User`s manual

26
Installation AppendixDefi nitions in
Confi guration
Introduction
How to Use
Administrator's features (Cont.)
For Best Real-time Video Images
To achieve good real-time visual effect, the network bandwidth should be large
enough to allow a transmission rate of greater than 20 image frames per second.
If the broadband network is over 1 Mbps, set the "Constant bit rate" to 1000Kbps
or 1200Kbps, or set "Fixed quality" at the highest quality. The maximum frame rate
is 30. If your network bandwidth is more than 512 Kbps, you can adjust the bit
rate according to your bandwidth and set the maximum frame rate to 30 fps. If the
images vary dramatically in your environment, you may want to slow the maximum
frame rate down to 20 fps in order to lower the rate of data transmission. This allows
for better video quality and the human eyes cannot readily detect the diff erences
between those of 20, 25, or 30 frames per second. If your network bandwidth is
below 512 Kbps, set the "Constant bit rate" according to your bandwidth and try to
get the best performance by fi ne-tuning with the "Maximum frame rate". In a slow
network, greater frame rate results in blur images. Video quality performance will
vary somewhat due to the number of users viewing on the network; even when the
parameters have initially been fi nely tuned. Performance will also suff er due to poor
connectivity because of the network's burst constraint.
Only Quality Images Will Do
To have the best video quality, you should set "Fixed quality" at "Detailed" or
"Excellent" and adjust the "Maximum frame rate" to match your network's bandwidth.
If your network is slow and you receive "broken" pictures, go to the TCP or HTTP
protocol in "MPEG-4 Protocol Options" and choose a more appropriate mode of
transmission. The images may suff er a time delay due to a slower connection. The
delay will also increase with added number of users.
Somewhere Between Real-time and Clear Images
If you have a broadband network, set "Fixed quality" at "Good" or better, rather
than setting "Constant bit rate". You can also fi x the bandwidth according to your
actual network speed and adjust the frame rate. Start from 30 fps down for best
results but not below 15 fps. If the image qualities are not improved, select a lower
bandwidth setting.