Ericsson MX8400, Справочное руководство

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Operating the Multiplexer using nCompass Control
Table 4.4 Suggested Bit rates for Various Programme Types (Mbps)
Resolution
(pixels) Sport News Film General
704 x 576 6.0 - 8.0 4.0 - 6.0 3.0 - 5.0 5.0 - 7.0
352 x 576 3.0 - 6.0 2.0 - 3.0 1.5 - 2.5 2.5 - 3.5
352 x 288 2.0 - 3.0 1.5 - 2.5 1.0 - 2.0 1.5 - 3.0
An example of a bit rate allocation is given in Table 4.5 . The Operator can monitor
the quality on each channel and adjust the bit rate allocation.
Table 4.5 Typical Bit rate Allocations
Encoder Resolution
(pixels)
Programme
Type Allocated Bit
rate (Mbps)
1 704 x 576 Sport Channel 6.0
2 352 x 576 Sport Channel 4.0
3 352 x 576 News Channel 3.0
4 352 x 576 Film Channel 2.0
TOTAL: 15.0
The more Encoders there are in a group, the more potential there is to reduce the
group bit rate, although this may have to be modified in the light of any
remultiplexing further downstream.
4.5.5.3 Weighting Factor
A weighting factor can be assigned to each Encoder in a group to create a bias to
that channel. In the example above, Encoder 1 can be given priority thus ensuring
higher picture quality in the event of a conflict. If no bias is required, the weighting
factor should be set to the same value.
Table 4.6 Example of Weighting Factor Allocation
Encoder Resolution
(pixels)
Target Picture
Quality Average Bit rate
(Mbps)
1 704 x 576 95 6.0
2 352 x 576 80 4.0
3 352 x 576 80 3.0
4 352 x 576 80 2.0
TOTAL: 15.0
2/1553-FGC 101 1014 Uen B 4-9