evertz EQT Series, Системное руководство

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EQT Router User Manual
Page 4
Revision 1.9.1
1.8. DEFINITIONS
4:2:2: The sampling ratio used in the HDTV 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).
16x9: A wide screen television format such as HDTV in which the aspect ratio of the screen
is 16 units wide by 9 high as opposed to the 4x3 of normal TV.
AES/EBU: (Sometimes abbreviated as AES) Refers to the digital audio standard (AES3-1992) set
by the Audio Engineering Society and European Broadcast Union and used by most
forms of digital audio from CDs to professional digital video.
ASPECT RATIO: The ratio of width to height in a picture. Theatre 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.
CCIR (International Radio Consultative Committee): An international standards committee. (This
organization is now known as ITU.)
CCIR-601: See ITU-R601.
CLIFF EFFECT: (also referred to as the ‘digital cliff’) This is a phenomenon found in digital video
systems that describes the sudden deterioration of picture quality when due to
excessive bit errors, often caused by excessive cable lengths. The digital signal will
be perfect even though one of its signal parameters is approaching or passing the
specified limits. At a given moment however, the parameter will reach a point where
the data can no longer be interpreted correctly, and the picture will be totally
unrecognizable.
COMPONENT ANALOG: The non-encoded output of a camera, video tape recorder, etc.,
consisting of the three primary colour signals: red, green, and blue (RGB) that together
convey all necessary picture information. In some component video formats these
three components have been translated into a luminance signal and two colour
difference signals, for example Y, B-Y, R-Y.
COMPONENT DIGITAL: A digital representation of a component analog signal set, most often Y,
B-Y, R-Y. The encoding parameters are specified by ITU-R709 for HDTV signals.
SMPTE 274M and SMPTE 296M specify the parallel interface.
COMPOSITE ANALOG: An encoded video signal such as NTSC or PAL video that includes
horizontal and vertical synchronizing information.
COMPOSITE DIGITAL: A digitally encoded video signal, such as NTSC or PAL video that
includes horizontal and vertical synchronizing information.