VIVOTEK
68 - User's Manual
■ B
it rate control
Constrained bit rate:
A complex scene generally produces a larger file size, meaning that higher bandwidth
will be needed for data transmission. The bandwidth utilization is configurable to
match a selected level, resulting in mutable video quality performance. The bit rates
are selectable at the following rates: 20Kbps, 30Kbps, 40Kbps, 50Kbps, 64Kbps,
128Kbps, 256Kbps, 512Kbps, 768Kbps, 1Mbps, 2Mbps, 3Mbps, 4Mbps, 6Mbps,
8Mbps, 10Mbps, 12Mbps, 14Mbps, ~ to 40Mbps. You can also select
Customize
and manually enter a value up to 40Mbps.
•
- Target quality
:
Select a desired quality ranging from Medium to Excellent
- Maximum bit rate
: select a bit rate from the pull-down menu. The bit rate ranges
from 20kbps to a maximum of 40Mbps. The bit rate then becomes the Average or
Upper bound bit rate number. The Network Camera will strive to deliver video streams
around or within the bit rate limitation you impose.
- Policy:
If Frame Rate Priority is selected, the Network Camera will try to maintain
the frame rate per second performance, while the image quality will be compromised.
If Image quality priority is selected, the Network Camera may drop some video
frames in order to maintain image quality.
Fixed quality:
On the other hand, if
Fixed quality
is selected, all frames are transmitted with the
same quality; bandwidth utilization is therefore unpredictable. The video quality
can be adjusted to the following settings: Medium, Standa
rd, Good, Detailed, and
Excellent. You can also select
Customize
and manually enter a value.
Maximum bit rate:
With the guaranteed image quality, you might still want to place
a bit rate limitation to control the size of video streams for bandwidth and storage
concerns. The configurable bit rate starts from 1Mbps to 40Mbps.
The Maximum bit rate setting in the Fixed quality configuration can ensure a
reasonable and limited use of network bandwidth. For example, in low light conditions
where a Fixed quality setting is applied, video packet sizes can tremendously
increase when noises are also produced with electrical gains.
You may also manually enter a bit rate number by selecting the
Customized
option.
