interlace Imaging, Progressive Imaging.
CCD
Short for "Charge Coupled Device", a type of imaging sensor. Uses a different method from CMOS to convert electric charges to voltage signals.
CCU
Short for "Camera Control Unit", a range of equipment and operations for partial or complete remote control of video/TV cameras.
CD
Short for "Compact Disc", an optical device for storing digital data. Standard-sized CDs have a 120mm diameter and can hold up 700 MB of data – about 80 minutes of uncompressed audio.
CD-R
Short for "Compact Disc - Recordable".
CD-ROM
Short for "Compact Disc-Read Only Memory". Cannot be written to; readable by a computer with CD-ROM drive.
CF
Short for "Compact Flash". Typically used to refer to a flash memory card.
Chroma Gain
Camera control that boosts the amounts of color (saturation, intensity) in the picture.
Chroma Key
Often referred to as greenscreen, bluescreen or color keying, it is a technique for mixing two images or frames together; a color or color range from one image is made transparent or removed, showing another image behind it.
Chrominance
The color information – hue and saturation – in a TV picture. Also known as chroma.
CG
Short for "Character Generator", a device or software producing static or animated text (e.g. crawls, rolls) to be placed into a video stream. Generally now computer-based, able to generate graphics as well as text.
CGI
Short for "Computer-Generated Imagery": using computer to create special effects, usually 3D.
CIE
Short for "Commission Internationale de l'Eclairage", or "International Commission on Illumination". An organization for cooperation and exchange of information on both the science and art of lighting and color.
Circular Polarizer
A polarizing filter reduces reflections from non-metallic surfaces and darkens the sky. SLR cameras require circular (rather than linear) polarizers to prevent focusing and metering problems associated with the camera's beam-splitter.
Clip
Short sequence or segment of video. Has been used to refer to any video shorter than a regular TV program.
Clip bin
A section of the editing screen window showing all the video sequences imported into the editing program.
Clipping
When a signal is stronger than the circuits can handle, the excess is cut off, creating distorted audio and/or chalky video.
C-Mount
A lens-to-camera connector with thread 1 inch (25mm) in diameter, 32 threads per inch, and with 7.526mm (0.69 in) distance from the camera's CCD to the rear mounting surface of the lens.
CMOS
Short for "Complementary Metal On Semiconductor", a type of imaging sensor. Uses different method than a CCD to convert an electrical charge into voltage signals.
Coax, or Coaxial Cable
A circular cable with single wire centered inside a shield, with insulating material and insulating jacket. Sometimes referred to professional model number: RG/59U.
Codec
Short for "compression/decompression" or "coder/decoder". Software or a hardware device that transforms one type of signals into another and vice versa.
Color background generator
Device to electronically create a color onscreen without using a camera, behind character-generated text, for example.
Color bars
A standardized pattern of colors used to test cameras and other video equipment so they will reproduce chrominance and luminance information correctly.
Color bar generator
An electronic device creating standard color bars as a test signal.
Color difference signals
Component video signals representing parts of a picture. For example, R-Y and B-Y are color difference signals.
Color Space
A mathematical model to specify, create and visualize color. Colors can be defined in different ways using different models. With video and computers, color is defined in terms of the excitations of red, green and blue phosphors on a screen or camera imager. Values may be converted from one color space to another, and may require a Look Up Table (LUT) for the translation. These LUTs are based on specific standards, such as SMPTE-C, SMPTE-240M, Rec-601-1, Rec-709, and Cineon.
Color Temperature
Description of a light source measured in degrees Kelvin. Lights have different color temperatures: tungsten light is 3200ºK, daylight is about 5500ºK. Tungsten delivers a redder light; daylight is blue.
Colorize
Electronically adding color. For example, converting B&W media to color in digital post production.
Component Video
A video signal with luminance (brightness) and chrominance (color) signals separate. There are 3 cables: they can be R, G, B or Y (luminance), Pb, Pr (analog color difference signals) or Y, Cb, Cr (digital color difference signals).
Composite Video
A video signal with luminance (brightness) and chrominance (color) combined. Typically used to describe NTSC or PAL video, which also includes horizontal and vertical synchronizing information and other data combined in one signal. Also refers to a direct video connection using an RCA-type plug and jack.
Compositing
The process of creating multiple layers of video, using such tools/techniques as painting, rotoscoping, keying, color correction, matting, etc.
Compression
The process of reducing the bandwidth or data rate in a video or audio signal. Often used with audio and video to reduce storage and transmission costs. Compression techniques common in digital imaging rely on removing both redundant data and data that is deemed less critical or imperceptible to the viewer. This can be done either within a frame (intra-frame compression) or across multiple frames (inter-frame compression). Compression systems are developed to reduce perceptible losses, however most compression systems in use today will exhibit some level of distortion.
Compression Ratio
Usually expressed as a ratio – such as 5:1 (5 to 1) – it's the difference between the original quantity of data and how much is left after bandwidth compression, or the degree to which the data has been reduced numerically.
Conform
Assembling recorded material by following a prepared scheme such as a rough cut or edit decision list (EDL). Autoconforming uses an EDL to directly control assembly in online editing.
Continuous White Balance
Camera control for ongoing, moment-by-moment adjustments to the color temperature of a scene.
Crawl
Text moving sideways across the bottom of the screen.
CRT
Short for "Cathode Ray Tube", a vacuum tube with an electron gun at one end and a phosphor screen at the other. The phosphors glow when struck by electrons. It is the 'tube' in older TV sets and computer monitors.
Cutaway
A short video sequence other than the main scene which interrupts the main scene. The cutaway often is a related shot, such as of an interviewer.
DAC, D/A
Short for "Digital to Analog Conversion", or simply "Digital to Analog".
DA
Short for "Distribution Amplifier", which creates multiple outputs of a signal.
DAT
Short for "Digital Audio Tape", a 3.8mm wide magnetic tape which records two channels of 16-bit digital audio, either at 48 KHz or 44.1 KHz.
dB
Shortform for "Decibel".
Decibel (dB)
A logarithmic unit of sound level measurement.
Depth of Field
The portions of a picture, both in front of and behind the main point of focus, which are in focus. Lens focal length, aperture, distance to focusing point, and imager or negative size all affect depth of field.
Digital
Referring to binary data (1s and 0s; on/off) and the methods and equipment used to process, store and distribute such data.
Digital Intermediate (DI)
The middle step in a film-to-video-to-film process. Film is scanned to create high quality digital file, to which is applied color treatment, special effects or other creative processes. The finished video is transferred back to film for final release (theatrical, for example). The file also can become the master for video duplication.
Digital Television (DTV)
The broadcast of a digital signal. The Advanced Television Systems Committee (ATSC) allows both standard definition and high definition programs transmitted digitally to be called DTV.
Direct Broadcasting via Satellite (DBS)
Receipt by consumers of TV programs directly from a satellite, typically using a small "dish" pointed at and locked onto a single satellite. The received, compressed signal enters a "black box" (usually referred to as a set-top box) where it is decoded for display on a standard TV.
Dissolve
The gradual transition from one image to another in film and video editing; in effect, a controlled double exposure.
DIT
A specialist technician and advisor, supporting the digital camera crew during preparation and production, and acting as a link between location and post-production.
D-ILA
Short for "Digital Image Light Amplifier", a JVC projection display technology producing 2k resolutions at high brightness and contrast ratios. Employs a reflective-mode active matrix liquid crystal display to control light output.
DLT
Short for "Digital Linear Tape", a data storage system.
Dolby AC3
The audio standard for DTV broadcasting, this audio compression technique from Dolby Laboratories is designed to produce discrete multichannel digital surround sound. It supports up to six audio channels (5.1 surround) at various bitrates. It is a distribution format, not directly editable.
Dolby E
Designed for the production of discrete multichannel digital surround sound and metadata, it is a digital audio compression technique created by Dolby Laboratories. It supports up to 8 channels in any combination (including 8 Mono, 4 Stereo, and 5.1 plus stereo). It is a production format, editable on frame boundaries, maintaining quality through multiple decode/encode cycles.
Dolby Pro-Logic
The more advanced form of Dolby Laboratories' Dolby Surround, it delivers a wider listening/viewing area and provides better channel separation, not only recovering surround information from encoded program material, but also adding a center channel, firmly positioning dialogue and center effects.
Dolby Surround
Dolby Laboratories' first generation home theater format. It delivers three channels: left, right, and surround (usually split into 2 rear speakers). The surround information is pulled from encoded program material and fed to a pair of surround speakers on the side walls next to the listening area.
Downconversion
Reducing high resolution video to lower resolution video. Often used so HD material can be handled offline on inexpensive standard definition editing systems before being assembled (conformed) in HD. May also be used to finish HD programs for delivery to non-HD clients.
Downsampling
The process of reducing the sampling rate of a signal, usually done to reduce the data rate and/or the quantity of data.
DPX
Short for "Digital Moving-Picture Exchange". A file format, specified by SMPTE, containing both an image and information about it.
Drop-Frame
Alteration of timecode to match the framerate of NTSC video to a time of day clock. NTSC video actually runs at 29.97 frames per second (30/1.001). To keep the timecode on an NTSC videotape synchronous with a time of day clock, it needs to make up 1 in 1001 frames. It does this by changing the count by two frames on nine out of every ten minutes. So the frame following 10:35:59:29 would be numbered as 10:36:00:02. 30 frame HD formats are often run at 29.97 to allow conversion and synchronization to NTSC video. These formats support Drop-Frame timecode. Note that there is no drop frame format for native 24-frame video formats. Also see
Non-Drop-Frame,
Timecode.
DV
Short for "Digital Video", a primarily consumer video tape format in two sizes, Standard and Mini, recording a 4:1:1 standard definition signal, 5:1 compression ratio, for a total bitrate of 25Mb/s. Audio can be 48khz 16 bit stereo or 32kHz 12 bit 4 channel.
DVD
Originally short for "Digital Video Disk", now "Digital Versatile Disk" because it can be used for many applications. The same size as a CD, it has a capacity of up to 17 Gbytes. A single-layer, one-sided DVD stores up to 4.7 Gbytes. Commonly, it is a distribution medium for MPEG-2 compressed video, multichannel audio, subtitles, menus, and other features for playback in industry standard players.
DVD Authoring
The process of creating a DVD image before burning the audio, video, still images and navigational menus to disk or copying to DLT tape for reproduction.
DVHS
A digital tape format developed by JVC based on the VHS tape transport. Most commonly used for HD delivery, it supports MPEG2 encoded video at rates up to 25Mb/s. There are currently 3 different types of DVHS tapes. D-Theater DVHS tapes are recorded with a special copy protection system for wide release of high definition content. Pro-HD DVHS offers the ability to record and playback in a password-protected mode for playback on Pro-HD DVHS equipment, giving content providers the ability to protect their material (this feature is often used for "Digital Dailies"). Pro-HD equipment will also playback D-Theater and Consumer DVHS tapes. Consumer DVHS offers recording and playback of non-copy-protected and off-the-air material and playback of D-Theater titles.
Edge Crop
Removal of the outer edges of a wider aspect ratio picture, leaving the center portion.
EDL
Short for "Edit Decision List", a description of how to assemble a program from the original tapes or digital files. This is used to transfer the edit form one MLE system to another - for example from off-line to on-line.
Fade
A gradual increase or decrease in the level of an audio or video signal, or the gradual transition from one image/clip to another, or to a blank screen/solid color.
Frame rate
The frequency with which a camera produces unique consecutive images (frames), measured in frames per second. The standard frame rate for motion picture capture is 24 fps.
Gamut
The range of colors that can be reproduced by a device. Think of it as a box; anything inside the walls of the box can be reproduced, while anything outside the walls cannot be ("illegal"), even though another box may be able to reproduce the illegal color.
Gigabit (Gb)
Short for 1 billion bits; about 125 megabytes.
Gigabyte (GB)
Short for 1 billion bytes.
HDCAM Format
A High Definition videotape format using 1/2-inch wide tape and recording 22:11:11 8 bit HD Video. The data rate is reduced approximately 7:1 to 140Mb/s using prefiltering and compression. Developed by Sony, the tape format supports 1920x1080 at 23.98P, 24P, 25P, 29.97P, 30P, 50i, 59.94i, and 60i.
HDCAM SR Format
A next generation High Definition videotape format using 1/2-inch wide tape stock recording either 22:22:22 10bit HD video, 22:11:11 10bit HD Video or a special double speed mode for 2 channels of 22:11:11 10 bit HD Video. Also developed by Sony, it uses a light compression scheme to reduce the data rate 2.7:1 (for 22:11:11) to approximately 440Mb/s.
HDTV Modes
High Definition video and broadcast standards: 1080i delivering 1080 horizontal scan lines, interlaced; 720p with 720 horizontal scan lines, progressive scan; 1080p delivering the highest-quality signal, used in most feature film production (1080p24, wherein the '24' refers to frames per second).
HDV
A next generation High Definition videotape format using 1/2-inch wide tape stock recording either 22:22:22 10bit HD video, 22:11:11 10bit HD Video or a special double speed mode for 2 channels of 22:11:11 10 bit HD Video. Also developed by Sony, it uses a light compression scheme to reduce the data rate 2.7:1 (for 22:11:11) to approximately 440Mb/s.
H.264
A block-oriented, motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG). A product of the Joint Video Team (JVT) partnership. The two standards – ITU-T H.264 and ISO/IEC 14496-10 - MPEG-4 Part 10 (aka ISO/IEC MPEG-4 AVC) – are jointly maintained with identical technical content.
IEEE
Short for "Institute of Electrical and Electronic Engineers", an organization which defines standards and specifications.
IMAX
An entertainment technology company which designs, leases, markets, maintains, and operates IMAX theatre systems, film development, production, post-production and distribution. Also colloquially refers to the 65mm film with an image area of 69.6mm wide and 48.5mm tall. The company is experimenting in HD and Digital Cinema electronic projection systems.
Interlaced
A single video frame is broken into two fields, one containing all the odd lines in the image and the other containing the even lines. Part of the 1080 HDTV broadcast standard.
IRE
Short for "Institute of Radio Engineers", a founding organization of IEEE. IRE units are a linear scale measuring the relative amplitude of the component of a television signal with a zero reference at the blanking level.
ISO
Short, in English, for International Organization for Standardization, responsible for defining standards and specifications.
ISO Speed
Initially, a measure of film's sensitivity to light, based on a standard created by the International Organization for Standardization (ISO). Now also an exposure index (EI) rating specified by a camera manufacturer so an sRGB image file created by the camera will have a lightness similar to that of a film of the same EI rating at the same exposure.
JPEG
Short for "Joint Photographic Experts Group". A "lossy" digital image file compression system; data is removed to create a smaller file size than if the file contained all the raw data.
kHz, Kilohertz
A measurement of frequency equal to 1,000 cycles per second.
Kilobit (Kb)
1,000 bits
Kilobyte (KB)
Can mean 1,000 bytes or 1,024 bytes depending on the usage.
LAN
Short for "Local Area Network", connecting computers in a limited physical space.
Letterbox Format
For displaying a wide aspect ratio format on a narrow aspect ratio screen, while maintaining the original aspect ratio. Letter boxing delivers a display with black bars at top and bottom of the screen.
LTC
Short for "Longitudinal Time Code" (pronounced LIT-See). This is information encoded on a videotape linear track which allows a time code reference to be read when tape is moving at play speeds or faster.
LUT
Short for "Look Up Table", which translates from one color space to another.
Megabit (Mb)
Can mean 1,000,000 (one million) bits or 1,048,576 bits depending on usage.
Megabyte (MB)
Can mean either 1000 or 1024 bytes depending on usage.
Megahertz (MHz)
A frequency measurement of 1,000,000 (one million) cycles per second.
Metadata
Structured information describing the file, i.e. data about the file data, making it easier to use the file. In digital video, this information may include title, director, actors, content summary, recording length, as well as file name, status.
.mov
Apple QuickTime video file format.
MPEG
Short for "Moving Picture Experts Group", creators of the MPEG video formats.
MPEG-4
An audio and video compression standard from the Moving Picture Experts Group. MPEG-4 was originally designed for video streaming but is also used for CD distribution, voice and broadcast applications.
Non-Drop-Frame
Unlike drop frame, this timecode counting system always counts 30 frames in a second, so the timecode will not match the time of day, as NTSC video runs at 29.97 frames per second. (There is no drop frame format for native 24p; specifying drop or non-drop frame is unnecessary.)
Non-Linear Editing, NLE
Allows random access to any frame in a digital video clip in film and TV post-production. Also used in consumer digital video editing programs.
NTSC
Short for "National Television Systems Committee". Also the name given to a 525-line, 30 frame per second color TV standard mainly used in North America, Central and South America and Japan.
Offline Editing
Designed to create an Edit Decision List (EDL) using less expensive editing equipment. The EDL will later be used for assembling a high definition program using more expensive HD equipment. With offline editing, EDLs carry information on shot selection and basic transitions.
OMF
Short for "Open Media Framework", a file type supporting video, audio, graphics, animation and effects as well as edit decision information in digital media post production.
Online Editing
Designed to produce a completed high definition master using more expensive high definition equipment. Using an Edit Decision List (EDL) created by an offline system can save time and money in online editing, allowing cuts to be automatically assembled in the proper order (conformed), ready for final touches.
Overcranking
In film recording, frames are recorded at a faster speed than the anticipated playback rate, creating a “slow-motion” effect on playback. An "undercranking" effect is possible with some video cameras
PAL
Short for "Phase Alternation Line". Refers to a 625-line, 25 frame per second standard definition color TV system used in the United Kingdom and Europe.
Pan and Scan
An alternative to letterboxing when showing motion picture or down converted HD video on a standard definition TV. Pan and scan shows the full image height but not its width, requiring the image to be moved from side to side to show its full width.
PCM Audio
Short for "Pulse-Code Modulation", a sampling technique for digitizing analog audio signals; the standard for digital audio in computers and compact disc audio. Not typically used for video because of the high bandwidth.
Petabyte (PB)
One quadrillion bytes; 1,000 terabytes.
Pixel
Shortform of "Picture Elements", the smallest unique point of a digital video image. Each such point is specified by luminance, chrominance and position.
Progressive segmented frame (PsF)
A high definition video format (sometimes called sF, SF) designed to acquire, store, modify, and distribute content using interlaced equipment and media. A progressive frame is divided into two segments, odd lines in one, even lines in the other, with both fields representing the same instant in time. (These segments appear equivalent to interlaced fields, but there is no motion between the two.) This allows for a progressive picture to be processed through the same electronics used to handle interlaced video.
Progressive scan
All lines in a video frame are captured at the same moment, delivering higher vertical resolution and a more "film-like" look than interlaced video. This requires much higher bandwidth.
Quantization
A lossy compression technique which decreases the amount of data needed to represent a signal by reducing a range of values to a single quantum value. For example, color quantization reduces the number of colors used in an image. Also may involve selectively discarding some data.
RAM
Short for "Random Access Memory", a volatile, temporary data storage area.
REI
Short for "Recommended Exposure Index". A camera manufacturer-specified, arbitrary exposure index for each model, based on the manufacturer’s opinion of what exposure index values will produce well-exposed sRGB images at various sensor sensitivity settings.
Resolution
The detail an image holds. This applies to any type of image, digital, film or other. The higher the resolution, the greater the image detail.
RGB
Short for "Red/Green/Blue", the colors used to create all color television and video signals.
ROM
Short for "Read-Only Memory", a permanent data storage area from which information can be read but not deleted or altered.
SECAM
Short for "Systeme Electronique Couleur Avec Memoire", the 625-line, 25 frame per second color television system used in France and the Middle East.
Secure Digital (SD)
A non-volatile memory card format for use in portable devices (Developed by Matsushita, SanDisk, and Toshiba.)
Secure Digital High Capacity (SDHC)
SDHC (Secure Digital High Capacity, SD 2.0) is an extension of the SD standard which increases card's storage capacity up to 32 GB. SDHC cards share the same physical and electrical form factor as older (SD 1.x) cards, allowing SDHC-devices to support both newer SDHC cards and older SD-cards. To increase addressable storage, SDHC uses sector addressing instead of byte addressing in the previous SD standard. Byte addressing supported card capacities up to 2GB, whereas sector addressing can theoretically support capacities up to 2 TB (2048 GB). The current standard limits the maximum capacity of an SDHC card to 32 GB.
Secure Digital Extended Capacity (SDXC)
A further extension of the SD standard, the Secure Digital Extended Capacity (SDXC) format was unveiled in 2009, with a maximum capacity of 2 TB (2048 GB). The initial maximum transfer rate was 104 MByte/s, but that is expected to increase to 300 MByte/s. Microsoft's proprietary exFAT file system is the standard for this memory card format, but it is possible to use another file system, i.e. FAT32, NTFS or ext2.
SMPTE
Short for "Society of Motion Picture and Television Engineers", the organization responsible for defining standards and specifications for the motion picture and broadcast industry.
SOS
Short for "Standard Output Sensitivity" or "Standard Output Specification". The average level in an sRGB image must be 18 percent gray (plus or minus 1/3 stop), with no exposure compensation, when exposed according to the specification. The output level is measured in the sRGB output from the camera so it is only applicable to sRGB images (JPEG, typically) and not raw image format. Not applicable with multi-zone metering.
sRGB
A standard RGB (Red Green Blue) color space using the ITU-R BT.709-5 primaries, the same used in studio monitors and HDTV, with a transfer function (gamma curve) typical of CRTs, allowing sRGB to be directly displayed on typical monitors.
Standard Definition (SD)
A video format compatible with NTSC or PAL, with 480 (576 for PAL) active lines of interlaced video.
Tape to Film Transfer
A process putting HD or computer graphics material on film.
Telecine
A film-to-video device operating in “real time” (at least 24 frames per second). Also used to describe the color correction/enhancement step in a production workflow.
Terabyte (TB)
One trillion bytes; 1,000 gigabytes.
Timecode (TC)
Standard format for recording time information on videotape or file. Each frame is given a unique number that is represented in the form of Hours: Minutes: Seconds: Frames. When used correctly, a specific frame of video can be located on a videotape by using its timecode number. When doing offline editing, proper timecode handling is critical because the timecode is what is used to reference the master tapes or files in the final assembly process. See LTC, VITC
Title Safe
Place on the screen where a title will be displayed in its entirety. In HD production it can be combined with the downconversion format; for example, “4x3 title safe” means all titles are positioned so when the HD program is downconverted edge-cropped to fit a 4x3 ratio screen, none of the titles will be cut off.
Undercranking
In film recording, frames are recorded at a slower speed than the anticipated playback rate, creating a “fast-motion” effect on playback An "undercranking" effect is possible with some video cameras.
Upconversion
Changing lower resolution video into higher resolution video.
Valid Gamut
A video signal with all colors within the gamut of all color spaces the video will be translated into. If a signal's colors are outside that gamut, the video may be distorted, folded, clipped or passed depending on the device's handling parameters.
VITC
Short for "Vertical Interval Timecode" (pronounced VIT-see). Timecode information encoded in the vertical blanking of a video signal. Allows a time code reference to be read when a videotape is in slow jog/shuttle or pause mode.
Wipe
In editing, the replacement of one image by another using a distinct edge that forms a shape – for example, a simple edge, an expanding circle, or the turning of a page.
WVHS
Based on the VHS tape transport, this analog High Definition format records/plays a 1035/1080i high definition signal.
Y, R-Y, B-Y
Terminology to describe the luminance (Y) and color difference signals (R-Y) and (B-Y) of component video. Y is luminance information and the R-Y and B-Y signals together provide the color information. These signals, derived from the original RGB source, are used in most video systems as a bandwidth reduction technique.
