Camera Setting Requirements Network - JVC VN-H37U Instructions Manual

Camera Setting Requirements
Network
● Ensure that there is sufficient network
bandwidth for the data volume to be sent out
by camera. Also, do not send multicast
stream that exceeds the bandwidth. If the
entire bandwidth is used by the multicast
stream, you may fail to control the camera via
the network.
● 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 JPEG file size, number of
clients, and number of frames requested by
clients. The total H.264 bit rate from camera is
determined by the number of distributions.
Design the system by considering these points.
Bit Rate of JPEG Stream
The JPEG file size per frame varies with the
encoding settings as well as input video signals.
When AFS (or Average File Size) is selected,
image is encoded so that the average size of
multiple JPEG files becomes the target file size.
If VFS (or Variable File Size) is selected, the
quantization table during JPEG encoding will be
maintained, and the file size will be increased or
decreased according to the input signals.
For JPEG file size details, see the "Encoding"
page. (A Page 26)
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 = 15 fps
4
If JPEG file size per piece is 120 KB, the total bit
rate will be:
120 KB x 15 fps = 1800 KB/s
= Approx. 14.4 Mbps
For detailed bit rate settings, see the "Encoding"
page. (A Page 26)
If Multi Resolution is selected, the JPEG file size
varies with the channels used.
For example, when 2 fps of 30 KB JPEG file and
3 fps of 10 KB JPEG file are sent, the total frame
rate will be:
30 KB x 2 fps + 10 KB x 3 fps = 90 KB/s
= Approx. 0.72 Mbps
Bit Rate of H.264 and MPEG-4 Streams
You can select either the Variable Bit Rate
(VBR) or Constant Bit Rate (CBR) system for
H.264 and MPEG-4 streams.
When the VBR system is selected, the bit rate
varies according to the condition of input video
signals. The VBR system delivers a stable
picture quality, but it is difficult to forecast the bit
rate.
When the CBR system is selected, data is
encoded at a fixed bit rate regardless of the
condition of input video signals. The picture
quality varies under the CBR system, but the bit
rage can be easily forecasted.
You can specify an estimated bit rate for both
VBR and CBR. (64 kbps to 8192 kbps)
Memo:
● "MPEG-4" is represented on this unit's
screens as "MPEG4".
Audio Data Size (for Audio-Compatible
Models Only)
Up to 2 streams of audio data can be sent. Up to
1 stream of audio data can be received. Each
audio data stream is 64 kbps. The size of audio
data can be calculated via the following formula:
64 kbps x number of streams
The number of streams should be the total of the
number of TCP streams being sent (the number of
clients) plus the number of multicast streams
being sent/received. For example, if the camera is
sending 2 streams of audio and receiving 1
stream of audio, the data size will be the following:
64 kbps x 3 = 192 kbps