User Manual

VIVOTEK
58 - User's Manual
This video server offers real-time H�264, MPEG-4, and MJPEG compression standards (Triple Codec)
for real-time viewing�
If H.264 / MPEG-4 mode is selected, the video is streamed via RTSP protocol� There are four parameters
for you to adjust the video performance:
■ Frame size
You can set up different video resolution for different viewing devices� For example, set a smaller
frame size and lower bit rate for remote viewing on mobile phones and a larger video size and a higher
bit rate for live viewing on web browsers. Note that a larger frame size takes up more bandwidth. The
frame sizes are selectable in the following resolutions: QCIF, CIF, 4CIF, and D1.
■ Maximum frame rate
This limits the maximum refresh frame rate per second� Set the frame rate higher for smoother video
quality� You can also select Customize and manually enter a value� The frame rate will decrease if you
select a higher resolution�
■ 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 le size, meaning that higher bandwidth will be needed
for data transmission� Therefore, if Constant bit rate is selected, the bandwidth utilization is xed 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, and 4Mbps� You can also select Customize and manually enter a value�
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 adjust the slider bar� You may adjust the slider bar to the right to have better video quality�
NOTE
►
Aspect ratio correction doesn’t support QCIF�
► When aspect ratio correction takes effect, the frame size for D1 will be adjusted to 640x480.