9 preview channel – Grass Valley LGK-3901 User Manual
Page 38
GUIDE TO INSTALLATION AND OPERATION
32 | LGK-3901/DSK-3901
4.9 Preview
Channel
The LGK-3901/DSK-3901 Preview Channel is used typically for previewing graphics and audio voice-overs prior to
bringing them to air on the Program Channel, but can also monitor a range of different video and audio signal paths
throughout the video chain.
The video output that is seen on PVW OUT depends on the following settings:
• Preview Input / Mix B Input
• Preview
Output
4.9.1 Preview Input / Mix B Input
Which of these settings is available to the user depends on the presence of the AB mixer option:
• Preview Input No AB mixer option present
• Mix B Input
LGK-3901-OPT-ABMIX or DSK-3901-OPT-ABMIX is present
The Preview Input / Mix B Input selection determines the background signal to be used for the Preview Channel. It
may be set to one of the following values via the front panel menu OPERATE > PREVIEW INPUT or OPERATE >
MIX B INPUT:
• PGM IN
Input is taken from PGM IN SDI (or associated color field / test pattern)
• FILL-2
Input is taken from FILL-2 SDI (or associated color field / test pattern)
The Preview Channel keying layers (see sections 1.3 and 2.3) are then used to overlay graphics onto the background
signal (see sections 1.3 and 2.3). The resulting output will be seen at PVW OUT provided that OPERATE >
PREVIEW OUTPUT is set to PREVIEW O/P.
4.9.2 Preview
Output
The Preview Output selection defines the SDI output to be viewed at PVW OUT. It may be set to one of the following
values via the front panel menu OPERATE > PREVIEW OUTPUT:
Selection
Description
LGK-3901
DSK-3901
PREVIEW O/P
Selects default Preview Output (see PREVIEW INPUT)
PROGRAM O/P
Selects a copy of PGM OUT as the Preview Output
PGM AB MIX
Selects output from PGM AB Mixer as the Preview Output
PGM DSK1 O/P
Selects output from PGM DSK1 as the Preview Output
PGM DSK2 O/P
Selects output from PGM DSK2 as the Preview Output
PGM DSK3 O/P
Selects output from PGM DSK3 as the Preview Output
PGM DSK4 O/P
Selects output from PGM DSK4 as the Preview Output
SDI PGM IN
Selects a copy of SDI PGM IN as the Preview Output
SDI FILL-1
Selects a copy of SDI FILL-1 as the Preview Output
SDI KEY-1
Selects a copy of SDI KEY-1 as the Preview Output