JVC VN-685U - Manual (Page 33)

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Network Setting
● Ensure that there is sufficient network
bandwidth for the data volume to be sent out
by the 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 the 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 the camera is
determined by the camera settings, number of
clients, and the client’s requested number of
frames. The total MPEG4 bit rate from the 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 may be used as a reference.
Ⅵ AFS (Average File Size)
When AFS is selected, encoding will be
performed such that the target file size is the
average size of multiple JPEG images.
Ⅵ VFS(Variable File Size)
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.
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
If the JPEG file size per frame is 30 KB, then the
total bit rate will be:
30 KB × 30 fps = 900 KB/s = Approx. 7.2
Mbps
Network Requirements
Selectable between 10 KB
to 100 KB Selectable between 3 KB
to 33 KB
VGA QVGA
1 (High) 80 KB 27 KB
2 60 KB 20 KB
3 40 KB 13 KB
4
(Medium) 30 KB 10 KB
5 25 KB 8 KB
6 20 KB 7 KB
7 (Low) 15 KB 5 KB