Specifications

Glossary
VTM Series Installation and Operation Handbook
C-4
ENG Electronic News Gathering
Encoded Clip Softness In the encoded legalization process, “softness,” as applied
to encoded clips, refers to the processing of the video at the point of the clip. The clips
are applied in YC
B
C
R
color space. The clip point is either an immediate limit (no
softness) or will have a range of values leading to the clip point, all reduced to smooth
the clip point to a less immediate limit (softness).
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 judgements.
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.