Chapter 3
Controls
62
<comparison op> ::= == | > | < | >= | <= | !=
<logic op> ::= && | ||
Comparisons can be
AND
ed together using
&&
, and then can be
OR
ed together using
||.
The
AND
operation always has precedence over the
OR
operation when
AND
and
OR
both
exist in a condition.
Parameter Control Script
To use a
Parameter Control Script,
select
Enable
in the
Activate Script
parameter
(
System Setup > Parameter Control Script
). Then create your content in
Script (Part I)
to change a parameter value based on some other parameters' value. If there is additional
script necessary, use the
Script (Part II to IV)
parameters.
Script Status
[RO] reports the parsing and active status of your custom input script.
The X50 make it possible for you to write user scripts for custom signal flow management,
so that you can dynamically change selected parameters when a signal flow changes. This
addresses the need for managing input video and audio signals that constantly change. In a
typical scenario, a preset is recalled by an operator, or the operator determines what is at
the input and then sets up the device to process the video and audio essence, data and
metadata. This is known as “user-scripted signal flow management” or a “rules engine.”
Example
Some broadcasters have compliance issues that need to be addressed by specialized signal
processing.
A common problem is the replacement of a mono audio channel dedicated to audio
content for the visually-impaired, if the channel is absent. Service for the visually-impaired is
required in Canada, and available soon in the United States and elsewhere. In Europe, this
service is known as the Audio Description. In North America, it is known as Descriptive
Video, DVS Descriptive Video Service, or Video Description.
When this mono audio channel is present at the input, the requirement is to pass it through
to the output and into the Secondary Audio Program (SAP) channel. However, if the signal
is absent, the X50 can detect the problem and perform one of the following through
scripts:
Sum and route the signal to the output channel feeding the SAP, if stereo audio is
present (one PCM)
Downmix to 2.0, then sum and route to the output channel feeding the SAP, if
surround sound is present (three PCMs)
Decode the audio, downmix to stereo, sum to mono, and then route to the output
channel that feeds the SAP, if Dolby Digital or Dolby E is present (one non-PCM)
Note:
In the above example, as audio channels change, the audio V-fades must be enabled
by setting the
Fade Time
to a non-zero value. This setting will prevent clinks or pops from
occurring downstream.
Summary of Contents for Selenio X50
Page 8: ......
Page 14: ...Preface Safety xiv...
Page 18: ...Chapter 1 Introduction 4 Front and Back Views Figure 1 1 Front and Back Views...
Page 112: ...Chapter 5 Specifications 98...
Page 136: ...122...