JVC VN-V225U series - Manual (Page 3)

3
Network Settings
● Ensure that there is sufficient network
bandwidth for the data volume to be sent out
by camera. Do not send multicast stream that
exceeds the bandwidth. If the entire bandwidth
is used by the multicast stream, control of this
camera via the network may fail.
● Data volume to be sent by camera varies with
the settings and number of distributions.
● The maximum bit rate for transmission is
about 20 Mbps.
Estimation of Total Bit Rate
The total JPEG bit rate from camera is
determined by the camera settings, number of
clients, and the client’s requested number of
frames. The total MPEG4 bit rate from camera is
determined by the number of distributions.
Develop a design upon taking the above into
consideration.
Bit Rate of JPEG Stream
The JPEG file size per frame varies with the
encoding settings as well as input video signals.
The following table shows typical sizes. When
VFS is selected, the quantization table during
JPEG encoding will be maintained, and the file
size will increase/decrease according to the input
signals. When AFS is selected, encoding will be
performed such that the target file size is the
average size of multiple JPEG images.
Ⅵ AFS (Average File Size)
(
TX) is applicable to VN-X series only.
Ⅵ VFS(Variable File Size)
(
TX) is applicable to VN-X series only.
The maximum number of distributions varies with
the bit rate settings as well as the client’s
requested frame rate. Up to 20 streams can be
distributed (including multicast). The total frame
rate refers to the sum of these frame rates.
For example, when 10 fps is requested by two
clients, and in addition, multicast is transmitted
at a rate of 10 fps, the total frame rate will be:
10 + 10 + 10 = 30 fps
For example, when 5 fps is requested by two
clients, and in addition, multicast is transmitted
at a rate of 5 fps, the total frame rate will be:
5 + 5 + 5 = 15fps
If JPEG file size per piece is 120KB, total bit rate will be:
120KB ן 15fps = 1800KB/s = 14.4Mbps
Bit Rate of MPEG4 Stream
You can select either the Variable Bit Rate (VBR)
or Constant Bit Rate (CBR) system for MPEG4
stream.
When the VBR system is selected, the bit rate
varies according to the condition of the input video
signals. The VBR system delivers a stable picture
quality, but forecast of the bit rate is difficult.
When the CBR system is selected, encoding is
performed at a fixed bit rate regardless of the
condition of the input video signals. The picture
quality varies under the CBR system, but the bit
rate can be easily forecasted.
You can specify an estimated bit rate for both
VBR and CBR. (64 kbps to 8000 kbps)
Network Requirements
Selectable Range for Distribution File Size
Quad
VGA( TX)
VGA QVGA
40 KB to
200 KB
10 KB to
100 KB
3 KB to 33 KB
Distribution File Size
(typical sizes)
Quad
( TX)
VGA QVGA
Setting
Values
for
Picture
Quality
1 (High) 180 KB 80 KB 27 KB
2 160 KB 60 KB 20 KB
3 140 KB 40 KB 13 KB
4
(Medium) 120 KB 30 KB 10 KB
5 100 KB 25 KB 8 KB
6 80 KB 20 KB 7 KB
7 (Low) 60 KB 15 KB 5 KB