Advanced Controls panel
Click the
Advanced
button in the Bandwidth Management panel to access this panel. The
controls in this area provide the complete set of VNC 325 image quality and bit rate tools
(see figure
33
). Some of the controls in the Bandwidth Management panel are duplicated
here; when controls are duplicated, settings in one panel automatically track to the other
panel.
1c
1d
1e
1f
1a
1b
Figure 33.
Advanced Controls Panel
The panel is divided into to two main categories:
•
Video Quality (spatial compression) settings
•
Bandwidth settings
Video Quality Management
Ä
Luminance
— This control sets the level of luminance spatial compression, from 0
(minimum compression) to 10 (maximum compression).
Å
Chrominance
— This
normally locked
field shows the level of chrominance spatial
compression, from 0 (minimum compression) to 11 (maximum compression). When
locked, chrominance is directly related to the Luminance control by an offset value of 2.
NOTES:
•
To manually set the chrominance compression, uncheck the Lock
check box.
•
A value of 2 is the optimal offset between luminance and chrominance.
•
Settings of 4 (Luminance) and 6 (Chrominance) provide visually lossless
compression for HD content.
•
By default, the offset between Luminance and Chrominance is set to 2
whenever the Advanced controls panel is hidden (the Bandwidth
Management controls panel Standard button is clicked)
.
û
Temporal Compression mode check box
— Applies temporal compression to the
bandwidth management, causing data to be transferred only when a change occurs
between frames. This box is selected by default and should always remain selected.
ü
Refresh Rate
— Controls how frequently the non-changing parts of the screen are
updated when temporal compression mode is enabled ( the
Temporal
Compression
check box is selected). This is useful when connecting new displays to a multicast source
and to fill in gaps in the data when using a lossy network transport such as RTP. A value
of 1 refreshes the screen in one second, a value of 0.1 refreshes the screen 10 times per
second. A value of 0 disables the refresh.
†
Threshold
— The threshold setting modifies the detection point of the temporal
compression algorithm. A value of 0 results in all changes between frames being sent.
As the threshold value is increased, only changes above a certain level are sent, thus
reducing the bit rate. As a general rule, always set this to a 1 for a camera originated
image.
VN-Matrix 325 Serial Digital Over IP CODEC • Operation
44
