4. Operating
Barco – Eos Workstation for Windows – DOC-3062-2 – Revision 12 – August-2004
____________________________________________________________________________
4-3
4.1.4
Amount of video and RGB windows
The number of video and RGB data that can be processed in an E
OS
system underlies the available bandwidth.
These are 10 0 MBps. The following table gives an overview about the bandwidth required for some standard
window sizes. In the last column there is in addition the value of maximal windows of that type. This value is
valid if only windows with the specified properties are displayed.
type
number of
pixels
frame rate
[fps]
color depth
[bpp]
bandwidth [MBps]
1:1 or higher / (2:1)
max. amount of windows
1:1 or higher / (2:1)
Sources of Quad Analog Video Card / Streaming Video Card
NTSC
640×480
30
16
19 / (5)
5 /
(21)
PAL/SECAM
720×540
25
16
20 / (5)
5 /
(20)
Sources of Dual RGB Input Card
XGA
1024×768
10
16
16 / (4)
6 /
(25)
XGA
1024×768
15
16
24 / (6)
4 /
(16)
XGA
1024×768
20
16
32 / (8)
3 /
(12)
SXGA
1280×1024
10
16
27 / (7)
3 /
(15)
SXGA
1280×1024
15
16
40 / (10)
2 /
(10)
SXGA
1280×1024
20
16
53 / (14)
1 /
(7)
UXGA
1600×1200
10
16
39 / (10)
2 /
(10)
UXGA
1600×1200
15
16
58 / (15)
1 /
(6)
UXGA
1600×1200
20
16
77 / (20)
1 /
(5)
Table 4-2
size of video/RGB data and number of displayable video windows in case that this card is the only type of input card used in the system
To calculate the bandwidth for windows of different sizes or frame rates the following formula can be used:
B = res
x
xx
x
* res
y
yy
y
* fr * 2
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 all scaling factors used to display the window. In general up-scaling is performed
in the O
MNI
S
CALER
therefore data is transferred 1:1 and the original resolution must be inserted into the for-
mula. If the source is displayed smaller than 1:1 the source is down-scaled in the input card. Only this re-
duced number of pixels is transmitted to the O
MNI
S
CALER
and must be considered. The original size of the dif-
ferent 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.
With the effective bandwidth of the E
OS
system of 100 MBps the sum of the bandwidth of the individual win-
dows may not be bigger than 100 MBps to provide optimal performance:
100 MBps = B
1
+ B
2
+ … + B
n
