Imagine Videotek VTM-2400, Инструкция по установке и эксплуатации

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Glossary
118 VTM-2400 Installation and Operation Handbook
Encoded Legalization
Limiting of the luminance and color difference signals such that,
once encoded into a composite video signal, the resultant encoded video does not violate the
maximum or minimum signal levels as defined by the specific encoding rules. NTSC and PAL
video plus various users of these types of video have many varied rules for maximum and
minimum encoding limits. Encoded legalization usually calculates first the encoded luminance
value and then the corresponding chroma value to make legalization judgments.
Encoded Video
A combined single video signal that is constructed from either separate
RGB or luminance and two color difference video signals. NTSC, PAL, and SECAM are all
examples of encoded video.
Envelope Detection
An RF signal detection technique that does not respond to phase
variations in the carrier signal, enabling measurement of a transmitter’s incidental phase.
When used together with synchronous detection, envelope detection helps isolate either
video and/or RF as the causes of phase distortion.
External Key Input
This is an alternate source for key cut. This is usually a separate external
input to a switcher
Fade-thru-Black
A production technique which is a two step process. The first step will fade
the program video to black. The second step will fade from black to the video selected on the
preview bus. This is usually used in major scene transitions.
Fade-to-Black
A production technique which simply fades the program video to black and
program audio to silent. This is used to end programs and to escape from embarrassing
pictures or sounds.
Field
A picture or picture portion which is produced within one cycle of vertical
synchronization. In interlaced systems, a full picture or frame requires two consecutive fields.
FM Trap
A circuit designed to minimize potential interference from strong FM signals in
receiving equipment, such as a TV demodulator. For example, an FM trap can attenuate
signals between 88-108 MHz to reduce interference on NTSC television channel 6.
Frame
A single full resolution picture as viewed in either a video or film system. In the case
of interlaced video, two consecutive fields provide all of the information of one frame. In non-
interlaced systems, one cycle of vertical synchronization produces a frame. A 60 Hz interlaced
system, produces 30 frames of video in one second. A 60 Hz progressive (or non-interlaced)
system, produces 60 frames of video in one second. Common frame rates are 24 (film) 25,
29.97, 30, 50, 59.94 and 60.
Frame Synchronizer
An electronic device that synchronizes two or more video signals.
Using one input as a reference, it locks a second signal to the reference.
Frame Store
An electronic method of capturing and storing a single frame of video.
Gamma
This term applies to the linearity of the change from black to white. Gamma controls
adjust the gray or 50% point of the video either up or down, with the effect of changing the
gray level of the video.
Gamut
The whole or total of whatever is being addressed. In color space, gamut refers to all
colors which are included in a particularly defined color group, such as 601 gamut.