Vivotek PZ7112 User Manual page 55

There are four parameters provided in MPEG-4 mode which allow you to adjust the video performance:
■ Frame size
Select the video size� Note that a larger frame size takes up more bandwidth� The frame sizes are
selectable in the following resolutions:
NTSC
704 x 480
CIF 352 x 240
QCIF 176 x 120
■ Maximum frame rate
This limits the maximal refresh frame rate per second� Set the frame rate higher for a smoother video
quality� The frame rates are selectable at 1fps, 2fps, 3fps, 5fps, 8fps, 10fps, 15fps, 20fps, 25fps, and
30fps� You can also select Customize and manually enter a value�
■ 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, 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 enter a value�
If JPEG mode is selected, the Network Camera continuously sends JPEG images to the client, producing
a moving effect similar to a filmstrip. Every single JPEG image transmitted guarantees the same image
quality, which in turn comes at the expense of variable bandwidth usage� Because the media contents
are a combination of JPEG images, no audio data is transmitted to the client�
There are three parameters provided in MJPEG mode to control the video performance:
■ Frame size
Select the video size� Note that a larger frame size takes up more bandwidth� The frame sizes are
selectable in the following resolutions:
NTSC
704 x 480
CIF 352 x 240
QCIF 176 x 120
PAL
704 x 576
352 x 288
176 x 144
PAL
704 x 576
352 x 288
176 x 144
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User's Manual - 55