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10.1.2 Understanding Video Layers
Although AV-HLC100’s internal
Progam
and
Preview
busses are not independently depicted in the
Live
Desktop
, they can be seen (and controlled) on the
Control Surface
. We mention them here to help you
understand how a number of video layers contribute to your ultimate program output.
•
The
Background Layer
o
The
Background
(also refered to as “BKGD”) video layer is the bottom-most layer of the
final composition ultimately sent to AV-HLC100’s
Program
output.
o
This layer comprises the current blend of two primary video layers,
Program
and
Preview
.
The
Program
row selection determines the dominant source of the
Background
layer
T
he
Preview
row
selection determines which source is queued up for display in the
Background
layer by the next transition.
o
During a transition, the
Background
layer
includes increasing greater portions of the
incoming
Preview
row video source until eventually, the outgoing source is completely
removed from output (having been swapped into the place of the former Preview row
selection).
•
Overlay Layers
o
Overlay layers (also called “downstream keys” may or may not appear above (or, if you
like, in front of) the
Background layer
.
Overlay
layers are typically used for overlaying
graphics and titles, etc., though they may serve other purposes as well.
o
AV-HLC100 really provides three
Overlay layers
(only the first two are shown in the
Live
Desktop
):
Picture in Picture
– This layer normally serves to let you display another video or
media source as a
Picture in Picture
(PiP) element over your
Program output
.
Titles –
This video overlay is dedicated to showing title pages.
Fade to Black (FTB)
–
FTB
constitutes a final overlay layer – one that obscures all
other layers when applied.
FTB
is controlled by the
Control Surface
.
• Program
• Preview
BKGD
PiP
Titles
FTB
Program
Out
