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A Brief Glossary of Film and Video Terms

1-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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2K: A Film image scanned into a computer file at a resolution of 2048 horizontal pixels.

3:2 Pulldown: The technique used to convert 24 frames per second film to 30 frames per second video. Every other film frame is held for 3 video fields resulting in a sequence of 3 fields, 2 fields, 3 fields, 2 fields, etc.

4K: A Film image scanned into a computer file at a resolution of 4096 horizontal pixels. 4K is considered to be a full-resolution scan of 35mm film.

4 fsc: Composite Digital video as used in D2 and D3 VTRs. Stands for 4 times the Frequency of Subcarrier, which is the sampling rate used.

4:2:2: The sampling ratio used in the D1 (CCIR 601) digital video signal. For every 4 samples of luminance there are 2 samples each of R-Y (Red minus Luminance) and B-Y (Blue minus luminance).

4:4:4: A sampling ratio that has equal amounts of the luminance and both chrominance channels.

16x9: A wide screen television format in which the aspect ratio of the screen is 16 units wide by 9 high as opposed to the 4x3 of normal TV.

A-Frame Edit: A video edit which starts on the first frame of the 5 video frame (4 film frame) sequence created when 24 frame film is transferred to 30 frame video (see 3:2 pulldown). The A-frame is the only frame in the sequence where a film frame is completely reproduced on one complete video frame. Here is the full sequence. (The letters correspond to film frames.) A-frame = video fields 1&2, B-frame = video fields 1&2&1, C-frame = video fields 2&1, D-frame = video fields 2&1&2.

A-Mode Edit: An editing method where the footage is assembled in the final scene order. Scene 1, scene 2, ...

ATV: Advanced Television. One of the many acronyms for the new digital television standards. See HDTV.

ATSC: Advanced Television Systems Committee. The group that recommended the new digital television standards to the FCC.

Active Picture Area: The part of a TV picture that contains actual picture as opposed to sync or other data. Vertically the active picture area is 487 lines for NTSC and 576 lines for PAL. The inactive area is called blanking.

AES/EBU: The digital audio standard set by the Audio Engineering Society and European Broadcast Union and used by most forms of digital audio from CDs to D1.

Aliasing: Defects in the picture caused by too low a sampling frequency or poor filtering. Usually scene as "jaggies" or stair steps in diagonal lines.

Analog: A signal that varies continuously. A digital signal by contrast varies in discreet steps.

Artifact: A visual effect caused by an error or limitation in the system.

Anti-aliasing: The process of removing aliasing artifacts.

Aspect Ratio: The ratio of width to height in a picture. Theater screens generally have an aspect ratio of 1.85 to 1, widescreen TV (16x9) is 1.77 to 1, and normal TV (4x3) is 1.33 to 1.

Auto Assembly: An edit in which the off-line edit decision list is loaded into the on-line edit computer and all the edits are assembled automatically with little or no human intervention.

B-Mode Edit: An editing method where the footage is assembled in the order it appears on the source reels. Missing scenes are left as black holes to be filled in by a later reel. Requires fewer reel changes and generally results in a faster edit session.

Bandwidth: The amount of information that can be passed in a given time. The lager the bandwidth the greater the picture detail.

Bit: A single element (1 or 0) of digital information.

Bit Rate: The amount of data transported in a given amount of time, usually defined in Mega (Million) bits per second (Mbps). Bit rate is one means used to define the amount of compression used on a video signal. Uncompressed D1 has a bit rate of 270 Mbps. Mpeg 1 has a bit rate to 1.2 Mbps. HDTV has a bit rate of 1.5Gbps (Giga bits per second).

Bit Stream: A continuous series of bits. commonly used to describe a large file such as MPEG video that is read as a stream instead of all at once.

Black Box: A term used to describe a piece of equipment dedicated to one specific function, usually involving a form of digital video magic.

Blanking: The part of the video signal that contains no picture information. This is the time that the scanning beam in a TV picture tube is blanked to allow it to track back to the begining without drawing diagonal lines across the screen.

Broadcast Quality: An nebulous term used to describe the output of a manufacturer's product no matter how bad it looks.

Bug: An error in a computer program. Also something that bites you on a camping trip.

Burned in Time Code: Time code numbers that are superimposed on the picture.

Byte: 8 bits. The combination of 8 bits into 1 byte allows each byte to represent 256 possible values. (see Megabyte, Gigabyte, Terabyte)

CBR: Constant Bit Rate. MPEG video compression where the amount of compression does not change.

CCIR 601: The standard for digitizing component video. Also sometimes called D1 after the VTR format that first used this signal.

Chrominance: The color part of a video signal.

Component Video: A video signal in which the Luminance and Chrominance signals are kept separate. This requires a higher bandwidth, but yields a higher quality picture.

Composite Video: The luminance and chrominance signals are combined in an encoder to create the common NTSC, PAL or SECAM video signals. Essentially a form of analog video compression to allow the economical broadcasting of video.

Compositing: Layering multiple pictures on top of each other. A cutout or matte holds back the background and allows the foreground picture to appear to be in the original picture.

Compression: The process of reducing the size of digital information, usually by throwing out redundant information, or calculating.

Compression Ratio: The ratio of the amount of data in the original video compared to the amount of data in the compressed video. The higher the ratio the greater the compression.

Control Track: A signal recorded on video tape to allow the tape to play back at a precise speed in any VTR. Analogous to the sprocket holes on film.

CRT: Cathode Ray Tube. The technical name for a picture tube or the scanning tube in a flying spot telecine.

Cutout: (see matte)

D1: Digital video tape format using the CCIR 601 standard to record 4:2:2 component video on 19mm tape. Currently the highest quality video tape format generally available. The first digital video tape format, hence D1.

D2: Digital video tape format using the 4fsc method to record composite digital video. Uses 19mm tape and a cassette similar to D1. The second digital video tape format, hence D2.

D3: Digital video tape format using 4fsc composite signals like D2, but recorded on *" tape. The third digital video tape format...

D4: Doesn't exist, so don't worry about it.

D5: Digital video tape format using CCIR 601, 4:2:2 video. Uses the same cassette as D3. Betcha can guess why its called D5.

DCT: Discrete Cosine Transform. A widely used method of video compression. Also an Ampex CCIR 601 digital VTR using DCT to compress the video before recording it to tape.

DDR: Digital Disk Recorder. A digital video recording device based on high speed computer disk drives. Commonly used as a means to get video into and out from computers.

DTV: Digital Television. Another acronym for the new digital television standards. See HDTV.

DVB: Digital Video Broadcast. A group of international standards for the broadcasting of Digital Video regardless of medium (ie. sattelite, terestrial, cable, etc.).

DVD: Digital Video Disk. Also Digital Versital Disk. A new format for putting full length movies on a 5" CD using MPEG-2 compression for "better than VHS" quality.

DVE: Digital Video Effects. A "black box" which digitally manipulates the video to create special effects. Common DVE effects include inverting the picture, shrinking it, moving it around within the frame of another picture, spinning it, and a great many more.

Digital: A form in which everything is defined by a series of ones and zeros.

Digital Betacam: Digital video tape format using the CCIR 601 standard to record 4:2:2 component video in compressed form on *" tape.

Digitizing: The act of taking analog video and converting it to digital form. In 8 bit digital video there are 256 possible steps between maximum white and minimum black.

Edge Numbers: Numbers printed on the edge of 16 and 35mm motion picture film every foot which allows frames to be easily identified in an edit list.

EDL: Edit Decision List. A list of edit decisions made during and edit session and usually saved to floppy disk. Allows an edit to be redone or modified at a later time without having to start all over again.

Field: One half of a complete video picture (frame), containing all the odd or even scanning lines of the picture.

Frame: One complete video image, or 2 video fields. There are 30 frames in one second of NTSC video. Also a single film image.

Gigabyte: 1 Billion bytes.

HDTV: High Definition Television. A TV format capable of displaying on a wider screen (16x9 as opposed to the conventional 4x3) and at higher resolution. Rather than a single HDTV standard the FCC has approved several different standards, allowing broadcasters to choose which to use. This means new TV sets will have to support all of them. All of the systems will be broadcast as component digital.; The New HDTV/SDTV Standards; i = interlaced, p = progressive scan; *SDTV

Interlace: A process in which the picture is split into two fields by sending all the odd numbered lines to field one and all the even numbered lines to field two. Field one is then displayed first, followed by field 2. This was necessary in the early days of TV when there was not enough bandwidth to send a complete frame fast enough to create a non-flickering image.

ISDN: Integrated Services Digital Network. Allows computers to communicate over existing phone lines using a digital telephone network at much higher speeds than are possible with an analog modem.

J

JPEG: Joint Photographic Experts Group. A standard for compressing still pictures.

Keykode: A barcode on the edge of motion picture film which allows the film edge numbers to be electronically read and inserted into an edit list. Very useful for generating a negative cut list from a video off-line EDL.

Kilobyte: One thousand bytes. Actually 1024 bytes because of the way computer math works out.

LTC: Linear Time Code. Time code recorded on a linear analog track on a video tape.

Letterbox: Placing a wide screen image on a conventional TV by placing black bands at the top and bottom of the screen.

Luminance: The black and white, or brightness, part of a component video signal.

Matte: A black & white high contrast image that suppresses or cuts a hole in the background picture to allow the picture the matte was made from to seamlessly fit in the hole.

Megabyte: 1 million bytes.

MPEG: Moving Picture Experts Group. A standard for compressing moving pictures. MPEG 1 uses a data rate of 1.2 Mbps (Mega Bits per Second), the speed of CD-ROM. MPEG 2 supports much higher quality with a data rate (also called bit rate) of from 2 to 10 Mpbs. MPEG 2 is the format most favored for video on demand and DVD.

NTSC: National Television Standards Committee. The television and video standard in use in the United States. Consists of 525 horizontal lines at a field rate of 60 fields per second. (Two fields equals one complete Frame). Only 487 of these lines are used for picture. The rest are used for sync or extra information such as VITC and Closed Captioning.

Off-Line Editor: A low resolution, usually computer and disk based edit system in which the creative editing decisions can be made at lower cost and often with greater flexibility than in an expensive fully equipped on-line bay..

On-Line Editor: An editing system where the actual video master is created. An on-line bay usually consists of an editing computer, video switcher, audio mixer, 1 or more channels of DVE, character generator, and several video tape machines.

PAL: Phase Alternating Line. The television and video standard in use in most of Europe. Consists of 625 horizontal lines at a field rate of 50 fields per second. (Two fields equals one complete Frame). Only 576 of these lines are used for picture. The rest are used for sync or extra information such as VITC and Closed Captioning.

PALplus: A widescreen (16x9) television standard in use in Europe that is compatible with existing 4x3 TV sets. Non-16x9 TVs show the picture in a letterboxed form.

Petabyte: 1000 Terabytes, or 1 million Gigabytes. You don't need it yet, but isn't it nice to know they've thought up a name for it?

Pixel: Short for Picture Element. The basic unit from which a video or computer picture is made. Essentially a dot with a given color and brightness value. D1 images are 720 pixels wide by 486 high. NTSC images are 640 by 480 pixels.

Progressive Scan: A scanning system for video screens where each line is displayed progressively (1,2,3,4...) as opposed to interlaced (1,3,5...2,4,6...). Computer monitors use progressive scan. Some of the new HDTV standards call for progressive scan.

Resolution: The amount of detail in an image. Higher resolution equals more detail. Also used to describe the size of an image, usually in pixels.

Resolution Independent: A term to describe equipment that can work in more than resolution. Most equipment can do film resolution or video resolution, but not both. Resolution independent equipment can work in both.

RGB: Red, Green, Blue. The primary colors of light. Computers and some analog component devices use separate red, green, and blue color channels to keep the full bandwidth and therefore the highest; quality picture.

Sampling Frequency: The number of sample measurements taken from an analog signal in a given period of time. These samples are then converted into numerical values stored in bytes to create the digital signal.

SDTV: Standard Definition Television. The new HDTV standards call for a range of different resolutions. Those that are higher than today's NTSC are considered HDTV. The ones that are comparable to NTSC are considered SDTV. Because SDTV is component and digital it will still be higher quality than NTSC.

TDL: Telecine Decision List. A list of the edits made in a telecine session which can be loaded into an off-line editor.

Telecine: A device that creates video from motion picture film.

Terabyte: 1 trillion bytes. A 2 hour HTDV movie at the maximum resolution of 1920 x 1084 would take about 1 terabyte to store in an uncompressed format.

Time Code: A time reference recorded on tape to identify each frame.

Vaporware: Software or hardware that is talked about, but may never actually appear.

VBR: Variable Bit Rate. MPEG video compression where the amount of compression can be varied to allow for minimum degradation of the image in scenes that are harder to compress.

VCR: Video Cassette Recorder.

VHS: Video Home System. *" consumer video cassette recorder.

VTR: Video Tape Recorder.

VITC: Vertical Interval Time Code. Timecode stored in the vertical interval of the video signal. Has the advantage of being readable by a VTR in still or jog. Multiple lines of VITC can be added to the signal allowing the encoding of more information than can be stored in normal LTC.

Resolution	Frame Rate	Aspect
1920 x 1080	30i, 30p, 24p	16 x 9
1280 x 720	60p, 30p, 24p	16 x 9
720 x 483*	60p, 30p, 24p	16 x 9
640 x 480*	30i	4 x 3