Vivotek PZ7121 - Manual (Page 50)

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50 - User's Manual
■ 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 the following rates: 1fps, 2fps, 3fps, 5fps, 8fps, 10fps, 15fps,
20fps and 25fps, and 30fps�
■ Intra frame period
Determine how often to plant an I frame� The shorter the duration, the more likely you will get a better
video quality, but at the cost of higher network bandwidth consumption� Select the intra frame period
from the following duration: 1/4 second, 1/2 second, 1 second, 2 seconds, 3 seconds and 4 seconds�
■ Video quality
A complex scene generally produces 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 performances� The bit rates are selectable at the
following rates: 20Kbps, 30Kbps, 40Kbps, 50Kbps, 64Kbps, 128Kbps, 256Kbps, 512Kbps, 768Kbps,
1Mbps, 2Mbps, 3Mbps and 4Mbps�
On the other hand, if Fixed quality is selected, all frames are transmitted with the same quality;
bandwidth utilization is therefore unpredictable� The video qualities are selectable at the following
settings: Medium, Standard, Good, Detailed and Excellent�
If JPEG mode is selected, the Network Camera continuously sends JPEG images to the clients,
producing dynamic effects similar to movies� Every single JPEG image transmitted guarantees the same
image quality, which in turn comes at the expense of variable bandwidth usage� And because the media
contents are a combination of JPEG images, no audio data is transmitted to the clients�
There are three dependent parameters provided in MPEG-4 mode for video performance adjustment:
■ Frame size
Select the video size� Note that a larger frame size requires more bandwidth� The frame sizes are
selectable in the following resolutions:
NTSC PAL
704 x 480 704 x 576
CIF 352 x 240 352 x 288
QCIF 176 x 120 176 x 144
■ 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 the following rates: 1fps, 2fps, 3fps, 5fps, 8fps, 10fps, 15fps,
20fps and 25fps, and 30fps�
■ Video quality
The video qualities are selectable at the following settings: Medium, Standard, Good, Detailed and
Excellent�