User guide

Chapter 6: Video Viewer Window 93
NOTE: The DVC algorithm upgrade is standard on all newer DS appliances/DSR switches. Older DS appliances/
DSR switches use standard video compression. For DVC algorithm upgrade purchase information, contact
Avocent Technical Support or your Avocent reseller.
Noise Threshold and Priority Threshold (Standard Video Compression)
The Noise Threshold and Priority Threshold values set the minimum levels in terms of changed
pixels per thousand that are allowed without updating the video block. The thresholds are
described below:
• Raising the Noise Threshold will usually make the packets/sec count decrease. The result will
be larger cursor image artifacts remaining on the screen. Decreasing the value will make the
size of these artifacts smaller.
• The Priority Threshold sets the level where a significant change is noted, such as a new cursor
position. Increasing the value will make the mouse movements more sluggish. The Priority
Threshold setting should always be greater than the Noise Threshold setting, and usually two
to three times its value. Setting these thresholds to zero (0) will cause a constant refresh of the
screen, which will make cursor tracking very difficult and may make it difficult for other net-
work users. The goal is to reduce the packet rate to 0.
Block Noise Threshold and Pixel Noise Threshold (DSR switch DVC
Algorithm Upgrade)
The Block Noise Threshold and Pixel Noise Threshold values set the minimum color levels in
terms of changed video blocks and pixels per thousand that are allowed. See Adjusting the View for
information on changing the color depth of a Video Viewer window. The thresholds are
described below:
• The Block Noise Threshold sets the minimum color change that will occur in a single video
block. Increasing the value will reduce the network bandwidth. Decreasing the value will make
the size of these artifacts smaller.
• The Pixel Noise Threshold sets the minimum color change in a single pixel. Decreasing the
value will reduce the number of low-contrast artifacts, but will increase network bandwidth.
Automatic video adjustment
NOTE: You may also select Tools - Automatic Video Adjust from the Video Viewer window menu to automatically
adjust the video.
In most cases, you will not need to alter the Video Settings from the default. The system will
automatically adjust and use the optimal video parameters. The DSView management software
performs best when the video parameters are set such that no (0) video packets are transmitted for a
static screen.