Operating the Equipment Locally — Setup Menu: Video Menu
Page 4-44
Reference Guide: Voyager E5784 and E5788 HD DSNG Encoder
ST.RE.E10137.3
NOTE…
In Seamless Modes 4, 5 and 6 coding performance is compromised a little to achieve lower B
min
s.
Bit-rate Option
This option enables the Bit-rate to be set. An error message is shown with
the correct range of bit-rates if the wrong rate is entered.
NOTE…
In SD mode, high bit-rates in low resolutions cannot always generate sufficient bits to match the
requested bit-rate. However, a valid picture will still be produced.
CAUTION…
When using the Encoder with a PRO IRD M2/PSR/3/422BAS in 4:2:2 SD mode the upper video bit-rate
limit of the IRD is 25 Mbit/s.
Bit-rate Tracking
If the Bit-rate option is set to its maximum then Bit-rate Tracking is
automatically switched on. In this mode, any changes which cause the
mux bit-rate to increase or decrease will cause the video rate to always fill
the available mux bit-rate. Changes which cause the mux rate to change
include varying audio bit-rate, RS-232 data bit-rate, changing symbol-rate
(on Voyager units).
NOTE…
On an Encoder fitted with a Remux card, only changes to the Host Bit-rate will cause the video rate to
track. Increasing the final bit-rate (e.g. by changing the symbol=rate) will NOT cause the video=rate of
the local service to increase. This is to allow the final rate to be increased to accommodate more
Remux services.
Bit-rate tracking is switched off by manually setting the video bit-rate to
any value lower than the maximum.
VBR Mode (HD)
This option is only available from the
Systems Menu
when the
M2/ESO2/HDVBR licence key is purchased.
The VBR Mode
5
option is selected from the
Menu
by pressing the VBR
Mode softkey. The option is used to provide spare capacity in the video
stream. Operating in a stuffing off mode or in a true variable bit rate
mode, a decision can be made as to how much impact there will be on the
broadcast service. The spare capacity these modes provide is ideal for
opportunistic data insertion.
5
The VBR licence M2/ESO2/HDVBR is needed with this option.