| A/B Roll Editing |
Editing from two source VCRs to a third recording VCR. A switcher or mixer is used to provide effects such as dissolves. |
| A-B Roll |
Two video sources played simultaneously, to be mixed or cut between. |
| Action Axis |
Imaginary line drawn between two subjects or along a line of motion as an aid in maintaining continuity of screen direction. Sometimes referred to as the "180-degree rule." |
| action axis |
An imaginary line drawn between two subjects or along a line of motion to maintain continuity of screen direction. Crossing it from one shot to the next creates an error in continuity. It is also referred to as the ?180-degree rule |
| Ad-Lib |
Unrehearsed, spontaneous act of speaking, performing, or otherwise improvising on-camera activity without preparation. |
| Administration metadata |
This includes digital rights, encryption, user access, air date scheduling, and other business administration. |
| ADO (Ampex Digital Optics) |
Trade name for digital effects system manufactured by Ampex. |
| ADPCM |
Adaptive Pulse Code Modulation is a compression scheme used by CD-I and CD-ROM XA formats. Used to interleave audio with data. |
| AFM |
(audio frequency modulation) The analog soundtrack of the 8mm and Hi8 video format. [See PCM] |
| AGC |
(automatic gain control) A circuit on most camcorders that automatically adjusts a microphone?s gain (volume) to match environmental sound levels. |
| AGC (Automatic Gain Control) |
Circuitry used to ensure that output signals are maintained at constant levels in the face of widely varying input signal levels. AGC is typically used to maintain a constant video luminance level by boosting weak (low light) picture signals electronically. Some equipment include gain controls which are switchable between automatic and manual control. |
| Aliasing |
Undesirable video display effects caused by excessive high frequency video information. Three examples are: Jaggies or Stair-stepping - Stepped or jagged edges of angled lines, especially at the slanted edges of letters. Raster scan aliasing - e.g., twinkling or strobing effects on sharp horizontal lines Temporal aliasing - e.g., rotating wagon wheel spokes apparently reversing direction. |
| AM (Amplitude Modulation) |
Amplitude modulation is a process used for some radio (AM broadcast) and television video transmission. A low frequency (program) signal modulates (changes) the amplitude of a high frequency RF carrier signal causing it to deviate from its nominal base amplitude). The original program signal is recovered (demodulated) at the receiver. This system is extensively used in broadcast radio transmission because it is less prone to signal interference and retains most of the original signal quality. See Frequency Modulation. |
| Ambient Sound |
(ambience) Natural background audio representative of a given recording environment. On-camera dialog might be primary sound; traffic noise and refrigerator hum would be ambient. |
| ambient sound |
(ambience) Natural background audio representative of a given recording environment. On-camera dialog might be primary sound; traffic noise and refrigerator hum would be ambient. |
| Amiga |
The video computer that created the desktop video revolution. |
| Ampere/Amperage (Amp) |
The standard unit of measurement for electric current. |
| amplify |
To magnify an audio signal for mixing, distribution and transducing purposes. |
| Analog |
An electrical signal using continuously varying electrical voltages. Analog video that is copied or edited several generations suffers from generation loss and is subject to degradation due to noise and distortion.The term analogue simply means like or similar. Traditional recording media have been analogue (magnetic recording tape and vinyl records). In analogue, the positive and negative aspects of a soundwave are converted via a transducer (microphone), to an A.C voltage. |
| Animatic |
Simple animation consisting of art work designed to be used as a video tape storyboard. Most commonly used for test commercials. |
| Animation |
Visual special effect whereby still progressive images displayed in rapid succession creates the illusion of movement. |
| animation |
Visual special effect whereby progressive still images displayed in rapid succession creates the illusion of movement. |
| ANSI |
American National Standards Institute. |
| Anti-Aliasing |
The process of electronically reducing aliasing, especially letters and genlocked graphic elements. |
| Aperture |
An adjustable opening in a lens which, like the iris in the human eye, controls the amount of light entering a camera. The size of the aperture is controlled by the iris adjustment and is measured in f-stops. A smaller f-stop number corresponds to a larger opening which passes more light. F-stop examples are F2, F2.8, F4, F5.6, F8, F11. F-stops are logarithmic. Each stop admits 100% more light than the previous one. |
| aperture/exposure |
A setting that manipulates the amount of light falling onto the camera's CCD(s). This control adjusts the size of the camcorder's iris. |
| artifacting |
The occurrence of unwanted visual distortions that appear in a video image, such as cross-color artifacts, cross-luminance artifacts, jitter, blocking, ghosts, etc. Artifacting is a common side effect of compression, especially at lower bit rates. |
| artifacts |
Unwanted visual distortions that appear in a video image, such as cross-color artifacts, cross-luminance artifacts, jitter, blocking, ghosts, etc. |
| Artificial Light |
Man-made illumination not limited to "indoor" variety: fluorescent bulbs, jack-o'-lanterns, a car's headlights. Has lower color temperature than natural light, and thus more reddish qualities. [See color temperature, natural light.] |
| artificial light |
Human-made illumination not limited to "indoor" variety: fluorescent bulbs, jack-o'-lanterns and a car's headlights all qualify. Typically, it has lower color temperature than natural light, and thus more reddish qualities. (See color temperature, natural light) |
| Aspect Ratio |
Proportional height and width of picture on screen. Current standard for conventional receiver or monitor is three by four (3:4); 3:5 for HDTV. |
| aspect ratio |
Proportional width and height of on-screen picture. Current standard for a conventional monitor is 4:3 (four-by-three); 16:9 for HDTV. |
| assemble edit |
Recording video and/or audio clips in sequence immediately following previous material; does not break control track. Consecutive edits form complete program. [See edit, insert edit] |
| Assembly Edit |
An edit wherein all existing signals on a tape, if any, are replaced with new signals. Assembly edits cannot be used for editing because since they erase the control track portion of the video tape. (See also Insert Edit) |
| Asymmetry |
Th relationship and position of I3 and I11 can be expressed in terms of asymmetry. This represents the ratio of pit to land length and can indicate the size of the pits on a Compact Disc. Positive asymmetry indicates the pits are longer than the lands. Red Book specifies and asymmetry of negative 20% to positive 20%. |
| ATV |
(amateur television) Specialized domain of ham radio, transmits standard TV signals on UHF radio bands. |
| Audio Bandwidth |
The range of audio* frequencies which directly influence the fidelity of a sound. The higher the audio bandwidth, the better the sound fidelity. The highest practical frequency which the human ear can normally hear is 20 kHz. An audio amplifier which processes all frequencies |
| Audio Dub |
Result of recording over prerecorded videotape soundtrack, or a portion, without affecting prerecorded images. |
| audio dub |
Result of recording over pre-recorded videotape soundtrack, or a portion thereof, without affecting pre-recorded images. |
| Audio Frequency Modulation |
(AFM) Method of recording hi-fi audio on videotape along with video signals. |
| audio frequency modulation |
(AFM) Method of recording hi-fi audio on videotape along with video signals. Used in VHS Hi-Fi Audio, and also the analog soundtrack of the 8mm and Hi8 video formats. |
| Audio Mixer |
Device with user-adjustable controls to blend multiple sound inputs into desired composite output. [See mix.] |
| audio mixer |
The piece of equipment used to gather, mix and amplify sounds from multiple microphones and send the signal on to its destination. |
| Audio-Follow-Video |
During video recording, the video signal is usually accompanied by an audio signal. Sometimes, during video editing*, it is often necessary to separate the audio from the video signal. Audio-follow-video mixers allow accompanying audio to "follow" the video when switching video sources or not. The Digital Video Mixer provides either function. |
| authoring |
The process of putting all of the elements of a project together. For a DVD in particular, it means getting all of the footage together, preparing menus and adjusting menu behavior as required. |
| Auto Assembly |
Process of assembling an edited video tape on a computerized editing system using an edit decision list. |
| Automatic Exposure |
Circuitry that monitors light levels and adjusts camcorder iris accordingly, compensating for changing light conditions. |
| automatic exposure |
Circuitry that monitors light levels and adjusts camcorder iris accordingly, compensating for changing light conditions. |
| Automatic Gain Control |
(AGC) Camcorder circuitry that adjusts incoming signal levels automatically, alleviating excessive image brightness and distortion of loud sound. |
| automatic gain control |
(AGC) Circuitry found on most camcorders that adjusts incoming audio levels automatically to match environmental sound levels. |
| AVAILABLE LIGHT |
Amount of illumination normally present in a particular environment: natural light, artificial, or a combination. |
| available light |
Amount of illumination present in a particular environment: natural light, artificial light or a combination of the two. |
| AVI |
(Audio Video Interleave) One of the oldest file formats for digital video on PCs. |
