VIVOTEK
■ 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
A complex scene generally produces a larger file size, meaning that higher bandwidth will be needed for data transmission. Therefore, if Constant bit rate is selected, the bandwidth utilization is fixed at 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, and 16Mbps. You can also select Customize and manually enter a value.
Bit rate restriction: The bit rate configuration is characterized either by the Average or the Upper
bound approaches: the target bit rate utilized can be fluctuating around an average bit rate value or using the bit rate value as an Upper bound threshold.
Policy: You may select Frame rate priority or Image quality priority. The firmware dynamically controls bit rate and image quality to maintain the frame rate. If quality priority is selected, frame rate will be slightly compromized.
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.
SVC
The SVC (Scalable Video Coding) feature enables streaming of videos for multiple clients from one single set of layered IP packets. Designed for saving bandwidth and CPU load on client stations, the frame rate of a video stream appearing through a view cell can be individually adjusted. This feature applies when an administrator experiences unstable video streaming due to the lack of network bandwidth, 
| 30fps |
VAST Server | Client PC |
|
SVC Packet | LAN |
Network Camera
StreamDemand
on
LAN/WAN | Stream | |
on Demand | ||
| ||
| onStream | |
| Demand | |
| Stream | |
| on | |
| Demand |
25fps
Notebook
5fps
3G Cell Phone
60fps
NVR Storage
VIVOTEK's VAST server (rev. 1.6.1 and later) automatically negotiates with a camera and determines whether a network camera comes with the SVC feature. The SVC checkbox appears if the network camera supports the feature. The same checkbox also appears in the Batch Insert Cameras window. Note that the maximum frame rate varies with different cameras.
The rest of the video configuration options in the SVC column is identical to that of the H.264 protocol.
60 - User's Manual
