4. Operating
Barco – TransForm A - X Terminal – DOC-3265-2 – user's manual – Revision 09 – September-2006
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4-16
To calculate the bandwidth for windows of different sizes or frame rates the following formula can be used:
B = res
x
* res
y
* fr * cd
The abbreviations have the following meaning:
•
res
x
,
res
y
– resolution of the source in x- and y-direction in pixels
It is important to consider the final scaling used to display the window. Up-scaling of the input sources is per-
formed in the O
MNI
S
CALER
therefore data is transferred 1:1 and the original resolution must be inserted into
the formula. If the source is displayed smaller than 1:1 the source is downscaled directly in the input card.
The original size of the different video types can be read from the table above.
•
fr – frame rate
For video a frame rate of 25fps (PAL/SECAM) and 30fps (NTSC) is standard. For dynamic RGB input a frame
rate of 20 fps in normal cases gives an acceptable performance. If the RGB-source is mostly static even lower
frame rates can be selected.
•
cd – color depth
For all video windows the color mode YUV 4:2:2 is used, which means the factor is
cd = 2
For RGB windows two different color modes may be useful, please refer to section
Color mode =
RGB 16 bpp
cd = 2
Color mode =
RGB 24 bpp
cd = 3
With the average bandwidth of the O
MNI
B
US
A12 of 200 MBps per input card the sum of the bandwidth demands
of the windows provided by one input card should not be bigger than this value. Anyhow also higher bandwidth
usage might be possible but the overall configuration should be considered (In case of doubt contact the Barco
support; please refer to section
.) :
200 MBps = B
1
+ B
2
+ … + B
n
With the effective bandwidth of the O
MNI
B
US
A18 of 400 MBps the sum of the bandwidth of the individual win-
dows may not be bigger than 400 MBps to provide optimal performance:
400 MBps = B
1
+ B
2
+ … + B
n
In a Processor configuration with 100 MBps the following correlation must be considered:
100 MBps = B
1
+ B
2
+ … + B
n
Bandwidth optimization for video and RGB windows:
All optimization settings are made by means of the X video client, please refer to the section
Displaying video and RGB signals
.
Frame rate
For video sources there are two settings with different frame rate reduction factors selectable to
optimize the bandwidth usage. For RGB sources the static reduction of the frame rate depends on
the input mode and the dynamic frame rate reduction is selectable. (Use the
Fps
setting for video
data and
Reduction
for RGB data respectively and refer to the subsection
Dual RGB Input Card
above)
Color depth
RGB sources can be digitized with 16 bpp or with 24 bpp (depending on the visual class of the X
server).
