User Guide Owner's manual

Bandwidth Management – Advanced Control
6. If necessary, click More Detail to open the Video Quality and Bandwidth panel:
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2
2
33
4
4
5
5
6
6
7
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8
8
Figure 51. Encoder Video Bandwidth Tab Advanced Control
Spatial compression luminance and chrominance settings
7. Set the Luminance (see figure 51,
1
) and Chrominance (see figure 51,
2
) values
from the appropriate drop‑down list. These controls are normally locked, using the Lock
check box (see figure 51,
3
), with an offset of 2 units between them.
A Luminance value of 0 provides the minimum spatial compression; a Luminance value
of 10 provides the maximum spatial compression.
8. If required, the Chrominance compression can be set independently by clearing the
Lock check box. A spatial compression setting of 4/6 (luma 4; chroma 6) provides
visually lossless compression.
9. Apply temporal compression by selecting the Temporal check box (see figure 51,
4
).
By default, this option is selected.
10. Adjust the Threshold (see figure 51,
5
) to modify 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.
NOTE: This control compensates for sources with high levels of noise.
11. Enable
Chroma (see figure 51,
6
) to determine whether the temporal algorithm should
consider changes in the color or chrominance of the image. Enabling Chroma gives
better results on digital simulation type sources but will result in a higher bit rate for any
given compression.
12. Adjust the Refresh Rate (see figure 51,
7
) to control how frequently the non‑changing
parts of the screen are updated in temporal compression mode. A refresh rate setting of
1 is suitable for most applications.
13. If it is necessary to set a bit rate limit, select the control
mode from the Mode drop‑down box (see figure 51,
8
and
see the figure at right).
See Bandwidth Management Panel on page 48 for a
complete explanation of these options.
None
None
Manual Frame Drop
Shared Flowrate (FD)
Peak Flowrate (FD)
PBR-F
PBR-F (FD)
None
VNM 250 • Configuration with the VNM 250 GUI 69