Network Requirements (continued)

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 forecast.

You can specify an estimated bit rate for both VBR and CBR. (64 kbps to 8000 kbps)

Restrictions on the Number of Distributions for Camera

The maximum number of distributions for this unit is determined by the settings as well as requirements from the client.

When only JPEG images are distributed, the maximum number of distributions is determined based on the highest bit rate within the stream. When a distribution request that exceeds the maximum number of distributions is received, this request is denied. For example, if Client A requests for and receives data at 1 Mbps, while Client B requests for and receives data at 5 Mbps, the maximum number of distributions is 4 streams according to the table below.

Maximum number of distributions when only JPEG data is distributed

 

Maxi

 

Distribution at

mum

 

numb

Total maximum

maximum bit

er of

bit rate

rate

distrib

 

 

 

 

utions

 

 

 

 

1 Mbps and

20

20 Mbps

below

 

 

 

 

 

5 Mbps and

4

20 Mbps

below

 

 

 

 

 

10 Mbps and

2

20 Mbps

below

 

 

 

 

 

Larger than 10

1

Maximum

Mbps

 

configurable value

 

 

(24 Mbps)

 

 

 

When only MPEG4 images are distributed, the maximum number of distributions is determined by the preset bit rate. When a distribution request that exceeds the maximum number of distributions is received, this request is denied.

When distributing only MPEG4 data

 

Maxi

 

 

mum

 

Preset bit rate

numb

Total maximum

er of

bit rate

 

 

distrib

 

 

utions

 

 

 

 

0.6 Mbps and

20

12 Mbps

below

 

 

 

 

 

3 Mbps and

4

12 Mbps

below

 

 

 

 

 

6 Mbps and

2

12 Mbps

below

 

 

 

 

 

Larger than 6

1

Maximum

Mbps

 

configurable value

 

 

(8 Mbps)

 

 

 

When both JPEG and MPEG4 images are distributed simultaneously, distribution up to two clients for JPEG and MPEG4 respectively is possible. However, distribution requests that exceed a total bit rate of 20 Mbps will be denied.

 

Maximum

Maximum

Total bit rate

number of

number of

distributions

distributions

 

 

for JPEG

for MPEG4

 

 

 

20 Mbps and

2

2

below

 

 

 

 

 

 

 

 

Insufficient network bandwidth

When there is insufficient bandwidth, the number of JPEG frames (frame rate) that the client can acquire will decrease. Delay will also occur in the distribution of images. In the case of MPEG4, noise interference may occur and playback may fail.

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