TANDBERG E5780, Руководство пользователя

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evolution 5000 E5780 and E5782 Encoder
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4.8 Set the Data Options
Navigate to the
Data Menu
. If serial data, either RS-232 or RS-422, is to
be encoded then configure the input source and bit-rates.
4.9 Set the Output Options
The
Output Menu
allows the output of the Encoder to be selected. This
is set to ASI unless an option card providing an alternative output is
fitted. If the output is set to ASI, a
Delivery Descriptor Menu
is
available, which allows all the parameters in the delivery descriptor to
be set.
4.10 Configuring Option Cards
For information regarding configuring any option cards that may be
fitted to the Encoder please refer to the Reference Guide.
4.11 Configuring the Encoder for Minimum Delay
There is a trade-off between encoding delay and picture quality for a
given bit-rate. The parameters that can be adjusted to reduce the
encoding delay are as follows:
! Clock Source - the Clock option is found in the
Mux Menu
. Setting
the clock source to either HSYNC or Video, means that the frame
resynchroniser in the video input of the Encoder is not used, which
removes between 0 and 40 ms of delay.
! Compression Mode - the Compression Mode option is found in
the
Video Encoder Menu
. There are three compression modes in
SD that reduce coding delay; Low Delay, Very Low Delay, and Mega
Low Delay and one in HD mode: Low Delay.
Low Delay mode reduces the size of the video rate buffer, which
results in a smaller encoding delay. This can compromise video
quality in some circumstances.
Very Low Delay mode also reduces the size of the video rate buffer,
but it also forces the GOP structure to IP, which removes the frame
reordering delay, and uses field pictures.
Mega Low delay mode is not fully DVB compliant. It has a smaller
video rate buffer than Very Low Delay mode, it also uses a GOP
structure of IP and different refresh techniques.