Barco TransForm A User Manual page 80

To calculate the bandwidth for windows of different sizes or frame rates the following formula can be used:
B = res * res * fr * cd * 2
x y
The abbreviations have the following meaning:
•
res , res – resolution of the source in x- and y-direction in pixels
x y
It is important to consider all scaling factors used to display the window. In general up-scaling is performed
in the O S therefore data is transferred 1:1 and the original resolution must be inserted into the for-
MNI CALER
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
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.
•
cd – color depth
For all video windows with the default Pixel format YUV 4:2:2 the factor is
For RGB windows two different Pixel formats may be useful:
Pixel format = RGB 5:6:5
Pixel format = RGB 8:8:8
With the average bandwidth of the O
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 + B
1 2
With the effective bandwidth of the O
dows may not be bigger than 400 MBps to provide optimal performance:
400 MBps = B + B
1 2
In a Processor configuration with 100 MBps the following correlation must be considered:
100 MBps = B + B
1 2
Bandwidth optimization for video and RGB windows:
All optimization settings are made in the video software of T
tions 4.3.3 Displaying analog
Displaying RGB-signals.
Number of pixels
Video and RGB data can be pre-scaled on the input card. The amount of pixels of a frame is recal-
culated to a lower amount. This reduced amount of pixels means lower need of bandwidth for the
transmission to the O
up-scaling to obtain a video window in the desired size. (Use Pre-Scale in the Scaler Settings
dialog). In the bandwidth formula only the reduced amount of pixels must be considered.
Frame rate
For video sources there are two settings for the frame rate selectable. 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 FrameRate settings; for RGB data refer in addition to section
Input Card.)
Color depth
RGB sources can be digitized with 16 bpp or with 24 bpp (Use Pixel Format in the Scaler Settings
dialog).
Barco – TransForm A - Workstation for Windows – DOC-3266-2 – Revision 13 – April 2006
cd = 1
cd = 1
cd = 1.5
B A12 of 200 MBps per input card the sum of the bandwidth demands
MNI US
8.3 Contact.) :
+ ... + B
n
B A18 of 400 MBps the sum of the bandwidth of the individual win-
MNI US
+ ... + B
n
+ ... + B
n
video, 4.3.4 Displaying streaming
S . On the O
MNI CALERS
S and must be considered. The original size of the dif-
MNI CALER
RANS
video,
S the factor for pre-scaling is considered during
MNI CALER
________________________________________________________________
F A, please refer to the sec-
ORM
4.3.5 Displaying digital video
4.1.4 Dual RGB
4. Operating
and 4.3.6
4-4