Rohde & Schwarz R&S UPP, Руководство пользователя

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Instrument Functions
R&S
®
UPP
446 User Manual 1411.1055.32 ─ 10
The "Lip Sync" generator function creates such a signal with user-configurable Active
and Mute Color pattern and a time offset of 0 (see also
Chapter 5.6.14, "Lip Sync" ,
on page 277).
The Lip Sync analyzer operates internally with two trigger events:
The video trigger is initiated as soon as a certain color value has been detected. With
the aid of a configurable threshold, a blurriness can be implemented, for example, if
the device under test reduces the color depth of the generator signal or falsifies color
values.
The audio trigger is initiated as soon as an audio sample exceeds the user-configura-
ble threshold. This allows implementing a blurriness, e.g. if the device under test per-
forms a sample rate conversion with corresponding filtering so that the audio data in
the mute phases do not measure exactly 0.
The offset of the audio signal to the video signal is measured from the time difference
of the trigger events. If the time shown is negative, then the video signal leads the
audio signal.
Application example for determining the threshold value in the Lip Sync analyzer
measurement function
Example 1: Normal color change combination
In the "Lip Sync" generator function, a color change is configured between "Mute
Color" = pure green (0,4095,0) and "Active Color" = pure red (4095,0,0). It is assumed
that the DUT for all three color components causes color falsification of some bits,
which is to be covered with a tolerance specification of ±100 bits. The "Mute Color"
must be outside of the specified range between Threshold Low and High.
Accordingly, configure the Video Trigger thresholds in the "Lip Sync" analyzer function
with "Active Color Low" = (3995,0,0) and "Active Color High" = (4095,100,100). The
values 4095 and 0 cannot be exceeded or undershot.
Example 2: Influence of the Color Depth on the Video Trigger
If the "Mute Color" and "Active Color" are very close to one another due to special con-
ditions of the DUT, the "Color Depth" in the Config range of the generator has to be
taken into account when calculating the threshold. With this kind of close color chang-
ing, the DUT is not permitted to make any color falsifications. "Mute Color" =
(1000,2000,3000) light blue, "Active Color "= (1010, 2010, 3010). Accordingly, the
Video Trigger thresholds in the "Lip Sync" analyzer function could be configured, for
example, with a tolerance of ±5 bits. "Active Color Low" = (1005,2005,3005) and
"Active Color High" = (1015,2015,3015)
Lip Sync analysis