4. Operating
Barco – TransForm A - Workstation for Windows – DOC-3266-2 – Revision 16 – August 2007
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4-8
4.2.6
Distributed video
When multiple O
MNI
B
US
devices are used to provide graphical output for the display wall, each of these O
MNI
B
US
devices corresponds to a display area on the display wall. Input cards are always limited to provide their source
just within one O
MNI
B
US
and therefore on one display area. To achieve anyhow freely movable and scalable video
windows, distributed video can be used. Distributed video can be applied to video sources of the S
TREAMING
V
IDEO
C
ARD
SVC-1,
S
TREAMING
V
IDEO
C
ARD
SVC-2,
S
TREAMING
V
IDEO
C
ARD
J2K, the Q
UAD
SDI
V
IDEO
C
ARD
, D
UAL
DVI
I
NPUT
C
ARD
or
Q
UAD
A
NALOG
V
IDEO
C
ARD
.
In contrast to the standard display of video (a video source is fixed to a video input of an input card), with dis-
tributed video one video source is related to a video window. This window is displayed by a group of video input
cards, with one video input card located in each O
MNI
B
US
.
Depending on the location of the video window on the
display wall, the video input card of the respective O
MNI
B
US
provides the video data. If the window is located on
the display areas of several O
MNI
B
US
devices all concerned video input cards contribute »their« part of the video
to the whole picture on the display wall.
Distributed video serves not only to enable unlimited upscaling, but also to have video windows that are freely
movable over all display areas. One group of distributed video may display as many video windows as video
channels are included. Nevertheless moving such a window into a display area where another window of this
group is already displayed, assigns the new video to the video input card of that display area. Therefore the
video window that has been there before appears in the background color of the window, as it is no longer pro-
vided with data.
If a group of distributed video displays several video windows all these video sources must be connected to each
of the video input cards. For that purpose a video switcher can be used for the Q
UAD
A
NALOG
V
IDEO
C
ARD
. The
S
TREAMING
V
IDEO
C
ARD
with its network adapter has anyhow access to all available video streams.
As many groups of distributed video can be configured and used at the same time as video channels (number of
all video channels of Q
UAD
A
NALOG
V
IDEO
C
ARDS
,
Q
UAD
SDI
V
IDEO
C
ARD
and S
TREAMING
V
IDEO
C
ARD
) are inserted in each
O
MNI
B
US
.
Distributed video is configured by means of the switcher definition file; please refer to section
control
dispaly area 1
dispaly area 2
O
MNI
B
US
1
O
MNI
B
US
2
G
G
G
G
G
G
G
G
O
O
O
O
O
O
Q
A
V
C
Q
A
V
C
O
O
Figure 4-1
distributed video: full-screen video on two display areas
The example above shows a simplified OmniBus configuration in order to demonstrate the principles of distrib-
uted video.
