VIVOTEK
User's Manual - 73
■ Intra frame period
Determine how often to plant an I frame. The shorter the duration, the more likely you will get better
video quality, but at the cost of higher network bandwidth consumption. Select the intra frame period
from the following durations: 1/4 second, 1/2 second, 1 second, 2 seconds, 3 seconds, and 4 seconds.
■ Video quality
• Constant 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 congurable 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, and 16Mbps. You can also select
Customize and manually enter a value up to 40Mbps.
- Target bit rate: select a bit rate from the pull-down menu. The bit rate ranges from 20kbps to a
maximum of 16Mbps. 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 sometimes be compromised. If Image quality
priority is selected, the Network Camera might 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, Standard, 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
congurable 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 produced with
electrical gain.
You may also manually enter a bit rate number by selecting the Customized option.